Pulsus alternans is a physical finding with arterial pulse waveform showing alternating strong and weak beats.[1] It is almost always indicative of left ventricular systolic impairment, and carries a poor prognosis.
Pulsus alternans | |
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Other names | Cardiac alternans, mechanical alternans |
Pulse pressure waveform displaying the variation in pressure between beats in pulsus alternans. | |
Specialty | Cardiology |
The condition is relatively rare, and patients with the greatest risk for developing pulsus alternans include those with heart failure, cardiomyopathy, coronary artery disease, or other cardiac risk factors.[2]
Pathophysiology edit
One explanation is that in left ventricular dysfunction, the ejection fraction will decrease significantly, causing reduction in stroke volume, hence causing an increase in end-diastolic volume. As a result, during the next cycle of systolic phase, the myocardial muscle will be stretched more than usual and as a result there will be an increase in myocardial contraction, related to the Frank–Starling physiology of the heart. This results, in turn, in a stronger systolic pulse. There may initially be a tachycardia as a compensatory mechanism to try to maintain cardiac output. Other explanation is due to the heterogeneity of the refractory period between the healthy and diseased myocardial cells.[citation needed]
Diagnosis edit
Pulsus alternans is diagnosed by first palpating the radial or femoral arteries, feeling for a regular rhythm but alternating strong and weak pulses. Next, a blood pressure cuff is used to confirm the finding: the cuff is elevated past systolic pressure and then slowly lowered cuff towards the systolic level. If alternating loud and soft Korotkoff sounds are heard, pulsus alternans is indicated.[3]
Clinical significance edit
A finding of pulsus alternans is indicative of severe left-sided heart failure. [4]
In literature edit
D.H. Lawrence describes pulsus alternans in his novel Sons and Lovers:
Then he felt her pulse. There was a strong stroke and a weak one, like a sound and its echo. That was supposed to betoken the end....
References edit
- ^ Euler, DE (June 1999). "Cardiac alternans: mechanisms and pathophysiological significance". Cardiovascular Research. 42 (3): 583–90. doi:10.1016/s0008-6363(99)00011-5. PMID 10533597.
- ^ Henery, Daniel; Tummala, Ramyashree (7 August 2022). Pulsus Alternans. StatPearls Publishing. PMID 32491574. Retrieved 10 February 2023.
- ^ Bates
- ^ (Bates)