Related Subjects:
|Supraventricular Tachycardia (SVT)
|Atrial Flutter
|Atrial Fibrillation
|Sinus Tachycardia
|Multifocal Atrial Tachycardia
|Junctional Tachycardia
๐ About Sinus Tachycardia
- Most often a physiological response (exercise ๐โโ๏ธ, anxiety ๐ฐ, pain).
- Can also reflect underlying pathology (sepsis ๐ฆ , hypovolaemia ๐, thyrotoxicosis ๐ฆ).
- Defined as sinus rhythm with rate >100 bpm.
๐ ECG Features
- Rate: >100 beats/min
- Rhythm: Sinus (normal P before each QRS)
- PR interval: ~0.20 sec (normal)
- QRS complex: Narrow & normal morphology
โ ๏ธ Causes
- Physiological: Stress ๐ฐ, exercise ๐โโ๏ธ, anxiety
- Endocrine: Hyperthyroidism ๐ฆ
- Systemic: Sepsis ๐ฆ , shock ๐จ, fever ๐ก๏ธ
- Cardiac: Heart failure โค๏ธ, pulmonary embolism ๐ซ
- Haematological: Anaemia ๐ฉธ, hypoxia
- Drugs: ฮฒ-agonists, caffeine โ, alcohol ๐ท, withdrawal states
๐งช Investigations
- ECG ๐ (confirm sinus rhythm)
- Bloods: U&E, FBC, LFTs, TFTs
- Chest X-ray if pulmonary cause suspected ๐ซ
- Consider troponin if cardiac cause suspected โค๏ธ
- Sepsis screen (cultures, lactate) if febrile ๐ฆ
๐ ๏ธ Management
- Often physiological โ no treatment needed โ
- Address underlying cause (e.g. fluids for hypovolaemia, antibiotics for sepsis, thyrotoxicosis treatment)
- Review medications ๐ (e.g. bronchodilators, stimulants)
- Beta-blockers or ivabradine may be considered if persistent & highly symptomatic (after excluding secondary causes)
๐ก Clinical Pearl:
Sinus tachycardia is usually a marker of another process, not a primary arrhythmia.
Always search for infection, hypoxia, bleeding, pain, or thyroid disease before treating the rate.
๐ Case Example
๐ฉ A 28-year-old woman presents with fever ๐ก๏ธ and productive cough.
Pulse: 120 bpm, regular. ECG shows sinus tachycardia ๐.
FBC: raised WCC, CRP elevated.
โ
Diagnosis: Community-acquired pneumonia with sinus tachycardia as a physiological response.
๐ ๏ธ Management: IV antibiotics + fluids. No rate-control needed.