Usefulness and limits of transthoracic echocardiography in the evaluation of patients with primary and chronic thromboembolic pulmonary hypertension.

The aim of the study was to evaluate the potential usefulness of transthoracic echocardiography in differentiating patients with primary or chronic thromboembolic pulmonary hypertension and to define the capability of echocardiography to assess right-heart performance in such patients. Right-heart catheterization and ultrasound examination were performed in 111 patients with chronic thromboembolic pulmonary hypertension and in 31 patients with primary pulmonary hypertension. All echocardiographic and Doppler parameters were similar in primary and chronic thromboembolic pulmonary hypertension. A significant correlation was found between the tricuspid annular plane systolic excursion and the right ventricular fractional area change and thermodilution-derived right ventricular ejection fraction (P <.001 for both). Furthermore, different patterns of the pulsed Doppler flow velocity curve into the superior vena cava were associated with different right-heart hemodynamic profiles. In conclusion, in patients with chronic pulmonary hypertension transthoracic echocardiography portends meaningful information on the capability of the right heart to confront the increased afterload but it does not permit etiologic differentiation.