ECHOCARDIOGRAPHIC ASSESSMENT IN PATIENTS WITH HEART FAILURE AND NORMAL LEFT VENTRICULAR EJECTION FRACTION

Pathophysiology of heart failure with normal ejection fraction (HFNEF) is poorly understood. The patients with severe HFNEF and abruptly terminated mitral A wave, were selected during past 2 years. Methods. We identified 7 patients (mean age 75±7 ys.) with HFNEF associated with interatrial block (IAB) and particular Doppler mitral inflow pattern; all underwent echo-Doppler, hemodynamic and electrophysiologic examinations. Results. Pulsed wave mitral Doppler was restrictive and triphasic, including high velocity E wave, a mid-diastolic “L” wave, and a delayed and shortened A wave. Mean E/A and E/E’ ratios were 3.7±1.3 and 23±4. Mean mitral A wave duration was 98±15ms compared to 170±24ms at the tricuspid valve (p = 0.001). TDI study of A’ at the lateral tricuspid and mitral annulus showed an interatrial mechanical delay of 110±43ms. Catheterization showed severe post-capillary pulmonary hypertension: mean pulmonary artery pressure 44±7, wedge pressure 26±5 with a V wave of 49±11mmHg. Electrophysiologic study showed an interatrial conduction delay of 140±20ms, a normal right atrio-ventricular interval (170±30ms), and a short left atrio-ventricular interval (30±20ms). Discussion. All 7 patients exhibited: 1) severely raised filling pressures, 2) decreased left atrial (LA) compliance, and 3) IAB with a delayed LA systole. We believe that severe IAB may be responsible for a delayed LA activation that occurs against a closing mitral valve, thereby interrupting the active LV filling. Furthermore, the hindered LA emptying may induce pressure overload and increase LA stiffness. Conclusion. We identified a category of HFNEF patients with a stereotyped presentation, in which IAB could be one major explanation. Whether these patients could be improved by atrial resynchronization deserves further investigation. Supported by grants MSM 021622402 & NS 10096/4