[Silent stress ischemia in patients after aortocoronary bypass]

In a group of 37 patients with chronic stable angina the authors compared results of bicycle ergometry after a load before and after coronary artery bypass grafting. The group included only patients who had to terminate initial ergometry performed during the last two months before operation on account of stenocardia and signs of myocardial ischaemia on the ECG tracing. On average 20 months after coronary artery bypass grafting ergometry was repeated. Nineteen patients (51%) lacked electrocardiographic signs of myocardial ischaemia, 18 patients (49%) suffered from ischaemia after a load (depression S-T greater than or equal to 2 mm). Of these in 18 patients 8 (44%) no stenocardial attacks were present in another 5 (28%) stenocardia developed only when the depressions were S-T greater than 2 mm. Six patients (33%) had depressions S-T greater than or equal to 3.5 mm at a time when during ergometry they had no complaints and were engaged in similar work loads occasionally also at home. The authors conclude that in the investigated group silent ischaemia after a load was frequent in patients after a coronary artery bypass grafting and frequently it was severe. Patients after coronary artery bypass grafting developed stencardia only after greater S-T depressions than before operation. All patients after coronary artery bypass grafting should be checked by means of loading tests.