Detection of coronary artery disease with positron emission tomography and rubidium 82.

Myocardial blood flow was evaluated in 31 subjects with not only visual but also, for the first time, circumferential profile analysis of rubidium 82 (82Rb) images acquired with positron emission tomography. Fifteen were control subjects and 16 subjects had significant coronary artery disease, defined as 50% or greater diameter stenosis in a major coronary artery or a first-order branch. Simultaneous 82Rb images at three myocardial levels were obtained before and after intravenous dipyridamole plus handgrip stress.

Myocardial dysfunction during percutaneous transluminal coronary angioplasty.

Balloon inflation during percutaneous transluminal coronary angioplasty (PTCA) transiently occludes the coronary artery, causing temporary ischemia. In patients without collaterals, regional hypokinesis of the ventricular myocardium at risk occurs within the first 20 seconds and persists throughout balloon inflation. Early PTCA procedures were performed with brief balloon inflations, but the desire to improve procedural results has led many operators to extend balloon inflation times to 45 seconds or longer.

Fractionated endocardial electrograms are associated with slow conduction in humans: evidence from pace-mapping.

Fractionated ventricular electrograms recorded during catheter mapping may arise from areas of asynchronous depolarization associated with slow conduction, the substrate for reentrant ventricular tachycardia, but can also be a nonspecific abnormality or even artifact. To determine whether fractionated sinus rhythm electrograms are associated with slow conduction in humans, the results of endocardial catheter mapping and pacing at 133 endocardial sites in 13 patients were analyzed. Eleven patients had sustained monomorphic ventricular tachycardia and two patients had old myocardial infarction without ventricular tachycardia.

Complicated atherosclerotic lesions: a potential cause of ischemic ventricular arrhythmias in cardiac arrest survivors who do not have inducible ventricular tachycardia?

Sudden cardiac death that is not due to acute myocardial infarction may be due to primary ventricular tachycardia or to an arrhythmia secondary to a transient episode of ischemia. The purpose of this study was to determine if the incidence of complicated coronary lesions, which may be a cause of unstable ischemic syndromes, is increased in survivors of an aborted sudden death, especially those without ventricular tachycardia inducible by programmed ventricular stimulation. Nineteen consecutive survivors of an aborted sudden death not due to an acute infarction who underwent coronary angiography and programmed ventricular stimulation within 3 weeks of the event were matched for age, sex, previous infarction, and severity of coronary artery disease with 38 control patients with stable coronary artery disease.