Exercise-induced ST segment elevation in a patient with effort angina pectoris and normal coronary arteries.

A 32 year old woman who complained of exercise-induced chest pain was found to have widespread elevation of the ST segment of the electrocardiogram during exercise testing. Coronary angiography demonstrated no obstructive lesions and no evidence of coronary artery spasm despite ergonovine administration, bicycle ergometry and rapid atrial pacing. Exercise thallium-201 scintigraphy demonstrated no perfusion defects despite ST segment elevation. Radionuclide blood pool imaging revealed a slight decrease in ejection fraction with exercise. The available evidence raises the possibility of small vessel coronary artery disease, either structural or vasotonic, as a cause of this patient's symptoms.

Nonemergent cardiac catheterization and risk-stratified revascularization following thrombolytic therapy for acute myocardial infarction. A critical analysis of therapy in the community setting. University of North Carolina Cardiology Consortium.

We evaluated a strategy for administering thrombolytic therapy without emergent cardiac catheterization to patients with acute myocardial infarction in community hospitals. Fifty-nine patients were treated with intravenous streptokinase and heparin, and referred for elective catheterization. Angioplasty or bypass surgery was performed only in patients judged to be at risk for reinfarction. One or more predetermined criteria for infarct segment viability were present in 47 (80%) of 59 patients. Angina recurred in 24 patients and enzyme-positive reinfarction in 9 patients, but only 2 patients developed new Q waves or a creatine kinase rise to over twice the normal value. Of 18 patients judged to be at low risk for reinfarction, only 1 required urgent angioplasty or bypass surgery. Fourteen-day mortality was 7% and infarct vessel patency was 94%. These data indicate that physicians in small community hospitals with a close relationship to a referral center and with a carefully designed protocol can administer thrombolytic therapy safely and effectively. By subsequent stratification of patients according to the risk of recurrent infarction, 22% of patients eligible for revascularization were spared urgent angioplasty or bypass surgery.

Lidocaine prophylaxis in acute myocardial infarction.

Primary ventricular fibrillation (PVF) occurs in approximately 3--10% of uncomplicated acute myocardial infarction (AMI) patients. The major reason for this variability in incidence appears to be population diferences in the time from symptom onset to admission. Other risk factors have not been consistently shown to influence the risk of PVF. Warning arrhythmias do not warn of impending PVF in from 20--80% of AMI patients; thus, antiarrhythmic therapy reserved for those with warning arrhythmias may fail to prevent PVF in a significant number of patients. Although a review of 13 controlled trials of lidocaine prophylaxis shows only two suggesting a protective effect from this drug, only one study was free of major defects in trial design. This trial showed a striking decrease in PVF incidence when lidocaine was employed. Lidocaine should probably be administered to all uncomplicated AMI patients during the first 48 hours after infarction. Its utility in preventing ventricular fibrillation in complicated AMI patients and in the very early AMI period is unclear.

Rapid determination and confirmation of low levels of hexachlorobenzene in adipose tissues.

The described procedure can be utilized for rapid, simple quantitation and confirmation of hexachlorobenzene in fatty tissue at levels as low as 5 ppb without the use of sophisticated and expensive equipment. Interferences can be circumvented in many instances without additional separation by selection and preparation of the appropriate derivative.