Right heart dysfunction in post-tuberculosis emphysema.
SETTING: University-affiliated general hospital. OBJECTIVE: To evaluate the pump performance of right heart before and after exercise in post-tuberculosis emphysema. DESIGN: In patients with post-tuberculosis or primary emphysema (similar lung volumes), body plethysmography, arterial blood gas analysis and echocardiography were performed at rest and after exercise. Right heart pump performance was evaluated with the ejection fraction. RESULTS: At rest, in post-tuberculosis emphysema, diffusing capacity (mean +/- SE 72.7 +/- 3.9 vs. 91.0 +/- 7.1% of reference) and right ventricular ejection fraction (57.5 + 1.4 vs. 61.3 +/- 1.2%) were lower and PaCO2 (42.7 +/- 1.1 vs. 38.6 +/- 0.7 mmHg) was higher, while lung compliance, airway resistance, PaO2, and alveolar-arterial oxygen difference were not different. After exercise, PaO2 (65.6 +/- 2.8 vs. 80.5 +/- 3.5 mmHg) and right ventricular ejection fraction (51.2 +/- 2.4 vs. 59.6 +/- 1.7%) were lower and PaCO2 (47.0 +/- 1.5 vs. 40.9 +/- 1.5 mmHg) was higher in post-tuberculosis emphysema, whereas alveolar-arterial oxygen difference was not different. PaCO2 and alveolar-arterial oxygen difference increased, and PaO2 and right ventricular ejection fraction decreased in post-tuberculosis emphysema, while they did not significantly change in primary emphysema. CONCLUSION: In post-tuberculosis emphysema, the impairment of gas exchange was more serious. Global assessment should be focused on right heart dysfunction which might be more affected than in primary emphysema.