Echocardiographic aspects of pulmonary arterial hypertension in chronic lung disease.
An echocardiographic M-mode study has been performed on 58 patients with pulmonary arterial hypertension at rest or on exercise, with chronic lung disease, either obstructive (41 cases of COLD) or restrictive (17 cases of interstitial lung disease, ILD) in nature. The average Ppa was practically the same (i.e. 27.3 +/- 11.7 mmHg and 26.0 +/- 8.0 mmHg respectively) in the two groups of patients, even though the COLD patients were older than the ILD patients (58.7 +/- 9.3 vs 38 +/- 11 years). The echo detection of the pulmonary valve was successful in only 35% of COLD patients and in 86% of ILD patients (p less than 0.01). A multiple regression analysis disclosed a rather weak, but nevertheless statistically significant, correlation (p less than 0.01) between 1) Ppa and the ratio of right ventricular to left ventricular end-diastolic volume, and 2) between right ventricular end-diastolic pressure and septal systolic displacement. The standard error of estimated versus actual Ppa taking into account the ventricular and septal echo variables was as high as +/- 7.63 mmHg, thus preventing a reliable prediction of Ppa in individual cases. An echocardiographic pattern of pansystolic mitral valve prolapse was observed in 29% of ILD patients, but never in cases with COLD.