Effort dyspnea after coronary bypass surgery

One hundred consecutive patients were followed up for 6-36 months after coronary artery bypass surgery (CABS) for angina pectoris. Of the 98 survivors, 35 reported effort angina. Of the 63 angina-free patients, nine (14%), also had to interrupt ordinary activities such as walking upstairs/uphill, though now because of dyspnea. In exercise tests all nine denied chest pain, the limiting symptom being dyspnea. Chest radiograms were normal in these nine cases, and spirometry was largely unchanged from the preoperative findings (normal in 3 cases). Exercise tolerance was normal or near normal in six patients. The other three underwent pulmonary scintigraphy and cardiac catheterization at rest and during supine exercise. The scintigrams revealed no pulmonary emboli. Catheterization showed hypokinesis and raised pulmonary capillary wedge pressure during exercise in all three patients. The cause of the left myocardial failure was not established. Long-term evaluation of CABS should take into account both effort angina and effort dyspnea.