Abnormal Pulse Patterns and Their Clinical Significance
1. Pulsus Paradoxus
Definition: An exaggerated decrease (>10 mmHg) in systolic blood pressure during inspiration.
🔍 Seen in:
- Pericardial tamponade (classic association)
- Superior vena cava (SVC) obstruction
- Chronic obstructive pulmonary disease (COPD) / Acute severe asthma
- Constrictive pericarditis
- Pulmonary embolism
- Hypovolemic shock
- Tension pneumothorax
- Large pleural effusion
📝 Exam Tip: Pulsus paradoxus is best detected using a sphygmomanometer rather than palpation. It is a key feature of cardiac tamponade.
2. Pulsus Alternans
Definition: Regular alteration of pulse pressure with a normal rhythm (single peak per beat). Indicates left ventricular systolic dysfunction.
🔍 Seen in:
- Left ventricular failure (LVF) (hallmark sign)
- Dilated cardiomyopathy
- Severe aortic stenosis
- Advanced hypertension
📝 Exam Tip: Pulsus alternans suggests poor left ventricular function and can be confirmed using sphygmomanometry or echocardiography.
3. Bisferiens Pulse
Definition: A pulse with two distinct systolic peaks per cardiac cycle. Best felt in the carotid artery.
🔍 Seen in:
- Aortic regurgitation + Aortic stenosis (AR + AS) (combined lesion)
- Hypertrophic obstructive cardiomyopathy (HOCM)
- Severe mitral regurgitation
📝 Exam Tip: Bisferiens pulse is classically associated with HOCM and can be differentiated from other pulses using Doppler echocardiography.
4. Dicrotic Pulse
Definition: A pulse with two palpable waves: one during systole and one during diastole.
🔍 Seen in:
- Dilated cardiomyopathy (DCM)
- Septic shock (low cardiac output states)
- Hypovolemia
- Conditions with reduced systemic vascular resistance
📝 Exam Tip: Dicrotic pulse occurs due to an exaggerated dicrotic notch. It is often a sign of severe myocardial dysfunction.
Additional High-Yield Exam Points:
- Collapsing (Water hammer) pulse: Seen in Aortic regurgitation (Corrigan’s sign).
- Anacrotic pulse: Seen in Aortic stenosis (slow-rising pulse with a delayed peak).
- Bounding pulse: Seen in sepsis, fever, anemia, and thyrotoxicosis.
- Paradoxical pulse vs Pulsus alternans: Pulsus paradoxus is linked to pericardial conditions, whereas Pulsus alternans suggests ventricular failure.
