Abstract
In 14 patients (pts) with aortic valve disease (A VD) left ventricular (LV) relaxation was assessed by the time constant (T) of LV pressure (tipmanometer) fall before and 19 months after successful aortic valve replacement (A VR). 12 control pts (CO) were studied by the same technique. Preoperative LV ejection fraction in AVD (64%) and in CO (69%) did not differ. In AVD T was increased (60 ms) as compared to the CO (38 ms, P< 0.05). During handgrip (HG) there was a similar increase of LV peak systolic pressure (LVSP), heart rate and peak measured contractile element velocity of shortening in A VD and in the CO. L V end-diastolic pressure varied minimally in both groups. T decreased during handgrip in CO (38 to 33 ms, P<0.01) and remained unchanged in A VD. Following AVR T at rest decreased insignificantly to 52 ms, but remained increased (P<0.025) as compared with CO. During postoperative HG however, a decrease to 47ms (P<0.05) was noted. Postoperative angiographic LV muscle mass (105 g/m2) and LVSP at rest (137 mmHg) remained elevated (P<0.02) as compared to CO (72 g/m2; 119 mmHg). It is concluded that (1) in A VD with normal ejection performance L V relaxation at rest is prolonged and the reaction of relaxation to HG is abnormal despite preserved contractile response, (2) following A VR the response of LV relaxation to HG becomes normal and (3) elevated postoperative T at rest appears to be related to residual hypertrophy and probably also to the still increased LVSP rather than to intrinsic disturbances of myocardial relaxation
Deuel, W