Increase of R-wave in pre-discharge 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 in relation to left ventricular injury (determined by 2-D echocardiography), ventricular arrhythmias (24-h Holter monitoring) and survival after myocardial infarction. It has been found that in patients with mild left ventricular injury (n = 51, Heger index < or = 3) the sum of the R-wave amplitude in 15 precordial leads recorded immediately after exercise decreased by 3.7 +/- 10% in comparison with resting values. In the patients with major left ventricular injury (n = 26, Heger Index > 3) the sum of R-wave amplitude after exercise increased by 12.9 +/- 17.5% (P < 0.001). Positive linear correlation (r = 0.35, P < 0.01) was observed between the level of left ventricular wall motion disturbances and R-wave amplitude changes. In patients with normal or slightly disturbed cardiac rhythm (n = 42, Lown scale 0-2) the sum of the R-wave amplitude after exercise decreased by 5 +/- 18% as compared to resting values, whereas in the patients with complex arrhythmias (n = 23, Lown scale 3-5) the sum of R-wave amplitude increased amounting 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.(ABSTRACT TRUNCATED AT 250 WORDS)
Bednarz
B
B
Postgraduate Medical School, Department of Cardiology, Warsaw, Poland.
Chamiec
T
T
Budaj
A
A
Dluzniewski
M
M
Ceremuzyński
L
L
D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D004452:Echocardiography; D004562:Electrocardiography; D005080:Exercise Test; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality*; D011379:Prognosis; D016277:Ventricular Function, Left / Q000502:physiology*