Prevention Of Atrial Flutter Research Articles

Invited commentary

There has been an explosion in the number of operations directed at treating atrial arrhythmias and more specifically atrial fibrillation. This has been aided by technological advances and the availability of new energy sources substituted for the “cut and sew” technique as developed by Cox in the 1980s. These new energy sources have in turn led to the development of the so-called minimally invasive approaches by some surgeons toward treating atrial fibrillation. Regardless of the surgical approach and the energy source used, the lesions set created have to be transmural to ensure success of the operation and curing the patient. After all, the high success rate of the gold standard cut and sew technique was due to its 100% transmurality of the surgical incisions.In the current issue, Lukac and colleagues [1Lukac P. Hjortdal V.E. Pedersen A.K. Mortensen P.T. Jensen H.K. Hansen P.S. et al.Prevention of atrial flutter with cryoablation may be proarrhythmogenic.Ann Thorac Surg. 2007; 83: 1717-1723Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] have looked at the subject of pro-arrhythmogenicity of nontransmural cryolesions in the right atrium in adult patients undergoing surgical repair of congenital heart defects, predominantly atrial septal defect. In their sophisticated electrophysiological studies they noted fractionated electrograms at the site of the cryolesion in all patients who did not have bidirectional block. This is an important point and something that all surgeons involved with treatment of atrial arrhythmias need to consider when using new technology and energy sources to avoid unintended consequences of nontransmural lesions. Transmurality of the lesion and complete block across the lesion should be verified intraoperatively if we are going to match the cure rate offered by surgical incisions. Using either custom made or commercially made available devices, surgeons should try to confirm the presence of complete block across the lesions intraoperatively.Lukac and colleagues [1Lukac P. Hjortdal V.E. Pedersen A.K. Mortensen P.T. Jensen H.K. Hansen P.S. et al.Prevention of atrial flutter with cryoablation may be proarrhythmogenic.Ann Thorac Surg. 2007; 83: 1717-1723Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] should be congratulated on a nice study. There has been an explosion in the number of operations directed at treating atrial arrhythmias and more specifically atrial fibrillation. This has been aided by technological advances and the availability of new energy sources substituted for the “cut and sew” technique as developed by Cox in the 1980s. These new energy sources have in turn led to the development of the so-called minimally invasive approaches by some surgeons toward treating atrial fibrillation. Regardless of the surgical approach and the energy source used, the lesions set created have to be transmural to ensure success of the operation and curing the patient. After all, the high success rate of the gold standard cut and sew technique was due to its 100% transmurality of the surgical incisions. In the current issue, Lukac and colleagues [1Lukac P. Hjortdal V.E. Pedersen A.K. Mortensen P.T. Jensen H.K. Hansen P.S. et al.Prevention of atrial flutter with cryoablation may be proarrhythmogenic.Ann Thorac Surg. 2007; 83: 1717-1723Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] have looked at the subject of pro-arrhythmogenicity of nontransmural cryolesions in the right atrium in adult patients undergoing surgical repair of congenital heart defects, predominantly atrial septal defect. In their sophisticated electrophysiological studies they noted fractionated electrograms at the site of the cryolesion in all patients who did not have bidirectional block. This is an important point and something that all surgeons involved with treatment of atrial arrhythmias need to consider when using new technology and energy sources to avoid unintended consequences of nontransmural lesions. Transmurality of the lesion and complete block across the lesion should be verified intraoperatively if we are going to match the cure rate offered by surgical incisions. Using either custom made or commercially made available devices, surgeons should try to confirm the presence of complete block across the lesions intraoperatively. Lukac and colleagues [1Lukac P. Hjortdal V.E. Pedersen A.K. Mortensen P.T. Jensen H.K. Hansen P.S. et al.Prevention of atrial flutter with cryoablation may be proarrhythmogenic.Ann Thorac Surg. 2007; 83: 1717-1723Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] should be congratulated on a nice study. Prevention of Atrial Flutter With Cryoablation May Be ProarrhythmogenicThe Annals of Thoracic SurgeryVol. 83Issue 5PreviewAtrial flutter is a serious problem after surgery for congenital heart disease. Full-Text PDF

Prevention of Atrial Flutter With Cryoablation May Be Proarrhythmogenic

Atrial flutter is a serious problem after surgery for congenital heart disease. We performed an intraoperative linear one-minute cryolesion between a right atriotomy and the tricuspid annulus to prevent atrial flutter in 17 consecutive adult patients undergoing surgery for congenital heart disease. Coronary angiography and electrophysiology study using an electroanatomic mapping system to assess the conduction across the line and to try to induce atrial flutter were performed three months after the operation in 15 patients. Eleven patients had bidirectional block in the cryolesion, four patients did not, and two patients refused the electrophysiology study and coronary angiography. All patients with terminal temperature below -151 degrees C had bidirectional block, while only one patient with terminal temperature above -151 degrees C had bidirectional block. No patient with bidirectional block and all patients without bidirectional block had inducible or spontaneous atrial flutter (p = 0.0007). No lesion of the right coronary artery was detected at coronary angiography. The success rate was suboptimal and the intervention is potentially proarrhythmogenic in patients without block. Preventive strategies targeting atrial flutter should be validated with regard to the block rate achieved.

Spontaneous Atrial Flutter in a Chronic Canine Model of the Modified Fontan Operation

Objectives. This study sought to 1) establish whether the atrial flutter (AFL) inducible acutely occurs spontaneously in a chronic canine model, and 2) characterize any reentrant circuits present chronically.Background. We previously demonstrated, in an acute canine model of the modified Fontan operation, that the lateral tunnel suture line creates a sufficient electrophysiologic substrate for AFL.Methods. Using cardiopulmonary bypass, a suture line was placed through a right atriotomy in adult dogs (n = 7) to simulate the lateral tunnel of the Fontan operation. Holter recordings were made preoperatively, on the first postoperative day and 2, 4 and 6 weeks postoperatively. At 6 to 8 weeks, through bilateral ventriculotomies, 253-point unipolar atrial electrodes were inserted. AFL was induced using atrial burst pacing, and endocardial activation sequence maps were created.Results. Preoperatively, all dogs were in sinus rhythm. Spontaneous AFL occurred in all dogs postoperatively, with a mean (±SD) cycle length of 192 ± 22 ms. At 6 weeks postoperatively, of six dogs that survived, four had intermittent AFL, and two had incessant AFL. At reoperation, sustained AFL was inducible in six of six dogs, with a mean cycle length of 194 ± 17 ms. Activation sequence maps demonstrated conduction block at the lateral tunnel suture line, which facilitated unidirectional conduction critical for propagation of the reentrant circuit. The AFL circuit was similar to that observed acutely.Conclusions. In a chronic canine model of the modified Fontan operation, the lateral tunnel suture line alone, in the absence of atrial stretch or hypertension, provides an electrophysiologic substrate that promotes spontaneous AFL. This model may be useful for evaluating various forms of treatment and prevention of AFL after the Fontan operation.

Beta blockade to prevent atrial dysrhythmias following coronary bypass surgery

Atrial fibrillation and atrial flutter (AF) frequently complicate coronary artery bypass surgery (CABG) and increase hospital stay as well as morbidity. Studies of drug prophylaxis to prevent AF with beta-adrenergic blocking agents administered in fixed doses have had conflicting results. One hundred patients were randomized to receive metoprolol or placebo following CABG. A dosing algorithm was used to achieve clinically significant beta-adrenergic blockade. There was no significant difference between the incidence of AF in the metoprolol (24%) and placebo (26%) groups. However, the incidence of AF in all patients having CABG at this institution declined over the period of the study from 31% to 23% (P < .025), in association with the adoption of a continuous technique of cardioplegia delivery. Metoprolol is not efficacious for the prevention of post-CABG AF even when dosage is titrated to achieve clinical evidence of beta blockade. It is likely that the adoption of a continuous cardioplegia technique caused a reduction in our incidence of post-CABG AF.

Effectiveness of Sotalol for Atrial Flutter in Children After Surgery for Congenital Heart Disease

This study describes the efficacy of oral sotalol in the treatment and prevention of atrial flutter in children after surgery for congenital heart disease. In 11 of 13 children (85%), conversion to sinus rhythm was achieved, and in 8 of 11 within 24 hours.

Prevention of atrial flutter with epicardial artilide

Prevention of atrial flutter with epicardial artilide

Effects of N-Acetylprocainamide and Recainam in the Pharmacologic Conversion and Suppression of Experimental Canine Atrial Flutter

The electrophysiologic determinants of the pharmacologic conversion and the prevention of atrial flutter are poorly defined. This study investigated the effects of pharmacologically induced changes in atrial conduction velocity and refractoriness, in the conversion and suppression of atrial flutter induced in the open-chest anesthetized dog by intercaval crush and rapid atrial pacing. The effects of an intravenous infusion of the new class III antiarrhythmic drug N-acetylprocainamide (30 mg/kg over 15 min) and the class Ic antiarrhythmic drug recainam (10 mg/kg over 20 min followed by 10 mg/kg/h) were evaluated. N-acetylprocainamide restored sinus rhythm in 10 of 15 (66%) dogs, while recainam converted only 2 of 10 (20%). N-acetylprocainamide prevented reinduction in 3 (20%), while recainam was effective in none. In the atria, N-acetylprocainamide induced significant increases in effective refractory period (+27%, p less than 0.01), functional refractory period (+22%, p less than 0.01), and in atrial flutter cycle length (+13%, p less than 0.01). Recainam increased effective refractory period (+28%, p less than 0.01), functional refractory period (+20%, p less than 0.01), conduction time at atrial paced cycle length of 150 msec (+70%, p less than 0.01) and atrial flutter cycle length (+56%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacologic conversion and suppression of experimental canine atrial flutter: differing effects of d-sotalol, quinidine, and lidocaine and significance of changes in refractoriness and conduction.

The electrophysiologic determinants of conversion and the prevention of atrial flutter are poorly defined. This issue was therefore investigated by evaluating the effects of the new class III antiarrhythmic drug d-sotalol and the class I antiarrhythmic drugs quinidine and lidocaine. Atrial flutter was reproducibly induced in the open-chest anesthetized dog with intercaval crush and rapid atrial pacing. In this preparation, intravenous d-sotalol restored sinus rhythm in 14 of 15 (93%) dogs, whereas quinidine converted nine of 15 (60%) and lidocaine two of 10 (20%). d-Sotalol prevented reinduction in eight (53%), whereas quinidine was effective in four (27%) and lidocaine in none (0%). In the atria, d-sotalol induced significant increases in effective refractory period (+32%; p less than .01), functional refractory period (+30%; p less than .01), conduction time at an atrial paced cycle length of 150 msec (+9%; p less than .05), and atrial flutter cycle length (+8%; p less than .01). Quinidine increased effective refractory period (+40%; p less than .01), functional refractory period (+27%; p less than .01), conduction time at sinus cycle length (+13%; p less than .01), conduction time at an atrial paced cycle length of 150 msec (+18%; p less than .01), and atrial flutter cycle length (+31%; p less than .01). Lidocaine decreased functional refractory period (-6%; p less than .05) while lengthening the atrial flutter cycle length (+13%; p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)