ACUTE AORTIC REGURGITATION IN CRITICALLY ILL PATIENTS - IMPORTANCE OF ECHO-DOPPLER STUDIES

The aim of this study was to determine the relative value of clinical, echocardiographic, Doppler, and catheterization examinations in recognizing the presence and estimating the severity of acute aortic regurgitation in critically ill patients. Retrospective analyses of clinical, echocardiographic, Doppler, and cardiac catheterization data were performed. Twenty-four acutely ill patients with echo-Doppler evidence of acute severe aortic regurgitation who either underwent aortic valve replacement (n = 21) or died and had autopsies (n = 3) were studied. Clinically, acute severe regurgitation was diagnosed in the presence of an early diastolic murmur accompanied by tachypnea, tachycardia, and bilateral basilar rales. By echo-Doppler, acute severe aortic regurgitation was diagnosed in the presence of early closure of the mitral valve on the M-mode echocardiogram and an aortic regurgitation velocity half-time < 280 ms by continuous-wave Doppler ultrasound. The sensitivity of the clinical findings and noninvasive studies was assessed against invasive estimates of regurgitation severity by aortography in 12 patients and ventricular sump flow at the time of aortic valve replacement in 21 patients. By clinical examination, aortic regurgitation was detected in 18 (75%) patients, but was considered severe in only 12 (50%). M-mode echocardiography detected the presence of aortic regurgitation in 12 patients, but premature closure of the mitral valve was seen in only 6 (25%). Doppler studies detected the presence of aortic regurgitation in all 24 patients, and Doppler half-time < 280 ms accurately predicted aortic regurgitation severity in all but 2 patients. The latter patients had a markedly elevated left ventricular end-diastolic pressure and a moderately severe rather than a severe aortic regurgitation by aortography. Aortography added little to the information already obtained by Doppler studies. Two patients died while waiting for aortography. Coronary angiography detected associated coronary artery disease in 3 of the 12 patients. Clinically, it is difficult to evaluate the severity of acute aortic regurgitation in the critically ill. The continuous-wave Doppler half-time method permits noninvasive, rapid detection and accurate estimation of aortic regurgitation severity. Cardiac catheterization is recommended only when the noninvasive evaluation is inconclusive or evaluation of the coronary anatomy is indicated.