Left atrial function in diastolic heart failure

Abnormalities in left ventricular (LV) structure and function occur in patients with diastolic heart failure (DHF). The reasons for the transition from asymptomatic dysfunction to heart failure need better definition, including noninvasive measurements that can detect the transition.

In 64 patients undergoing right heart catheterization, simultaneous echocardiographic imaging was performed. As a control group, 27 healthy subjects were included. There were 25 with ejection factor (EF) <50%, 20 in DHF, and 19 with normal EF and LV hypertrophy but not in heart failure (diastolic dysfunction). LV volumes, mass, left atrial (LA) volumes and EF, annular atrial velocity (a'), and LA strain during systole (LA(S)), and atrial contraction (LA(A)) were measured. The ratio of wedge pressure to LA(S) strain was used as an index of LA stiffness, as was the ratio of E/e' to LA(S) strain. All 3 patient groups had increased LA volumes and depressed LA EF, a', and LA(A) strain, with no significant difference between patients with DHF and diastolic dysfunction in LA systolic function indices, LV mass, LA volumes, LV, and arterial elastance. LA(S) strain was lower in patients with DHF, and LA stiffness (invasive and noninvasive) was higher (both P<0.01), related well to pulmonary artery systolic pressure (r=0.79, P<0.001), and was most accurate in identifying DHF patients from those with diastolic dysfunction (invasive area under the curve: 0.93, noninvasive: 0.85).

Patients with DHF have increased LV mass and LA volume in comparison with normal controls, but not versus patients with LV hypertrophy who are not in heart failure. On the other hand, LA(S) strain is significantly reduced and LA stiffness is the most accurate index in identifying patients with DHF.