Makindo Medical Notes

Related Subjects: |Examining the Arterial Pulse

🩺 Introduction

• The arterial pulse is a vital sign reflecting cardiovascular function.
• Pulse examination reveals heart rate, rhythm, and the character of blood flow.
• The waveform has a percussion wave from ventricular ejection and a dicrotic notch marking aortic valve closure (onset of diastole).

🎯 Objectives of Pulse Examination

• Assess the rate (bpm).
• Determine rhythm (regular, irregular).
• Evaluate character (volume, contour).
• Check for radio-radial or radio-femoral delay.
• Identify abnormal pulses indicating pathology.

🛠️ Technique

The radial artery at the wrist is most accessible:

• Arm relaxed and supported at heart level.
• Use index and middle finger pads, just proximal to wrist crease.
• Apply light pressure — enough to feel pulsation without occluding it.

📊 Pulse Characteristics

• Volume: Pulse pressure & stroke volume.
• Contour: Speed of upstroke/downstroke.
• Regularity: Consistency of beats.
• Equality: Compare both sides.

⚡ Pulse Variations & Clinical Significance

• ✅ Normal: Regular, normal volume/contour.
• 🔥 Bounding: Fever, thyrotoxicosis, anaemia, AR, PDA (rapid up & down).
• 💧 Collapsing (Waterhammer): AR, PDA, high-output states (forceful, quick collapse).
• 🐢 Slow-rising (Anacrotic): Aortic stenosis (slow upstroke, low amplitude).
• 🎢 Bisferiens: Mixed aortic disease, HOCM (double systolic peak).
• ↔️ Pulsus alternans: Severe LV dysfunction (alternating strong/weak beats).
• 🌬️ Pulsus paradoxus: Cardiac tamponade, constrictive pericarditis, severe asthma, tension pneumothorax (exaggerated inspiratory fall in SBP).
• ⚡ Jerky (Spike & Dome): HOCM.
• 🩸 Thready: Shock, hypovolaemia (weak, rapid).
• 🚫 Absent: Arterial occlusion, dissection, Takayasu.
• ⏱️ Radio-femoral delay: Coarctation of aorta.

❤️ Heart Rate

• Normal: 60–100 bpm.
• Bradycardia (<60): Athlete, hypothyroid, hypothermia, beta-blockers, AV block, sick sinus.
• Tachycardia (>100): Exercise, fever, stress, anaemia, thyrotoxicosis, SVT (AVNRT, AVRT), AF, atrial flutter, VT, VF.

📈 Pulse Rhythm

• 🔄 Regular: Sinus rhythm, sinus brady/tachy.
• 📐 Regularly irregular: Mobitz I block, bigeminy.
• 🎲 Irregularly irregular: AF, multifocal atrial tachycardia.
• ⚡ Extrasystoles: PACs, PVCs (ectopic beats).

📉 Pulse Deficit

In AF, not all heartbeats produce a palpable peripheral pulse. Compare apical rate (stethoscope) with radial rate to detect a deficit.

🩻 Radio-Radial & Radio-Femoral Delay

• Radio-radial delay: Subclavian stenosis, aortic dissection, cervical rib.
• Radio-femoral delay: Coarctation of aorta, severe peripheral vascular disease.

🧪 Clinical Examples

• 🔥 Bounding: Hyperdynamic states (fever, anaemia, thyrotoxicosis).
• 💧 Collapsing: AR (best felt by raising arm while palpating radial pulse).
• 🌬️ Pulsus paradoxus: Measured with sphygmomanometer; tamponade/asthma.
• ↔️ Pulsus alternans: Severe LV failure → needs echo.

✅ Conclusion

A systematic pulse exam (rate, rhythm, character, delay) is a cornerstone of cardiovascular assessment. Subtle variations provide diagnostic clues to structural heart disease, pericardial pathology, or systemic illness.

📚 References

• Bickley LS, Szilagyi PG. Bates’ Guide to Physical Examination. Wolters Kluwer, 2017.
• Kasper DL, Fauci AS, Hauser SL, et al. Harrison’s Principles of Internal Medicine. McGraw-Hill, 2018.
• Epstein O, Perkin GD, Cookson J, de Bono DP. Clinical Examination. Mosby, 2008.
• McGee S. Evidence-Based Physical Diagnosis. Elsevier, 2018.