Echocardiographic assessment of cor pulmonale in cystic fibrosis.

The early clinical recognition and assessment of cor pulmonale are frequently difficult. To evaluate the usefulness of echocardiographic measurement of right ventricular dimension and septal motion in assessing cor pulmonale, we studied 94 patients with cystic fibrosis of varying severity. There was a significant relationship between increasing right ventricular dimension index (RVDI) and (1) decreasing clinical score, vital capacity, forced expiratory volume in one second (FEV1), and maximal midexpiratory flow rate (MMFR); and (2) increasing residual volume and thoracic gas volume. There was no correlation between right ventricular dimension index and PaO2. These findings were supported by electrocardiogram and pathologic evidence of right ventricular involvement. Abnormal septal motion was observed more frequently in patients with severe obstructive airway disease as measured by decreased vital capacity, FEV1, and MMFR. The data show that there is echocardiographic evidence of mild right ventricular enlargement and/or hypertrophy much earlier in the course of cystic fibrosis than previously suspected and that the echocardiogram is a useful tool in the evaluation of cor pulmonale in patients with cystic fibrosis.