Conversion Of Atrial Flutter Research Articles

ВЛИЯНИЕ АРТЕРИАЛЬНОЙ ГИПЕРТЕНЗИИ И ХРОНИЧЕСКОЙ СЕРДЕЧНОЙ НЕДОСТАТОЧНОСТИ НА ЭФФЕКТИВНОСТЬ ВОССТАНОВЛЕНИЯ СИНУСОВОГО РИТМА У БОЛЬНЫХ С ТРЕПЕТАНИЕМ ПРЕДСЕРДИЙ

The use of overdrive transesophageal cardiac pacing (OTECP) in atrial flutter (AF) can reduce the number of external electrical cardioversion (EEC) in arrhythmia refractory to drug-induced cardioversion. The conversion of AF to atrial fibrillation (AFib) with subsequent spontaneous sinus rhythm (SR) restoration with the help of OTECP and accompanying antiarrhythmic therapy (AAT) was carried out in 59 patients with diseases of the cardiovascular system aged 40 to 77 years. The duration of AF before pacing was 35.93 ± 5.25 days. The efficiency of OTECP was 71.19%, and the time for spontaneous SR restoration was on average 16.92 ± 2.67 h. During pacing, the combined AAT has no advantages over monotherapy, despite its higher efficiency before OTECP. The obtained results indicate that the duration of AF prior to the OTECP procedure did not affect either the effectiveness of the procedure or the timing of spontaneous SR restoration. Inadequate control of blood pressure during treatment was a risk factor for reducing the effectiveness of OTECP, and contributed to the persistence or recurrence of arrhythmia. In patients with AF without AH, a decrease in left ventricular contractility and severe grade of CHF with an increase in left ventricular chamber dimension at end systole, a decrease in ejection fraction (EF) and fractional shortening (FS), reduces the likelihood of spontaneous SR restoration after OTECP, while additional administration of digoxin to increase myocardial contractility did not influence the effectiveness the therapy being carried out. The enlarged dimensions of the left atrium, which did not go beyond the critical dimensions, also had no influence on the effectiveness of the therapy. The efficiency of SR restoration against the background of AAT was 71.19%. Taking into account the EEC accompanied by the treatment performed corresponds to 83.05%. The effectiveness of OTECP when performed on the background of mono- or combined AAT did not differ significantly and amounted to 70.83 and 71.43%, as well as the terms of spontaneous SR restoration — 16.94 ± 2.86 and 16.89 ± 2, 48 hours respectively. The effectiveness of OTECP during mono- or combined AAT was 70.83% and 71.43%, respectively, and the time for spontaneous SR restoration was 16.94 ± 2.86 and 16.89 ± 2.48 hours. Medicamentous cardioversion of AF prior to the OTECP procedure is effective in 54.29% of cases and only with the combined AAT.

Ibutilide therapy in the conversion of atrial flutter in neonates

Overview Atrial flutter (AFL) is an uncommon arrhythmia in the fetal and neonatal period, and without appropriate treatment, it can lead to hydrops fetalis and even death. Treatment for neonatal AFL includes medications, transesophageal overdrive pacing, or synchronized direct current cardioversion (DCC). Ibutilide is an accepted pharmacological method of cardioversion in adults and younger children, but there are no documented uses of it in neonates. We report the successful cardioversion of AFL with slow intravenous (IV) infusion of 0.01 mg/kg of ibutilide in 2 neonatal patients.

Effects of Ibutilide on Inhibiting Heart Rate and Rapidly Terminating Atrial Flutter in Canine

Ibutilide is a newer class-III antiarrhythmic agent approved for clinical use. We sought to investigate its electrophysiological effects in canines and also the underlying mechanism of conversion of atrial flutter (AFL). For this purpose, 15 male mongrel dogs were anesthetized, intubated with tracheal tube, and heart was exposed and connected to electrodes. Electrophysiologic variables were measured with and without ibutilide (10-min infusion-dose: 0.10mg/kg; 30-min later, maintaining dose: 0.01mg/min) which included heart rate, conduction of intra- and inter-atrium, conduction ratio of isthmus, and ERP. Ibutilide had a significant inhibitory effect on sinus atrial node, peak response time was 20-30min, and heart rate returned to the baseline after 2h. One canine had 5s sinus pause, and the other had 2:1 atrioventricular conduction post-administration. Atrial, ventricular, and pulmonary vein ERP was significantly prolonged (P<0.05). No significant differences were observed regarding conduction of intra-atrium, inter-atrium, and isthmus. It was, therefore, concluded that ibutilide had suppressive effect on sinus atrial and atrioventricular nodes. Ibutilide rapidly terminated AFL due to the reentrant wave front's inability to proceed as the refractory period was protracted and hence caused the whole excitable gap of the reentrant circuit to be affected by refractoriness.

Conversion of atrial flutter to sinus rhythm during landiolol infusion

A 73-year-old male patient with a past history of hypertension and atrial premature contraction underwent endoscopic restoration of the left bubonocele. Sinus rhythm was confirmed by preoperative electrocardiography, but paroxysmal atrial flutter developed when abdominoscopy was started. Continuous administration of landiolol hydrochloride at a dose of 0.005 mg kg(-1) min(-1) after a loading dose of 0.04 mg kg(-1) min(-1) for 1 min resulted in control of heart rate without a decrease in blood pressure. Atrial flutter was converted to sinus rhythm 3 min after the start of administration. Landiolol hydrochloride was administered continuously until the morning of the following day and sinus rhythm was maintained postoperatively.

Arrhythmic complications of electrical cardioversion: Relationship to shock energy

Background Existing guidelines for electrical cardioversion (ECV) of atrial arrhythmias suggest starting at a low energy setting on the grounds that shocks of high energy might damage the myocardium or trigger more serious arrhythmias. We hypothesised that more powerful shocks would exceed the upper limit of vulnerability for inducing ventricular fibrillation. The initial use of higher energy could therefore reduce arrhythmic complications. Methods We collected data on the sequence of shocks delivered and the resulting changes in cardiac rhythm in 1896 patients who underwent transthoracic ECV. Rhythm strips derived from 200 consecutive ECV attempts were studied to verify the accuracy of the synchronisation of the shocks delivered. Results In 2522 attempts at transthoracic ECV, 6398 shocks were delivered, 1243 in atrial flutter or atrial tachycardia, the others in AF. Ventricular fibrillation was significantly more common after shocks of < 200 J (5 of 2959 vs. 0 of 3439 shocks, p < 0.05, Fischer's exact test). Conversion of atrial flutter or atrial tachycardia to AF was also more common at < 200 J (20 of 930 shocks vs. 1 of 313 shocks at ≥ 200 J, p < 0.05, χ 2 test). Sinus bradycardia or sinus arrest complicated 0.95% of cardioversion attempts, but none required emergency pacing. The incidence of bradycardia was not related to the energy used. Conclusions Shocks of > 200 J are associated with fewer tachyarrhythmic complications, and do not increase the risk of other serious complications. Bradycardia after cardioversion is very rarely of clinical importance.

606 Is biphasic DC shock more effective than monophasic in conversion of atrial flutter?

606 Is biphasic DC shock more effective than monophasic in conversion of atrial flutter?

606 Is biphasic DC shock more effective than monophasic in conversion of atrial flutter?

606 Is biphasic DC shock more effective than monophasic in conversion of atrial flutter?

Clinical Comparison of Ibutilide and Propafenone for Converting Atrial Flutter

To evaluate the efficacy and safety of intravenous ibutilide and propafenone for immediate treatment of atrial flutter. Forty patients with atrial flutter with an arrhythmia duration of three hours to 90 days were randomized to receive up to two 10-minute infusions of ibutilide (1 and 1 mg) or propafenone (70 and 70 mg) with a 10-minute interval. Ibutilide was superior to propafenone for treating atrial flutter (90% vs. 30%, p < 0.01). The median conversion time in the ibutilide group was 11 min (the 25th and 75th percentile was 10 and 45 min), and the median conversion time in the propafenone group was 35 min (range 20-55 min). In all patients, the duration of arrhythmia before treatment was a predictor of arrhythmia termination, although this was more obvious in the group that received ibutilide. Conversion of atrial flutter by ibutilide was characterized mainly by increased cycle length variability. Bradycardia (2/20) and hypotension (4/20) were more common side effects with propafenone. Of 20 patients given ibutilide, 8 (40%) who developed monomorphic ventricular extrasystoles or repetitive atrial flutter with aberrant conduction tachycardia, no one required any specific treatment except for the interruption of ibutilide infusion. Ibutilide is highly effective for rapidly terminating atrial flutter. This new class III drug, under monitored conditions, is a potential alternative to currently available cardioversion options.

Embolic complications of direct current cardioversion of atrial arrhythmias: association with low intensity of anticoagulation at the time of cardioversion

ObjectivesThe goal of this study was to identify the factors responsible for embolic complications of direct current (DC) cardioversion of atrial arrhythmias. BackgroundDirect current cardioversion of atrial fibrillation (AF) carries a risk of thromboembolism, which is reduced, but not eliminated, by anticoagulation. The risk of embolism after conversion of atrial flutter is believed to be lower. No series to date has included enough patients receiving anticoagulants or enough patients with atrial flutter to estimate the risk in these groups. MethodsWe reviewed the case records of 1,950 patients who underwent 2,639 attempts at DC cardioversion. ResultsCardioversion was performed within two days of the apparent onset of the arrhythmia in 443 episodes, 352 without subsequent prolonged anticoagulation with one embolic complication. Cardioversion was preceded by warfarin therapy for ≥3 weeks in 1,932 instances. No embolic complication occurred in 779 attempts performed with an international normalized ratio (INR) of ≥2.5 (95% confidence limits 0% to 0.48%). Of 756 cases in which the INR was <2.5 or was not measured before conversion, nine were complicated by thromboembolism. Embolism was significantly more common at an INR of 1.5 to 2.4 than at an INR ≥2.5 (0.93% vs. 0%, p = 0.012). The incidence of embolism after conversion of atrial flutter or tachycardia was similar to that after cardioversion of AF (0.72% vs. 0.46%, p = NS). ConclusionsThe INR should be ≥2.5 at the time of cardioversion if the duration of AF is uncertain or >2 days. Cardioversion of atrial flutter presents similar risks and requires similar anticoagulation.

The repolarization-excitability relationship in the human right atrium is unaffected by cycle length, recording site and prior arrhythmias

OBJECTIVESThe goal of this study was to determine the relationship between repolarization and excitability in the human atrium under various conditions.BACKGROUNDAction potential duration (APD) measurements from monophasic action potential (MAP) recordings provide a surrogate for measuring the effective refractory period (ERP) in human ventricle. The relationship between repolarization and refractoriness in human atrium and the effect of prior atrial fibrillation/flutter on the ERP/APD correlation are unknown.METHODSSeven patients with sinus rhythm and 15 patients after conversion of atrial flutter or fibrillation were evaluated. Monophasic action potentials were recorded at multiple right atrial sites and during different basic cycle lengths from 300 to 700 ms, while ERPs were determined by extrastimulus technique using the MAP recording-pacing combination catheter.RESULTSThere was a close correlation between ERP and APD at 70% repolarization (APD70, r = 0.97; p < 0.001) and 90% repolarization (APD90, r = 0.98; p < 0.001), respectively. Refractoriness occurred at a repolarization level of 72 ± 8%. The ERP/APD70and ERP/APD90ratios averaged 1.06 ± 0.10 and 0.86 ± 0.08, respectively. These ratios were nearly constant over the entire range of basic cycle lengths, between different sites in individual patients and between different patients. Patients cardioverted from atrial fibrillation or flutter exhibited no significant differences in the ERP/APD relationship compared with patients with sinus rhythm.CONCLUSIONSEffective refractory period and APD are closely related in the human right atrium. Using the MAP recording technique, atrial ERPs can be assessed by measurement of APDs. Effective refractory period is most closely reflected by APD70. Thus, MAP recordings allow investigation of the local activation and repolarization time course beat by beat, visualizing the excitable gap.

Conversion of atrial flutter in pediatric patients by transesophageal atrial pacing: A safe, effective, minimally invasive procedure: L.A. Rhodes, E.P. Walsh, J.P. Saul. Children's Hospital, Department of Cardiology, Boston, MA. Am Heart J 1995;130:323–7

Conversion of atrial flutter in pediatric patients by transesophageal atrial pacing: A safe, effective, minimally invasive procedure: L.A. Rhodes, E.P. Walsh, J.P. Saul. Children's Hospital, Department of Cardiology, Boston, MA. Am Heart J 1995;130:323–7

Conversion of atrial flutter by ibutilide is associated with increased atrial cycle length variability

This study was designed to test the hypothesis that conversion of atrial flutter in humans by ibutilide, a new class III antiarrhythmic agent, is characterized by an increase in atrial cycle length variability. Conversion of tachyarrhythmias has been associated with increased oscillations of cycle length. Electrograms and monophasic action potentials from the right atrium in 35 patients with spontaneous, sustained atrial flutter were recorded before, during and after intravenous ibutilide (0.005 to 0.025 mg/kg body weight, n = 25) or placebo (n = 10). Atrial cycle length, cycle length variability (coefficient of variation), diastolic interval and diastolic interval variability were measured from 10 consecutive cycles at baseline and 3 min before, 1 min before, 30 s before and immediately before conversion. Similar measurements were made in patients who received ibutilide or placebo but did not convert. Ibutilide converted atrial flutter in 14 of 25 patients 25 +/- 16 min (mean +/- SD) after initiation of the infusion, whereas placebo converted no patients. Atrial cycle length was prolonged to the same extent in ibutilide converters and nonconverters (36 +/- 19 vs. 38 +/- 21 ms, p = NS) and was not affected by placebo. Beat-to-beat variability in atrial cycle length (baseline 1.2 +/- 0.7 vs. preconversion 7.3 +/- 4.9, p < 0.01) and diastolic interval (baseline 11 +/- 8 vs. preconversion 33 +/- 23, p < 0.05) increased significantly just before atrial flutter conversion and remained unchanged in ibutilide nonconverters and placebo group patients. Ibutilide prolongs atrial cycle length, but conversion of atrial flutter by ibutilide is characterized by increased variability in atrial cycle length and diastolic interval.

Conversion of atrial flutter in pediatric patients by transesophageal atrial pacing: A safe, effective, minimally invasive procedure

Atrial reentry tachycardia, often termed atrial flutter, is an arrhythmia that is uncommon in the general pediatric population but is seen frequently in patients with congenital heart disease. One goal in treating the arrhythmia is to terminate it, returning the atrium to its underlying rhythm. This report describes the use of transesophageal atrial pacing to attempt termination of atrial reentry in 102 pediatric patients (158 episodes). The patients ranged in age from 1 hour to 41.5 years. Conversion was successful for 112 (71%) of 158 episodes. Six of the 112 episodes required an infusion of procainamide after initial attempts at pacing led to atrial fibrillation. There were no significant differences between the ages of patients or the duration of the tachycardia in comparing successful versus unsuccessful conversions. In contrast, the atrial cycle lengths for the successfully converted tachycardias were significantly greater than for unsuccessful attempts. Transesophageal atrial pacing is a safe and effective means of terminating atrial flutter in the pediatric population. It is minimally invasive, it can often be performed in an outpatient setting, and the technique may occasionally be facilitated by infusion of intravenous procainamide.

Does left atrial appendage “stunning” occur following conversion of atrial flutter?

Does left atrial appendage “stunning” occur following conversion of atrial flutter?

Atrial stunning lasts more than one week after conversion of atrial flutter

Atrial stunning lasts more than one week after conversion of atrial flutter

Atrial pacing for conversion of atrial flutter

Atrial pacing for conversion of atrial flutter

Conversion of atrial flutter: rapid atrial pacing as a bedside technique.

Eleven patients with atrial flutter underwent intracardiac right atrial pacing at bedside in an attempt to terminate this dysrhythmia. Nine of the eleven patients were converted to sinus rhythm; the remaining two patients were converted to atrial fibrillation with a slower ventricular rate. There were no complications. The potential hazards of direct current cardioversion (anesthesia, fractures, muscle strain, myocardial injury, etc.) were avoided. In contrast to rapid atrial pacing in the electrophysiology laboratory, the bedside technique did not require a special laboratory setting, electronic or x-ray equipment, or technical personnel. Transportation of critically ill patients was obviated. Atrial flutter can be converted at the bedside to a more favorable rhythm; the expediency, safety, and low cost of this bedside cardioversion technique not only makes it feasible, but also it is often the procedure of choice.

Conversion of atrial flutter by rapid atrial stimulation

Conversion of atrial flutter by rapid atrial stimulation

Failure of rapid atrial pacing in the conversion of atrial flutter

Rapid atrial pacing, at rates of 150 to 600/min with stimulus strength up to 15 ma, was attempted in 15 patients with atrial flutter. In 13 of the patients, atrial capture was achieved with changes in both atrial and ventricular rates. In 7 of these, flutter resumed upon cessation of pacing. In the other 6, rapid atrial pacing produced atrial fibrillation which persisted until cardioversion. In 2 patients, atrial capture could not be obtained because of increased atrial refractoriness secondary to flutter. Thus, rapid atrial pacing was ineffective in converting atrial flutter to normal sinus rhythm in all 15 patients. This was in contrast to direct-current cardioversion which was successful in 12 of the patients, in all of whom stable sinus rhythm developed. The 3 patients who did not undergo cardioversion subsequently experienced spontaneous conversion to sinus rhythm. These results suggest that rapid atrial pacing has little place in the management of atrial flutter.

Electroshock for Atrial Flutter and Atrial Fibrillation

The electrical conversion of atrial flutter and fibrillation to normal sinus rhythm is effective and safe. However, follow-up study of 50 patients showed that sinus rhythm persisted in only 42% of those patients whose arrhythmias were initially converted. The mean follow-up time was ten months. The immediate and long-term results were much better in patients with atrial flutter and in those with atrial fibrillation of less than two years' duration.