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.

Cardiovascular effects of marine omega-3 fatty acids.

Much evidence shows that the marine omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid have beneficial effects in various cardiac disorders, and their use is recommended in guidelines for management of patients after myocardial infarction. However, questions have been raised about their usefulness alongside optimum medical therapies with agents proven to reduce risk of cardiac events in high-risk patients. Additionally, there is some evidence for a possible pro-arrhythmic effect in subsets of cardiac patients. Some uncertainly exists about the optimum dose needed to obtain beneficial effects and the relative merit of dietary intake of omega-3 polyunsaturated fatty acids versus supplements. We review evidence for the effects of omega-3 polyunsaturated fatty acids on various cardiac disorders and the risk factors for cardiac disease. We also assess areas of uncertainty needing further research.

Migraine following trans-septal access for catheter ablation of cardiac arrhythmias.

There is increasing recognition that migraine with aura may be associated with intra-cardiac shunting because of a patent foramen ovale. Radio-frequency ablation to treat cardiac arrhythmias is an increasingly popular means of treating cardiac arrhythmias. Trans-septal puncture is routinely performed to gain access to the left atrium in order to ablate arrhythmias originating in the left heart. We report several cases of migraine triggered acutely by trans-septal puncture at our center.

Treatment of tachycardia: bradycardia syndrome in a patient with obstructive sleep apnoea.

Obstructive sleep apnoea (OSAS) affects 4% of men and 2% of women aged 30-65 years. It is diagnosed in the presence of excessive daytime sleepiness and an apnoea-hypopnoea index (AHI) of ≥5 on polysomnography. Rhythm disturbances are common in OSAS and continuous positive airway pressure (CPAP) has been shown to be beneficial. We present a case of a patient with obesity, atrial fibrillation with fast ventricular response, significant nocturnal pauses (3.9 s) and tachycardiomyopathy. A polysomnography confirmed severe OSAS (AHI=64.25). CPAP improved bradycardia and allowed for the introduction of ß-blockers. Subsequent Holter monitoring revealed better rate control with the longest pause of 2 s and the patient's left ventricular systolic function improved. CPAP prevented our patient from invasive treatment, allowed for rate control and improvement of tachycardiomyopathy. With such a high prevalence of OSAS, clinicians should be aware that CPAP may aid arrhythmia control.

Takotsubo cardiomyopathy case series: typical, atypical and recurrence.

Takotsubo cardiomyopathy (TCM) is characterised by a transient left ventricular (LV) dysfunction, ECG changes that can imitate acute myocardial infarction and positive cardiac biomarkers in the absence of obstructive coronary artery disease. The exact pathogenesis of TCM is unclear but emotional or physical stress is a common denominator. We present three cases encompassing a spectrum of the disease: A typical TCM with apical LV dyskinesis, an atypical TCM with mid-ventricular regions affected and a TCM recurrence. Our cases show that TCM symptoms vary between individuals and may vary in the same patient. All our patients reported acute emotional stress prior to the onset of symptoms, had LV systolic dysfunction, positive cardiac biomarkers and non-obstructed coronary arteries. In all cases, LV systolic dysfunction eventually improved. TCM may account for 0.7-2.5% of acute coronary syndromes. It is more prevalent in the female population and can reoccur. Treatment is mainly supportive.

Risk assessment for sudden cardiac death in dialysis patients: how relevant are conventional cardiac risk factors?

Patients with end stage renal disease on long term dialysis support have a very high risk of sudden cardiac death (SCD) presumably due to serious ventricular arrhythmias. Implantable cardioverter defibrillators (ICD) can be life saving in patients with SCD but their role in dialysis patients is unclear. Much of the current evidence on this important clinical issue limits to retrospective analysis of patients who received an ICD for conventional cardiac indication. It appears that there are certain factors that are unique to patients with renal failure which pre-disposes them to such high incidence of SCD and by applying the conventional risk assessment model on this sub-group of patients we are likely to miss a significant proportion of patients who would not fulfil that criteria but would be at high risk of SCD. In order to clarify this issue, we performed a retrospective screening of patients with end stage renal disease on haemodialysis using conventional risk assessment model and compared the outcome with the known incidence of SCD in this sub-group.

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.

Apolipoprotein E alleles and bicuspid aortic valve stenosis in monozygotic twins.

Aortic valve disease is a common valvular heart disease but the underlying pathology that leads to the severe dysfunction of the aortic valve is unclear. There is increasing interest in the role of hypercholesterolaemia in the causation and progression of aortic valve disease. Apolipoprotein E is an essential component of cholesterol and previous studies have reported conflicting results on the association between various apolipoprotein E alleles and aortic valve disease. We report two interesting cases of severe dysfunction of bicuspid aortic valves in twin brothers who presented to us at the same time.

Prolonged combination anti-platelet therapy following per-cutaneous coronary intervention (PCI) is impractical in the elderly.

A prolonged course of anti-platelet therapy is increasingly recommended following per-cutaneous coronary intervention based on the evidence from several clinical trials. However, the practicality and risk of such therapy in unselected patient population is as yet unclear. This study shows that such prolonged regimes of anti-platelet therapy are not practical in the elderly sub-group of patients.