Synonyms: mechanical alternans
- Pulsus alternans was first described by Ludwig Traube in 1872 and defined as the beat-to-beat variability of the pulse amplitude in a patient with a sinus rhythm, independent of the respiratory cycle.
- Only the strong beats but not the weak beats are appreciated as phase I Korotkoff sounds when the cuff pressure is initially lowered.
- Pulsus alternans reflects myocardial dysfunction associated with cyclic fluctuations in preload, afterload, and contractility.
- Pulsus alternans typically occurs with heart failure and may be precipitated by aortic regurgitation, hypovolemia, and tachycardia.
- Aortic regurgitation
- Ectopic beats in aortic stenosis
- Left ventricular heart failure
- Sympathetic activation in myocardial ischemia