Pathophysiology of exercise heart rate recovery: a comprehensive analysis.

Expanded use of exercise heart rate recovery (HRR) has renewed interest in the pathophysiology of heart rate control. This study uses basic physiologic principles to construct a unique model capable of describing the full time course of sympathetic and parasympathetic activity during HRR. The model is tested in a new study of 22 diverse subjects undergoing both maximal and submaximal treadmill exercise.

Disparate opinions regarding indications for coronary artery revascularization before elective vascular surgery.

Despite consensus guidelines, the optimal strategy for preoperative cardiac risk management among patients scheduled for major noncardiac surgery remains controversial. This study assesses current opinion about the role of preoperative coronary revascularization for patients with coronary artery disease scheduled for elective vascular surgery. Thirty-one practicing cardiologists recruited from 4 different regions reviewed case records, imaging tests, and coronary angiograms of 12 patients with coronary artery disease participating in the Coronary Artery Revascularization Prophylaxis (CARP) trial.

Assessing autonomic function by analysis of heart rate recovery from exercise in healthy subjects.

Although delayed recovery of heart rate (HR) after exercise indicates poor prognosis, the relative role of parasympathetic reactivation versus sympathetic withdrawal in controlling exercise HR recovery remains controversial. Quantifying HR recovery is difficult because the rate of recovery varies with exercise level. This study develops a model of HR recovery applicable to multiple exercise levels simultaneously.

Comparison of plasma concentrations for two amiodarone products.

Background: A generic formulation of amiodarone was recently approved by the Food and Drug Administration based on single-dose equivalence data. Because amiodarone has complex pharmacokinetic properties, a narrow therapeutic range, and a significant adverse effect profile, concern about equivalency persists.

Objective: To compare steady-state plasma concentrations of the brand-name reference product Cordarone with the AB-rated generic formulation, Pacerone, in patients exposed to both products.