Pulmonary hypertension in progressive muscular dystrophy of the Duchenne type.

Right heart catheterization was performed in 8 patients with progressive muscular dystrophy of the Duchenne type (DMD) at the advanced stage. A mean pulmonary arterial pressure in excess of 20 mmHg was observed in all cases. Five of them showed severe pulmonary hypertension with a mean pressure above 40 mmHg. Since pulmonary hypertension was relieved by correction of hypoxemia, this represented a precapillary pulmonary hypertension caused by constriction of the pulmonary artery. Furthermore, elevation of the mean right atrial pressure above 5 mmHg was observed in 6 of the 8 cases, indicating the possible presence of right ventricular failure. Despite the presence of left ventricular dysfunction as assessed by echocardiogram, no manifestations of left ventricular failure, such as dyspnea and pulmonary rales, were noted in any of the patients. In conclusion, it can be said that even in the terminal stage of DMD, the left ventricular function may, in fact, still remain not markedly involved, and that respiratory failure, as well as right ventricular failure caused by precapillary pulmonary hypertension, will tend to occur frequently and may play a determinant role in prognosis of the advanced DMD patient.