Radionuclide evaluation of aortic regurgitation: assessment of ventricular function by Fourier phase analysis.

Forty patients with chronic isolated aortic regurgitation were studied by phase analysis of equilibrium radionuclide ventriculography to see whether this technique could detect changes in left ventricular (LV) function before the onset of symptoms. This technique was compared to the radionuclide ejection fraction and echocardiography. The severity of LV volume overload was assessed using the radionuclide regurgitant index. Patients with clinically severe aortic regurgitation had severe volume overload (high regurgitation index), increased echocardiographic left ventricular dimensions and significantly increased phase spread (loss of synchrony of wall motion) compared to mild and moderate groups. All but one had well maintained global left ventricular function assessed by the ejection fraction. All seven patients with definite symptoms had a marked increase in phase spread and severe volume overload.