RETROGRADE ATRIAL KICK IN ACUTE AORTIC REGURGITATION - STUDY OF MITRAL AND PULMONARY VENOUS FLOW VELOCITIES BY TRANSTHORACIC AND TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Background and hypothesis: The purpose of this study was the comprehen sive evaluation of the changes in pulmonary venous and mitral flow vel ocities of patients with acute and chronic severe aortic regurgitation . Transmitral flow velocities obtained with pulsed-wave Doppler echoca rdiography have been used to provide information on left ventricular ( LV) filling and diastolic function. Pulmonary venous flow tracings are an important adjunct to LV inflow pattern in assessing LV diastolic f unction. Methods: Fourteen patients with severe aortic regurgitation ( 8 chronic and 6 acute) and in sinus rhythm were examined by transthora cic and transesophageal pulsed Doppler echocardiography. Mitral and pu lmonary flow velocities were recorded and compared. All patients had e jection fractions > 40%. Results: Early mitral flow peak velocity was higher in patients with acute regurgitation (p<0.001). The mitral A wa ve was absent in five patients with acute regurgitation. In contrast, a prominent reverse atrial pulmonary systolic wave AR was demonstrated in these patients. Peak diastolic velocity of the pulmonary venous Bo w was greater in patients with acute aortic regurgitation (0.76 +/- 0. 13) than in patients with chronic aortic regurgitation (0.40 +/- 0.09) (p<0.001). Peak systolic velocity did not differ significantly betwee n the two groups. The systolic fraction of pulmonary venous now in pat ients with acute aortic regurgitation was lower (0.43 +/- 0.05) than t hat of patients with chronic regurgitation (0.63 +/- 0.1) (p<0.01). Al l patients with acute aortic regurgitation had an S/D ratio < 1, while those with chronic regurgitation had an S/D > 1 (p<0.001) and an E/A < 1. Conclusion: Patients with severe acute aortic regurgitation showe d a retrograde atrial kick (absence of transmitral A wave with promine nt pulmonary AR wave). These patients had an S/D ratio < 1 (restrictiv e Doppler pattern). Patients with chronic aortic regurgitation exhibit ed a Doppler pattern of abnormal LV relaxation (E/A < 1, S/D > 1).