The character of a pulse refers to its strength and volume, and can suggest various pathologies. The carotid pulse should be used when assessing the character of the pulse; palpation should show a smooth rapid upstroke and a more gradual downstroke with each pulse.
Pathological pulse characters
Waterhammer/Large volume pulse
A waterhammer pulse has a sharper upstroke and increased amplitude. It is typically caused by aortic regurgitation.
A slow-rising pulse has, as the name suggests, a slower upstroke and reduce amplitude. It is typically caused by aortic stenosis
Pulsus bisfiriens has a character of two narrowly separated peaks during systole. It is caused by mixed aortic stenosis with aortic regurgitation valve disease.
Pulsus alternans develops in left ventricular systolic impairment. The pulse alternates between low and high volume; a low ejection fraction produces the low volume pulse, which leads to ventricular filling and a stronger contraction in the subsequent pulse due to Startling’s law.
Pulses paradoxus refers to a large drop in pulse volume (corresponding to >10mmHg blood pressure) upon inspiration.
- Pericardial effusion
- Severe asthma
Double impulse apex beat
When palpating the apex beat, a feeling of 2 beats within a single systole is suggestive of hypertrophic obstructive cardiomyopathy (HOCM).
Absent radial pulse
Occasionally, a radial pulse may be completely absent and cannot be palpated or found on ultrasound.
- Iatrogenic e.g. post-catheterisation, radial artery harvest
- Congenital absence
- Aortic dissection involving the subclavian artery
- Peripheral artery embolism
- Compression by cervical rib
- Takayasu’s arteritis
- Morris DC. The Carotid Pulse. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 20. Available from: https://www.ncbi.nlm.nih.gov/books/NBK312/