A review of current surgical treatment of patients with atrial fibrillation.

Surgical therapy for patients with atrial fibrillation has undergone significant advances over the past 30 years. The Cox Maze III technique is currently the gold standard of care for these patients. However, Maze IV, a less complex procedure using alternative energy sources, is rapidly replacing the Cox Maze III in clinical practice. The use of alternative energy sources such as cryothermy and radiofrequency eliminates some of the "cut and sew" lesions of the Maze III, resulting in an easier and faster procedure with less morbidity. Video-assisted technology and hybrid procedures have further ushered in the future of surgical therapy. This article presents the latest surgical therapeutic options for patients with atrial fibrillation. The history of these procedures is presented, followed by a discussion of modern-era techniques, including concomitant ablation and standalone (also referred to as "lone") procedures. Finally, the article explores breaking developments and future directions for the surgical treatment of patients with atrial fibrillation.

History of surgery for atrial fibrillation.

There is a rich history of surgery for atrial fibrillation. Initial procedures were aimed at controlling the ventricular response rate. Later procedures were directed at converting atrial fibrillation to normal sinus rhythm. These culminated in the Cox Maze III procedure. While highly effective, the complexity and morbidity of the cut and sew Maze III limited its adoption. Enabling technology has developed alternate energy sources designed to produce a transmural atrial scar without cutting and sewing. Termed the Maze IV, this lessened the morbidity of the procedure and widened the applicability. Further advances in minimal access techniques are now being developed to allow totally thorascopic placement of all the left atrial lesions on the full, beating heart, using alternate energy sources.

Minimally invasive pulmonary vein isolation and partial autonomic denervation for surgical treatment of atrial fibrillation.

BACKGROUND: We seek to demonstrate the rationale and efficacy of a minimally invasive surgical approach to the treatment of atrial fibrillation (AF) that combines pulmonary vein antral isolation with targeted partial autonomic denervation. METHODS: The literature supporting the rationale of this approach is reviewed. Seventy-four patients underwent video-assisted bilateral pulmonary vein antral isolation with confirmation of block and partial autonomic denervation with follow-up of 6 months or greater and have a long-term rhythm monitor at 6 months. RESULTS: Success was defined as no episodes greater than 15 seconds of AF on long-term monitoring. Treatment was successful in 83.7% of patients with paroxysmal AF and 56.5% of patients with persistent/long-standing persistent AF. CONCLUSIONS: There are evidence-based data that support both pulmonary vein electrical isolation and targeted partial autonomic denervation in the treatment of AF. These techniques can be combined in a minimally invasive surgical approach. Early data suggest this is a safe and efficacious approach for the treatment of paroxysmal AF. Techniques are being developed for the minimally invasive surgical treatment of persistent AF from an epicardial approach.

Rationale for minimally invasive pulmonary vein isolation and partial autonomic denervation for surgical treatment of atrial fibrillation.

We seek to demonstrate the rationale of a minimally invasive surgical approach to the treatment of atrial fibrillation which combines pulmonary vein antral isolation with targeted partial autonomic denervation. The literature supporting the rationale of this approach is reviewed. There is evidence-based literature that supports both pulmonary vein electrical isolation and targeted partial autonomic denervation in the treatment of atrial fibrillation. These techniques can be combined in a minimally invasive surgical approach.

Ventricular epicardial lead placement for resynchronization by determination of paced depolarization intervals: technique and rationale.

BACKGROUND: Cardiac resynchronization therapy has been shown to be an effective treatment to improve functional status and prolong survival among patients with advanced congestive heart failure. However, as many as 30% of patients do not respond. Nonresponse may be due to suboptimal left ventricular lead placement. Studies have indicated that leads placed in the midlateral left ventricle (LV) wall usually result in improved dP/dT and increased pulse pressure, compared with other locations. When the surgeon is placing the leads thoracoscopically, however, in a chest with multiple adhesions, anatomic landmarks can be obscured. It is desirable to have an objective physiologic method to determine optimal lead placement. The optimal LV pacing site may be best determined by locating the site with the latest depolarization. METHODS: A pacing lead attached to a pulse analyzer was introduced through a thoracoscopic port and used as a mapping electrode to electrically map exposed areas of the left ventricle. The right ventricular pacing lead was also attached to the pulse analyzer and the interval between the right ventricular pulse and the LV depolarization (paced depolarization interval) was measured in 19 patients undergoing thoracoscopic LV lead placement. A site with a paced depolarization interval less than 110 ms was not accepted. RESULTS: Electrical mapping was possible in 19 of 29 consecutive patients in whom it was attempted. The most frequent reason for not mapping was the presence of extensive scarring. In 7 of 19 patients (36.8%) mapped, the site that would have been chosen by anatomic landmarks was not the site with the longest paced depolarization interval, and thus the lead placement was altered. CONCLUSIONS: The site with the longest paced depolarization interval is only selected 63.2% of the time when utilizing anatomic landmarks for placement. Nonresponse may be due to suboptimal LV lead placement. Measurement of paced depolarization intervals provides a physiologic method of determining optimal LV lead placement.

Reduced atrial fibrillation in patients immediately extubated after off-pump coronary artery bypass grafting.

BACKGROUND: We analyzed data from patients undergoing off-pump isolated coronary artery bypass grafting surgery (OPCABG) to determine if immediate extubation in the operating room affected the incidence of postoperative atrial fibrillation. METHODS: The study group comprised 2,376 consecutive OPCABG patients operated on between January 1, 2000, and December 31, 2004, by 22 surgeons at 18 hospitals. The data were subjected to univariate, multivariate analysis of variance, and logistic analysis. Logistic regression of matched groups was used to eliminate the effect of some confounding variables. RESULTS: Patients immediately extubated after surgery had a reduced incidence of atrial fibrillation (10.6% versus 18.5%; p < 0.001), shorter length of stay (4.8 +/- 3.5 versus 6.3 +/- 5.2 days; p < 0.001), and also reduced mortality (1.1% versus 2.4%; p = 0.04). Logistic analysis identified as significant factors for postoperative atrial fibrillation, postoperative ventilator usage (p < 0.001; odds ratio [OR] = 1.63; 95% confidence interval [CI]: 1.24 to 2.14), male sex (p = 0.002; OR = 1.51; 95% CI: 1.17 to 1.96), previous CABG (p = 0.005; OR = 0.43; 95% CI: 0.24 to 0.78). Congestive heart failure may also be a contributing factor. In patient groups matched for their risk of mortality, postoperative ventilator use (p < 0.001; OR = 1.80; 95% CI: 1.31 to 2.47), increasing age, and male sex were all statistically significant risk factors. When patient groups were matched on a combination of factors including preoperative beta-blocker usage, pulmonary disease, and smoking, postoperative ventilator use (p = 0.005; OR = 1.66; 95% CI: 1.16 to 2.38), along with increasing age, male sex, and previous CABG (reduced odds of atrial fibrillation developing) were statistically significant. CONCLUSIONS: Immediate extubation after OPCABG appears to reduce the incidence of postoperative atrial fibrillation independent of comorbidities.