Sinus Rhythm Maintenance Rate Research Articles

Therapie von Vorhofflimmern

Atrial fibrillation is a common and in most patients recurrent arrhythmia. Atrial fibrillation can increase mortality and causes at times severe symptoms in affected patients. Timely initiation of sustained oral anticoagulation is indicated in patients with atrial fibrillation at risk for stroke to prevent thromboembolic complications. Patients at risk for stroke can be identified by clinical characteristics using validated score systems, e.g., the CHADS(2) score or the Framingham score. Drugs that slow AV nodal conduction can improve symptoms associated with high ventricular rate. Cardioversion can acutely terminate atrial fibrillation in almost all patients, but many patients suffer from recurrent atrial fibrillation. The prevention of arrhythmia recurrences ("rhythm control therapy") is indicated in patients with severe arrhythmia-related symptoms. Antiarrhythmic drugs can approximately double the maintenance rate of sinus rhythm. Other drugs that were not primarily developed as antiarrhythmic agents, e.g., ACE inhibitors, sartans, and possibly statins, can further improve maintenance of sinus rhythm in selected patient groups. Catheter-based isolation of the pulmonary veins is a recently developed intervention that can cure some forms of atrial fibrillation. It is likely that a multimodal therapeutic approach will in the future allow rhythm control therapy to become more effective.

AB8-4: The mechanisms and radiofrequency catheter ablation of atrial tachycardia following surgery for atrial fibrillation

Surgery is highly effective in curing atrial fibrillation (AF), with a maintenance rate of sinus rhythm of approximately 90%. However, atrial tachycardia (AT) develops in some patients postoperatively and its mechanism has not been examined in detail. We studied the mechanism of the postoperative AT, and determined the feasibility of radiofrequency (RF) catheter ablation in treating it.

One-Year Outcome of Cardioversion of Atrial Fibrillation in Patients With Mitral Stenosis After Percutaneous Balloon Mitral Valvuloplasty

Our objectives were to study the success rate of electrical cardioversion after percutaneous balloon mitral valvuloplasty (PBMV) in patients with symptomatic moderate-to-severe mitral stenosis and atrial fibrillation (AF) and the maintenance rate of sinus rhythm for < or =1 year. We studied patients with mitral stenosis and AF who were scheduled for PBMV. Electrical cardioversion was performed 1 month after PBMV. Amiodarone 200 mg/day was started the day after PBMV. The primary outcomes studied were the rate of successful cardioversion and the maintenance rate of sinus rhythm at 12 months. Of 272 patients scheduled for PBMV, 70 were enrolled. The average age was 45 +/- 10 years. The average mitral valve area was 0.82 +/- 0.22 cm(2). Cardioversion was successful in 50 patients (71%). Logistic regression analysis revealed that left atrial size and associated aortic valvular disease were predictors of successful cardioversion. Of the 50 patients with successful cardioversion, AF recurred in 24 (48%). An increased left atrial diameter was the only factor associated with AF recurrence at 12 months. In conclusion, good candidates for cardioversion after PBMV were those with a left atrial diameter of <60 mm and no associated aortic valvular disease -- approximately 43% of patients with AF scheduled for PBMV. In this group, about 2/3 were in sinus rhythm at 12 months after cardioversion.

Comparison of acute and long-term effects of single-dose amiodarone and verapamil for the treatment of immediate recurrences of atrial fibrillation after transthoracic cardioversion

Amiodarone and verapamil have been employed to treat immediate recurrences of AF (IRAF) after cardioversion. This study compares the efficacy of these agents for the treatment of IRAF. One hundred and eighty-five patients underwent transthoracic cardioversion (CV) for AF. AF recurred within 10 min in 20 patients (10.8%). These patients were randomized to verapamil (seven patients), or amiodarone (13 patients). After administration of verapamil and repeat CV, five patients (71%) experienced IRAF, compared with seven patients (54%) receiving amiodarone (P = 0.4). Including the results after crossover, IRAF occurred in 8/10 patients (80%) who received verapamil, compared with 7/15 patients (47%) who received amiodarone (P = 0.1). The combination of these agents prevented IRAF in 10/20 patients (50%). After a follow-up of 319+/-189 days, 42% of the IRAF patients treated with verapamil and/or amiodarone remained in sinus rhythm, which did not differ from patients without IRAF (53%, P = 0.7). IRAF occurs in 10% of patients undergoing CV. Amiodarone and verapamil are effective in preventing IRAF and result in a sinus rhythm maintenance rate of 50%. Since there is no difference in the long-term maintenance of sinus rhythm between patients with and without IRAF, attempts to restore sinus rhythm after pharmacological pretreatment are justified.

Left Mitral Isthmus Ablation Associated with PV Isolation: Long‐Term Results of a Prospective Randomized Study

The deployment of an ablation line connecting the left inferior PV to the mitral annulus (mitral isthmus line [MIL]) enhances the efficacy of pulmonary vein disconnection (PVD) in preventing atrial fibrillation (AF) recurrences. To investigate the long-term effect of the additional linear lesion in a prospective randomized study. One hundred and eighty-seven patients (37 females, mean age: 55 +/- 11 years) with paroxysmal (126) or persistent (61 patients) AF, were prospectively randomized into two groups: PVD (group A, 92 patients) or PVD combined with MIL (group B, 95 patients), performed by means of an irrigated-tip ablation catheter. Successful disconnection of all PVs was achieved in all patients. A bidirectional block (BB) along the left atrial isthmus was obtained in 72 of 95 (76%) patients in group B, most of whom required additional RF pulses from within the distal CS. A transient ischemic attack occurred in 1 patient of group A, and a cardiac tamponade occurred in 1 patient of group B. At 1 year, 53 +/- 5% (group A) and 71 +/- 5% (group B) remained arrhythmia free (P = 0.01); subgroup analysis highlights a higher improvement among patients with persistent AF (74 +/- 9% vs 36 +/- 9%; P < 0.01) than what was observed in paroxysmal AF (76 +/- 6% vs 62 +/- 6%; P < 0.05); antiarrhythmic drugs were continued in 56% and 50%, respectively, in groups A and B (P = ns). The addition of mitral isthmus line to the PV disconnection allows a significant improvement of sinus rhythm maintenance rate, particularly in patients with persistent AF, without the risk for major complications.

Identification of Good Responders to Rhythm Control of Paroxysmal and Persistent Atrial Fibrillation by Transthoracic and Transesophageal Echocardiography

Background: Identification of good responders to rhythm control in the management of atrial fibrillation (AF) is worthwhile in terms of increasing hemodynamic benefit and decreasing the likelihood of unstable anticoagulation even after the Atrial Fibrillation Follow-Up Investigation of Rhythm Management. Methods: We tested the hypothesis that atrial substrate determines the risk of recurrence on rhythm control both in patients with paroxysmal AF (PAF) and in those with persistent or sustained AF (≧1 week, SAF). There were 90 consecutive patients (mean age 63 ± 12 years, 67 males and 23 females) with previous PAF (n = 66) or SAF (n = 24). They were maintained in sinus rhythm successfully for at least 1 month after conversion and then studied by transthoracic and transesophageal echocardiography. All of the patients were followed regularly by determination of symptoms, 12-lead ECG and intermittent Holter recording to determine recurrence of AF after echocardiographic study. Results: After 9.1 ± 3.8 (range 3–12) months of follow-up, 23 of the 90 (26%) patients had documented recurrence of AF (67 without recurrence). Univariate analysis of demographic characteristics, medications, ECG and echocardiographic parameters revealed that, compared with the group of patients without recurrent AF, the group of those with it included more members of the SAF group (11/27 vs. 13/67, p = 0.039), included more male subjects (22/23 vs. 45/67, p = 0.045), had a larger left atrial volume index (LAVI; 27 ± 9 vs. 22 ± 9 ml/m², p = 0.024) and had lower LA appendage peak emptying velocity (LAAPEV; 42 ± 15 vs. 55 ± 22 cm/s, p = 0.01). Multivariate Cox proportional hazards regression analysis adjusted for age, gender and AF group revealed that patients with LAVI <30 ml/m² and LAAPEV >46 cm/s had the least recurrence of AF (relative risk 0.18, 95% confidence interval 0.06–0.55, vs. with LAVI >30 ml/m² or LAAPEV <46 cm/s, p = 0.002). Kaplan-Meier probability of freedom from AF recurrence was significantly better when LAVI <30 ml/m² (log-rank p = 0.02), LAAPEV > 46 cm/s (p = 0.013) or both (p = 0.004). The superiority to predict the rate of sinus rhythm maintenance was the same in the PAF and SAF groups. Conclusions: Good responders to rhythm control in the PAF and SAF groups share the characteristics of smaller LA volume and better LAA contractile function, emphasizing the critical role of atrial substrate remodeling in recurrence of AF.

Long-term follow-up after radiofrequency catheter ablation of atrial fibrillation: Role of the acute procedure outcome and of the clinical presentation

This study is a single centre long-term experience on a consecutive cohort of patients with paroxysmal or persistent atrial fibrillation (AF) undergoing electrical disconnection of pulmonary veins (PVs) by means of catheter ablation. Long-term outcome was analyzed in relation to acute procedure success and to the clinical presentation. Two hundred and thirty-four patients (182 males, mean age 55.9+/-10.6 years), affected by paroxysmal (78%) or persistent AF, underwent an electrophysiologically guided isolation of PVs. ECG, Holter and clinical follow-up were obtained at 1, 3, 6 and 12 months. At discharge an antiarrhythmic drug, Flecainide, was given only in cases with incomplete disconnection; Amiodarone was administered in all persistent AF pts. Successful disconnection of all PVs was achieved in 90% of cases. The rate of stable sinus rhythm maintenance was 85%, 74%, 72% and 65% at 1, 3, 6 and 12 months, respectively. The one-year arrhythmia free survival rates were higher among patients with paroxysmal AF (68% vs. 54%, P 0.008), those with complete disconnection of all PVs and in patients younger than 55 years. The electrical disconnection of all the pulmonary veins should be the minimal endpoint of radiofrequency catheter ablation in patients with either paroxysmal or persistent AF. Incomplete disconnection of the PVs is predictive of recurrence. Long-term results of the ablation procedure were significantly better in patients with paroxysmal AF.

Hyperthyroidism and the management of atrial fibrillation.

Atrial fibrillation is often induced in patients with hyperthyroidism and may trigger heart failure. Its prevalence and outcome were examined to obtain up-to-date information. Persistent atrial fibrillation was observed in approximately 1.7% of new hyperthyroid patients. It occurs more frequently in males (2.86%) than in females (1.36%), even though the number of male hyperthyroid patients is only one fifth of female patients. The rate increased with age, being 8% in the patients older than 70 years old. The initial treatment is to control the heart rate with routine pharmacologic therapy and to start antithyroid therapy as quickly as possible. Attempted cardioversion should be deferred until approximately the fourth month of maintaining a euthyroid state, because more than 56% of atrial fibrillation spontaneously reverts to sinus rhythm when the thyroid hormone levels start to decline. Elective cardioversion for those whose atrial fibrillation persists is highly effective and sinus rhythm maintenance rates were 56.7% and 47.6% at the 10th and the 14th year, respectively, even though the duration of atrial fibrillation prior to cardioversion was extremely long (35.0 +/- 29.0 months).

Effects of Pulmonary Vein Isolation Using Intraoperative Radiofrequency Catheter Ablation for the Treatment of Atrial Fibrillation Associated with Mitral Valvular Heart Diseases

Background and Objectives:The pulmonary veins and surrounding ostial areas frequently house focal triggers or reentrant circuits critical to the genesis of atrial fibrillation (AF). The purpose of this study was to assess the efficacy of pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, for the treatment of AF associated with mitral valvular heart disease. Subjects and Methods:32 consecutive patients with AF associated with mitral valvular disease, requiring mitral valvular replacement or valvuloplasty were included. We divided these patients into two groups. The first group, PVI, consisted of 16 patients that had mitral valvular operations with intraoperative radiofrequency pulmonary vein isolation, and the other 16 patients, the controls, had mitral valvular operation only. The conversion rate to sinus rhythm and other clinical data were compared between the two groups. Results:Circumferential pulmonary vein isolation, with radiofrequency catheter ablation, was achieved in an average of 15±3 min. There were no mortalities or morbidities associated with this procedure. In the immediate postoperative period, the conversion rate to normal sinus rhythm in the PVI group was significantly higher than in the controls (81% vs. 37.5% p=0.016). After 21±4 weeks of follow up, the sinus rhythm maintenance rates in PVI group was also significantly higher than those of the control group (75% vs. 31.2% p=0.01). Conclusion:Circumferential pulmonary vein isolation, aided by intraoperative radiofrequency catheter ablation, is simple and effective for the treatment of chronic atrial fibrillation associated with mitral valvular disease. (Korean Circulation J 2002;32(7):596-603)

Survival and sinus rhythm maintenance after modified Cox/maze procedure and mitral valve operation in patients with chronic atrial fibrillation.

Sinus rhythm gained after the Cox/maze procedure concomitant with mitral valve operation has demonstrated long-term attrition during the follow-up, no information exists on whether the type of mitral valve operation--(repair vs. replacement)--affects this sinus rhythm maintenance rate. We retrospectively studied patients undergoing concomitant mitral valve operation and Cox/maze procedure to answer this question. Between April 1993 and August 1995, 87 consecutive patients--35 men and 52 women (mean age: 59.3 years)--with chronic atrial fibrillation and mitral valve disease underwent the modified Cox/maze procedure and concomitant mitral valve operation, with 56 having mitral valve repair (repair group) and 31 mitral valve replacement (replacement group). Patients were followed up and changes in rhythm studied retrospectively. Follow-up for a mean 51.3 +/- 11.6 months was completed in 82 of 83 long-term survivors (99%). Repair group surgery survival was 98.1 +/- 1.9% at 1 year and 94.2 +/- 3.2% at 5 based on the Kaplan-Meier method. Replacement group surgery survival was 85.7 +/- 5.9% at 1 year and 82.9 +/- 6.4% at 5. Probability in sinus rhythm maintenance for the repair group at 1 year was 88.6 +/- 5.4% and at 5 years was 67.6 +/- 9.1%. Probability in sinus rhythm maintenance for the replacement group at 1 year was 95.7 +/- 4.3% and at 5 years was 65.0 +/- 11.1%. Medium-term results after the Cox/maze III procedure concomitant with mitral valve operation are good. The attrition of sinus rhythm maintenance appears similar by the completion of 5-year follow-up.

High maintenance rate of sinus rhythm after cardioversion in post-thyrotoxic chronic atrial fibrillation

We performed rhythm conversion on 33 euthyroid patients with post-thyrotoxic atrial fibrillation who do not revert spontaneously to sinus rhythm from atrial fibrillation. The duration of atrial fibrillation ranged from 9 to 59 months (mean 25 ± 14). The protocol of rhythm conversion was to first attempt pharmacological conversion with disopyramide and then to perform electrical cardioversion on the non-converters. Of 33 patients, 25 were converted to sinus rhythm (6 by disopyramide and 19 by electrical cardioversion), resulting in 8 non-converters. However, it was later discovered that cardioversion had been applied to 4 of the 8 non-converters when these patients had had a recurrence of thyrotoxicosis. These 4 patients were subjected to a second electrical cardioversion after attaining the euthyroid state. Sinus rhythm was restored in all 4 patients, giving a cardioversion rate of 88%. The sinus rhythm was maintained in 25 of the total 29 converters (86%) at the time of follow-up (10–68 months, mean 35 ± 19 months). Our studies suggest that cardioversion should be encouraged for thyrotoxic atrial fibrillation, even if the duration of atrial fibrillation is long-standing, since there is excellent maintenance of sinus rhythm and even delayed application of cardioversion may improve its success rate.

Long-term results of direct-current cardioversion after open commissurotomy for mitral stenosis

For a 7-year period, cardiac rhythm before and after surgery was determined in 106 patients with mitral stenosis presenting with atrial fibrillation (AF) who had undergone open mitral commissurotomy. Forty-three of the patients reverted to sinus rhythm (SR) after primary or secondary direct-current (DC) cardioversion after surgery and maintained it until discharge from hospital. Thirty patients maintained SR for 3 months to 7.2 years (mean 2.5 years) after surgery. The actuarial maintenance rate of SR was 50% 7 years after surgery in these 43 patients. The duration of AF, preoperative left atrial dimension by M-mode echocardiogram and pathologic classification of the mitral valve were factors supposedly influencing the maintenance of SR for a long period after DC cardioversion. In 30 patients who reverted back to SR and maintained SR late postoperatively, the preoperative duration of AF was up to 5 years, and 35% of the patients had had AF for more than 1 year. Also, in 40% of these 30 patients, the preoperative cardiothoracic ratio was more than 60%. It is concluded that if sinus rhythm is restored by DC cardioversion before discharge from hospital after open mitral commissurotomy, it has a 50% chance of being maintained for 7 years after surgery. Long duration of AF and large cardiothoracic ratio should probably not dissuade one from attempting secondary DC cardioversion in these patients.

Pharmacy Art at Canadian Meeting

Electrical cardioversion is widely used to restore sinus rhythm in patients with atrial fibrillation. However, the long term clinical event and sinus rhythm maintenance rates following electrical cardioversion still remains unclear. This study evaluated one year incidence and risk factors for cardiovascular events and atrial fibrillation recurrence in a single center clinical practice.In a prospective study 188 patients with atrial fibrillation who underwent electrical cardioversion were enrolled. Patients and their primary care physicians were followed up one year after cardioversion and patient clinical and arrhythmic event rate was evaluated. Data obtained from patients and general practitioners were combined and the results were analyzed with PSPP 0.8.5 software.Electrical cardioversion success rate was 90.4%. Within a year after cardioversion one patient (0.6%) suffered myocardial infarction, three patients (1.9%) had a stroke/transitory ischemic attack (TIA), three patients (1.6%) died and three patients (1.9%) had a bleeding event that required hospitalization. The presence of diabetes mellitus was the only factor with a tendency to increase the risk of combined event of myocardial infarction, stroke/TIA and bleeding (P = 0.096). At follow up 30.0% of patients reported having atrial fibrillation and within a year 62.2% had suffered at least one atrial fibrillation paroxysm. The proportion of patients who underwent additional cardioversions after the initial hospitalization was 32.5%. The factors that significantly increased the risk of atrial fibrillation recurrence were history of stroke/TIA (P = 0.014) and increased left atrial volume index on echocardiography (P = 0.039). Greater left atrial diameter had a tendency toward an increased risk (P = 0.087).Cardiovascular event rate one year after electrical cardioversion was low. Electrical cardioversion had a high immediate success rate, however, maintenance of stable sinus rhythm in the long term was low.