No abstract

An 80 year old diabetic male with evidence of peripheral and autonomic neuropathy was admitted with chest pain. He was found to have atrial flutter at a ventricular rate of 70/min which slowed down to 30-40/min when nifedipine (60mg) in 3 divided doses, during which he was paced at a rate of 70/min. This is inconsistent with the well-established finding that nifedipine induces tachycardia in normally innervated hearts. However, in hearts deprived of compensatory sympathetic drive, it may lead to bradycardia.

SUMMARYExercise electrocardiography with or without thallium-201 scintigraphy was performed (pre-hospital discharge) in 66 asymptomatic survivors of a first inferior myocardial infarction (IMI). Although coronary angiography revealed an 82% incidence of multivessel coronary artery disease (MV-CAD) in the total cohort, the sensitivity of exercise ECG for MV-CAD in the group with absent anterior ST-depression in the acute phase was low (11%). In contrast the presence of acute phase anterior STsegment depression improved the yield for MV-CAD to 55%.Forty-six patients agreed to a symptom-limited exercise ECG plus/ minus thallium imaging at 8-10 weeks post IMI. The sensitivity of detecting MV-CAD improved by 15% in patients with no acute phase anterior ST-segment depression and 16% in patients with acute phase anterior ST-segment depression. At each exercise protocol, thallium improved the sensitivity of exercise in detecting ischemia in the noninfarct zone.It is concluded that following IMI, a high percentage of asymptomatic patients whose acute phase ECG showed anterior ST-segment depression will have MV-CAD detected by heart-rate limited and, more so, by symptom-limited exercise ECG. The detection rate will double in patients with no anterior ST-segment depression if exercise testing is delayed until 8-10 weeks post IMI. Additional Indexing Words: Exercise electrocardiographyInferior myocardial infarction Anterior ST depression Timing VER since the safety of a limited exercise protocol in the early postinfarction period has been demonstrated,1),2) most patients routinely undergo stress testing prior to discharge.Beyond its safety, exercise testing