Left ventricular relaxation at rest and during handgrip in aortic valve disease before and after valve replacement

In 14 patients (pts) with aortic valve disease (A VD) left ventricular(LV) relaxation was assessed by the time constant (T) of LVpressure (tipmanometer) fall before and 19 months after successfulaortic valve replacement (A VR). 12 control pts (CO) were studiedby the same technique. Preoperative LV ejection fraction inAVD (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 velocityof shortening in A VD and in the CO. L V end-diastolic pressurevaried minimally in both groups. T decreased during handgripin 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. Duringpostoperative HG however, a decrease to 47ms (P<0.05) wasnoted. Postoperative angiographic LV muscle mass (105 g/m²)and LVSP at rest (137 mmHg) remained elevated (P<0.02) ascompared to CO (72 g/m²; 119 mmHg). It is concluded that (1)in A VD with normal ejection performance L V relaxation at restis prolonged and the reaction of relaxation to HG is abnormaldespite preserved contractile response, (2) following A VR theresponse of LV relaxation to HG becomes normal and (3) elevatedpostoperative T at rest appears to be related to residual hypertrophyand probably also to the still increased LVSP rather than tointrinsic disturbances of myocardial relaxation.