Prognostic value of changes in R-wave amplitude during exercise testing after a first acute myocardial infarction.
To investigate the prognostic value of exercise-induced changes in R-wave amplitude and their relation to other exercise and angiographic variables, 303 consecutive patients who underwent maximal exercise testing and coronary angiography within 2 months of a first acute myocardial infarction were studied. R-wave amplitude at peak exercise increased or was unchanged in 159 patients (57.4%) and decreased in 118 (42.6%). Increased R-wave amplitude was significantly related to underlying 3-vessel disease (p = 0.0001), the extent of ST-segment depression on exercise (p = 0.0001), and the time to 1 mm ST depression (p less than 0.05). Follow-up information was available in 285 patients (86.4%) at a mean of 4 +/- 1.8 years. Death from cardiac causes occurred in 25 patients (9%); 18 (6.5%) developed recurrent myocardial infarction, and 32 (11.6%) developed angina. Variables with a predictive value for cardiac death were maximal exercise heart rate (p = 0.0005), occurrence of exercise-related supraventricular arrythmia (p = 0.02), and number of diseased vessels (p = 0.02). R-wave changes had no predictive value. No variable had a predictive value for recurrent infarction. Maximal exercise heart rate (p = 0.02) and increased R-wave amplitude (p = 0.0001) were significantly related to the occurrence of angina at follow up. Exercise-related R-wave increases were associated with the presence of angina at follow-up, but had no predictive value for cardiac death or recurrent infarction; their association with subsequent angina appears to reflect an association with more severe underlying coronary disease.
Leroy
F
F
Service de Cardiologie B et Hémodynamique, Hôpital Cardiologique, Lille, France.
Lablanche
J M
JM
Bauters
C
C
McFadden
E P
EP
Bertrand
M E
ME
D000787:Angina Pectoris / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D004562:Electrocardiography / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality*; D011379:Prognosis; D012008:Recurrence