Cardiomyopathy (Complete)

• Related Subjects: |Heart Failure |Pulmonary Oedema |Cardiac Resynchronisation |Acute Coronary Syndrome |Ivabradine
• Foundations: Definition and Clinical Importance | Classification and Major Phenotypes | Pathophysiology: Four Mechanisms | Causes and Aetiological Clues | Symptoms and Red Flags
• Recognition: History and Examination | Baseline Investigations | ECG Patterns Worth Recognising | Echocardiography and Dynamic Testing | Cardiac MRI: Pattern Recognition | Genetic Testing, Family Screening and Biopsy
• Phenotypes: Dilated Cardiomyopathy (DCM): Definition and Causes | DCM: Management and Prognosis | Hypertrophic Cardiomyopathy (HCM): Definition and Forms | HCM: Dynamic LVOT Obstruction | HCM: Clinical Features and Examination | HCM: Symptom Treatment and Septal Reduction | HCM: Sudden Death Risk and Atrial Fibrillation | Arrhythmogenic Cardiomyopathy and ARVC | Non-dilated LV Cardiomyopathy and LV Non-compaction | Restrictive Cardiomyopathy (RCM)
• Specific diseases: ATTR Cardiac Amyloidosis | AL Cardiac Amyloidosis: Urgent Diagnosis | Cardiac Sarcoidosis | Haemochromatosis, Fabry and Metabolic Disease | Myocarditis and Inflammatory Cardiomyopathy | Takotsubo (Stress) Cardiomyopathy | Peripartum Cardiomyopathy (PPCM) | Alcohol, Chemotherapy and Tachycardia-mediated Disease
• Management: Acute Presentation and Cardiogenic Shock | Heart Failure Treatment Across Cardiomyopathies | Ventricular Arrhythmias, ICD and CRT | Common Adult Drugs and Doses | Monitoring and Safety | Pregnancy, Exercise and Family Advice | Complications, Follow-up and Prognosis
• Revision: High-yield Comparisons for MRCP | MRCP and Clinical Pearls | Selected References and UK Resources

🫀 Cardiomyopathies are disorders of the heart muscle that may cause heart failure, arrhythmia, syncope, thromboembolism or sudden cardiac death. The main phenotypes are dilated, hypertrophic, arrhythmogenic, restrictive and non-dilated LV cardiomyopathy. Some are inherited; others result from inflammation, infiltration, metabolic disease or toxins.
Clinical priority: Define the phenotype, identify the cause, assess sudden-death risk, treat symptoms and protect family members.

Definition and Clinical Importance

Cardiomyopathy describes structural or functional disease of the heart muscle that is not explained solely by coronary artery disease, abnormal loading conditions, congenital heart disease or valve disease. It may present with heart failure, arrhythmia, thromboembolism or sudden cardiac death, and can be genetic or acquired.

• Clinical perspective: A morphological label such as dilated or hypertrophic cardiomyopathy is the beginning of a diagnosis, not the end: the cause, genotype, risk of sudden death and implications for family members must be investigated.
• Main priorities: Assess haemodynamic stability; establish the phenotype; identify treatable causes; assess arrhythmia and sudden-death risk; treat heart failure or obstruction; arrange genetic and family evaluation when indicated.
• Important distinction: Ischaemic cardiomyopathy is commonly used clinically for LV dysfunction due to coronary disease, but coronary disease is not classified as a primary cardiomyopathy in the ESC phenotypic scheme.
• Typical presentations: Exertional dyspnoea, orthopnoea, oedema, chest pain, palpitations, exertional syncope, ventricular arrhythmia, incidental ECG abnormalities or an affected relative.

💡 Clinical / MRCP Pearl: Unexpected syncope during exercise or a family history of sudden unexplained death is a major clue to inherited arrhythmogenic disease and warrants urgent specialist risk assessment.

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Classification and Major Phenotypes

The 2023 ESC cardiomyopathy guideline uses a phenotype-first approach, followed by an aetiological and genetic diagnosis.

• Dilated cardiomyopathy (DCM): LV or biventricular dilatation with systolic dysfunction not adequately explained by coronary disease or abnormal loading.
• Hypertrophic cardiomyopathy (HCM): Unexplained increase in LV wall thickness; may be obstructive or non-obstructive.
• Arrhythmogenic cardiomyopathy (ACM): Myocardial disease with ventricular arrhythmias, often fibrotic replacement; includes classic arrhythmogenic right ventricular cardiomyopathy (ARVC) and left-dominant forms.
• Restrictive cardiomyopathy (RCM): Non-dilated or small ventricles with impaired filling, high filling pressures and frequently marked biatrial enlargement; systolic function may initially be preserved.
• Non-dilated LV cardiomyopathy (NDLVC): Non-ischaemic LV scar or other specified dysfunction without LV dilatation; important because arrhythmic risk can precede impaired EF.
• Other recognisable entities: Left ventricular non-compaction morphology, takotsubo syndrome, peripartum cardiomyopathy and inflammatory, toxic or infiltrative myocardial disease need mechanistic consideration rather than automatic classification as separate inherited phenotypes.

💡 Clinical / MRCP Pearl: A normal or mildly reduced ejection fraction does not exclude an important cardiomyopathy; myocardial fibrosis and ventricular arrhythmias may precede overt pump failure.

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Pathophysiology: Four Mechanisms

Different cardiomyopathies cause different haemodynamic and electrical problems.

• Systolic pump failure: Myocyte injury, sarcomeric abnormalities and remodelling reduce contractility and stroke volume, especially in DCM.
• Diastolic dysfunction: Hypertrophy, abnormal relaxation or infiltration reduces compliance: small increments in filling volume cause marked increases in ventricular and atrial pressures.
• Dynamic outflow obstruction: In obstructive HCM, septal hypertrophy and abnormal mitral–septal interaction produce a variable LVOT gradient and mitral regurgitation.
• Electrical instability: Fibrosis, cell-to-cell uncoupling and altered electrical propagation generate ventricular ectopy, NSVT, sustained VT and VF.
• Remodelling: Persistent sympathetic and RAAS activation promotes myocardial fibrosis, chamber enlargement and functional valve regurgitation.
• Thromboembolism: AF, reduced systolic function and apical aneurysm or thrombus predispose to systemic embolisation.

💡 Clinical / MRCP Pearl: In some inherited cardiomyopathies, preventing sudden arrhythmic death is as important as treating symptoms or improving ejection fraction.

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Causes and Aetiological Clues

Always assess common acquired causes while recognising that inherited disease and external triggers may coexist.

• Inherited sarcomeric disease: MYH7 and MYBPC3 are common in HCM; TTN truncating variants are an important cause of DCM.
• Arrhythmogenic genotypes: PKP2, DSP, DSG2, DSC2 and JUP are associated with desmosomal disease; LMNA, FLNC, PLN and RBM20 may confer important arrhythmic risk.
• Acquired injury: Myocarditis, long-term excess alcohol, tachyarrhythmia-mediated dysfunction and cancer treatment cardiotoxicity.
• Metabolic or infiltrative: ATTR or AL amyloidosis, haemochromatosis, Fabry disease, sarcoidosis, thyroid disease and thiamine deficiency.
• Peripartum: New LV systolic dysfunction towards the end of pregnancy or following delivery, sometimes with an inherited susceptibility.
• Look for reversible contributors: Uncontrolled hypertension, valve disease, coronary disease, untreated thyroid disease, AF with rapid ventricular rate and potentially cardiotoxic drugs.

💡 Clinical / MRCP Pearl: An apparent non-ischaemic cardiomyopathy may have several contributors: for example, a pathogenic TTN variant with added toxicity from alcohol or chemotherapy.

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Symptoms and Red Flags

Presentations range from asymptomatic family-screening findings to cardiac arrest.

• Heart failure: Exertional dyspnoea, orthopnoea, PND, fatigue, oedema, abdominal congestion and reduced exercise tolerance.
• Arrhythmia: Palpitations, episodic light-headedness, syncope or documented ventricular tachycardia; AF is common in HCM and amyloidosis.
• Ischaemic symptoms: Angina in HCM may reflect microvascular ischaemia despite unobstructed epicardial coronary arteries.
• Red flags: Exertional syncope, resuscitated cardiac arrest, sustained VT, unexplained family deaths below 50, new high-grade AV block, rapidly progressive HF and haemodynamic instability.
• Extra-cardiac clues: Carpal tunnel syndrome and neuropathy suggest ATTR; renal dysfunction or macroglossia can suggest AL; angiokeratomas and neuropathic pain suggest Fabry; extracardiac sarcoid and conduction disease suggest cardiac sarcoidosis.

💡 Clinical / MRCP Pearl: Ask specifically about drowning, single-vehicle collisions and presumed epilepsy in relatives: a sudden arrhythmic death may be hidden behind these descriptions.

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History and Examination

Use a targeted cardiovascular history and examination to connect symptoms with the underlying phenotype.

• History: Onset of dyspnoea or exercise limitation; exertional syncope; palpitations; previous myocarditis or viral illness; chemotherapy; alcohol and stimulant exposure; pregnancies; neuromuscular symptoms; drugs and toxins.
• Family history: Construct a three-generation pedigree documenting sudden death, cardiomyopathy, AF, heart failure, ICDs, pacemakers, transplantation and unexplained accidents.
• General signs: Blood pressure, rhythm, postural symptoms, volume status, cachexia, oedema, JVP and signs of systemic disease.
• Cardiac examination: Displaced apex and S3 in DCM; forceful apex or S4 in HCM; variable ejection systolic murmur in obstructive HCM; restrictive physiology often has raised JVP and systemic congestion.
• Neurological/systemic: Peripheral neuropathy, autonomic dysfunction, muscle weakness, skin changes, hearing impairment or hepatosplenomegaly can suggest a multisystem cause.

💡 Clinical / MRCP Pearl: The physical findings do not reliably quantify sudden-death risk. A patient with mild symptoms may have substantial fibrosis or a high-risk genotype.

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Baseline Investigations

Combine structural imaging, electrical assessment and selected laboratory tests; avoid indiscriminate rare-disease panels.

• ECG: 12-lead ECG for hypertrophy, repolarisation changes, conduction delay, pre-excitation, AF, Q waves and ventricular ectopy.
• Blood tests: FBC, U&E/eGFR, LFT, TSH, glucose/HbA1c, calcium, ferritin/TSAT, NT-proBNP and troponin when myocardial injury is suspected.
• Echocardiography: Assess LV and RV size/function, maximal wall thickness, chamber volumes, diastolic filling, valve disease and resting/provoked LVOT gradient.
• Ambulatory rhythm monitoring: 24–48-hour or longer ECG for NSVT, AF, conduction disease and symptom–rhythm correlation; prolonged monitoring when episodes are intermittent.
• Cardiac MRI (CMR): Quantifies ventricular structure; detects oedema, non-ischaemic late gadolinium enhancement (LGE), infiltration, ventricular aneurysms and tissue patterns.
• Coronary assessment: CT coronary angiography or invasive angiography when ischaemic disease is plausible or results would influence management.
• Targeted testing: Serum free light chains with serum/urine immunofixation for suspected amyloid; alpha-galactosidase A and GLA genetics for Fabry; iron studies/genetic evaluation for haemochromatosis; FDG-PET for selected suspected sarcoidosis.

💡 Clinical / MRCP Pearl: ECG, echo and CMR are complementary. CMR non-ischaemic LGE distribution often helps distinguish scar-related inherited disease from infarction.

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ECG Patterns Worth Recognising

The ECG may suggest the phenotype, but normal findings never fully exclude disease.

• HCM: LVH criteria, deep narrow Q waves, inferolateral or giant T-wave inversion (especially apical HCM), left atrial abnormality or AF.
• DCM: LBBB, nonspecific QRS widening, AF, ventricular ectopy and sometimes pathological Q waves unrelated to coronary infarction.
• ARVC: T-wave inversion in right precordial leads beyond adolescence, ventricular ectopy/VT with LBBB morphology; epsilon waves are characteristic when present but insensitive.
• Fabry: LVH and conduction abnormalities; PR shortening may occur early.
• Amyloid: Low QRS voltage relative to substantial LV wall thickening, pseudoinfarction Q waves, conduction disease and AF; low voltage is not universal.
• Cardiac sarcoidosis: Unexplained high-grade AV block, bundle-branch block, ventricular ectopy or VT.
• Myocarditis: ST–T abnormalities, arrhythmias and conduction disturbance; ECG may resemble ACS.

💡 Clinical / MRCP Pearl: In a young patient with unexplained complete heart block, search for cardiac sarcoidosis and inherited conduction/cardiomyopathy disorders rather than assuming age-related fibrosis.

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Echocardiography and Dynamic Testing

Echocardiography establishes morphology and haemodynamic consequences.

• DCM: Enlarged LV cavity with reduced EF; functional mitral regurgitation, RV dysfunction and intracardiac thrombus may be present.
• HCM: Assess maximum segmental wall thickness, hypertrophy distribution, systolic anterior motion (SAM), mitral regurgitation, LVOT gradient and apical aneurysm.
• LVOT provocation: Record resting gradient and assess with Valsalva, standing and sometimes exercise echocardiography where indicated.
• RCM: Non-dilated ventricles, impaired filling, large atria and abnormal Doppler measures; assess for constrictive pericarditis as a treatable mimic.
• Arrhythmogenic disease: Regional RV akinesia/dyskinesia, RV dilatation or impaired function; investigate LV involvement.
• Strain imaging: Reduced global longitudinal strain with relative apical sparing may support amyloidosis, but is not sufficient by itself to establish the diagnosis.

💡 Clinical / MRCP Pearl: In suspected HCM, failing to check a provoked LVOT gradient can miss clinically important obstruction in a patient whose resting gradient is low.

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Cardiac MRI: Pattern Recognition

CMR is particularly useful where echo is limited or the aetiology remains uncertain.

• Ischaemic scar: Subendocardial or transmural LGE following a coronary territory.
• Non-ischaemic DCM: Mid-wall septal or other non-coronary LGE, a marker of myocardial fibrosis and arrhythmic risk.
• HCM: Asymmetric hypertrophy, patchy mid-wall LGE at hypertrophied regions, apical HCM or apical aneurysm.
• Myocarditis: Myocardial oedema and non-ischaemic LGE, commonly subepicardial or mid-wall, interpreted under updated Lake Louise principles.
• Amyloidosis: Diffuse subendocardial or transmural LGE, abnormal myocardial nulling and raised extracellular volume.
• Sarcoidosis: Patchy, often multifocal LGE; FDG-PET may add evidence of active inflammation.
• ARVC/left-dominant ACM: Ventricular volumes, regional wall-motion abnormalities and characteristic non-ischaemic scar distribution.
• Haemochromatosis: Low myocardial T2* suggesting iron loading.

💡 Clinical / MRCP Pearl: Late gadolinium enhancement represents abnormal tissue characteristics, often fibrosis. Its presence and extent can influence risk assessment even where EF is only mildly abnormal.

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Genetic Testing, Family Screening and Biopsy

Cardiomyopathy assessment is frequently family medicine as well as individual diagnosis.

• Genetic testing: Use a phenotype-directed panel and pre/post-test counselling when diagnosis, prognosis, treatment or family screening can benefit.
• Cascade testing: When a pathogenic or likely pathogenic familial variant is identified, offer targeted testing and clinical surveillance to relatives where appropriate.
• Variant of uncertain significance: Do not use a VUS alone to label relatives affected or unaffected; interpretation may change with new evidence.
• First-degree relatives: Offer ECG and imaging, with repeat surveillance when genotype or family phenotype indicates ongoing risk; intervals depend on age, disease and genotype.
• Endomyocardial biopsy: Reserved for selected cases, especially where histological diagnosis changes urgent treatment (e.g. suspected giant-cell myocarditis or infiltrative disease).
• Conduction disease clues: LMNA, DES, SCN5A and other inherited disorders may present with AV block before overt LV dilatation.

💡 Clinical / MRCP Pearl: A negative gene panel does not exclude an inherited cardiomyopathy, and an apparently unaffected relative may develop disease later because penetrance is age-dependent.

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Dilated Cardiomyopathy (DCM): Definition and Causes

DCM is characterised by ventricular dilatation and systolic dysfunction not fully explained by abnormal loading or coronary disease.

• Common presentation: Progressive breathlessness, fatigue, orthopnoea, oedema, AF, ventricular ectopy or thromboembolism; some patients present abruptly with acute decompensation.
• Familial/genetic: TTN, LMNA, FLNC, RBM20, BAG3, DSP and other genes; family history may be absent because of variable penetrance.
• Inflammatory: Post-myocarditis cardiomyopathy or persistent inflammatory disease.
• Toxic: Alcohol, anthracyclines and some targeted cancer therapies.
• Rate-related: Persistent AF, flutter, atrial tachycardia or frequent PVCs may produce reversible tachycardia-/PVC-mediated cardiomyopathy.
• Other: Peripartum cardiomyopathy, endocrine disease, nutritional deficiency and systemic disorders.
• Investigations: Echo confirms phenotype; CMR tissue characterisation, rhythm assessment, coronary evaluation and cause-directed blood tests refine the diagnosis.

💡 Clinical / MRCP Pearl: DCM is not synonymous with irreversible disease. Some patients recover strikingly after control of tachycardia, removal of cardiotoxins or treatment of a specific inflammatory process.

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DCM: Management and Prognosis

Separate relief of congestion from disease modification and arrhythmic protection.

• Disease-modifying HFrEF treatment: Introduce the four foundational drug classes when indicated and tolerated: ACE inhibitor/appropriate ARNI strategy, evidence-based beta blocker, MRA and SGLT2 inhibitor.
• Congestion: Loop diuretic for symptomatic volume overload; monitor weight, BP, kidney function, sodium and potassium.
• Cause-specific treatment: Treat rapid AF or high PVC burden; stop alcohol/cardiotoxic exposure; consider immunosuppression only for selected proven inflammatory conditions.
• Arrhythmia risk: Assess NSVT, syncope, scar on CMR, EF and genotype; selected high-risk variants can justify ICD consideration even when EF exceeds 35%.
• Devices: Consider ICD and CRT according to symptoms, rhythm, EF, QRS morphology and specialist criteria.
• Advanced disease: Discuss transplant/VAD assessment for refractory severe disease; consider palliative care in parallel with active management.
• Recovered EF: Improvement does not guarantee cure: generally continue disease-modifying treatment because withdrawal may trigger relapse.

💡 Clinical / MRCP Pearl: An LMNA or FLNC-related DCM phenotype can carry arrhythmic risk disproportionate to the reduction in EF; do not rely on EF alone.

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Hypertrophic Cardiomyopathy (HCM): Definition and Forms

In adults, HCM usually requires LV wall thickness ≥15 mm unexplained by loading conditions; 13–14 mm can be significant with a suggestive family/genetic context. In an affected adult first-degree relative, ≥13 mm may meet diagnostic criteria.

• Typical inherited cause: Autosomal dominant sarcomeric disease, often MYH7 or MYBPC3; variable expressivity and incomplete penetrance.
• Structural forms: Asymmetric septal, apical, concentric, midventricular or focal hypertrophy; some patients eventually develop LV systolic dysfunction.
• Obstructive HCM (HOCM): Dynamic LVOT obstruction at rest or with provocation, often from systolic anterior motion (SAM) of the mitral valve.
• Non-obstructive HCM: Myocardial stiffness, microvascular dysfunction, AF or ventricular arrhythmias may cause symptoms despite absent LVOT obstruction.
• Important mimics: Hypertension, aortic stenosis, athletic heart, amyloidosis, Fabry disease, Danon disease (LAMP2) and PRKAG2 syndrome.
• Imaging: Echo and CMR assess distribution, LVOT gradient, mitral anatomy, scar, apical aneurysm and EF.

💡 Clinical / MRCP Pearl: Marked LV hypertrophy in an older adult with carpal tunnel syndrome should not automatically be called sarcomeric HCM: investigate ATTR amyloidosis.

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HCM: Dynamic LVOT Obstruction

Dynamic obstruction is a haemodynamic phenomenon, not simply a fixed septal narrowing.

• Mechanism: Rapid systolic flow and abnormal mitral apparatus create systolic anterior motion (SAM); the mitral leaflet moves towards the septum, narrowing the outflow tract and often producing posteriorly directed MR.
• Diagnostic gradient: A peak instantaneous LVOT gradient ≥30 mmHg indicates obstruction; ≥50 mmHg at rest or provocation is clinically important when considering advanced treatment in symptomatic patients.
• Worsens with: Reduced preload (standing, Valsalva), reduced afterload (vasodilators), tachycardia and increased contractility (inotropes/exertion).
• Improves with: Increased preload or afterload, reduced contractility and longer diastolic filling time.
• Clinical consequences: Exertional angina, dyspnoea, presyncope or syncope, mitral regurgitation and sometimes haemodynamic collapse.
• Acute hypotension: Avoid reflex inotropes and vasodilators where obstruction is responsible; specialist treatment often uses cautious fluids and a pure vasoconstrictor, with consideration of beta blockade.

💡 Clinical / MRCP Pearl: The classical HCM murmur becomes louder on standing or Valsalva and softer with squatting, opposite to the response expected in many fixed outflow lesions.

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HCM: Clinical Features and Examination

The combination of exertional symptoms, family history and an unusual dynamic systolic murmur should prompt echocardiography.

• Symptoms: Exertional dyspnoea, chest tightness, dizziness, syncope, palpitations, AF, or sudden arrhythmic death.
• Apex and heart sounds: Forceful or double apical impulse and S4 may occur; S4 requires coordinated atrial contraction and is therefore absent in AF.
• Murmur: Harsh crescendo–decrescendo systolic murmur at the left sternal edge; variation with preload/afterload may help distinguish dynamic obstruction.
• ECG: LVH, deep narrow Q waves, lateral T-wave inversion or giant T-wave inversions in apical HCM.
• Echo: Measure rest and provoked LVOT gradient; assess SAM, MR, maximal wall thickness and diastolic function.
• CMR: Helps identify apical disease, extent of LGE, apical aneurysm and differential diagnoses.
• Differential: Aortic stenosis, hypertensive LVH and infiltrative cardiomyopathy require specific consideration.

💡 Clinical / MRCP Pearl: Exertional syncope in HCM can result from LVOTO, an inappropriate vascular response or VT. It must be treated as a high-risk symptom until properly investigated.

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HCM: Symptom Treatment and Septal Reduction

Management depends first on whether haemodynamically important LVOT obstruction is present.

• First-line obstructive HCM: Non-vasodilating beta blocker, titrated to response and tolerated heart rate/BP.
• Alternative: Verapamil or diltiazem if beta blocker cannot be used; avoid or use extreme caution in marked gradients, hypotension, severe pulmonary hypertension or significant LV systolic impairment.
• Persistent obstruction: Expert addition of disopyramide (with QT and anticholinergic monitoring) or mavacamten according to NICE eligibility; consider septal reduction therapy.
• Mavacamten: Cardiac myosin inhibitor; NICE TA913 permits add-on use for eligible symptomatic obstructive HCM (NYHA II–III). CYP2C19-guided dosing and serial LVEF/LVOT echocardiography are essential.
• Septal reduction: Surgical septal myectomy or alcohol septal ablation at an experienced centre for persistent limiting symptoms and significant obstruction despite optimal treatment.
• Avoid precipitating obstruction: Unnecessary dehydration, aggressive diuresis, nitrates and strong vasodilators may worsen LVOTO; diuretics may be used cautiously for genuine congestion.
• Non-obstructive HCM: Treat diastolic symptoms, AF and coexisting HF; beta blockers or non-dihydropyridine calcium antagonists may help selected patients.

💡 Clinical / MRCP Pearl: Substantial obstruction can coexist with a normal/high EF. Giving a potent inotrope for hypotension due to LVOTO can worsen the gradient and reduce forward output.

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HCM: Sudden Death Risk and Atrial Fibrillation

Sudden-death prevention and thromboembolism prevention require dedicated assessment even if angina is controlled.

• SCD markers: Previous sustained VT/VF, unexplained syncope, family history of HCM-related sudden death, marked LV hypertrophy, NSVT, extensive LGE, apical aneurysm and LV systolic dysfunction.
• ESC HCM Risk-SCD model: Estimates 5-year sudden-death risk using age, maximum wall thickness, left atrial size, maximal LVOT gradient, family history, NSVT and recent unexplained syncope; additional factors influence expert decisions.
• ICD: Recommended for survivors of relevant VT/VF arrest; primary prevention decisions require specialist shared decision-making using risk models and modifiers.
• AF: Common and can sharply worsen filling because the stiff LV depends on atrial contraction.
• Anticoagulation: In HCM with clinical AF, oral anticoagulation is generally recommended irrespective of conventional CHA2DS2-VASc score, unless contraindicated.
• Cardioversion/ablation: Rhythm control is often valuable; ensure appropriate anticoagulation and specialist management.

💡 Clinical / MRCP Pearl: An HCM patient with AF may require anticoagulation even with a CHA2DS2-VASc score of zero; the usual AF score underestimates HCM-associated thromboembolic risk.

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Arrhythmogenic Cardiomyopathy and ARVC

Arrhythmogenic disease may involve the RV, LV or both. Classic ARVC is frequently associated with desmosomal gene variants and progressive fibrofatty myocardial replacement.

• Presentation: Palpitations, exercise-induced syncope, frequent ventricular ectopy, VT or sudden death, occasionally before overt ventricular dysfunction.
• ECG findings: T-wave inversion in V1–V3 beyond adolescence, terminal QRS abnormalities and VT of RV origin with LBBB morphology; epsilon waves are uncommon but characteristic.
• Investigations: Holter/patch monitoring, exercise history, echo/CMR for chamber structure and scar, and cardiogenetic assessment.
• Genes: PKP2 and DSP are important; left-dominant forms may have non-desmosomal genotypes and significant LV scar.
• Management: Individualised beta blockade/antiarrhythmic treatment, ICD for high-risk disease and catheter ablation for recurrent VT where appropriate.
• Exercise advice: High-intensity endurance/competitive sport can accelerate disease expression and ventricular arrhythmia risk; specialist exercise counselling is essential.
• Family members: Genetic counselling, cascade testing when possible and ongoing surveillance of at-risk relatives.

💡 Clinical / MRCP Pearl: A young athlete with exercise-related syncope and ventricular arrhythmias should not be labelled as having benign athletic ECG changes without investigation.

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Non-dilated LV Cardiomyopathy and LV Non-compaction

These phenotypes illustrate why EF and cavity size cannot be the only measures of myocardial disease.

• NDLVC: Non-dilated LV with non-ischaemic scar or regional/global dysfunction; may be a presentation of inherited disease such as DSP, FLNC or LMNA.
• Importance: Substantial myocardial scar may generate serious ventricular arrhythmias despite preserved or mildly reduced EF.
• LV non-compaction (LVNC): Prominent myocardial trabeculations with deep recesses; can be isolated, familial or occur with other structural disease.
• Interpretation: Excessive trabeculation on CMR is not always pathological; consider LV function, symptoms, thrombus, family history and underlying genotype.
• Management: Treat heart failure or arrhythmia when present; risk-stratify and arrange family evaluation if inherited disease is likely.

💡 Clinical / MRCP Pearl: “LVNC” on an imaging report should not lead to automatic anticoagulation or ICD implantation without other evidence of risk.

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Restrictive Cardiomyopathy (RCM)

RCM is caused by abnormal myocardial stiffness, leading to impaired ventricular filling and elevated venous pressures, often with near-normal LV size and EF early in disease.

• Clinical presentation: Exercise intolerance, oedema, elevated JVP, ascites, AF and thromboembolism; pulmonary congestion may occur.
• Echo/CMR: Biatrial enlargement, non-dilated ventricles, restrictive filling and cause-specific tissue abnormalities.
• Major causes: Amyloidosis, endomyocardial fibrosis, iron overload, certain inherited sarcomeric conditions and some infiltrative/storage disorders.
• Constrictive pericarditis: A crucial treatable mimic: pericardial constriction causes prominent ventricular interdependence and characteristic septal movement; CMR/CT and invasive haemodynamics may clarify.
• Management: Gentle decongestion, control AF/thromboembolism, cause-specific therapy and advanced HF assessment where needed.
• Haemodynamic caution: Both underfilling and excessive fluid loading can be poorly tolerated in a stiff ventricle.

💡 Clinical / MRCP Pearl: Preserved EF in restrictive disease does not imply normal cardiac output; small stroke volumes and elevated filling pressures may coexist.

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ATTR Cardiac Amyloidosis

Transthyretin amyloid cardiomyopathy (ATTR-CM) arises from deposition of misfolded transthyretin, either wild-type or hereditary, and commonly presents with HFpEF or conduction disease in older adults.

• Clinical clues: Unexplained LV thickening, AF, conduction disease, disproportionate NT-proBNP, bilateral carpal tunnel syndrome, lumbar spinal stenosis, biceps tendon rupture or neuropathy.
• Echo/CMR: Increased wall thickness, biatrial enlargement and sometimes relative apical sparing of strain; CMR often shows diffuse LGE and raised extracellular volume.
• First rule out AL: Obtain serum free light chains PLUS serum and urine immunofixation. A bone scan must not be interpreted as diagnostic of ATTR without excluding a monoclonal light-chain disorder.
• ATTR confirmation: Technetium-labelled bone scintigraphy (e.g. DPD) can establish ATTR non-invasively in an appropriate setting; TTR genetic testing then distinguishes hereditary from wild-type disease.
• Heart failure care: Cautious diuresis and rhythm management; hypotension and poor tolerance of conventional HFrEF drugs are common in advanced infiltrative disease.
• Disease modification: NICE supports tafamidis (TA984), vutrisiran (TA1115) and acoramidis (TA1121) in eligible adults; choice and funding pathway are specialist-led.
• AF and thrombus: Thromboembolic risk is high; anticoagulate documented AF unless contraindicated and assess for atrial thrombus before cardioversion.

💡 Clinical / MRCP Pearl: ATTR amyloidosis is increasingly treatable in the NHS. Recognising it early matters because disease-modifying treatment aims to slow progression, not reverse established scar.

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AL Cardiac Amyloidosis: Urgent Diagnosis

AL amyloidosis results from deposition of monoclonal immunoglobulin light chains, generally produced by a plasma-cell clone. Cardiac involvement is often rapidly progressive and needs urgent haematology input.

• Clinical features: Restrictive heart failure, orthostatic hypotension, nephrotic proteinuria, peripheral/autonomic neuropathy, weight loss, macroglossia or periorbital purpura (not always present).
• Laboratory assessment: Serum free light chains with ratio, serum and urine immunofixation, troponin, NT-proBNP, renal function and urine protein.
• Confirm amyloid type: Tissue biopsy with Congo red and accurate amyloid typing when indicated; a monoclonal protein alone does not prove AL cardiac amyloidosis.
• Specialist treatment: Rapid plasma-cell-directed therapy (for example a daratumumab-based regimen where appropriate), with haematology/cardiology coordination.
• Supportive treatment: Cautious diuresis, hypotension management and vigilance for arrhythmias and thrombosis.
• Diagnostic pitfall: Positive bone scintigraphy does not rule out AL in a patient with a monoclonal gammopathy.

💡 Clinical / MRCP Pearl: In suspected cardiac amyloid, complete the light-chain screen immediately. Missing AL amyloidosis while assuming ATTR can delay treatment of a rapidly progressive, potentially treatable disease.

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Cardiac Sarcoidosis

Granulomatous inflammation may affect the cardiac conduction system or myocardium and cause arrhythmias, heart failure or sudden death.

• Clinical clues: Unexplained high-grade AV block in a younger patient, ventricular tachycardia, syncope, LV dysfunction or established systemic sarcoidosis.
• Investigations: ECG, prolonged rhythm monitoring, echo, CMR for scar/inflammation and FDG-PET for active inflammation; biopsy of an accessible extracardiac site may be preferable.
• Pathology: Granulomatous inflammation and patchy myocardial scar create substrate for both conduction block and re-entry VT.
• Treatment: Specialist corticosteroid/immunosuppressive therapy for active inflammatory disease when indicated; evidence and regimen depend on phenotype and progression.
• Device therapy: Pacemaker may be required for AV block, but consider ICD because ventricular arrhythmia risk may exceed the pacing indication alone.
• Monitoring: Repeat imaging and rhythm assessment to evaluate activity and treatment response.

💡 Clinical / MRCP Pearl: High-grade AV block in a 35-year-old warrants evaluation for cardiac sarcoidosis and inherited disease, not simply pacemaker implantation without an aetiological assessment.

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Haemochromatosis, Fabry and Metabolic Disease

Several cause-specific cardiomyopathies have targeted treatments and important extracardiac clues.

• Haemochromatosis: Iron overload may cause restrictive or dilated cardiomyopathy and arrhythmias; assess ferritin/TSAT and use CMR T2* for myocardial iron. Venesection or iron chelation is guided by aetiology and specialist assessment.
• Fabry disease: X-linked GLA-related lysosomal storage disorder: LVH, renal dysfunction, neuropathic pain, angiokeratomas, reduced sweating or corneal verticillata. Confirm with enzyme testing and molecular assessment; enzyme replacement or migalastat in appropriate mutations.
• Danon disease: LAMP2-related storage disease, often severe early-onset hypertrophy with skeletal myopathy and conduction/pre-excitation abnormalities.
• PRKAG2 syndrome: Hypertrophy with pre-excitation and conduction disease; can mimic sarcomeric HCM.
• Endomyocardial fibrosis: Produces restrictive physiology and often atrioventricular valve regurgitation; context and imaging guide diagnosis.
• Thyroid/other endocrine: Hyperthyroidism can precipitate tachyarrhythmia-mediated dysfunction; hypothyroidism may cause bradycardia and effusion; investigate selectively.

💡 Clinical / MRCP Pearl: LV hypertrophy plus renal, skin or neurological abnormalities is a cue to look beyond hypertensive heart disease and sarcomeric HCM.

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Myocarditis and Inflammatory Cardiomyopathy

Myocarditis is myocardial inflammation due to infections, immune-mediated disorders, drug toxicity or other causes. It can recover completely, cause chronic cardiomyopathy or lead to life-threatening arrhythmia.

• Presentation: Chest pain resembling ACS, dyspnoea, fatigue, palpitations, AV block, VT or cardiogenic shock, sometimes following a viral syndrome.
• Initial investigations: ECG, troponin, NT-proBNP, inflammatory markers, echo and coronary exclusion as clinically appropriate.
• CMR: Look for oedema and non-ischaemic LGE; CMR supports diagnosis but sensitivity depends on timing and disease pattern.
• Biopsy: Consider in severe unexplained or refractory HF, malignant arrhythmias or conduction block where identifying giant-cell, eosinophilic or other treatable myocarditis would alter management.
• Management: Monitor rhythm and haemodynamics; use phenotype-appropriate HF therapy, avoid strenuous exercise during active disease, and treat specific underlying causes.
• Immunosuppression: Not routine for presumed viral myocarditis; reserved for selected proven immune-mediated subtypes in specialist care.
• Follow-up: Repeat LV function and arrhythmia assessment before returning to intense exercise, often after a 3–6-month restriction depending on diagnosis and guidance.

💡 Clinical / MRCP Pearl: Not every troponin-positive young patient has ACS. Myocarditis may closely mimic infarction and requires an integrated clinical/ECG/imaging assessment.

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Takotsubo (Stress) Cardiomyopathy

Takotsubo syndrome causes transient regional LV systolic dysfunction, often following severe physical or emotional stress. It may resemble STEMI/NSTEMI and is often seen in postmenopausal women.

• Mechanism: Likely catecholamine-mediated myocardial stunning and microvascular dysfunction; several LV contraction patterns occur.
• Presentation: Chest pain, dyspnoea, ST–T changes, troponin rise and possible acute HF or shock.
• Imaging: Characteristic wall-motion abnormalities, classically apical ballooning, usually beyond a single epicardial coronary territory.
• Exclude alternatives: Coronary disease and myocarditis must be investigated; takotsubo can coexist with coronary disease.
• Treatment: Initially manage as possible ACS until clarified; then supportive HF therapy and treatment of triggers, arrhythmias or complications.
• LVOT obstruction: May develop acutely and makes inotropes or vasodilators problematic; echo guides shock management.
• Prognosis: LV function often recovers over weeks, but acute complications include VT, thrombus, severe MR, pulmonary oedema and shock.

💡 Clinical / MRCP Pearl: A transient cardiomyopathy is not automatically harmless. Takotsubo can cause cardiogenic shock and ventricular arrhythmia during the acute phase.

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Peripartum Cardiomyopathy (PPCM)

PPCM is heart failure due to LV systolic dysfunction (usually LVEF <45%) developing near the end of pregnancy or in the months following delivery, when no other adequate cause is found.

• Presentation: New breathlessness, orthopnoea, oedema, fatigue, palpitations or thromboembolism; normal pregnancy symptoms can delay recognition.
• Evaluation: ECG, NT-proBNP, echo for EF/RV function and LV thrombus; CMR in selected cases; exclude PE, ACS, valve disease and other cardiomyopathy.
• Risk markers: Very low EF, enlarged LV and RV impairment are adverse prognostic features; recovery may occur but is not guaranteed.
• Treatment: Urgent pregnancy-heart-team/cardiology care; treat congestion and heart failure using pregnancy- or lactation-compatible drugs as appropriate.
• Pregnancy cautions: ACE inhibitors, ARBs, ARNIs, MRAs and SGLT2 inhibitors are generally avoided during pregnancy; medication compatibility changes after delivery and with breastfeeding.
• Bromocriptine: May be considered in selected severe cases by specialists; prophylactic LMWH should be considered because thrombosis risk increases.
• Counselling: Discuss future pregnancy recurrence risk, contraception, genetics and continued follow-up even if EF normalises.

💡 Clinical / MRCP Pearl: A woman with persistent dyspnoea after delivery needs cardiac assessment rather than an assumption that symptoms are physiological or due to anxiety.

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Alcohol, Chemotherapy and Tachycardia-mediated Disease

The cause may be modifiable and timely intervention can prevent permanent myocardial damage.

• Alcohol-related cardiomyopathy: Long-term excess intake can cause DCM; support abstinence and nutritional treatment, particularly thiamine when deficient, plus appropriate HF therapy.
• Anthracycline cardiotoxicity: Doxorubicin and related agents can cause dose-related myocardial injury; baseline and serial EF/strain and biomarkers are used in higher-risk patients.
• Trastuzumab and targeted therapies: Can cause potentially reversible LV dysfunction; cardio-oncology review guides treatment interruption and re-challenge.
• Tachycardia-mediated cardiomyopathy: Sustained rapid AF/flutter or other SVT can depress LV function; rhythm control or appropriate rate control is central to recovery.
• PVC-mediated cardiomyopathy: A high burden of ectopy may reduce EF; ambulatory quantification and catheter ablation can be useful in selected cases.
• Follow-up: Reassess LVEF after correcting the trigger; even if EF improves, assess residual scar and genetic risk before assuming complete recovery.

💡 Clinical / MRCP Pearl: When AF and LV dysfunction occur together, ask whether AF is a consequence of DCM or its principal cause: the distinction changes treatment priorities.

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Acute Presentation and Cardiogenic Shock

Manage unstable patients as a medical emergency while recognising phenotype-specific hazards.

• Initial ABCDE: ECG, monitoring, IV access, oxygen for hypoxaemia, blood tests including troponin/NT-proBNP and urgent focused echocardiography.
• Acute congestion: IV loop diuretics where overloaded; careful blood pressure, renal and electrolyte assessment.
• Cardiogenic shock: Urgent ICU/cardiology input; identify pump failure versus RV failure, severe LVOT obstruction, acute valve pathology or arrhythmia.
• Arrhythmia: Treat unstable VT or AF according to resuscitation and cardioversion protocols; investigate reversible precipitants.
• HCM with LVOTO: Avoid inappropriate inotrope escalation and excessive preload reduction; specialist-directed fluids, vasoconstriction and negative inotropy may be needed.
• Myocarditis/PPCM: Consider specialised shock centres and temporary mechanical circulatory support where indicated.
• Thrombus risk: Assess LV thrombus, AF and apical aneurysm; do not prescribe prophylactic anticoagulation indiscriminately to all cardiomyopathy patients.

💡 Clinical / MRCP Pearl: The same hypotension may require opposite treatments: a dilated low-output ventricle and an obstructed hypercontractile HCM ventricle are haemodynamically different.

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Heart Failure Treatment Across Cardiomyopathies

Treat the underlying cardiomyopathy and any heart-failure phenotype rather than assuming one regimen applies to every disease.

• HFrEF/DCM: Offer NICE-recommended foundational therapy: ACE inhibitor or appropriate ARNI plan, evidence-based beta blocker, MRA and SGLT2 inhibitor, with loop diuretic if congested.
• HCM with obstruction: Beta blocker or verapamil/diltiazem, then appropriate specialist options; avoid aggressive vasodilatation and overdiuresis.
• RCM/amyloid: Relief of congestion with cautious diuretics; monitor postural BP and renal function; conventional vasodilators may be poorly tolerated.
• Arrhythmogenic disease: Ventricular arrhythmia risk management is central even before HF develops.
• Treat secondary causes: Rate/rhythm control, alcohol abstinence, revascularisation for coexisting CAD where justified, iron removal, disease-specific therapy or immunosuppression when indicated.
• Monitor: Symptoms, NYHA functional class, BP, ECG, kidney function, electrolytes, LV/RV function and rhythm burden.

💡 Clinical / MRCP Pearl: A beta blocker is a core drug in both DCM and obstructive HCM, but the timing, titration goals and supporting medicines can be completely different.

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Ventricular Arrhythmias, ICD and CRT

Device decisions should combine EF-based criteria with phenotype, genotype, CMR scar and clinical arrhythmic history.

• ICD secondary prevention: Usually indicated after appropriately defined VT/VF arrest or haemodynamically significant sustained ventricular arrhythmia when a reversible cause has not removed the risk.
• ICD primary prevention: Consider in selected HCM, DCM, ARVC and NDLVC patients after individualised risk assessment; EF alone is insufficient in high-risk genetic disease.
• CRT: For selected patients with HF, reduced LVEF, broad QRS (especially LBBB) and appropriate symptom criteria, following NICE device guidance.
• Antiarrhythmics: Beta blockers and selected drugs (e.g. amiodarone, sotalol or disopyramide in specific settings) may control arrhythmias; assess QT, bradycardia and organ toxicity.
• Catheter ablation: Useful for recurrent monomorphic VT, AF or PVC-related dysfunction in selected patients; it does not automatically remove ICD need.
• Shared decision-making: Discuss quality of life, future shocks, procedural risks, frailty and advanced-care preferences.

💡 Clinical / MRCP Pearl: An ICD prevents arrhythmic death but does not treat the underlying myocardial disease or prevent progressive pump failure.

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Common Adult Drugs and Doses

Use the two-column table below. These are educational adult examples and must be checked against the BNF, current SmPC, renal function, interactions and local specialist protocols.

⚠️ Prescribing note: These are examples, not automatic prescriptions. Review contraindications, BNF/SmPC, drug interactions, pregnancy, renal function and cardiac specialist advice; particularly for disopyramide, mavacamten and amyloid disease-modifying drugs.

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Monitoring and Safety

Cardiomyopathy therapy frequently requires serial ECG, biochemistry and echocardiography.

• ACE inhibitor/ARB/ARNI/MRA: Check BP, potassium and eGFR before and after initiation or dose escalation; monitor hypotension and hyperkalaemia.
• Beta blocker: Titrate when stable; check pulse, BP, fatigue, AV block and evidence of congestion.
• SGLT2 inhibitor: Assess kidney function and volume status; explain genital infection and euglycaemic DKA precautions and sick-day holding advice.
• Mavacamten: Specialist CYP2C19-guided dose with mandatory serial LVEF/gradient imaging; avoid initiation if LVEF <55% and interrupt when required by product information.
• Disopyramide: QTc and anticholinergic side-effect monitoring; caution in glaucoma, urinary retention and interacting drugs.
• Amyloid therapies: Specialist treatment selection and monitoring; vutrisiran requires attention to vitamin A supplementation.
• Anticoagulation: Assess AF, LV thrombus and genotype-specific risks; adjust for kidney function and bleeding risk.

💡 Clinical / MRCP Pearl: Sacubitril/valsartan must not be combined with an ACE inhibitor; an ACE inhibitor washout of at least 36 hours is needed.

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Pregnancy, Exercise and Family Advice

Counselling should be tailored to diagnosis, genotype, symptom burden and measured arrhythmic risk.

• Pregnancy: Pre-conception counselling for all women with significant inherited cardiomyopathy; very high-risk disease warrants a specialist pregnancy heart team.
• Drugs: Review ACEi/ARB/ARNI, MRA and SGLT2 inhibitors before conception; do not assume heart-failure medications are safe in pregnancy or breastfeeding.
• Activity: Moderate exercise is beneficial for many; exercise prescription should be individualised rather than automatic prohibition.
• Arrhythmogenic disease: High-intensity endurance sport may exacerbate ARVC and is often discouraged.
• HCM: Offer an informed exercise plan based on symptoms, obstruction, arrhythmia and sudden-death risk, with specialist advice about competitive activity.
• Family support: Genetic counselling and targeted cascade testing for pathogenic variants; screen first-degree relatives when familial disease is suspected.

💡 Clinical / MRCP Pearl: Sudden-death prevention is not achieved through blanket exercise bans; it depends on accurate phenotype and genotype-specific risk stratification.

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Complications, Follow-up and Prognosis

Clinical course ranges from lifelong mild disease to progressive HF or fatal arrhythmia.

• Complications: AF, stroke, sustained VT/VF, sudden death, worsening HF, pulmonary hypertension, LV thrombus, apical aneurysm and conduction disease.
• Prognostic factors: Previous arrhythmia/arrest, unexplained syncope, extent of fibrosis, genotype, RV involvement, EF, NYHA class, NT-proBNP and treatment response.
• Follow-up: Repeat clinical evaluation and ECG/echo generally every 1–2 years or sooner with symptoms; rhythm and CMR surveillance are individualised.
• Family considerations: Revisit family histories and variant classifications over time; an initially negative assessment may not end surveillance.
• Advanced care: Refer refractory disease for VAD/transplant consideration when appropriate, with palliative symptom and planning support where beneficial.
• Medication withdrawal: Do not assume restored EF means permanent remission, especially with inherited DCM.

💡 Clinical / MRCP Pearl: A good follow-up plan addresses symptoms, electrical risk, genetics and family health—not just the latest ejection fraction.

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High-yield Comparisons for MRCP

Use these phenotype contrasts as rapid bedside and examination discriminators.

• DCM: Large LV + low EF + S3; think inherited, myocarditis, alcohol, chemotherapy and tachycardia; treat HFrEF and assess arrhythmic risk.
• Obstructive HCM: Thickened septum + SAM + dynamic systolic murmur louder with Valsalva; avoid preload/afterload reduction when symptomatic obstruction.
• ARVC: Ventricular arrhythmia in younger patient + right precordial repolarisation abnormalities, exercise association and genetic/family implications.
• RCM: Stiff non-dilated ventricles + large atria + congestion; consider amyloid and constrictive pericarditis.
• ATTR: Older patient + HFpEF/LVH + carpal tunnel; complete light-chain screen then DPD-type scintigraphy and TTR genotyping.
• AL: Rapid restrictive HF + monoclonal light-chain findings and systemic clues: urgent haematology evaluation.
• Sarcoid: Young adult with high-grade AV block or VT and infiltrative CMR/FDG-PET findings.
• Takotsubo: Acute ACS mimic after stress with characteristic transient wall-motion abnormality; exclude coronary occlusion and myocarditis.
• PPCM: New HF towards end of pregnancy or postpartum with LVEF <45%; pregnancy-specific therapy and recurrence counselling.

💡 Clinical / MRCP Pearl: If the ventricular wall is thick, ask why; if the ventricle is dilated, ask why; if the ECG is malignant with near-normal echo, still ask why.

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MRCP and Clinical Pearls

A concise checklist for clinical exams, PACES and acute medical practice.

• 1. Cardiomyopathy is a phenotype; search for the cause and family implications.
• 2. A normal EF does not exclude HCM, amyloidosis or arrhythmogenic disease.
• 3. Exercise syncope and family sudden death require urgent arrhythmic risk evaluation.
• 4. HCM LVOTO usually worsens with standing/Valsalva and may improve with squatting.
• 5. The LVOT gradient threshold ≥30 mmHg indicates obstruction; ≥50 mmHg guides consideration of advanced symptomatic treatment.
• 6. Non-vasodilating beta blockers are first-line for symptomatic obstructive HCM.
• 7. HCM with AF generally requires anticoagulation regardless of usual stroke risk score.
• 8. DCM may improve with tachycardia control, toxin cessation and HFrEF therapy.
• 9. High-risk LMNA/FLNC and other genotypes may prompt ICD consideration despite EF >35%.
• 10. ARVC management includes individual exercise restrictions and SCD assessment.
• 11. Non-ischaemic LGE on CMR may imply a higher arrhythmia risk.
• 12. Exclude AL with serum free light chains plus serum and urine immunofixation before diagnosing ATTR non-invasively.
• 13. New high-grade AV block in a younger adult suggests sarcoid or inherited myocardial disease.
• 14. Takotsubo may be reversible but can still cause shock and arrhythmia.
• 15. Peripartum cardiomyopathy requires pregnancy-safe treatment and future pregnancy counselling.
• 16. Do not use a VUS alone as evidence that a relative carries a pathogenic familial disease.

💡 Clinical / MRCP Pearl: In MRCP questions, the next best test is often directed by the phenotype: echo for dynamic obstruction, CMR for scar, targeted amyloid testing for unexplained LVH, and Holter/genetics for arrhythmic family disease.

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Selected References and UK Resources

Clinical guidance should be checked against current NICE appraisals, ESC recommendations and product information.

• ESC 2023: ESC Cardiomyopathy Guideline — diagnostic phenotypes, genetics, screening and risk stratification.
• NICE heart failure: NICE NG106 — diagnosis and medical therapy for chronic HF.
• NICE device therapy: NICE TA314 — ICD and CRT eligibility.
• NICE mavacamten: NICE TA913 — symptomatic obstructive HCM.
• NICE ATTR therapy: Tafamidis TA984; vutrisiran TA1115; acoramidis TA1121.
• Myocarditis: ESC Clinical Practice Guidelines — consult the 2025 myocarditis guidance.
• Pregnancy: ESC Clinical Practice Guidelines — consult the 2025 cardiovascular disease and pregnancy guideline.
• Dosing: Use current BNF, SmPC, renal guidance and centre-specific cardiac pharmacy protocols for final prescribing decisions.

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