Restoration of heart rate turbulence by titrated beta-blocker therapy in patients with advanced congestive heart failure: positive correlation with enhanced vagal modulation of heart rate.

Introduction: Heart rate turbulence (HRT) is a powerful novel predictor for cardiovascular mortality. Chronic congestive heart failure is associated with abnormal HRT. Whether antiadrenergic beta-blocker therapy can restore control of HRT in patients with chronic congestive heart failure is unknown.

Use of double-potential barrier to identify functional isthmus at the cavotricuspid isthmus for facilitating catheter ablation of isthmus-dependent atrial flutter.

Introduction: The aim of the study was to identify an alternative target for more effective radiofrequency catheter ablation (RFCA) of isthmus-dependent atrial flutter (AFL).

Methods And Results: We hypothesized that a functional isthmus formed by preexisting double potential barrier at the cavotricuspid isthmus (CTI) could serve as a new target site for facilitating RFCA of AFL. Forty-three consecutive patients with recurrent isthmus-dependent AFL were studied using three-dimensional navigated magnetic mapping and ablation technique.

Electrophysiological mapping and histological examinations of the swine atrium with sustained (> or =24 h) atrial fibrillation: a suitable animal model for studying human atrial fibrillation.

Objectives: Interventional elimination of chronic persistent atrial fibrillation (AFib) remains difficult. An animal model mimicking the clinical situation is important.

Methods And Results: Twenty-five adult pigs were implanted with a high-speed atrial pacemaker.

Tight mechanism correlation between heart rate turbulence and baroreflex sensitivity: sequential autonomic blockade analysis.

Introduction: Heart rate turbulence is a powerful de novo risk predictor for patients surviving acute myocardial infarction. However, little is known about its underlying physiologic mechanism.

Methods And Results: Hypothesizing that heart rate turbulence is barorceptor reflex related, we studied heart rate and blood pressure fluctuations at rest and after systematically introduced ventricular premature beats in 16 patients without structural heart disease (10 men and 6 women; mean age 45 +/- 17 years) before and after sequential sympathetic (esmolol 4-mg bolus followed by 120 microg/kg/min intravenously), parasympathetic (atropine 0.