Combined Ventricular Systolic and Diastolic Dysfunction
It is not uncommon in chronic heart failure to have a combination of both systolic
dysfunction. Therefore, the slope of the end-systolic pressure-volume relationship
(ESPVR) is decreased and the slope of the passive filling curve (reciprocal of compliance) is increased in the ventricular pressure-volume loop
shown to the right. When this occurs, there is a dramatic reduction in stroke volume (width of pressure-volume loop) because end-systolic volume is increased and end-diastolic volume is decreased. Both ejection fraction
and stroke work
are also decreased. The changes shown in the figure assume that heart rate and systemic vascular resistance are both unchanged; however, in patients both of these parameters will likely be increased because of reflex sympathetic activation.
This combination of systolic and diastolic dysfunction, coupled with compensatory volume expansion, can lead to very high end-diastolic pressures that can cause pulmonary congestion and edema, as well as systemic edema and ascites (particularly when the right ventricle is in failure).