ABSTRACT
Chronic Compensated MR Many patients with acute MR require immediate surgery to relieve heart failure by correcting the leaking valve. However, if severe MR develops more gradually allowing for LV and LA adaptation, the patient may enter a chronic compensated phase (Fig. 2.1B). In this phase eccentric cardiac hypertrophy develops, leading to a large increase in LV end diastolic volume, allowing for increased LV total and forward stroke volume. Increased LV radius increases the systolic wall stress from its reduced level in the acute phase to normal in this phase. However, increased preload in conjunction with normal contractile function still maintains a higher-than-normal ejection fraction. In this phase the LA has also enlarged, allowing it to receive the regurgitant volume at a lower fi lling pressure. Thus, compensated with normal forward output and left-sided fi lling pressures, the patient may be entirely symptom free despite severe MR.
