Long-term sinus rhythm stability after intraoperative ablation of permanent atrial fibrillation.

INTRODUCTION: Short- and medium-term sinus rhythm (SR) rates after intraoperative radiofrequency ablation to treat permanent atrial fibrillation (AF) are well documented. Is rhythm success stable during a long-term follow-up? METHODS AND RESULTS: A total of 130 patients who had undergone intraoperative radiofrequency cooled-tip endocardial ablation (SICTRA) of permanent AF (mean AF duration 6+/-5 years) concomitant to open heart surgery more than 3 years ago were followed up using electrocardiogram (ECG), Holter-ECG, and echocardiography and compared with 12-month follow-up data. In 55% of patients, only the left atrium and in 45%, both atria were treated using SICTRA. Mitral valve replacement was performed in 21, mitral valve reconstruction in 25, aortic valve replacement in 13, CABG procedures in 51 (including 11 patients with additional mitral valve surgery), and complex procedures in 20 patients. Sixty-nine percent of patients (90/130) were in stable SR after a median period of 48 months, whereas 28% (36/130) were in AF and 3% (4/130) were in atrial flutter. In between the 12-month follow-up and the long-term follow-up, seven patients converted to AF after having documented SR, two patients converted to typical right atrial flutter after being in SR, and two patients from AF to left atrial macroreentry. After left and biatrial SICTRA, SR rates were comparable (73% vs 66%, P = 0.45). Echocardiography revealed 73% of patients in SR to have effective left atrial contraction. CONCLUSIONS: SICTRA restores long-term stable SR in 69% of all patients. Nine percent of patients reconverted back to atrial arrhythmia after having documented SR at 12 months.

Left atrial versus bi-atrial Maze operation using intraoperatively cooled-tip radiofrequency ablation in patients undergoing open-heart surgery: safety and efficacy.

OBJECTIVES: We sought to determine whether limited left atrial Maze surgery encircling each of the pulmonary veins, using cooled-tip radiofrequency (RF) ablation, is as effective as the bi-atrial approach? BACKGROUND: The original Cox/Maze operation effectively restores sinus rhythm (SR) in patients with atrial fibrillation (AF). Ablation procedures aimed at eliminating pulmonary vein foci have produced promising short-term success. METHODS: This was a prospective analysis of patients with chronic AF undergoing open-heart surgery in addition to the Maze operation, using intraoperatively cooled-tip RF ablation either in the left atrium alone (group A) or in both atria (group B). RESULTS: Patients in group A (n = 21) and group B (n = 49) did not differ in terms of their baseline characteristics. Concomitant open-heart surgical procedures included mitral valve replacement (3 vs. 25), mitral valve plasty (0 vs. 2), mitral and aortic valve replacement (1 vs. 1), aortic valve replacement (4 vs. 6) and coronary artery bypass grafting (13 vs. 15) in groups A and B, respectively. Follow-up ranged from 1 to 50 months. The overall cumulative rates of SR were 82% in group A and 75% in group B, without a statistically significant difference (p = 0.571). Bi-atrial contraction was revealed in 92.3% of patients in SR in group A and in 79.2% in group B. The cumulative survival rates were 90.5% in group A and 77.9% in group B (p = 0.880). CONCLUSIONS: A left or bi-atrial Maze operation using intraoperatively cooled-tip RF ablation can safely be combined with open-heart surgery. A left atrial Maze procedure seems to be as effective as the bi-atrial procedure and restores SR in 82% of patients.

Concomitant anti-arrhythmic procedures to treat permanent atrial fibrillation in CABG and AVR patients are as effective as in mitral valve patients.

OBJECTIVE: Concomitant anti-arrhythmic procedures, to treat permanent atrial fibrillation, are not routinely performed in non-mitral valve surgery, such as coronary artery bypass grafting (CABG) and aortic valve (AVR) procedures. This study evaluated the sinus rhythm (SR) conversion rate of a concomitant anti-arrhythmia procedure in non-mitral valve surgery compared to mitral valve surgery. METHODS: Between 1997 and 2003, 128 patients with a documented permanent atrial fibrillation had a concomitant anti-arrhythmic procedure using unipolar endocardial radiofrequency ablation; 65 mitral valve surgery (group I) and 63 aortic valve surgery or CABG (group II). Follow-up was complete and included standard ECG and echocardiogram at 3, 6, 12 months and each consecutive year. Stability of SR was confirmed with a 24-h ECG registration. RESULTS: Type of procedures was MVR 42 (32.8%), MVP 23 (18.0%), CABG 40 (31.2), AVR 21 (16.4%), other 2 (1.6%). Thirty-day mortality for groups I and II were 4.6% (3/65) and 3.2% (2/63). Group II patients were distinctly older (69.3 versus 64.8 years; P=0.04), but the size of the left atrium was smaller (45.9 versus 52.4mm; P=0.0001) and the aortic cross-clamp time was shorter (91 versus 99min; P=0.05). The cumulative postoperative SR percentages for the groups I and II patients at 12 months were 71 versus 79%. A bi-atrial contraction was observed in 65.6% (21/32) and 68.3% (28/41) of the groups I and II patients, who had a stable SR. The mean (SD) follow-up for groups I and II was 24.4 (19.4) and 21.0 (17.2) months. The cumulative survival rate at 1, 2 and 3 years for groups I and II were 85 versus 88%, 83 versus 85%, 79 versus 85% (log-rank test P=0.60). CONCLUSION: A concomitant anti-arrhythmic procedure in CABG and AVR patients is as effective as in mitral valve patients, although these patients tend to be older, but with a smaller left atrial size.

Surgical treatment of atrial fibrillation; a systematic review.

UNLABELLED: In this review the efficacies of the alternative sources of energy (radiofrequency-microwave and cryo ablation; group I) and the classical 'cut and sew' Cox-Maze III (group II), which claims a 97-99% sinus rhythm (SR) success rate, were evaluated in the surgical treatment of atrial fibrillation (AF). A computerized search in the PubMed and Medline database was conducted. Only original, English written, clinical manuscripts on the surgical treatment of atrial fibrillation using an alternative source of energy or the classical 'cut and sew' Cox-Maze III technique, citing the clinical outcome, including the postoperative sinus rhythm, were included. The data included in this review were the number and percentage of treated patients, gender distribution, the type of arrhythmia and surgery, postoperative morbidity, pacemaker implantation rate, 30-day mortality, survival- and sinus rhythm conversion rates. Mean values for age, left atrial diameter, preoperative duration of AF and left ventricular ejection fraction were also recorded. Forty-eight studies were included comprising 3832 patients; 2279 in group I and 1553 in group II. The mean duration of AF, left atrial diameter and LVEF were 5.4 vs. 5.5 years (p=0.90), 55.5 vs. 57.8 mm (p=0.23) and 57 vs. 58% (p=0.63). The postoperative SR rates for group I and II were 78.3 vs. 84.9% (p=0.03). However, the "cut and sew" Cox-Maze III was conducted in younger patients (55.0 vs. 61.2 years; p=0.005), more often to treat paroxysmal (22.9 vs. 8.0%; p=0.05) and lone AF (19.3 vs. 1.6%). Alternative sources of energy were predominantly used to treat permanent AF (92.0%), almost always as a concomitant surgical procedure (98.4%) and increasingly in combination with non-mitral valve surgery (18.5%). After correction for these variations, the postoperative SR conversion rates for group I and II did not differ significantly anymore (p=0.260). CONCLUSIONS: We could not identify any significant difference in the postoperative SR conversion rates between the classical 'cut and sew' and the alternative sources of energy, which were used to treat atrial fibrillation.

Concomitant anti-arrhythmic surgery, using irrigated cooled-tip radiofrequency ablation, to treat permanent atrial fibrillation in CABG patients: expansion of the indication?

OBJECTIVES: The effectiveness of a concomitant anti-arrhythmic surgical procedure in coronary artery bypass grafting (CABG) patients with permanent atrial fibrillation (AF) was evaluated. METHODS: This prospective study included 36 CABG patients, who had a concomitant anti-arrhythmic procedure using irrigated cooled-tip radiofrequency ablation. Follow-up included a 24 h EKG and ultrasound examination at 3, 6, 12 months. RESULTS: Mean (SD) age was 68.7 years (8.0), left atrial diameter 44.9 mm (6.7), preoperative duration of AF 67 months (73), left ventricular ejection fraction 54% (14), euroscore 5.5 (2.6), number of distal anastomoses 3.3 (1.2), aortic cross-clamp time 90 (19)min, extracorporeal bypass time 156 (38)min. Thirty-day mortality was 2.8% (1/36). Mean (SD) follow-up was 25.3 months (17.9). Cumulative survival rates (SE) at 12 and 24 months were 0.94 (0.04) and 0.90 (0.06). Cumulative postoperative sinus rhythm (SR) rates (SE) at 6 and 12 months were 0.60 (0.08) and 0.75 (0.08). Restored bi-atrial contraction occurred in 73% (19/26) of all SR patients. As a consequence coumadine was stopped, after the 6th postoperative month, in 76% (16/21) in this subset of patients, corresponding with 44% (16/36) of all study group patients. One patient experienced a sick sinus syndrome 12 months postoperatively, for which a DDD pacemaker was implanted. Three out of five patients with a preexistent VVI pacemaker regained a stable postoperative SR with bi-atrial contraction, obviating the need of any pacemaker support.

Intra-operative cooled-tip radiofrequency linear atrial ablation to treat permanent atrial fibrillation.

AIMS: To demonstrate the safety and efficacy of saline irrigated cooled-tip atrial linear endocardial radiofrequency ablation (SICTRA) concomitant to open-heart surgical procedures in the treatment of permanent atrial fibrillation (AF). METHODS AND RESULTS: Two hundred and twenty-two patients presenting with permanent AF and the need for cardiac surgery were included. In addition to the cardio-surgical procedure [mitral valve (MV) surgery (n = 94), aortic valve replacement (n = 29), bypass surgery (n = 76 including 24 patients with additional MV surgery), and combined procedures (n = 23)] concomitant SICTRA was performed. In 116 patients, the ablation pattern was restricted to the left atrium alone. During the mean follow-up of 29 months, 174 patients (78%) converted to sinusrhythm (SR). In patients with SICTRA restricted to the left atrium conversion rates were not different compared to a biatrial approach (83 vs. 74%, P = 0.47). Thirty-days mortality was found to be 4% (9/222). Post-mortem evaluation revealed 23% of all lesions to be histologically non-transmural. In the overall group, only 4% of patients developed sustained secondary regular atrial arrhythmia. CONCLUSIONS: SICTRA safely and effectively restores stable SR in 78% of patients with permanent AF undergoing open-heart surgery. Rhythm outcome is not influenced by treatment of the right atrium. Sustained regular atrial arrhythmia with the need for invasive treatment strategies occurs in 4% although intra-operative ablation lesions are often non-transmural.

Catheter ablation of regular atrial arrhythmia following surgical treatment of permanent atrial fibrillation.

UNLABELLED: Ablation of Atrial Tachycardia after Antiatrial Fibrillation Surgery. INTRODUCTION: Surgical treatment of atrial fibrillation (AF) is gaining widespread acceptance. However, therapeutic modalities for secondary regular atrial tachycardia are still empiric. METHODS AND RESULTS: After linear atrial cooled-tip radiofrequency ablation (SICTRA) during cardio-surgical procedures to cure permanent AF, patients with regular atrial tachycardia were identified. Invasive electrophysiology including electroanatomic mapping was performed. Catheter ablation was directed to suppress atrial arrhythmia depending on activation mapping findings. Follow-up was performed after 3 months and then after every 6 months. Of 238 patients, 12 (5.0%) were identified with regular secondary arrhythmias (12 +/- 7 months after surgery) including 9 (3.8%) with persistent forms originating from the right atrium (RA) in six (66%) (isthmus-dependent macroreentry in 4, incisional macroreentry in 1, and RA ectopy in 1). All patients with RA origin of the tachycardia were successfully ablated. Two patients had left atrial (LA)-macroreentry circling around the mitral valve indicating insufficiency of the intraoperative ablation procedure: one patient was successfully ablated within the LA isthmus, in the other patient no complete conduction block could be induced. One patient had LA-macroreentry degenerating into AF, and ablation was not performed. During follow-up (9 +/- 4 months), no recurrences of atrial tachycardias were documented after successful ablation. CONCLUSIONS: Persistent regular "secondary" arrhythmia occurred in 3.8% (9/238) of patients after SICTRA to treat permanent AF. Predominantly (67%; 6/9), the arrhythmia was located in the RA mostly incorporating the RA-isthmus. Catheter ablation was highly effective for RA tachycardia (100%). In three cases (33%), LA-macroreentry was documented and catheter ablation was successful in only one patient (overall success 78%).

Histopathology of intraoperatively induced linear radiofrequency ablation lesions in patients with chronic atrial fibrillation.

AIMS: Radiofrequency (RF) energy has been extensively used in ablation of arrhythmia but so far no analysis of morphological effects in human left atria has been conducted. METHODS AND RESULTS: We studied 59 ablation lesions from seven patients who died 2 to 22 days after open heart surgery plus intraoperative cooled-tip RF ablation to treat permanent atrial fibrillation (AF) (mean 4, 1-11 years). The ablation area was studied by macroscopy and histological analysis. RF ablation produced clearly delineated coagulation necrosis (up to a depth of 5.5 mm) bordered by an irregular zone of incomplete necrosis and fresh bleeding even 22 days post-operatively. No superficial charring, thrombotic deposition, or perforation was documented. Endocardium and subendocardium displayed oedematic loosening and microfragmentation of connective tissue fibres. Early after ablation (2-6 days), interfibrillar disseminated bleeding and necrosis without tissue removal response were found. Later after ablation (21, 22 days), mild inflammatory reaction and granulation tissue appeared. Twenty-five per cent of all studied lesions, especially in the thick region in between left pulmonary veins and mitral annulus (left atrial isthmus) (86%), were non-transmural. Nerve fibres with different degrees of thermal injury were detected in the pulmonary vein ostial region. CONCLUSION: Intraoperative cooled-tip ablation in AF resulted in coagulation necrosis of endocardium, subendocardium, and the atrial myocardial layer to a depth of 5.5 mm bordered by an irregular zone of incomplete thermal damage. Transmurality of the lesions could only be found in 75% of intraoperatively applied lesions.

Irrigated radiofrequency ablation is a safe and effective technique to treat chronic atrial fibrillation.

OBJECTIVE: The safety of intraoperative non-irrigated temperature-controlled radiofrequency ablation to treat atrial fibrillation is a matter of debate. This study evaluates a different operative technique using saline-irrigated-cooled-tip radiofrequency ablation (SICTRA) to treat atrial fibrillation. PATIENTS AND METHODS: One hundred and twenty-four concomitant anti-arrhythmic procedures, using SICTRA were performed; 113 to treat chronic AF (>6 months) and 11 to cure paroxysmal AF. RESULTS: Twenty-eight MVP, 42 MVR, 17 AVR and six double valve procedures with or without CABG, one ASD closure and 30 solitary CABG were performed. The mean (S.D.) left atrial diameter, preoperative duration of AF, aortic cross-clamp time were 50.5 mm (9.8), 57 months (64) and 99 min (21). Thirty day mortality was 4.8% (6/124; euroscore 17, 11, 8, 8, 6, 5). Autopsies did not reveal any esophageal, pulmonary orifice, or circumflex artery injuries. No ablation related bleeding was observed. Mean follow-up (S.D.) was 19.7 months (14.4). Fourteen patients died during follow-up. The cumulative postoperative SR at 6 and 12 months was 60% and 70%. The cumulative survival at 1 and 2 years was 86% and 83%. CONCLUSION: Irrigated radiofrequency ablation was effective. It was not associated with procedural complications in our series.

A possible surgical technique to avoid esophageal and circumflex artery injuries using radiofrequency ablation to treat atrial fibrillation.

A surgical technique using unipolar radiofrequency ablation is described, which minimizes the risk of damaging adjacent cardiac structures. The left atrium was fully mobilized. Linear, non-thrombogenic, white blistering lesions were created with a hand-held malleable pen-catheter, making oscillating movements, while preserving a stable endocardium contact, without pressing the atrial wall to adjacent mediastinal structures. The ablated atrial tissue was lifted up with forceps. Each pulmonary vein orifice was circumferentially ablated and interconnected on the ipsi- and to the contra-lateral side, and to the left auricle and mitral valve annulus. No esophageal or circumflex artery injuries were observed.

Antiarrhythmic surgery to cure atrial fibrillation--subgroups and postoperative management.

Antiarrhythmic surgical procedures to cure atrial fibrillation (AF) are widely used in cardiac surgery. Whereas the Cox maze procedure remains the highly effective gold-standard a variety of different antiarrhythmic procedures aim at reducing the extent and duration of the procedure. Antiarrhythmic procedures are especially effective in patients undergoing mitral valve surgery. In 110 patients with permanent AF undergoing various surgical procedures sinus rhythm was re-established in 75%. Subgroup analyses revealed no significant differences in rhythm or survival after antiarrhythmic intraoperative ablation indicating the usefulness and feasibility of this procedure in patients with a wide range of characteristics. Because conversion usually occurs spontaneously within the first 6 months and antiarrhythmic medication does not increase the incidence of conversion it seems reasonable to wait for spontaneous occurrence of sinus rhythm after antiarrhythmic intraoperative ablation. In patients with permanent AF undergoing open heart surgery additional antiarrhythmic procedures have been shown to be safe and effective.