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. 