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Regional Ventricular Function in Pulsus Alternans
Published in Samuel Sideman, Rafael Beyar, Analysis and Simulation of the Cardiac System — Ischemia, 2020
Pulsus alternans, a regular alternation in pulse pressure accompanied by a regular rhythm without appreciable variation in cardiac cycle length, was described about a century ago.1 Alternation in ventricular pressure has been reported to indicate a depressed or a failing heart.2–5 Such alternation was observed to be associated with either an alternation in end-diastolic pressure, systolic pressure, aortic flow, or stroke volume. The stronger pulse is always associated with a larger stroke volume and the weak pulse is associated with a smaller stroke volume. This led some investigators to propose the Frank-Starling mechanism as the primary mechanism responsible for its occurrence.6 Others, however, suggested that the contractility may be changing, thus disputing the Frank-Starling mechanism as the causative factor. This latter was termed the alternating contractile state theory.7–9 These two theories centered on the mechanism of the occurrence of pulsus alternans have been widely pursued, but are still conflicting.
Physiological interpretation of pressure waveforms
Published in John Edward Boland, David W. M. Muller, Interventional Cardiology and Cardiac Catheterisation, 2019
Heart rate plays a role in determining the significance of pulsus alternans in heart failure. At heart rates of 50 bpm, it is an indicator of significant failure but if a tachycardia exists (>100 bpm) its significance decreases as heart rate increases. When not obvious, pulsus alternans may become prominent following an ectopic beat.1,4
A guide to cardiac examination
Published in Swati Gupta, Alexandra Marsh, David Dunleavy, Kevin Channer, Cardiology and the Cardiovascular System on the move, 2015
Swati Gupta, Alexandra Marsh, David Dunleavy, Kevin Channer
CharacterHyperdynamic pulse is a large-volume bounding pulse seen in anaemia, sepsis, thyrotoxicosis and pregnancy.Slow-rising pulse (pulsus parvus et tardus) is a pulse increasing gradually in volume that occurs with aortic stenosis.Bisferiens pulse is a slow-rising pulse with two systolic peaks, felt in aortic stenosis combined with aortic regurgitation.Pulsus alternans alternates between normal and low volume and occurs in conditions such as mitral or aortic valve stenosis, severe ventricular failure or effusive pericarditis.Collapsing pulse (water hammer) has an early peak with a rapid decrease in volume that can be exaggerated by raising the arm above the level of the heart (occurs in severe aortic regurgitation).
Teaching the physical examination by context and by integrating hand-held ultrasound devices
Published in Medical Teacher, 2020
The least important PE signs (Table 4) are those that are no longer employed because of the availability of ancillary tests. For example, pulse oximetry may detect reduced blood oxygenation at earlier stages than cyanosis, and PoCUS/cardiac US may detect left ventricular dysfunction at an earlier stage than pulsus alternans.