Comparison of unipolar versus bipolar ablation and single electrode control versus simultaneous multielectrode temperature control.

Background: Creation of linear lesions using multielectrode catheters may be effective at treating cardiac arrhythmias.

Objective: We compared unipolar versus bipolar ablation, evaluated the effects of varying effective electrode areas, and compared single electrode versus multielectrode temperature control during multielectrode radiofrequency ablation.

Methods: Intramural radiofrequency ablation was performed on five greyhounds at thoracotomy, from an epicardial approach using a 0.

Change in size of lesions over 3 weeks after radiofrequency ablation of left ventricle.

Introduction: The initial success or failure of radiofrequency ablation (RFA) does not always reflect the long-term outcome that can lead to complications such as late atrioventricular block or recurrence of accessory pathways. We hypothesize that these occurrences may be due to a change in lesion size over time.

Methods And Results: Intramural RFAs were performed on five greyhounds at thoracotomy using an epicardial approach into the left ventricular (LV) wall.

Comparison of radiofrequency ablation in normal versus scarred myocardium.

Introduction: Reentrant circuits causing ventricular tachycardia are closely associated with previously scarred myocardium. The presence of scar has been blamed for the poor success rate of radiofrequency ablation (RFA) in that context. This article investigates the in vivo effects of radiofrequency ablation in myocardium scarred from acute myocardial infarction.

Effect of inter-electrode distance on bipolar intramural radiofrequency ablation.

Objectives: We aimed at evaluating bipolar radiofrequency ablation by correlating inter-electrode distance (ILD) with lesion dimensions and continuity.

Background: Previous reports indicated that bipolar radiofrequency (RF) current applied to two adjacent sites in vitro, synergistically increased lesion sizes greater than that observed for unipolar RF current delivery using the same electrodes.

Methods: Ablations were performed intramurally to ensure that each electrode surface (radius = 0.

Intramural radiofrequency ablation: effects of electrode temperature and length.

The aim of this study was to evaluate intramural temperature-controlled radiofrequency ablation by determining the intramural temperature profile during ablation and by correlating lesion geometry with intramural electrode size and temperature. Intramural ablation might be useful to create deeper lesions for ventricular tachycardia secondary to underlying heart disease. Intramural radiofrequency ablation was performed in 17 greyhounds at thoracotomy, from an epicardial approach, using a 21-gauge needle electrode.

Effects of simultaneous insertion of 66 plunge needle electrodes on myocardial activation, function, and structure.

Transmural recordings using plunge needle electrodes are useful in mapping ventricular tachyarrhythmia, but they interfere with activation sequences or damage the myocardium. This study evaluated the effects of insertion of 66 transmural needles on myocardial activation, structure, and function. Epicardial maps were performed at thoracotomy using a 40-electrode plaque in five mongrel dogs.