Author + information
- David H. MacIver, MB, BS, MD⁎ ()
- ↵⁎Department of Cardiology, Taunton & Somerset Hospital, Musgrove Park, Taunton TA1 5DA, United Kingdom
Further to the review article on heart failure with a normal ejection fraction (HFNEF) (1), the authors note that HFNEF is associated with hypertension in up to 88% of individuals. Observational studies have shown that there is a significant increase in left ventricular mass but with a relatively normal end-diastolic volume compared with control patients (2). The authors also confirm that there are contractile abnormalities as assessed by strain, strain rate, and peak annular systolic velocities (1,3). Interestingly, systolic velocities correlate (r = 0.81) with the severity of the diastolic velocities in bothheart failure with preserved ejection fraction and in heart failure with a reduced ejection fraction (4). An example of a nonhypertensive etiology of HFNEF is sarcomeric hypertrophic cardiomyopathy. This disorder is associated with myocardial disarray and is caused by a number of gene abnormalities, each of which encodes a contractile protein; both of these abnormalities would be expected to cause contractile dysfunction, and yet the ejection fraction is usually normal or increased.
This apparent contradiction of a normal ejection fraction with widespread (i.e., global) and significant contractile abnormalities in HFNEF is difficult to understand. However, it is plausible that an increase in left ventricular end-diastolic wall thickness would lead to greater thickening in systole given the same longitudinal and mid-wall circumferential shortening. Therefore, in the presence of contractile dysfunction and concentric left ventricular hypertrophy, radial wall thickening (end-systolic wall thickness minus end-diastolic wall thickness) could be within normal limits. The external volume of the heart alters little during the cardiac cycle; therefore, the inward endocardial displacement, endocardial fractional shortening, and ejection fraction would be normal. In summary, at least some examples of HFNEF may be explained by the combination of concentric left ventricular hypertrophy and contractile dysfunction despite the ejection fraction being preserved (5).
- American College of Cardiology Foundation
- Maeder M.T.,
- Kaye D.M.
- Sanderson J.
- MacIver D.,
- Townsend M.