Objectives Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. A variety of POAF risk factors has been reported, but study results have been inconsistent or contradictory, particularly in patients with preexisting atrial fibrillation. The incidence of POAF was evaluated in a group of 10,390 cardiac surgery patients among a comprehensive range of risk factors to identify reliable predictors of POAF. Methods This 20-year retrospective study examined the relationship between POAF and demographic factors, preoperative health conditions and medications, operative procedures, and postoperative complications. Multivariate logistic regression models were used to evaluate potential predictors of POAF. Results Increasing age, mitral valve surgery (OR=1.91), left ventricular aneurysm repair (OR=1.57), aortic valve surgery (OR=1.52), race (Caucasian) (OR=1.51), use of cardioplegia (OR=1.36), use of an intra-aortic balloon pump (OR=1.28), previous congestive heart failure (OR=1.28), and hypertension (OR=1.15) were significantly associated with POAF. The nonlinear relationship between age and POAF revealed the acceleration of POAF risk in patients 55 or older. In patients undergoing coronary artery bypass grafting, increasing age and previous congestive heart failure were the only factors associated with a higher risk of POAF. There was no trend in incidence of POAF over time. No protective factors against POAF were detected, including commonly prescribed categories of medications. Conclusions The persistence of the problem of POAF, and the modest predictability using common risk factors, suggest that limited progress has been made in understanding its etiology and treatment.

The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.

Isolating the entire posterior left atrium by creating a box lesion instead of a single connecting lesion between the pulmonary veins showed a significantly lower incidence of early atrial tachyarrhythmias, higher freedom from atrial fibrillation recurrence at 1 and 3 months, and lower use of antiarrhythmic drugs at 3 and 6 months. A complete box lesion should be included in all patients undergoing the Cox maze procedure.

Objectives Surgical ablation of ganglionated plexi (GP) has been proposed to increase the efficacy of the surgical treatment of atrial fibrillation (AF). This experimental canine study examined the electrophysiological attenuation and recovery of atrial vagal effects following GP ablation alone and combined with standard surgical lesion sets used to treat AF. Methods Dogs were divided into 3 groups: Group 1 (N=6) had focal ablation of the 4 major epicardial GP fat pads; Group 2 (N=6) had pulmonary vein isolation with GP ablation; and Group 3 (N=6) had posterior left atrial isolation with GP ablation. All fat pads were ablated. Sinus and atrioventricular (AV) interval changes during bilateral vagosympathetic trunk stimulation were examined before, after, and at four weeks post-ablation. Vagally induced effective refractory period (ERP) changes and mean QRST area changes (index of local innervation) were examined in 5 atrial regions. Results Sinus and AV interval changes and heart rate variability decreased immediately following ablation, but only sinus interval changes were restored significantly after 4 weeks in all groups. Ablation modified vagal effects on ERP or QRST area changed heterogeneously in Groups 1 and 2. In Group 3, regional vagal effects were attenuated extensively post-ablation in both atria. Posterior left atrial isolation with GP ablation incrementally denervated the atria. Chronically, vagal stimulation increased QRST area changes over control values in all groups. Heart rate variability was also assessed. Conclusions GP ablation significantly reduced vagal innervation to the atria. Restoration of vagal effects at 4 weeks suggested early atrial reinnervation.

The overall incidence of retained or newly passed CBD stones on IOC during LC after a preoperative ERCP is 12.9%. Although the natural history of residual CBD stones after preoperative ERCP is not known, the routine use of IOC should be considered in patients with CBD stones on preoperative ERCP undergoing an interval LC.

During the study period, SAVR volume gradually declined and TAVR volume dramatically increased. This was mostly due to a new group of patients with lower STS PROM who were designated as higher risk by a Heart Team due to characteristics not completely captured by the STS PROM score.

Objective The effects of the Cox maze procedure on atrial function remain poorly defined. The purpose of this study was to investigate the effects of a modified Cox maze procedure on left and right atrial function in a porcine model. Methods After cardiac magnetic resonance imaging, 6 pigs underwent pericardiotomy (sham group), and 6 pigs underwent a modified Cox maze procedure (maze group) with bipolar radiofrequency ablation. The maze group had preablation and immediate postablation left and right atrial pressure–volume relations measured with conductance catheters. All pigs survived for 30 days. Magnetic resonance imaging was then repeated for both groups, and conductance catheter measurements were repeated for the right atrium in the maze group. Results Both groups had significantly higher left atrial volumes postoperatively. Magnetic resonance imaging–derived reservoir and booster pump functional parameters were reduced postoperatively for both groups, but there was no difference in these parameters between the groups. The maze group had significantly higher reduction in the medial and lateral left atrial wall contraction postoperatively. There was no change in immediate left atrial elastance or in the early and 30-day right atrial elastance after the Cox maze procedure. Although the initial left atrial stiffness increased after ablation, right atrial diastolic stiffness did not change initially or at 30 days. Conclusions Performing a pericardiotomy alone had a significant effect on atrial function that can be quantified by means of magnetic resonance imaging. The effects of the Cox maze procedure on left atrial function could only be detected by analyzing segmental wall motion. Understanding the precise physiologic effects of the Cox maze procedure on atrial function will help in developing less-damaging lesion sets for the surgical treatment of atrial fibrillation.

The introduction of ablation technology has revolutionized the surgical treatment of atrial fibrillation (AF). It has greatly simplified surgical approaches and has significantly increased the number of procedures being performed. Various energy sources have been used clinically, including cryoablation, radiofrequency, microwave, laser, and high-frequency ultrasound. The goal of these devices is to create conduction block to either block activation wavefronts or to isolate the triggers of AF. All present devices have been shown to have clinical efficacy in some patients. The devices each have their unique advantages and disadvantages. It is important that surgeons develop accurate dose-response curves for new devices in clinically relevant models on both the arrested and beating heart. This will allow the appropriate use of technology to facilitate AF surgery.