Transoesophageal echocardiography-guided cardioversion of atrial fibrillation or flutter. Selection of a low-risk group for immediate cardioversion.

AIMS: Despite exclusion of left atrial thrombi by transoesophageal echocardiography, cardioversion-related thromboembolism has been reported in atrial fibrillation or flutter. To define a low-risk group for cardioversion without previous anticoagulation, patients were selected for immediate cardioversion if there were no thrombi, no echo spontaneous contrast and the outflow velocity of the left atrial appendage was greater than 0.25 m. s(-1)on transoesophageal echocardiography. METHODS AND RESULTS: Two hundred and forty-two consecutive patients referred for cardioversion of atrial fibrillation or flutter with a duration of more than 2 days and no anticoagulation therapy were examined with transoesophageal echocardiography. After the transoesophageal echocardiography examination, patients who were eligible for immediate cardioversion were anticoagulated with low molecular weight heparin (dalteparin) subcutaneously, together with warfarin prior to cardioversion. Dalteparin treatment was continued until the patient had reached therapeutic prothrombin values. Based on the transoesophageal echocardiographic findings the patients were divided into two groups: immediate cardioversion, group A, with a mean age of 62+/-13 years (n=162); or conventional warfarin treatment before cardioversion, group B, with a mean age of 67+/-10 years (P<0.05) (n=80). In group A, lone atrial fibrillation or flutter was more common (53%; 95% CI: 45-61) compared to group B (34%; 95% CI: 23-44, P<0.05), while heart disease was more common in group B (45%; 95% CI: 34-56) compared to group A (31%; 95% CI: 24-39, P<0.05). Echocardiography revealed thrombi in 5% (95% CI: 2.6-8) of the patients, left atrial size was larger, fractional shortening lower, and a higher proportion had impaired left ventricular function in group B. No thromboembolic event occurred at or after cardioversion in any of the patients; however, before planned cardioversion one transitory ischaemic attack, one lethal stroke and one cardiac death occurred in three of the patients with thrombi despite warfarin therapy. One-month follow-up maintenance of sinus rhythm was 75% in group A compared to 45% in group B (P<0.01). CONCLUSION: After using our transoesophageal echocardiographic exclusion criteria (no thrombi, no spontaneous echo contrast and left atrial appendage outflow velocity > or = 25 m. s(-1)) cardioversion can safely be performed in 2/3 of patients with atrial fibrillation or flutter without previous anticoagulation therapy. These patients maintained sinus rhythm significantly better after 1 month compared to patients with prolonged warfarin therapy before cardioversion.     

Oral anticoagulation in surgical procedures: risks and recommendations

Surgery in anticoagulated patients is problematic. Coumarin therapy is often discontinued or reversed to reduce the perioperative bleeding risk. Meanwhile, the thromboembolic risk is enhanced. We sought to determine the frequency of bleeding and thromboembolism in anticoagulated patients undergoing routine surgery and to investigate the role of patient characteristics and the level of anticoagulation. We studied patients who attended the Leiden Anticoagulation Clinic for treatment relating to mechanical heart valve prostheses, atrial fibrillation or myocardial infarction and underwent surgery at the Leiden University Medical Centre between 1994 and 1998. Outcome events were bleeding and thromboembolism in the perioperative period. Seventy-two complications occurred in 603 interventions, yielding an overall frequency of 11.9% [95% confidence interval (CI): 9.3-14.9], 9.5% (n = 57) for haemorrhage and 2.5% (n = 15) for thromboembolism. Younger patients tended to have more complications [odds ratio (OR) for >65 years of age: 0.5, 95% CI 0.3-1.0] as did patients with atrial fibrillation (OR for atrial fibrillation versus mechanical heart valve prostheses: 1.8, 95% CI 0.8-4.2). High postoperative levels of anticoagulation were associated with a slightly increased risk of complications [OR international normalized ratio (INR) > 3 vs. INR < 2: 1.3, 95% CI 0.6-3.0]. We conclude that routine surgery in anticoagulated patients yields a high perioperative bleeding and thromboembolic risk. While neither patient characteristics nor the level of anticoagulation appeared to play a major role in the occurrence of complications, the risk was clearly associated to the type of surgery, with the highest risk in thoracic surgery.     

Restoring sinus rhythm improves excessive heart rate response to exercise in patients with atrial fibrillation

The aim of this study was to investigate improvement in the cardiovascular response to isometric and isotonic exercises after reverting rhythm to sinus in patients with atrial fibrillation. Twenty seven cases with nonvalvular paroxysmal atrial fibrillation were included in the study. Sinus rhythm could not be restored in two cases so they were excluded. The remaining cases were divided into two groups according to the existence of cardiac diseasc. Group 1 (n:14, mean age. 60.8 +/- 14.9 years) included cases with cardiac diseases (8 of the patients had hypertension in addition to the cardiac disease) and group 2 (n:11, mean age. 64.8 +/- 13.9 years) included those without cardiac disease (patients with hypertension and diabetes mellitus). Isometric and isotonic exercise tests were performed in all of the patients before and 48 hours after the rhythm was reverted to sinus and the values in atrial fibrillation were compared with those in sinus rhythm (following cardioversion). The isotonic exercise period increased significantly in only group 1 patients following cardioversion (P = (0.0061). In both groups, the increase in heart rate during atrial fibrillation was significantly higher compared to those after being reverted to sinus, at all stages of the isotonic exercise (in groups 1 and 2, heart rate in patients with atrial fibrillation increased from 96.5 +/- 19.3 to 173.3 +/- 19.3 beats/min and 96.1 +/- 12.6 to 185.0 +/- 12.1 beats/ min, respectively; and in sinus rhythm, it ranged from 85.1 +/- 11.4 to 164.6 +/- 9.1 beats/min and 81.3 +/- 11.4 to 157.6 +/- 15.1 beats/min, respectively). Systolic arterial pressure increased significantly during atrial fibrillation in group 1, at the 2nd stage of the isotonic exercise test (P = 0.0070). In group 2, systolic arterial pressure increased significantly at the 3rd stage in sinus rhythm and at the 4th stage when in rhythm in atrial fibrillation. Also, diastolic arterial pressure increased significantly during atrial fibrillation only at the 3rd stage of the exercise. As a result, restoring sinus rhythm by cardioversion improves excessive heart rate responses to exercise significantly in patients with atrial fibrillation during both isometric and isotonic exercises. Also, we have revealed that the exercise time increased significantly by restoring sinus rhythm in patients with heart disease.     

Predictors of left atrial appendage clot: a transesophageal echocardiographic study of left atrial appendage function in patients with severe mitral stenosis

BACKGROUND: The purpose of this study was to prospectively evaluate a large group of consecutive, non-anticoagulated patients with severe rheumatic mitral stenosis and to analyze the left atrial appendage function in relation to left atrial appendage clot and spontaneous echo contrast formation. METHODS AND RESULTS: We prospectively studied left atrial appendage function in 200 consecutive patients with severe mitral stenosis who underwent transesophageal echocardiography and correlated it with spontaneous echo contrast and left atrial appendage clot. The mean age was 30.2 +/- 9.4 years. Fifty-five (27.5%) patients were in atrial fibrillation. Left atrial appendage clot was present in 50 (25%) patients and 113 (56.5%) had spontaneous echo contrast. The older age, increased duration of symptoms, atrial fibrillation, spontaneous echo contrast, larger left atrium, depressed left atrial appendage function and type II and III left atrial appendage flow patterns correlated significantly (p<0.05) with the left atrial appendage clot. Left atrial appendage ejection fraction was significantly less in patients with clot (21.8 +/- 12.8% v. 39.1 +/- 13.2%, p<0.0001) and in those with spontaneous echo contrast (30.3 +/- 16.2 % v. 40.3 +/- 11.8%, p<0.001). Left atrial appendage filling (18.0 +/- 11.7 v. 27.6 +/- 11.8 cm/s, p <0.0001) and emptying velocities (15.4 +/- 7.0 v. 21.5 +/- 9.6 cm/s, p<0.001) and filling (1.4 +/- 1.0 v. 2.5 +/- 1.4 cm, p<0.0001) and emptying (1.5 +/- 1.2 v. 2.1 +/- 1.2 cm, p <0.05) velocity time integrals were also significantly lower in patients with clot as compared to those without clot. On multivariate regression analysis, atrial fibrillation (odds ratio 6.68, 95% CI 1.85-24.19, p=0.003) and left atrial appendage ejection fraction (odds ratio 1.06, 95% CI 1.00 - 1.11, p=0.04) were the only two independent predictors of clot formation. Incidence of clot was 62.59% in patients with left atrial appendage ejection fraction < or = 25% as compared to 10.4% in those having left atrial appendage ejection fraction >25%. Similarly patients with spontaneous echo contrasthadlower filling (21.7 +/- 11.5 v. 29.4 +/- 12.7 cm/s, p<0.0001) and emptying (17.0 +/- 8.1 v. 23.9 +/- 10.9 cm/s, p<0.0001) velocities, as well as filling (1.9 +/- 1.3 v. 2.7 +/- 1.3 cm, p<0.01) and emptying (1.7 +/- 1.0 v. 2.3 +/- 1.4 cm, p<0.01) velocity time integrals as compared to patients without spontaneous echo contrast. In a subgroup of the patients with normal sinus rhythm, the left atrial appendage ejection fraction was significantly less in patients with clot compared to those without clot (31.2 +/- 13.2 v. 41.3 +/- 11.5 %, p<0.01). CONCLUSIONS: In the patients with severe mitral stenosis, besides atrial fibrillation, a subgroup of patients in normal sinus rhythm with depressed left atrial appendage function (left atrial appendage ejection fraction < or = 25%) had a higher risk of clot formation in left atrial appendage and these patients should be routinely anticoagulated for prevention of clot formation.     

Effect of acute atrial fibrillation on phasic coronary blood flow pattern and flow reserve in humans.

AIMS: To assess the effect of experimentally induced atrial fibrillation on coronary flow in humans. METHODS AND RESULTS: In 16 patients (10 men, mean age 43+/-13 years) with normal coronary vessels, baseline and hyperaemic blood pressure and Doppler phasic coronary flow velocity were measured, using a 0.014 inch intracoronary Doppler flow wire, during sinus rhythm, experimentally induced atrial fibrillation, and right atrial pacing at a similar heart rate to that during atrial fibrillation. Coronary flow velocity integral per minute increased significantly during both right atrial pacing and atrial fibrillation compared to sinus rhythm, but during right atrial pacing the increase was greater (85+/-43% vs 52+/-25%, P<0.001). This difference persisted even after correction for the product of heart rate and blood pressure (1.15+/-0.51 vs 0.97+/-0.46, respectively, P<0.02). In a further 12 paced patients (seven men, mean age 54+/-10 years) with complete atrioventricular block the induction of atrial fibrillation (atrial fibrillation with regular RR interval) caused no significant changes in coronary flow velocity variables. CONCLUSIONS: Acute atrial fibrillation in humans causes an increase in coronary flow that is, however, insufficient to compensate for the augmented myocardial oxygen demand, mainly because of the irregularity in the ventricular rhythm that exists during atrial fibrillation.     

Deleterious effects of long-term single-chamber ventricular pacing in patients with sick sinus syndrome: the hidden benefits of dual-chamber pacing.

Nine hundred fifty patients who received three modes of primary pacemaker systems (581 dual-chamber universal [DDD], 84 atrioventricular-sequential ventricular-inhibited [DVI] and 285 ventricular-inhibited [VVI]) over 12 years were studied retrospectively to determine the effect of pacing mode on patient longevity and the subsequent development of chronic atrial fibrillation or flutter. All patients were followed up continuously for 7 to 8 years. Patients were classified according to indication for permanent pacing (sick sinus syndrome or other indication), age at pacemaker implantation (less than or equal to 70 or greater than 70 years) and history of atrial tachyarrhythmia. Fourteen percent of patients developed atrial fibrillation at some time during the study period. Of those, 4% had a DDD pacemaker, 8% had a DVI pacemaker and 19% had a VVI pacemaker. At 7 years, atrial fibrillation was significantly more frequent in the VVI group than in the DDD and DVI groups. In patients with sick sinus syndrome, the incidence rate was even higher in the VVI group but approximately the same in the DDD and DVI groups. Patients in the VVI and DVI groups who had had previous atrial tachyarrhythmia had a significantly higher incidence of atrial fibrillation at 7 years than did those in the DDD group. During the entire period there were 130 deaths in the study group, including 22% of patients with a DDD pacemaker, 38% of those with a DVI pacemaker and 50% of those with a VVI pacemaker. Patient survival at 7 years was lower in the VVI group than in the DDD or DVI groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effectiveness and safety of d,l-sotalol in the ambulatory treatment of atrial fibrillation and flutter]

Data on short and long term efficacy and safety of d,l sotalol in patients with atrial fibrillation or atrial flutter is limited. The aims of this study were to (1) assess the antiarrhythmic efficacy of d,l sotalol maintaining normal sinus rhythm in patients with refractory atrial fibrillation or flutter, (2) evaluate the efficacy of d,l sotalol in preventing recurrences of paroxysmal atrial fibrillation or flutter, (3) evaluate the control of ventricular rate in patients with paroxysmal or refractory atrial fibrillation or flutter unsuccessfully treated with other antiarrhythmic agents, (4) determine predictors of efficacy (5) assess the safety of d,l sotalol in this setting. Two hundred patients with chronic or paroxysmal atrial fibrillation or atrial flutter or both, who had failed one to six previous antiarrhythmic drug trials were treated with d,l sotalol 80 to 440 mg/day orally. Fifty four percent was female, age 47 +/- 16 years (range 7-79), follow up period 7 +/- 7 months (range 1 to 14 months), 79% of patients had the arrhythmia for more than one year. The atrial fibrillation in 37.5% of patients was chronic and paroxysmal in 23.5. The atrial flutter was chronic in 31% of patients and paroxysmal in 8%. Eighty two percent of patients was in functional class I (NYHA) and 82% had cardiac heart disease: left atrial (LA) size 44 +/- 10 mm, right atrial (RA) size 37 +/- 7 mm and left ventricular ejection fraction (LVEF) 58 +/- 8%. Total success was achieved in 58% of patients (atrial fibrillation 40% and 18% in atrial flutter), partial success in 38% (atrial fibrillation in 18% and 20% in atrial flutter) and 4% of patients failure. It was p < 0.07 when compared total success vs partial success among atrial fibrillation and atrial flutter groups. Patients with cardiac heart disease responded worst (p = 0.10) to the drug than those without it, specially if the heart was dilated. We concluded that d,l sotalol has moderate efficacy to convert and maintain normal sinus rhythm, as well as it acts controlling paroxysmal relapses and ventricular heart rate.     

Bipolar atrial sensing thresholds in sinus rhythm and atrial tachyarrhythmias. A comparative analysis in patients with DDDR pacemakers.

Automatic mode switching (AMS) function in dual chamber pacemakers depends on adequate detection of atrial tachyarrhythmias. There are few data on showing how intra-operative atrial signal amplititude during sinus rhythm can predict atrial tachyarrhythmias after pacemaker implantation. In 43 patients undergoing DDDR pacemaker implantation and atrioventricular nodal ablation for the treatment of drug-refractory paroxysmal atrial fibrillation, atrial sensing thresholds during sinus rhythm and during induced atrial tachyarrhythmias (24-48 h after device implantation) were analysed. Five different DDDR pacemaker systems were implanted (Chorus 7034, Ela Medical n = 13; Meta DDDR 1254, Telectronics Pacing Systems n = 12; Vigor DR 1230, Guidant n = 6; Trilogy DR 2364, Pacesetter, n = 2; Kappa DR 401, Medtronic USA n = 10). Every patient received a steroid-eluting, screwing, bipolar atrial lead (Medtronic, Capsure-Fix 4068). The mean P wave amplitude during implantation was 3.91 +/- 1.14 mV. The mean atrial sensing threshold during sinus rhythm and during all modes of induced atrial tachyarrhythmias was 3.35 +/- 1.0 mV, and 1.52 +/- 0.92 mV, respectively (P < 0.001). Atrial fibrillation was induced in 36 patients. The mean sensing threshold during sinus rhythm in this patient group was 3.39 +/- 1.01 mV, the mean sensing threshold during atrial fibrillation was 1.27 +/- 0.56 mV, reflecting a 63% reduction of sensing threshold compared with sinus rhythm (P < 0.001). Atrial flutter was induced in seven patients. The mean sensing threshold during sinus rhythm was 2.92 +/- 1.19 mV, the mean sensing threshold during atrial flutter was 2.79 +/- 1.26 mV, reflecting a reduction of 5% (ns) compared with sinus rhythm. Atrial sensing thresholds during sinus rhythm were significantly correlated with sensing thresholds during atrial tachyarrhythmias (r = 0.44; P < 0.002), but there were significant variations in intra-individual results. The reduction of atrial sensing thresholds between sinus rhythm and induced atrial tachyarrhythmias ranged from 30% to 82%. CONCLUSION: Bipolar atrial sensing thresholds during sinus rhythm are correlated with sensing thresholds during atrial tachyarrhythmias, but there is a large degree of variance in individual patients. A 4:1 to 5:1 atrial sensing safety margin based on sensing threshold during sinus rhythm is a predictor for adequate postoperative detection of atrial tachyarrhythmias and the function of AMS devices.     

Prevalence and incidence of cardiovascular disease in 1160 older men and 2464 older women in a long-term health care facility.

BACKGROUND: We report the prevalence and incidence of cardiovascular disease in older men and women in a long-term health care facility. METHODS: The prevalence of hypertension, chronic atrial fibrillation, pacemaker rhythm, coronary artery disease (CAD), thromboembolic stroke, and symptomatic peripheral arterial disease (PAD) and the incidence of new coronary events, thromboembolic stroke, and congestive heart failure (CHF) were investigated in 1160 men, mean age 80 +/- 8 years, and in 2464 women, mean age 81 +/- 8 years, in a long-term health care facility. Mean follow-up was 46 +/- 30 months. RESULTS: The prevalences of hypertension, pacemaker rhythm, CAD, and thromboembolic stroke were similar in men and women. The prevalence of atrial fibrillation was higher in men (16%) than in women (13%; p =.019). The prevalence of PAD was higher in men (32%) than in women (26%; p =.0001). At the 46-month follow-up, the incidences of new coronary events, thromboembolic stroke, and CHF were similar in men and women. CONCLUSIONS: Older men and women in a long-term health care facility have a high prevalence and incidence of cardiovascular disease. The prevalences of hypertension, pacemaker rhythm, CAD, and thromboembolic stroke and the incidences of new coronary events, thromboembolic stroke, and CHF were similar in men and women. However, the prevalences of atrial fibrillation and of PAD were higher in men than in women.     

Pharmacological cardioversion with intravenous propafenone in atrial fibrillation

The efficacy and safety of intravenous propafenone for conversion of recent-onset and chronic atrial fibrillation was assessed in 46 patients. 40 with atrial fibrillation associated with or without structural heart disease (mean age 63 +/- 14 years) and 6 patients with atrial fibrillation related to the Wolff-Parkinson-White syndrome (mean age 34.8 +/- 13 years). Propafenone treatment was administered at 2 mg/kg over 15 minutes under continuous electrocardiographic monitoring. In 28 of 32 (87.5%) patients with paroxysmal and/or recent-onset atrial fibrillation a stable sinus rhythm was restored within 1 hour after propafenone (mean 17 +/- 11 minutes) and in only 3 of 8 (37.5%) with chronic atrial fibrillation (p < 0.05). Conversion to sinus rhythm was obtained in 5 of 6 (83.3%) patients with atrial fibrillation related ventricular preexcitation, mean time 21 +/- 12 minutes. Propafenone had an additional effect reducing mean heart rate (141 +/- 21 to 102 +/- 15 beat per minute, p < 0.05) and the shortest preexcited R-R intervals was increased, mean 231.6 +/- 27.8 to 355 +/- 37.2 milliseconds (p < 0.001) in cases associated with ventricular preexcitation. Dizziness, hypotension and transient conduction disturbances occurred in only one patient with rheumatic valvular heart disease: EF 40%. Propafenone is an effective and safe antiarrhythmic drug for converting paroxysmal and/or recent-onset atrial fibrillation of various origins with a more limited efficacy in chronic atrial fibrillation.     

The predictive factors for cerebral infarction in patients with non-rheumatic atrial fibrillation

To investigate possible factors predicting cerebral infarction (CI) in patients with non-rheumatic atrial fibrillation, we reviewed the clinical records of 79 patients in whom conversion from sinus rhythm to persistent atrial fibrillation was confirmed by serial electrocardiographic tracings. The patients averaged 68.4 years in age and their average observation period after transition to persistent atrial fibrillation was 4.1 years. During the observation period, 20 patients developed CI. CI occurred in 10 of 22 patients with hypertensive heart disease, but in only three of 30 patients with lone atrial fibrillation and the difference was statistically significant (p less than 0.01). We compared demographic and pathophysiologic factors recorded at the onset of fixed atrial fibrillation between groups with and without CI. There were no significant differences in age, sex, smoking habits, diabetic complications and serum cholesterol level, but hematocrit level was significantly higher in patients with CI than in those without CI (45.3 +/- 3.2% vs 42.3 +/- 4.4%, p less than 0.01). The cardiothoracic ratio was not significantly different, but echocardiographic left atrial dimension was significantly greater in patients with CI than in those without CI (43.7 +/- 3.3 mm vs 38.6 +/- 5.8 mm, p less than 0.01). The left ventricular ejection fraction was significantly lower in patients with CI than in those without CI (62.2 +/- 16.6% vs 72.9 +/- 8.2%, p less than 0.05) and congestive heart failure was significantly more frequent in patients with CI than in those without CI (40.0% vs 13.6%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Restoration of sinus rhythm with flecainide in patients with atrial fibrillation

The efficacy of flecainide acetate for conversion of atrial fibrillation into sinus rhythm was assessed in 69 patients (mean age of 63 +/- 14 years). Mean duration of the arrhythmia was 49 +/- 45 days. Mean cardiothoracic index was 0.49 +/- 0.03. Flecainide treatment was started intravenously with a bolus of 2 mg/kg over 10 minutes, followed by oral treatment (200 to 300 mg/day) according to body weight. Conversion to sinus rhythm was obtained in 49 patients (71%). The mean delay between initiation of treatment and restoration of sinus rhythm was 301 minutes (range 5 to 1,600). The left atrial diameter was smaller (40 +/- 1 mm) in patients who had successful cardioversion than in those who did not (46 +/- 1 mm) (p less than 0.05). Patients with atrial fibrillation lasting for less than 10 days had a higher conversion rate (79%) than patients with long-standing atrial fibrillation, in whom the conversion rate was only 38% (p less than 0.05). Conversion to sinus rhythm occurred in 33 patients during the first 5 minutes after injection. Adverse effects necessitated discontinuation of treatment in 4 patients (5.8%). Gastrointestinal disorders and dizziness occurred in 5 other patients but did not necessitate discontinuing treatment. In conclusion, flecainide is an effective drug for converting atrial fibrillation into sinus rhythm. Unlike quinidine, flecainide can be administered intravenously. The conversion rate with flecainide is higher in patients with a shorter duration of atrial fibrillation and smaller atria.     

Low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion: results and long-term follow-up.

AIM: Low-energy internal cardioversion is a new electrical treatment for patients with persistent atrial fibrillation. This paper evaluates the efficacy and safety of low-energy internal cardioversion in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion, and the clinical outcome of such patients. METHOD AND RESULTS: The study population consisted of 55 patients [32 male, mean age 65 +/- 10 years, 48 (87%) with underlying heart disease] with long-lasting (mean 18 +/- 34 months) atrial fibrillation in whom external cardioversion had failed to restore sinus rhythm. Two custom-made catheters were used: one positioned in the right atrium and one in the coronary sinus or the left pulmonary artery. A standard catheter was inserted into the right ventricular apex to provide R wave synchronization. Sinus rhythm was restored in 52 patients (95%) with a mean defibrillating energy of 6.9 +/- 2.6 J (320 +/- 60 V). No complications were observed. During follow-up (mean 18 +/- 9 months), 16 patients (31%) suffered early recurrence (< or = 1 week) of atrial fibrillation and 20 patients (38%) had late recurrence (> 1 week, mean 3.5 +/- 3.6 months) of atrial fibrillation. Six patients with a late recurrence again underwent cardioversion and five of these maintained sinus rhythm. Therefore, a total of 21/52 patients (40%) were in sinus rhythm at the end of follow-up. No clinical difference was found between patients with and without recurrences. CONCLUSIONS: Low-energy internal cardioversion is a useful means of restoring sinus rhythm in patients with long-lasting atrial fibrillation refractory to external electrical cardioversion. More than one-third of patients maintained sinus rhythm during long-term follow-up.     

Left Versus Bi-Atrial Intraoperative Saline-Irrigated Radiofrequency Modified Maze Procedure for Atrial Fibrillation

BACKGROUND: This study was conducted to evaluate the effectiveness of the saline-irrigated radiofrequency modified maze operation for the treatment of chronic atrial fibrillation (AF) and compare the results of the left and bi-atrial procedures. MATERIAL AND METHOD: During a period of two years, 105 patients with chronic AF having concomitant cardiac surgery underwent the procedure. Patients underwent either a bi-atrial ( n = 48) or left atrial ( n = 57) maze procedure. The first twenty patients underwent a bi-atrial maze procedure regardless of the pathology. In the following patients we adopted the bi-atrial approach in patients with a history of atrial flutter and where the right atrium has to be opened. Otherwise the procedure is restricted to the left atrial side. Mean age was 52 +/- 11 years in bi-atrial group and 54 +/- 9 years in left atrial group. RESULTS: Three patients died early postoperatively (2.9%). There were 4 revisions for bleeding (3.8%). Two patients in bi-atrial group received a permanent pacemaker (4.1%). Patients in both groups were free of AF at the end of the procedure. (Bi-atrial group: sinus: 79.2%, pacemaker: 20.8%), (Left atrial group: sinus: 82.5%, pacemaker: 17.5%) ( p > 0.05). During the last follow-up, sinus rhythm was maintained in 79.6% of cases in bi-atrial group, while this rate was 75.6% in left atrial group ( p > 0.05). CONCLUSION: Saline irrigated radiofrequency modified maze procedure was performed safely and efficiently. Both the left and bi-atrial procedures were successful in terms of restoring sinus rhythm. Our current policy is to adopt the bi-atrial approach in patients with a history of atrial flutter and where the right atrium has to be opened. Otherwise the procedure is restricted to the left atrial side.     

Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. OBJECTIVE: The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. PATIENTS AND METHODS: One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. RESULTS: Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, p<0.0001; Mean PicV: 44 +/- 15.8 vs. 31.4 +/- 13,7 cm/s, p<0.0001). This difference was maintained on multivariate analysis (p=0.002 for SOG and p=0.005 for PicV). In patients with recent atrial fibrillation, only left atrial area can predict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and PeV for conversion of atrial fibrillation into sinus rhythm are respectively 25 cm2 and 20 cm/sec. In patients who converted into sinus rhythm; LAA predict maintenance of sinus rhythm at the end of 12 months of survey (p=0.04) with a threshold value of 25 cm2. In the subgroup of patients admitted with chronic atrial fibrillation, PeV predicts better the maintenance of sinus rhythm (p=0.05) with a threshold value of 60 cm/sec, p=0.06; whereas LAA remains better in patients with a recent atrial fibrillation. (p=0.02). CONCLUSION: In addition to the anatomic study of cardiac structure and the search of intracavitary thromboses before reduction of atrial fibrillation, echocardiography allows prediction of cardioversion success (LAA and PeV) and maintenance of sinus rhythm within 12 months.     

Rate control vs rhythm control in patients with nonvalvular persistent atrial fibrillation: the results of the Polish How to Treat Chronic Atrial Fibrillation (HOT CAFE) Study

STUDY OBJECTIVES: The relative risks and benefits of strategies of rate control vs rhythm control in patients with atrial fibrillation (AF) remain to be fully explored. DESIGN: The How to Treat Chronic Atrial Fibrillation (HOT CAFE) Polish trial was designed to evaluate in a randomized, multicenter, and prospective manner the feasibility and long-term outcomes of rate control vs rhythm control strategies in patients with persistent AF. PATIENTS: Our study population comprised 205 patients (134 men and 71 women; mean [+/- SD] age, 60.8 +/- 11.2 years) with a mean AF duration of 273.7 +/- 112.4 days. The mean observation period was 1.7 +/- 0.4 years. One hundred one patients were randomly assigned to the rate control group and received rate-slowing therapy guided by repeated 24-h Holter monitoring. Direct current cardioversion and atrioventricular junctional ablation with pacemaker placement were alternative nonpharmacologic strategies for patients with tachycardia that was resistant to medical therapy. One hundred four patients were randomized to sinus rhythm restoration and maintenance using serial cardioversion supported by a predefined stepwise antiarrhythmic drug regimen (ie, disopyramide, propafenone, sotalol, and amiodarone). In both groups, thromboembolic prophylaxis followed current guidelines. MEASUREMENTS AND RESULTS: At the end of follow-up, 63.5% of patients in the rhythm control arm remained in sinus rhythm. No significant differences in the composite end point (ie, all-cause mortality, number of thromboembolic events, or major bleeding) were found between the rate control group and the rhythm control group (odds ratio, 1.98; 95% confidence interval, 0.28 to 22.3; p > 0.71). The incidence of hospital admissions was much lower in the rate control arm (12% vs 74%, respectively; p < 0.001). New York Heart Association functional class improved in both study groups, while mean exercise tolerance, as measured by the maximal treadmill workload, improved only in the rhythm control group (5.2 +/- 5.1 vs 7.6 +/- 3.3 metabolic equivalents, respectively; p < 0.001). The rhythm control strategy led to an increased mean left ventricular fractional shortening (29 +/- 7% vs 31 +/- 7%, respectively; p < 0.01). One episode of pulmonary embolism occurred in the rate control group despite oral anticoagulation therapy, while three patients in the rhythm control arm of the study experienced ischemic strokes (not significant). CONCLUSIONS: The Polish HOT CAFE study revealed no significant differences in major end points between the rate control group and the rhythm control group.     

Clinical and echocardiographic predictors of left atrial clot and spontaneous echo contrast in patients with severe rheumatic mitral stenosis: a prospective study in 200 patients by transesophageal echocardiography

The objective of this study was to prospectively investigate various clinical and echocardiographic variables to predict the left atrial and left atrial appendage clot and spontaneous echo contrast in patients with severe rheumatic mitral stenosis. We studied 200 consecutive patients (112 males and 88 females; mean age 29.6+/-9.6 years). Left atrial clot and spontaneous echo contrast were present in 26 and 53.5% of cases, respectively. There were no significant differences in the mitral valve area, mean transmitral diastolic gradient and left ventricular ejection fraction between patients with and without clot. Patients with clot were older (34.4+/-11.4 vs. 28.2+/-8.5 years, P<0.001), had longer duration of symptoms (41. 4+/-36.0 vs. 28.8+/-22.9 months, P<0.001), more frequent atrial fibrillation and spontaneous echo contrast (69.2 vs. 16.9%, P<0. 00001 and 76.9 vs. 45.3%, P<0.00001, respectively) and larger left atrial area and diameter (41.0+/-12.7 vs. 29.9+/-7.4 cm(2), P<0.00001 and 53.9+/-8.3 vs. 47.6+/-7.4 mm, P<0.0001, respectively) as compared to patients without clot. Similarly patients with spontaneous echo contrast were older (31+/-10.4 vs. 27.8+/-8.3 years, P<0.01), had more frequent atrial fibrillation (48.6 vs. 9.7%, P<0.0001), left atrial clot (37.4 vs. 12.9%, P<0.0001), larger left atrial area and diameter (37.6+/-11.2 vs. 28.1+/-6.7 cm(2), P<0.00001 and 52.2+/-8.3 vs. 45.9+/-6.5 mm, P<0.00001, respectively) and smaller mitral valve area (0.77+/-0.14 vs. 0.84+/-0.13 cm(2), P<0.01) as compared to patients without spontaneous echo contrast. There were no significant differences in the mean transmitral diastolic gradient and left ventricular ejection fraction. On multiple regression and discriminant function analysis, atrial fibrillation and left atrial area were independent predictors of left atrial clot formation. In a subgroup of patients with sinus rhythm, larger left atrial area and presence of spontaneous echo contrast were significantly associated with the presence of clot in left atrium and appendage. We conclude that in patients with severe mitral stenosis, the presence of atrial fibrillation and in the subgroup of the patients with sinus rhythm the presence of large left atrium (> or =40 cm(2)) and spontaneous echo contrast were associated with higher risk of clot formation in the left atrium and might be benefited by prophylactic anticoagulation.     

Open heart radio frequency left atrial compartmentation during mitral valve surgery: an alternative to the labyrinth procedure?

The authors report their experience of radiofrequency left atrial compartimentation during open heart mitral valve surgery on 37 patients with a 42 +/- 12 months history of atrial fibrillation. The preoperative left ventricular ejection fraction was 62 +/- 8%; the left atrial diameter was 59 +/- 11 mm. The mean operative time was 245 +/- 60 minutes, which included 19 +/- 5 minutes for the ablation procedure. There were 2 early postoperative deaths and 2 deaths from non-cardiac causes at 3 and 6 months. The left ventricular ejection fraction and left atrial dimension were significantly decreased at the time of hospital discharge (54 +/- 12% and 51 +/- 7 mm respectively) (p < 0.01). After an average follow-up of 1 year, 81% of patients were free of atrial fibrillation: 6 patients had undergone DC cardioversion and 1 had a dual-chamber pacemaker. Patients in sinus rhythm after the ablation were associated with shorter periods of atrial fibrillation and smaller left atrial dimensions postoperatively than those who remained in fibrillation. The authors conclude that radiofrequency compartimentation of the left atrium associated with antiarrhythmic therapy can interrupt atrial fibrillation in 81% of patients at 1 year: the ablation procedure takes only 8% of the operation time. Predictive factors of success of ablation should be defined to determine which patients benefit most from this technique.     

Low-energy internal cardioversion of atrial fibrillation after failed external cardioversion: Texas Heart Institute experience and review of the literature.

In patients with atrial fibrillation, low-energy internal cardioversion may be used to restore sinus rhythm after external cardioversion fails. We used this method in 8 consecutive patients with a mean age of 69.5+/-8.3 (SD) years, 7 (87.5%) of whom were successfully treated with a mean 9.1 J (range, 4 to 14 J). No patient had ventricular arrhythmias at the time of cardioversion, or local groin complications afterward. One patient had recurrent atrial fibrillation the morning after cardioversion, and another patient had an embolus to the renal artery 20 days posttreatment. After 1 month, 5 patients were still in sinus rhythm, and 1 patient was lost to follow-up. This study confirms the efficacy of internal cardioversion in this setting and stresses the importance of a standard anticoagulation protocol before and after cardioversion.     

Predictors of atrial rhythm after atrioventricular node ablation for the treatment of paroxysmal atrial arrhythmias

OBJECTIVE: To assess the natural history of the atrial rhythm of patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation. DESIGN AND SETTING: A retrospective cohort study of consecutive patients identified from the pacemaker database and electrophysiology records of a tertiary referral hospital. PATIENTS: 62 consecutive patients with paroxysmal atrial arrhythmias undergoing atrioventricular node ablation and permanent pacemaker implantation between 1988 and July 1996. MAIN OUTCOME MEASURES: (1) Atrial rhythm on final follow up ECG, classified as either ordered (sinus rhythm or atrial pacing) or disordered (atrial fibrillation, atrial flutter or atrial tachycardia). (2) Chronic atrial fibrillation, defined as a disordered rhythm on two consecutive ECGs (or throughout a 24 hour Holter recording) with no ordered rhythm subsequently documented. RESULTS: Survival analysis showed that 75% of patients progressed to chronic atrial fibrillation by 2584 days (86 months). On multiple logistic regression analysis a history of electrical cardioversion, increasing patient age, and VVI pacing were associated with the development of chronic atrial fibrillation. A history of electrical cardioversion and increasing patient age were associated with a disordered atrial rhythm on the final follow up ECG. CONCLUSIONS: Patients with paroxysmal atrial arrhythmias are at high risk of developing chronic atrial fibrillation. A history of direct current cardioversion.