Effects of time required for reperfusion (thrombolysis or angioplasty, or both) and location of acute myocardial infarction on left ventricular functional reserve capacity several months later.

The purpose of this study was to determine whether reperfusion of acute myocardial infarction (AMI) by recombinant tissue-type plasminogen activator (rt-PA) or percutaneous transluminal coronary angioplasty, or both, would improve left ventricular (LV) function when it is measured several months later at rest or maximal bicycle exercise, or both. Radionuclide angiography was performed in 44 patients 5 months (range 6 weeks to 9 months) after AMI to assess function, and tomographic myocardial thallium-201 imaging was performed at maximal exercise and delayed rest to determine whether there was any evidence of myocardial ischemia. As expected, no patient had chest pain or redistribution of a thallium defect during the exercise test, because patients had undergone angioplasty (n = 28) or coronary bypass graft surgery (n = 5) where clinically indicated for revascularization. The LV ejection fraction was plotted as a function of the time elapsed between the onset of chest pain and the time when coronary angiography confirmed patency of the infarct-related artery (achieved in 91% of 44 patients by rt-PA [n = 31] or percutaneous transluminal coronary angioplasty [n = 9] ). Functional responses differed markedly between patients with anterior (n = 20) versus inferior (n = 24) wall AMI. LV ejection fraction during exercise correlated with time to reperfusion in patients with an anterior wall AMI (r = -0.58; standard error of the estimate = 11.9%; p less than 0.02) but not in patients with an inferior AMI (r = 0.10; standard error of the estimate = 13.1%; difference not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved infarct-related arterial patency after high dose, weight-adjusted, rapid infusion of tissue-type plasminogen activator in myocardial infarction: results of a multicenter randomized trial of two dosage regimens.

To determine whether a weight-adjusted high dose (2 mg/kg body weight over 3 h) rapid infusion of recombinant tissue-type plasminogen activator (rt-PA) was more efficacious than a weight-adjusted standard dose (1.25 mg/kg over 3 h) in achieving reperfusion in the setting of acute myocardial infarction, 175 patients were entered into a randomized multicenter trial. Eighty-four patients were entered into the high dose group, receiving 1.2 mg/kg (10% given as a bolus injection) over 1 h, followed by 0.8 mg/kg over the next 2 h. Ninety-one patients were given 0.75 mg/kg (10% given as a bolus injection) in 1 h, followed by 0.5 mg/kg administered over the next 2 h. The median dose in the group that received 2 mg/kg dose was 145 mg, compared with 100 mg in the group that received 1.25 mg/kg. The 90 min patency rate in the group that received 2 mg/kg was 84% compared with 70% in the group that received 1.25 mg/kg (p = 0.003). Sixty-four percent of the patients in each group underwent coronary angioplasty at the time of cardiac catheterization. The infarct-related artery patency rate at the end of catheterization was 91% in the group that received 2 mg/kg compared with 83% in the group that received 1.25 mg/kg (p = 0.08). Among patients with a patent infarct-related coronary artery after catheterization, the 6 month mortality rate in the group that received 2 mg/kg was 2.9% compared with 9.8% in the group that received 1.25 mg/kg (p = 0.15). The bleeding complication rate in the two groups was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute myocardial infarction temporally related to cocaine use. Clinical, angiographic, and pathophysiologic observations.

Ischemic chest pain syndromes and myocardial infarction occurred within minutes to hours of cocaine use in nine persons ages 23 to 39 years. Five developed symptoms after taking cocaine intranasally; three, after intravenous use; and one, after smoking cocaine. Four were habitual users and five were recreational users; eight also smoked cigarettes heavily. Ischemic syndromes recurred in five who continued to use cocaine. Coronary arteriography showed an abnormal infarct-related vessel (more than 50% stenosis, total occlusion, or intraluminal thrombus) in seven patients. The noninfarct-related vessels were normal in eight patients. The left anterior descending coronary artery and the anteroapical left-ventricular wall were involved in all patients. After three patients had successful thrombolysis of the obstructed infarct-related vessel, angiography showed a normal underlying vessel.

Self-heard venous hums.

We describe two patients with symptomatic, self-heard venous hums. The venous hum was secondary to chronic anemia in one patient and was idiopathic in the other. The idiopathic hum was not heard in the neck but could be heard by auscultating the right auditory canal. Ligation of the right internal jugular vein abolished the idiopathic hum, which had been present for 14 years.