Transesophageal atrial pacing: a first-choice technique in atrial flutter therapy

Here we report on a study of 181 episodes of spontaneous atrial flutter (AF) (mean atrial cycle length 250 +/- 32 msec) treated by transesophageal atrial pacing (TAP) in 138 patients (92 men and 46 women; mean age 59.5 +/- 12.6 years). TAP was effective in 163 episodes (90%); sinus rhythm resumption was immediate in 36 (19.9%) and followed a short period of atrial fibrillation in 64 (35.3%); in 63 episodes (34.8%) a stable atrial fibrillation was obtained. TAP was unsuccessful in 18 cases (10%). All the patients tolerated the procedure well. A statistical elaboration with the Fisher exact test did not evidence a correlation between efficacy and age, sex, atrial cycle length, or underlying heart disease but showed a significant correlation between efficacy and AF duration of less than 1 day (p less than 0.05) and absence of antiarrhythmic pharmacologic pretreatment (p less than 0.01). These data strongly support the immediate first-choice use of TAP in AF therapy.     

Effects of flecainide on termination of atrial flutter by rapid atrial pacing

Rapid atrial pacing is effective in terminating atrial flutter,but often results in transient or permanent atrial fibrillationrather than sinus rhythm. Class Ia antiarrhythmic drugs haveearlier been shown to facilitate the direct conversion of atrialflutter to sinus rhythm. The present study was performed totest the hypothesis that flecainide, a group 1c antiarrhythmicdrug, increases the direct conversion to sinus rhythm. In aseries of 30 consecutive clinical episodes of atrial fluttertreated with rapid atrial pacing, 12 episodes were in patientson flecainide treatment (group A), while in 13 episodes no patientswere on group 1 antiarrhythmic drugs (group B). Direct conversionto sinus rhythm was achieved more often in group A (75%) thanin group B (31%) P = 0.034. Both the flutter rates and the pacingrates used were lower in group A, 240 vs 280 beat. Min^–1and 375 vs 430 b. min^–1, respectively. Patients with atrialflutter in whom rapid atrial pacing is to be performed shouldbe considered for pretreatment with flecainide.     

Comparison of atrial overdrive pacing with and without extrastimuli for termination of atrial flutter.

Atrial overdrive pacing has been successfully used to terminate atrial flutter. This study compared the efficacy of atrial extrastimuli following a rapid pacing train to overdrive pacing without atrial extrastimuli for the termination of atrial flutter. Patients were randomized to treatments of short or long burst atrial overdrive pacing or atrial overdrive pacing followed by atrial extrastimuli in a crossover study design. A total of 22 patients (73%) had successful conversion of atrial flutter to sinus rhythm. The success rates in patients exposed to each therapy, including crossover therapies, were 62% with the atrial extrastimuli method, 8% with the short burst pacing method, and 8% with the long burst pacing method (p less than 0.001). Transient atrial fibrillation developed in 15 patients and in 9 of these this arrhythmia preceded conversion to sinus rhythm. Sustained atrial fibrillation was induced in 3 additional patients but never with the atrial extrastimuli method. In conclusion, the method of delivering atrial extrastimuli after a rapid pacing train is highly efficacious for the termination of atrial flutter. Furthermore, this method is more effective than atrial overdrive pacing methods delivered at the same pacing cycle length. These observations have important implications for the programming of antitachycardia pacemakers.     

Electrophysiologic determinants of recurrent atrial flutter after successful termination by overdrive pacing

The potential ability of electrophysiologic abnormalities to predict recurrence of atrial flutter was evaluated. Twenty-five patients with chronic atrial flutter resistant to combined digitalis and quinidine therapy were studied electrophysiologically after restoration of sinus rhythm by overdrive pacing or by eventual direct current cardioversion. Recurrence of atrial flutter was observed in 12 patients during a mean follow-up period of 17 months (range 3 to 50). Electrophysiologic testing included programmed high right atrial stimulation at a paced drive cycle length of 600 ms and incremental pacing up to 200-ms paced intervals. When coupling intervals of 90% of the drive cycle length were compared to coupling intervals of 48% of the drive cycle length, the increase in S1A1 interval, defined as the interval between the stimulus artifact and the atrial activation near the atrioventricular junction, was greater in patients with subsequent recurrence of atrial flutter (47 +/- 11 vs 21 +/- 18 ms). Stepwise logistic regression analysis identified the S1A1 increase to be the sole independent predictor of recurrence (p = 0.0082) while previous episodes of atrial flutter or the presence of organic heart disease were identified as dependent variables. Reclassification showed a 91% sensitivity and a 92% specificity. Correct classification was achieved in 92% of patients. The initiation of atrial dysrhythmia had no predictive value. The assessment of the S1A1 interval by programmed atrial stimulation appears helpful in delineating the patient risk of recurrent atrial flutter after termination by overdrive pacing.     

Efficacy and safety of ibutilide vs. transoesophageal atrial pacing for the termination of type I atrial flutter.

AIMS: Comparing efficacy and safety of ibutilide vs. transoesophageal atrial pacing (ATP) for the termination of type I atrial flutter (AFL). METHODS AND RESULTS: Eighty-seven patients affected by AFL lasting between 2 h and 30 days were randomized in two groups: Group 1-i.v. ibutilide treatment, up to 2 mg, and Group 2-ATP, with "burst" and "ramp" pacing protocols. Sinus rhythm was restored in 36/45 (80%) patients in Group 1 vs. 18/42 (43%) in Group 2 (P<0.0005). In Group 1, mean AFL duration was 11.4 +/- 7.7 days in responders vs. 12.1 +/- 7.6 in non-responders (P=ns), while in Group 2 it was 2.7 +/- 1.4 vs. 14.2 +/- 5.4 days (responders vs. non-responders, respectively, P<0.0001); 30/36 (83%) responders in Group 1 had AFL >48 h vs. 10/18 (56%) responders in Group 2 (P<0.05). Non-sustained polymorphic ventricular tachycardia occurred in 2 patients in Group 1 vs. none in Group 2 (P=ns). It did not require any specific treatment except the interruption of ibutilide infusion. CONCLUSION: Both ibutilide and ATP proved to be safe and effective for recent onset type I AFL termination, but ibutilide was more effective when the arrhythmia had lasted longer than 48 h.     

Atrial pacing for conversion of atrial flutter

Fifty-seven episodes of atrial flutter in 46 consecutive medically treated patients (aged 60 +/- 17 years) were treated by rapid atrial pacing. Thirty-three patients (72%) had structural heart disease. Most pacing trials were conducted in patients receiving digoxin (88%) and antiarrhythmic drugs (77%). In 51 of 57 trials (89%), patients were successfully converted to normal sinus rhythm. Multivariate analysis revealed that patients who had congestive heart failure and who were older were more likely to be refractory to pacing. Left atrial size did not influence outcome. Confirmation of local atrial capture with a bipolar atrial electrogram and use of multiple atrial pacing sites enhanced the success rate. Eight patients (17%) demonstrated sinus node suppression after atrial pacing; sinus node disease was previously unsuspected in 4 of these patients. These bradyarrhythmias were easily managed because a pacing catheter was already in place. The only significant complication was femoral vein thrombosis in 1 patient. It is concluded that atrial pacing is an effective, safe and convenient method for the elective conversion of atrial flutter in the general population of medically treated patients. This technique is an attractive alternative to transthoracic cardioversion, and may be preferable in many patients.     

Transesophageal electrocardiography using a temporary pacing balloon-tipped electrode in acute cardiac care

STUDY OBJECTIVE: The study was undertaken to determine the feasibility of obtaining esophageal ECGs using resterilized 3F temporary pacing balloon-inflated electrodes in place of the more expensive pill-electrode and its associated expensive preamplifier. SETTING: Tests were conducted in the emergency department and ICU. TYPE OF PARTICIPANTS: Subjects were 12 acutely ill patients for whom standard 12-lead surface ECGs were insufficient to afford accurate, immediate arrhythmia diagnosis. INTERVENTIONS: Reasonable quality esophageal ECGs were obtained by use of the electrodes, generally with minimal patient discomfort. The test never required more than ten minutes. Of the 12 patients who participated in this preliminary study, esophageal ECGs enabled definitive diagnoses to be made in ten cases. CONCLUSION: The use of resterilized temporary pacing balloon-inflated electrodes enables esophageal ECGs to be obtained in an acute care setting.     

应用经食道心房调搏技术鉴别Mahaim纤维

目的:通过食道心房调搏技术鉴别Mahaim纤维。方法:回顾性分析53例旁道具有前传功能患者的食道电生理检查。其中Mahaim纤维组7例,Kent氏束组46例,对比两组的经食道心房起搏后S-R间期、旁道递减功能（ΔS-R）、旁道不应期（AP-ERP）、及心动过速发作特点。结果:在经食道心房调搏检查中,S1S1起搏时Mahaim纤维组S-R间期较Kent氏束组长［(71±20)ms vs. (28±14)ms,P<0.05］;Mahaim纤维组可见ΔS-R［(103±28)ms vs.(12±11)ms,P<0.01);两者的AP-ERP无显著差异。Mahaim纤维组7例均诱发出宽QRS波心动过速,Kent氏束组3例为宽QRS波心动过速。结论:应用经食道心房调搏可鉴别Mahaim纤维。     

A comparison of transoesophageal atrial pacing and direct current cardioversion for the termination of atrial flutter: a prospective, randomised clinical trial.

OBJECTIVE--To compare the safety and efficacy of transoesophageal atrial pacing (TAP) with an easily swallowed pill electrode and direct current cardioversion (DCC) in patients with atrial flutter that was refractory to appropriate medical treatment. DESIGN--Prospective, randomised clinical trial. SETTING--Community based United States naval hospital. SUBJECTS--Twenty one consecutive patients with refractory atrial flutter selected consecutively from the inpatient cardiology consultation service. All patients were haemodynamically stable and medical treatment with a class IA or IC antiarrhythmic agent had failed. Eleven patients were treated with TAP and 10 patients were treated with DCC. INTERVENTIONS--Digoxin was given to all patients to control the ventricular rate to < 100/minute. MAIN OUTCOME MEASURE--Conversion to normal sinus rhythm and arrhythmias after cardioversion. RESULTS--Conversion to normal sinus rhythm was similar in both groups (TAP 8/11, DCC 9/10, p = 0.31). Arrhythmias after cardioversion including third degree heart block and non-sustained ventricular tachycardia were more frequent in the DCC group (TAP 0/11, DCC 6/10, p = 0.02). CONCLUSION--Transoesophageal atrial pacing with an easily swallowed pill electrode is safe, well tolerated, and is as efficacious as DCC for refractory atrial flutter.     

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.     

Atrial flutter treatment by rapid atrial pacing

49 patients with 53 episodes of atrial flutter were treated by rapid atrial pacing. Sinus rhythm was attained in 55%, atrial fibrillation in 26%, type II flutter in 9% of patients. In the other cases, the effect on atrial action was only slight or short-lasting. Among the causes of the unsuccessful outcome of treatment, the authors include--besides insufficient rate and duration of pacing, bad electrode contact in the atrium and insufficient outlet current--specific properties of the type of flutter (impure flutter, type II flutter, type I atrial fibrillation, uncommon flutter) as well as unsuitable indication (mitral defect, thyrotoxicosis).     

Transesophageal stimulation in the treatment of atrial flutter and tachysystole

Transoesophageal left atrial pacing was used to reduce 102 episodes of ectopic atrial rhythms (79 common flutters and 23 ectopic tachycardias) in 83 patients (64 men, 19 women) aged 33 to 85 years (average 61 years). Overdrive pacing, at a faster rate than that of the spontaneous rhythm, was delivered via a bipolar pacing catheter introduced nasally and positioned behind the atrium under fluoroscopic and/or electrocardiographic control. Long pulse durations (up to 20 ms) were used to capture the atria with intensities of less than 20 mA for better tolerance. The overall results were: a) conversion to sinus rhythm in 60.8 p. 100 of cases (47 p. 100 directly and 13.8 p. 100 after transient atrial fibrillation), b) atrial fibrillation lasting over 24 hours in 7.8 p. 100 of cases, c) failure (31.4 p. 100) due to non-capture or intolerance (20.6 p. 100) or recurrence of the arrhythmia after transient atrial fibrillation (10.8 p. 100). Atrial flutter is more accessible to pacing than tachycardia (restoration of sinus rhythm in 63.3 p. 100 and 52.2 p. 100, respectively). Arrhythmias in the postoperative period of cardiac surgery, and isolated and recent arrhythmias were more easily converted. Prior antiarrhythmic therapy did not seem to improve results. Fifty per cent of failures of oesophageal pacing were converted to sinus rhythm by endocavitary pacing. These results show that atrial flutter or tachycardia may be successfully treated by oesophageal pacing in over 50 p. 100 of cases without having to use other forms of electrotherapy (endocavitary pacing or cardioversion).     

Autodecremental pacing for the interruption of ventricular tachycardia and atrial flutter

The efficacy and safety of autodecremental pacing (ADP) to interrupt ventricular tachycardia (VT) and atrial flutter was examined. Once tachycardia was recognized, ADP was initiated using a short train of stimuli with gradual shortening (3%) of the interstimulus interval. ADP was applied to 13 consecutive patients during 75 episodes of VT (mostly following induction by ventricular stimulation). Successful interruption of VT occurred in 88% of the episodes. In 6 episodes (8%), ADP resulted in ventricular fibrillation and in 3 episodes VT was unaffected by ADP. The only significant discriminator between the failure or success of ADP was the rate of VT. ADP was also applied to 17 consecutive patients with an atrial flutter that was resistant to conventional antiarrhythmic agents. Successful conversion of atrial flutter to sinus was seen in only 8 patients (47%). A temporary acceleration to atrial fibrillation appeared in 3 patients (18%), and in 6 patients atrial flutter was unaffected by ADP. ADP was successful in 70% (7/10) of patients with type 1 (< 300 beats/min) atrial flutter. The authors conclude that ADP is beneficial in the interruption of VT and atrial flutter in a selected group of patients, especially with a slower rate of tachyarrhythmia (atrial rate during atrial flutter < 300 beats/min and ventricular tachycardia < 180 beats/min).     

Atrial pacing for the prevention and termination of atrial fibrillation

Atrial fibrillation (AF) affects about 2% of the general population and 8%–11% of those older than 65 years. The demand for effective therapeutic strategies for AF is anticipated to increase substantially as the proportion of the elderly population increases. Atrioventricular nodal ablation accompanied by permanent pacemaker implantation is an established option in elderly patients with intractable arrhythmia and poor ventricular rate control. However, it renders most patients pacemaker dependent and does not eliminate symptoms associated with loss of atrial transport or reduce the risk of stroke. The considerable limitations of rhythm or rate control strategies prompted interest in preventative atrial pacing, which may reduce the incidence of AF by either eliminating the triggers and/or by modifying the substrate of AF. Atrial or dual-chamber pacing has been proven to prevent or delay progression to permanent AF in elderly patients with sinus node dysfunction as compared with ventricular pacing. Patients with advanced atrial conduction delay may benefit from 'atrial resynchronization' pacing. There may be additional benefits associated with the use of particular sites of pacing, specific pacing algorithms designed to target potential triggers of AF, and pace-termination of atrial tachycardia. Preventive and antitachycardia pacing algorithms incorporated in implantable cardioverter-defibrillators and pacemakers are currently under investigation and may offer a valuable alternative to antiarrhythmic drug therapy in elderly patients with left ventricular dysfunction at high risk of proarrhythmia or worsening heart failure. The evolution of 'hybrid' therapy, in which two or more different strategies are employed in the same patient, may be the most effective approach to management of AF.     

伊布利特转复心房颤动/心房扑动的临床观察

目的探讨静脉应用伊布利特转复心房颤动(房颤)/心房扑动(房扑)的有效性及安全性。方法筛选18~80岁,持续时间≤90d(3h~90d)、心室率≥60次/min的阵发或持续性房颤/房扑患者共31例,随机分为伊布利特组和普罗帕酮组各16和15例。伊布利特组体重≥60kg者首剂1mg、体重<60kg者首剂0.01mg/kg,如无效10min后再给予1mg或0.01mg/kg;普罗帕酮组首剂70mg,如无效10min后再给予35mg。结果两组均能有效降低房颤/房扑的心室率,但组间比较差异无统计学意义;转复率:伊布利特组62.5%(10/16),普罗帕酮组26.7%(4/15),两组差异有统计学意义(P<0.05);普罗帕酮组转复失败的病例中有6例改用伊布利特,其中2例转为窦性心律,而伊布利特组转复失败的4例改用普罗帕酮后均未转复。转复时间伊布利特组显著短于普罗帕酮组(12.70±10.27)min对(39.75±10.08)min,(P<0.01)。副作用:伊布利特组1例合并有左心室功能不良者用药后即刻出现尖端扭转性室性心动过速(室速),经直流电击后转复为窦性心律;普罗帕酮组1例出现左心衰竭,另1例出现头晕、手麻。结论伊布利特转复房颤/房扑的疗效高于普罗帕酮,转复时间短于普罗帕酮,但须在严格监控下进行。     

Atrial pacing for cardioversion of atrial flutter in digitalized patients

To test the safety and reliability of atrial pacing as a conversion technique in patients with atrial flutter who are receiving digitalis therapy, atrial pacing conversion was attempted for 49 episodes of atrial flutter in 32 consecutive patients. All patients except one were receiving digitalis. To control ventricular rates most patients had received larger than usual therapeutic doses of digitalis glycoside before pacing. Fourteen of the 25 patients whose serum levels were measured had glycoside concentrations greater than 2 ng/ml. Before atrial pacing the mean atrial and ventricular rates were, respectively, 290 +/- 20.6 and 134 +/- 27.9/min (mean +/- standard deviation). Successful rhythm conversion was achieved on 48 occasions (98%) in 31 patients. One patient required transthoracic direct current synchronized countershock cardioversion. With atrial pacing, the atrial flutter rhythm reverted immediately to sinus mechanism in 23 instances, and there were 25 episodes of atrial fibrillation. Among those who experienced atrial fibrillation, the rhythm spontaneously reverted to sinus mechanism within 24 hours on 14 occasions; on 11 occasions; the rhythm reverted to atrial flutter and repeat pacing was required. Sinus mechanism was eventually established in all 31 patients.