Right ventricular diastolic function in beta-thalassemia major: Echocardiographic and clinical correlates

Background Cardiac hemochromatosis remains the most frequent cause of death in beta -thalassemia major. Previous studies suggest an important right ve ntricular (RV) contribution to cardiac morbidity and mortality. Studies wit h Doppler echocardiography have shown contradictory results regarding left ventricular (LV) filling, whereas the RV filling characteristics have not b een studied yet. We prospectively studied the pattern of RV filling and inv estigated echocardiographic and clinical correlates during baseline and Fol low-up examinations in patients with beta -thalassemia major. Methods and Results The study included 79 patients, aged 24.2 +/- 8.0 years , with homozygous beta -thalassemia major without symptoms of heart failure with normed LV function and 51 healthy control subjects, matched For age, sex, and body surface area. Doppler echocardiographic indexes of systolic a nd diastolic ventricular function were assessed. Hemodynamic measurements w ere obtained in 8 patients by right heart catheterization. An abnormal RV r elaxation pattern was evident in the patient group. The LV filling characte ristics indicated increased preload without abnormal alteration, whereas ca theterization findings were consistent with a high cardiac output state. Sh ort tricuspid deceleration time (DT) had the best predictive value for subs equent cardiac events. Repeat echocardiographic study in 35 asymptomatic pa tients at 19 +/- 7 months demonstrated deterioration of LV systolic functio n, chamber enlargement, and shortening of DT of tricuspid and mitral inflow . Conclusions In patients with homozygous beta -thalassemia major without car diac disease, the pattern of RV filling is abnormally altered, indicating i mpaired relaxation. In contrast, the LV filling is compatible with increase d preload, as in chronic anemia. Short DT of early tricuspid inflow carries important prognostic value. LV remodeling occurs over time along with tran sition toward a restrictive ventricular filling pattern.