Current perspectives on cardiac function in patients with diastolic heart failure.

摘要

Despite recent advances in the diagnosis and management of heart failure, the rate of hospitalizations for this condition is increasing. At least 50% of patients present with heart failure despite a normal ejection fraction (EF) and are referred to as having heart failure with normal EF or diastolic heart failure (DHF). Recently, a group of investigators met to address the issue of nomenclature and agreed that the term DHF is preferred but that it does not refute the presence of other abnormalities in this condition. We therefore use this term throughout the present review.There are several opinions about the pathophysiology of this condition that have been expressed passionately by many groups. They include issues pertaining to left ventricular (LV) systolic properties, ventricular arterial coupling, and last but not least, LV diastolic function. Recent studies that used novel imaging modalities and others that used conductance catheters in DHF patients have provided additional data that are pertinentto the ongoing debate and have potential therapeutic implications. However, before discussing the recent studies, it is important to comment on certain morphological characteristics in DHF patients that are distinct from those in patients with systolic heart failure. In particular, LV dimensions and volumes are normal in DHF patients,2 whereas wall thickness and LV mass are increased, although the latter finding is not universal. In an exception to the above findings, a recent study3 reported that LV end-diastolic volumes were increased in DHF patients. However, a single M-mode measurement was used to convert LV dimensions to volumes, only 51% of the original sample size was included, and 90% of DHF patients had normal LV volumes, with only 10% showing LV dilatation. In light of the above, it is reasonable to conclude that LV volumes are normal in most DHF patients. The most recent set of criteria for diagnosing DHF by the European Society of Cardiology recognize the presence of an EF >45% and a LV end-diastolic volume index <97 mL/m~2 as 1 of 3 essential criteria to establish this diagnosis. The other 2 criteria are signs and symptoms of heart failure and abnormalities in LV diastolic function/ filling. Notwithstanding the need for uniformly accepted definitions, a number of disease processes result in DHF and affect cardiac function in such a way that there can be different pathophysiological changes, depending on the pop-ulation studied. We devote this review to 3 fundamental aspects of cardiac function in DHF: systolic properties, ventricular-arterial coupling, and diastolic function.