Relationship between exercise hyperpnea, hemodynamics, and blood gases before and during glyceryl trinitrate infusion in patients with exercise‐induced elevation of pulmonary artery wedge pressure

Background: The mechanisms underlying the excessive ventilatory response to exercise in patients with cardiac failure are still not fully understood. Hypothesis: This study was undertaken to investigate the mechanisms behind exercise hyperpnea in patients with exercise‐induced left ventricular dysfunction. Methods: In 18 patients, aged 57–82 years, all with atherosclerotic lumbar aorta aneurysm and pulmonary artery wedge pressure (PAWP) >25 mmHg during supine exercise, ventilation (V), central hemodynamics, and arterial and venous blood gases were examined during supine rest and exercise, before and during infusion of glyceryl trinitrate (GTN). Results: Before GTN, exercise PAWP was 32.2 ± 6.1 mmHg and V/V O2 was 33.8 ± 7.7 1/1 (130% of predicted). With GTN, exercise PAWP was markedly reduced to 15.3 ± 3.8 mmHg (p < 0.001), whereas V/V O2 was only marginally reduced to 32.3 ± 3.0 1/1 (124% of predicted) (p