Omega-3 fatty acids do not alter P-wave parameters in electrocardiogram or expression of atrial connexins in patients undergoing coronary artery bypass surgery.

AIMS: We previously reported omega-3 polyunsaturated fatty acids (n-3PUFAs) supplementation does not reduce atrial fibrillation (AF) following coronary artery bypass graft (CABG) surgery. The aim of the present study is to evaluate the impact of n-3 PUFAs on electrocardiogram (ECG) atrial arrhythmic markers and compare with expression of gap-junction proteins, Connexins. METHODS AND RESULTS: Subset of clinical trial subjects with right atrial sampling during CABG surgery included. Twelve-lead ECG performed at recruitment and at surgery [after supplementation with n-3 PUFA (∼1.8 g/day) or matched placebo] for ∼14 days. Electrocardiograms analysed for maximum P-wave duration (P-max) and difference between P-max and minimum P-wave duration, P-wave dispersion (PWD). Right atrial specimens analysed for expression of Connexins 40 and 43 using real-time quantitative polymerase chain reaction (qPCR) and western blot. Serum levels of n-3 PUFA at baseline, at surgery, and atrial tissue levels at surgery collated from file. Postoperative AF was quantified by analysing data from stored continuous electrograms. A total of 61 patients (n-3 PUFA 34, Placebo 27) had ECG analysis and AF burden, of which 52 patients (26 in each group) had qPCR and 16 (8 in each group) had western blot analyses for Connexins 40 and 43. No difference between the two groups in ECG parameters or expression of Connexin 40 or 43. P-wave dispersion in the preoperative ECG independently predicted occurrence of AF following CABG surgery. CONCLUSIONS: Omega-3 polyunsaturated fatty acids supplementation does not alter pro-arrhythmic P-wave parameters in ECG or connexin expression in human atrium with no effect on the incidence of AF following CABG surgery.

Omega-3 fatty acid supplementation does not reduce risk of atrial fibrillation after coronary artery bypass surgery: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been reported to reduce the risk of sudden cardiac death presumed to be due to fatal ventricular arrhythmias, but their effect on atrial arrhythmias is unclear. METHODS AND RESULTS: Patients (n=108) undergoing coronary artery bypass graft surgery were randomly assigned to receive 2 g/d n-3 PUFA or placebo (olive oil) for at least 5 days before surgery (median, 16 days; range, 12 to 21 days). Phospholipid n-3 PUFA were measured in serum at study entry and at surgery and in right atrial appendage tissue at surgery. Echocardiography was used to assess left ventricular function and left atrial dimensions. Postoperative continuous ECG monitoring (Lifecard CF) for 5 days or until discharge, if earlier, was performed with a daily 12-lead ECG and clinical review if patients remained in the hospital beyond 5 days. Lifecard recordings were analyzed for episodes of atrial fibrillation (AF) > or =30 seconds (primary outcome). Clinical AF, AF burden (% time in AF), hospital stay, and intensive care/high dependency care stay were measured as secondary outcomes. One hundred three patients completed the study (51 in the placebo group and 52 in the n-3 PUFA group). There were no clinically relevant differences in baseline characteristics between groups. n-3 PUFA levels were higher in serum and right atrial tissue in the active treatment group. There was no significant difference between groups in the primary outcome of AF (95% confidence interval [CI], -6% to 30%, P=0.28) in any of the secondary outcomes or in AF-free survival. CONCLUSIONS: Omega-3 PUFA do not reduce the risk of AF after coronary artery bypass graft surgery. Clinical Trial Registration- www.ukcrn.org.uk. Identifier: 4437.

Biventricular pacing in a patient with ventilatory and inotropic dependant heart failure following coronary artery by-pass surgery.

Resynchronisation of intra- and interventricular conduction delay by biventricular pacing has become a proven therapy for selected heart failure patients. We present a case of biventricular pacing, used with great success, as a 'bail out' for a patient with refractory congestive heart failure following by-pass surgery.

Ventricular pacing in the presence of tricuspid valve disease.

Pacemaker implantation following tricuspid valve surgery remains challenging, but recent developments in lead technology have significantly improved the options for ventricular pacing. In the presence of significant tricuspid regurgitation, steroid-eluting active-fixation leads should be used routinely, and in patients with a tricuspid prosthesis, the use of a dedicated cardiac venous pacing system is likely to be the best option.