Dicrotic pulse in pericardial tamponade

Abstract

ANALYSIS OF THE arterial pressure waveform is useful to the clinician in that alterations in the waveform morphology may indicate changes in cardiovascular parameters, such as stroke volume, systemic vascular resistance, or preload. Distinct arterial waveform morphologies, such as pulsus alternans and pulsus paradoxus, may indicate specific conditions and are helpful in directing therapy. The dicrotic pulse is a unique arterial pressure waveform associated with specific physiologic conditions. Recognition and understanding of factors associated with dicrotic pulse formation should aid the clinician in patient management. As opposed to anacrotic and biferious pulses, in which 2 pulsations occur during systole, a dicrotic pulse is characterized by 2 palpable pulsations with 1 upstroke in systole and 1 upstroke in diastole. Meadows et al1 defined a fully dicrotic pulse when the dicrotic wave (peak of the dicrotic wave pressure dicrotic notch pressure) is 30% of the pulse pressure and when the pressure difference between the dicrotic notch and the diastolic pressure is 10% of pulse pressure. A dicrotic pulse historically has been associated with typhoid fever and more recently described with a variety of low cardiac output states.1,2 After mitral or aortic valve replacement, a dicrotic pulse has been correlated with left ventricular dysfunction and is an indicator of a poor postoperative prognosis.3 This case report describes the occurrence of a dicrotic pulse in a patient with cardiac tamponade that resolved after surgical drainage of pericardial fluid.