Diagnosis of intermittent severe aortic regurgitation through a mechanical aortic valve based on arterial pressure waveform changes: A case report

Abstract

　We describe a case of aortic regurgitation (AR) secondary to intermittent dysfunction of a mechanical aortic valve, which remained undetected on transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and fluoroscopy but was diagnosed as residual intermittent AR based on arterial pressure waveform changes observed during intensive care unit monitoring. The patient thereafter underwent redo aortic valve replacement.

　Intermittent dysfunction of a mechanical valve is rare. Although the severity varies and depends on the frequency of disk immobilization, early detection is important to avoid fatal hemodynamic deterioration in cases of permanent dysfunction. TTE, TEE, and fluoroscopy are commonly used to diagnose prosthetic valve dysfunction; however, it may remain undiagnosed in cases of intermittent regurgitation if imaging fails to record the regurgitant jet in real-time. In this case, the patient underwent arterial pressure monitoring in the intensive care unit, and characteristic changes in radial artery pressure waveforms (which showed intermittent loss of the dicrotic notch and decrease in diastolic pressure) were useful for diagnosis.