A pilot study to estimate the feasibility of assessing the relationships between polymorphisms in hKv1.5 and atrial fibrillation in patients following coronary artery bypass graft surgery.

Background: Postoperative atrial fibrillation (AF) is a frequent complication following cardiac surgery. Risk factors leading to the development of postoperative AF are not well known and may be influenced by mutations of specific channels involved in atrial repolarization. Recently, the authors have identified three single nucleotide polymorphisms (SNPs) (R87Q, A251T and P307S) in the voltage-gated potassium channel hKv1.

Visceral obesity and the heart.

Obesity and particularly its deleterious form, visceral adiposity, has reached a high prevalence in the industrialized world owing to the lack of exercise and the widely available energy-dense diet. As a consequence, cardiovascular diseases and metabolic disorders are afflicting an unprecedented number of individuals at a world-wide scale. Over the last decades, investigations have established firm links between visceral obesity and the development of cardiovascular diseases.

A simple Doppler echocardiography method to evaluate pulmonary capillary wedge pressure in patients with atrial fibrillation.

Objective: The accuracy of E/E' ratio has not been validated in atrial fibrillation (AF). The objective of this study is to compare the accuracy of the E/E' ratio averaged over a sample of 10 cardiac cycles and E/E' ratio obtained in the cycle with the longest RR interval for the estimation of wedge pressure in patients with AF using a simultaneous pulmonary artery occlusive pressure measured with a Swan-Ganz catheter.

Design: Twenty-four consecutive patients with AF with a Swan-Ganz catheter were recruited in this study.

Incidental mobile aortic valve lesion: a case of aortic valve fenestration.

The case is reported of a 72-year-old patient with a mobile aortic valve lesion discovered incidentally by echocardiography performed in the setting of coronary artery bypass graft (CABG) surgery. Definitive identification of this lesion was not possible by transthoracic echocardiography or transesophageal echocardiography alone. Pathological examination of the excised aortic valve led to a diagnosis of aortic valve fenestration (AVF) bridging strand rupture.

Safety of the cardiac triple therapy: the experience of the Quebec Heart Institute.

Background: Contemporary treatment of acute coronary syndrome is based on the combination of acetylsalicylic acid (ASA) and clopidogrel. However, an increasing proportion of patients with cardiovascular disease also have an indication for anticoagulant therapy with warfarin. The combination of ASA, clopidogrel and warfarin, also called the cardiac triple therapy (CTT), is emerging in clinical practice, although little is known about its safety.

Direction of persistent ischemic mitral jet after restrictive valve annuloplasty: implications for interpretation of perioperative echocardiography.

Background: Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty (MVA) and is associated with a poor prognosis. It was hypothesized that the anterior displacement of the posterior aspect of the annulus caused by annuloplasty could induce a change in the direction of MR jet.

Methods: The echocardiograms of 21 patients who underwent restrictive MVA for ischemic MR and who had detectable postoperative MR were analyzed before and early after surgery to evaluate the direction of MR jet.

New concepts in valvular hemodynamics: implications for diagnosis and treatment of aortic stenosis.

Aortic valve stenosis (AS) is the third-most frequent heart disease after coronary artery disease and arterial hypertension, and it is associated with a high incidence of adverse outcomes. Recent data support the notion that AS is not an isolated disease uniquely limited to the valve. Indeed, AS is frequently associated with abnormalities of the systemic arterial system, and, in particular, with reduced arterial compliance, which may have important consequences for the pathophysiology and clinical outcome of this disease.

The 'valvulo-metabolic' risk in calcific aortic valve disease.

Calcific aortic stenosis (AS) has been considered a degenerative and unmodifiable process resulting from aging and 'wear and tear' of the aortic valve. Over the past decade, studies in the field of epidemiology, molecular biology and lipid metabolism have highlighted similarities between vascular atherosclerosis and calcific AS. In particular, work from the Quebec Heart Institute and from that of others has documented evidence of valvular infiltration by oxidized low-density lipoproteins and the presence of inflammatory cells, along with important tissue remodelling in valves explanted from patients with AS.

Ischemic, genetic and pharmacological origins of cardiac arrhythmias: the contribution of the Quebec Heart Institute.

Research in the field of basic electrophysiology at the Quebec Heart Institute (Laval Hospital, Quebec City, Quebec) has evolved since its beginning in the 1990s. Interests were focused on cardiac arrhythmias induced by drugs, allelic variants and metabolic factors produced during ischemia. The results have contributed to the creation of new standards in drug development, more specifically, testing all new drugs for their potential effects on cardiac potassium currents, which could produce life-threatening proarrhythmic effects.

The Quebec Heart Institute: 50 years of excellence in cardiology.

The Quebec Heart Institute was established in 1957 at the Laval Hospital in Sainte-Foy, Quebec. Since then, clinical and research activities have made this Institute one of the largest tertiary care cardiology centres in Canada. With its vast catchment area of more than 3,000,000 people, the Institute has developed a strong collaboration with referral physicians centred on clinical, teaching and research interests.

Life-threatening left atrial wall hematoma secondary to a pulmonary vein laceration: an unusual complication of catheter ablation for atrial fibrillation.

Background: Several complications may occur during catheter ablation for atrial fibrillation (AF). We report an unusual case of left atrial wall hematoma without pericardial effusion secondary to a right inferior pulmonary vein (PV) laceration. The use of real-time transesophageal echocardiography (TEE) during the procedure can be useful for early detection of this potentially lethal complication.

Association between plasma LDL particle size, valvular accumulation of oxidized LDL, and inflammation in patients with aortic stenosis.

Objective: In patients with severe aortic stenosis (AS), we examine the association between: (1) the content of oxidized LDL (oxLDL) in the aortic valve and the degree of inflammation and remodeling; (2) The proportion of small dense LDL particles in the plasma and the presence of oxLDL in the valve along with hemodynamic progression of valve stenosis.

Methods And Results: We have examined 102 explanted AS valves. Tissue remodeling, inflammation, and accumulation of oxLDL were determined.

Cholesterol levels in small LDL particles predict the risk of coronary heart disease in the EPIC-Norfolk prospective population study.

Aims: To evaluate the association of low-density lipoprotein cholesterol (LDL-C) levels in small and large LDL particles with risk of incident coronary heart disease (CHD).

Methods And Results: We performed a prospective case-control study nested in the EPIC-Norfolk cohort. Cases were apparently healthy men and women aged 45-79 years who developed fatal or non-fatal CHD (n = 1035), and who were matched by age, gender, and enrollment time to 1920 controls who remained free of CHD.

Association between circulating oxidised low-density lipoprotein and fibrocalcific remodelling of the aortic valve in aortic stenosis.

Introduction: Aortic stenosis (AS) is the most common valvular heart disease in westernized societies. AS is a disease process akin to atherosclerosis in which calcification and tissue remodelling play a crucial role. In patients with moderate/severe AS, we sought to determine whether the remodelling process would be in relationship with transvalvular gradients and circulating oxidised low-density lipoprotein (ox-LDL) levels.

Congenital absence of the pericardium presenting as acute myocardial necrosis.

Congenital absence of the pericardium is a rare defect of which recognition is critical because it can be associated with catastrophic outcomes. While some carriers of this condition may present with a lethal complication, most are asymptomatic, and the defect is found incidentally. The case of a 49-year-old woman is described who presented with acute myocardial necrosis and absence of obstructive coronary artery disease, and in whom a complete left pericardial defect was found.

Predictors of aorto-saphenous vein bypass narrowing late after coronary artery bypass grafting.

The objective of this study was to evaluate the clinical and angiographic factors associated with significant saphenous vein graft (SVG) atherosclerosis progression at mid-term follow-up in a series of unselected coronary patients who had previously received a coronary artery bypass graft (CABG). A total of 123 SVGs from 86 patients who underwent cardiac catheterization twice, 15 +/- 12 months apart, were included in the study. None of the SVGs presented any > or =50% diameter stenosis (DS) lesion or underwent any intervention at baseline.

Use of nitinol-U clips and flow characteristics of LIMA-LAD anastomoses.

The aim of this study was to compare flow characteristics of LIMA-LAD anastomoses constructed using two different techniques. Thirty patients underwent MIDCAB using either simple continuous suture (20) or separate nitinol U-clips (10). Intraoperative transit time flow measurements were recorded.

Cardiovascular disease under the influence of excess visceral fat.

Diabetes and cardiovascular disease have emerged as major threats to human health, and the risk of developing these chronic conditions is increased in individuals with abdominal obesity and the metabolic syndrome. Excess visceral abdominal tissue (VAT) accumulation appears to be a key feature of abdominal obesity contributing to the development of the metabolic syndrome. For instance, excess VAT is accompanied by elevated triglycerides, reduced high-density lipoprotein (HDL) cholesterol, elevated blood pressure, and/or elevated fasting plasma glucose.

The endocannabinoid system: a new target for the regulation of energy balance and metabolism.

Recent studies have provided evidence that the endocannabinoid (EC) system has very significant effects on energy balance and metabolism through the central control of appetite and by affecting peripheral metabolism. Endocannabinoids are endogenous phospholipid derivatives which bind and activate cannabinoid receptors type 1 and type 2 (CB1 and CB2 receptors). The CB1 receptor, a G-protein coupled receptor, is believed to be responsible for the majority of the central effects of endocannaboids on appetite.

Comparison of surgical and transcatheter treatment for native coarctation of the aorta in patients > or = 1 year old. The Quebec Native Coarctation of the Aorta study.

Background: The objectives of this study were to compare, in the current era, the immediate results, complications, and midterm outcomes obtained by surgical repair versus transcatheter treatment of coarctation of the aorta (CoA).

Methods: The study was of retrospective nature and included 80 consecutive patients > or = 1 year old (mean age 12 +/- 10 years) treated for an isolated CoA in 4 university centers in Quebec between 1998 and 2004. Fifty patients underwent aortic angioplasty, with stent implantation in 19, and 30 had surgical repair.

Can prolonged exercise-induced myocardial ischaemia be innocuous?

Aims: To evaluate the innocuousness of intense and prolonged exercise training above the threshold for myocardial ischaemia (1 mm ST-segment depression).

Methods And Results: Twenty-two patients with ischaemic heart disease (IHD) were randomized to exercise training either at a target intensity that induced myocardial ischaemia (ischaemic group) or that adhered to current guidelines (control group). Training was progressively increased to 60 min under continuous electrocardiographic (ECG) monitoring.

Paradoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival.

Background: Recent studies and current clinical observations suggest that some patients with severe aortic stenosis on the basis of aortic valve area may paradoxically have a relatively low gradient despite the presence of a preserved left ventricular (LV) ejection fraction. The objective of the present study was to document the prevalence, potential mechanisms, and clinical relevance of this phenomenon.

Methods And Results: We retrospectively studied the clinical and Doppler echocardiographic data of 512 consecutive patients with severe aortic stenosis (indexed aortic valve area < or = 0.

Different thresholds of myocardial ischemia in ramp and standard bruce protocol exercise tests in patients with positive exercise stress tests and angiographically demonstrated coronary arterial narrowing.

Gradual instead of abrupt increases in workload favor a more physiologic response in terms of hemodynamic and gas exchange parameters. Therefore, we investigated whether myocardial ischemia is attenuated with a ramp compared with a standard Bruce exercise protocol in patients with coronary artery disease. We compared electrocardiographic ischemic parameters on the standard Bruce protocol treadmill and the individualized ergocycle ramp protocol in 18 men with coronary artery disease and a reproducible ischemic electrocardiographic exercise test.