Changes in the severity of aortic regurgitation at peak effort during exercise.

Background: Chronic aortic regurgitation can be well tolerated for a long time. Some patients with normal ventricular function can even reach high levels of sporting performance. How the severity of regurgitation may change during exercise, however, is little known, although some studies suggest it diminishes. The present work examines, during exercise, the functional capacity, ventricular function, and regurgitation fraction (RF) in asymptomatic subjects with moderate or severe aortic regurgitation with preserved ejection fraction.

Methods: The study subjects (n=32; 23 men, 9 women) were patients referred to our echocardiography laboratory with moderate or severe aortic regurgitation, preserved left ventricular systolic function, and sinus rhythm into NYHA functional class I. All underwent transthoracic echocardiography at rest and at peak effort during an exercise protocol involving an inclined cycloergometer. Left atrial and ventricular volume indices were recorded, along with diastolic and systolic function, cardiac index, peripheral resistance, and RF.

Results: The mean age of the subjects was 43.8±18.2years; 59% suffered moderate regurgitation, 41% severe aortic regurgitation, and 84% had a dilated left ventricle. All subjects managed exercise loads adequate for their age. Peak effort was associated with a significant reduction (mean 44.5% [range 10-95%]) in the RF (21.8±13.2 vs. 39.3%±14.7% at rest; p=0.0001). The absolute reduction in the RF at peak effort was greater among the subjects with severe aortic regurgitation (21.2% vs. 13.3% in those with moderate regurgitation; p=0.018).

Conclusions: The RF becomes smaller during exercise in asymptomatic subjects with moderate or severe aortic regurgitation and preserved ventricular function.