Clinical value of early exercise testing after myocardial infarction.

The clinical utility of predischarge exercise ECGs was assessed prospectively in 47 patients 17 +/- 2 days after myocardial infarction. The graded-interval ergometric exercise protocol was terminated at 450 kilopond-m/min (kpm/min), a heart rate greater than 75% of predicted maximum, or for established clinical indications. Prior to testing, the attending physician and resident indicated their clinical impressions with regard to anticipated (1) angina, (2) exercise capacity, (3) arrhythmias during limited exercise, as well as anticipated discharge medications and activity prescriptions.

The metabolic and respiratory alterations of heat stroke.

The metabolic and respiratory changes of 21 patients with heat stroke were studied. Admission arterial blood gas levels were measured, and serum bicarbonate, lactate, calcium, phosphorus, and anion gap determinations were performed. Seven patients had a metabolic acidosis (pH 7.

Increasing pre-excitation during exercise and isoproterenol infusion. Evidence for a catecholamine sensitive bypass tract.

A patient with atypical chest pain developed pre-excitation during exercise and isoproterenol infusion, with "ischemic" ST depression only during the pre-excited beats. Coronary angiography and myocardial lactate extraction showed no evidence of abnormal coronary vessels. Electrophysiologic study and pacing-induced tachycardia did not induce pre-excitation, whereas exercise induced progressive increase in pre-excitation.