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External Cardioversion (external + cardioversion)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Quadruple Pads Approach for External Cardioversion of Atrial Fibrillation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2001
NASSIR F. MARROUCHE
MARROUCHE, N.F., et al.: Quadruple Pads Approach for External Cardioversion of Atrial Fibrillation. This study examined the alternative of transthoracic quadruple pads shock delivery of two simultaneous 360-J shocks to convert refractory AF in patients failing standard external cardioversion. Forty-six patients (mean age 58 ± 11 years, 23 men) with chronic AF (duration 14 ± 17 months, range 1,60 months) were included. The left atrial diameter was 47 ± 7 mm. The left ventricular ejection fraction was 59 ± 11%. Antiarrhythmic drugs had failed to convert 44 (96%) of these patients. All patients underwent conventional external transthoracic cardioversion with pads applied in the antero-apical position using energy settings of 200 and 360 J, consecutively. In all patients who failed conventional cardioversion, quadruple pads were applied. Quadruple pads consisted of four pads, two in the antero-posterior position and two in a second apex-posterior position. Standard cardioversion to sinus rhythm was successful in 19 (41%) patients after use of a single 200-J shock and an additional 8 (17%) after a single 360-J shock. The total success rate was 58% after conventional cardioversion. The quadruple pads were successful in 14 (74%) of the remaining 19 patients. Four of the five patients who failed the quadruple pads approach subsequently also failed internal cardioversion. Thus, the cardioversion success rate was increased from 48% using the conventional approach to 89% using the quadruple pads approach. Quadruple pads external cardioversion is highly effective in converting chronic AF refractory to standard shock protocols to sinus rhythm. Moreover, the failure of the quadruple pads approach seems to predict poor response to internal cardioversion. [source]

Perioperative Ventricular Arrhythmias in Patients Undergoing Partial Left Ventriculectomy

JOURNAL OF CARDIAC SURGERY, Issue 2 2001
Toshimi Ujiie M.D.
Background: Although incidence of ventricular arrhythmias after partial left ventriculectomy (PLV) has been reported, there are no studies comparing incidence before and after PLV. Although operative scars may give rise to arrhythmias, improved energetic efficiency after PLV may decrease their incidence. Methods: Pre- and postoperative ventricular arrhythmias were monitored by Holter ECG and analyzed in 17 patients undergoing PLV in Curitiba, Brazil. Results: Although total 24-hour heart beat (THB) increased significantly (p = 0.018), ventricular premature contractions (VPCs) decreased markedly (p = 0.036), excluding one patient dying in low cardiac output (LOS) who had terminal arrhythmias increased multifold. In the remaining 16 patients, VPC pairs were also reduced significantly on the average (p = 0.038). In contrast, ventricular tachycardia (VT; more than three consecutive VPCs) disappeared in five patients, decreased in two patients, and newly occurred in four patients, with five patients showing no change; one of them developed a prolonged VT, successfully reversed by external cardioversion. Conclusions: Despite notable significant increase in THB immediately after PLV, PVC and PVC pairs were significantly decreased in contrast to VT, which disappeared in some patients and newly occurred in other patients, remaining constant on the average. Sustained VT occurring in a patient with all other arrhythmias suppressed may suggest a unique electrophysiological substrate, may justify prophylactic use of amiodarone or an implantable cardioverter-defibrillator, and may underscore the importance of further and extended studies. [source]

A Single Pulmonary Vein as Electrophysiological Substrate of Paroxysmal Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2006
HE HUANG M.D.
Introduction: It has been demonstrated that pulmonary veins (PVs) play an important role in initiation and maintenance of paroxysmal atrial fibrillation (AF). However, it is not clearly known whether a single PV acts as electrophysiological substrate for paroxysmal AF. Methods and Results: This study included five patients with paroxysmal AF. All patients underwent complete PV isolation with continuous circular lesions (CCLs) around the ipsilateral PVs guided by a three-dimensional mapping system. Irrigated radiofrequency (RF) delivery was performed during AF on the right-sided CCLs in two patients and on the left-sided CCLs in three patients. The incomplete CCLs resulted in a change from AF to atrial tachycardia (AT), which presented with an identical atrial activation sequence and P wave morphology. Complete CCLs resulted in AF termination with persistent PV tachyarrhythmias within the isolated PV in all five patients. PV tachyarrhythmia within the isolated PV was PV fibrillation from the left common PV (LCPV) in two patients, PV tachycardia from the right superior PV (RSPV) in two patients, and from the left superior PV in one patient. All sustained PV tachyarrhythmias persisted for more than 30 minutes, needed external cardioversion for termination in four patients and a focal ablation in one patient. After the initial procedure, an AT from the RSPV occurred in a patient with PV fibrillation within the LCPV, and was successfully ablated. Conclusion: In patients with paroxysmal AF, sustained PV tachyarrhythmias from a single PV can perpetuate AF. Complete isolation of all PV may provide good clinical outcome during long-term follow-up. [source]

Low Energy Biphasic Waveform Cardioversion of Atrial Arrhythmias in Pediatric Patients and Young Adults

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2006
LEONARDO LIBERMAN M.D.
Background: Low-dose biphasic waveform cardioversion has been used for the termination of atrial arrhythmias in adult patients. The energy required for termination of atrial arrhythmias in pediatric patients is not known. The objective of this study is to determine the minimum energy required for successful external cardioversion of atrial arrhythmias in pediatric patients using biphasic waveform current. Methods: Prospective study of all patients less than 24 years of age with and without congenital heart disease undergoing synchronized cardioversion for atrial arrhythmias. Patients were assigned to receive an initial biphasic energy shock of 0.2,0.5 J/kg and if unsuccessful in terminating the arrhythmia, subsequent sequential shocks of 1 and 2 J/kg would be administered until cardioversion was achieved. The end point of the cardioversion protocol was successful cardioversion or delivery of three shocks. Results: Between June 2005 and June 2006, 16 patients underwent biphasic cardioversion for atrial flutter or fibrillation. The mean age was 14.7 ± 6.4 years (range: 2 weeks to 24 years). The mean weight was 51 ± 21 kg (range: 3.8,82 kg). Seven patients had normal cardiac anatomy, three had a single ventricle (Fontan), two had a Senning operation; the remaining four patients had varied forms of congenital heart disease. The median length of time that the patients were in tachycardia was 12 hours (range: 5 minutes to 2 months). Using either transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE), no thrombi were identified in any patient. All patients were successfully cardioverted with biphasic waveform energy. The successful energy shock was 0.35 ± 0.19 J/kg (range: 0.2,0.9 J/kg). All but one patient were successfully cardioverted with less than 0.5 J/kg. The transthoracic impedance range was between 41 and 144 ,; one patient had an impedance of 506 , (2-week-old infant with a weight of 3.8 kg). The mean current delivered was 5.4 ± 2.2 A (range: 1,11 A). Conclusion: Low-dose energy using biphasic waveform shocks can be used for successful termination of atrial arrhythmias in pediatric patients with and without congenital heart disease. [source]

Termination of Persistent Atrial Fibrillation Resistant to Cardioversion by a Single Radiofrequency Application

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2003
BENGT HERWEG
This report describes the termination of persistent AF refractory to multiple cardioversions and antiarrhythmic therapy in a patient without structural heart disease, with a single radiofrequency application delivered in the left upper pulmonary vein. The observations and failure of repeated internal and external cardioversion suggest a rapidly firing arrhythmia focus sustaining atrial fibrillation amenable to curative pulmonary vein ablation. (PACE 2003; 26:1420,1423) [source]

Reversion and Maintenance of Sinus Rhythm in Patients with Permanent Atrial Fibrillation by Internal Cardioversion Followed by Biatrial Pacing

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002
NIKOLAOS FRAGAKIS
FRAGAKIS, N., et al.: Reversion and Maintenance of Sinus Rhythm in Patients with Permanent Atrial Fibrillation by Internal Cardioversion Followed by Biatrial Pacing. Patients in atrial fibrillation (AF) who fail external cardioversion are usually regarded as in permanent AF. Internal cardioversion may revert many such patients into sinus rhythm (SR) but the majority relapse rapidly into AF. We investigated whether internal cardioversion followed by biatrial pacing is an effective to restore and subsequently maintain SR in patients with permanent AF. Patients in permanent AF underwent internal cardioversion that was followed by biatrial temporary pacing for 48 hours. Those who remained in SR received a permanent biatrial pacemaker programmed to a rate responsive mode with a lower rate 90 beats/min. Primary end point of the study included maintenance in SR 3 months after internal cardioversion. Sixteen patients (14 men, 57 ± 11 years) were cardioverted. The median duration of AF was 24 months (quartiles, Q1= 8.5 and Q3= 102) and mean left atrium diameter was 48 ± 04 mm. A permanent biatrial pacemaker was implanted in 11 patients. At a mean follow-up of 15 months (range 4 to 24), 8 patients remained in SR for more than 3 months. AF was eliminated in 5 patients, while in two a second internal cardioversion on amiodarone was required. Antiarrhythmic therapy was used in half of our population and did not predict the long-term maintenance of SR. Following internal cardioversion with continuous biatrial pacing, 50% of patients with permanent AF were maintained for prolonged periods in SR. This is a new modality of treatment of permanent AF directed to the maintenance of SR that provides a further therapeutic option in end-stage AF. [source]