INCREASE OF R-WAVE IN PREDISCHARGE ERGOMETRIC TEST AFTER MYOCARDIAL-INFARCTION INDICATES ADVANCED LEFT-VENTRICULAR INJURY, LATENT SERIOUS ARRHYTHMIAS AND WORSE PROGNOSIS

Changes in R-wave amplitude during exercise tests performed soon after myocardial infarction (15-31 days, mean 22) were analyzed in 78 men i n relation to left ventricular injury (determined by 2-D echocardiogra phy), ventricular arrhythmias (24-h Holter monitoring) and survival af ter myocardial infarction. It has been found that in patients with mil d left ventricular injury (n = 51, Heger index less-than-or-equal-to 3 ) the sum of the R-wave amplitude in 15 precordial leads recorded imme diately after exercise decreased by 3.7 +/- 10% in comparison with res ting values. In the patients with major left ventricular injury (n = 2 6, Heger Index > 3) the sum of R-wave amplitude after exercise increas ed by 12.9 +/- 17.5% (P < 0.001). Positive linear correlation (r = 0.3 5, P < 0.01) was observed between the level of left ventricular wall m otion disturbances and R-wave amplitude changes. In patients with norm al or slightly disturbed cardiac rhythm (n = 42, Lown scale 0-2) the s um of the R-wave amplitude after exercise decreased by 5 +/- 18% as co mpared to resting values, whereas in the patients with complex arrhyth mias (n = 23, Lown scale 3-5) the sum of R-wave amplitude increased am ounting to 9.9 +/- 17% (P < 0.001). Out of 17 patients who died during 5-year follow up, 16 displayed an increase or no change of the sum of R-wave amplitude. The same kind of relations between R-wave amplitude changes and left ventricular injury or cardiac arrhythmias were noted in patients with anterior and inferior myocardial infarction. These r esults suggest that an increase of R-wave amplitude during exercise te sting early after myocardial infarction might be considered as a marke r of left ventricular injury, predictor of cardiac arrhythmias and unc ertain prognosis.