Contribution of visceral adiposity to the exaggerated postprandial lipemia of men with impaired glucose tolerance.

Objective: Impaired glucose tolerance (IGT) has been associated with alterations in numerous coronary heart disease risk factors, including postprandial hyperlipidemia. An excess visceral adipose tissue accumulation is also predictive of IGT and of an exaggerated postprandial lipemia. The objective of the present study was therefore to compare the respective contributions of visceral adipose tissue accumulation versus IGT with the variation in postprandial lipemia.

The impact of brain death on survival after heart transplantation: time is of the essence.

Background: It has been suggested that the modality of brain death and time from brain death until harvest impact survival and rejection after heart transplantation.

Methods: Donor files from 475 adult heart-transplant recipients were examined. From these files, a total management time (time from incident leading to brain death until aortic cross clamp) was determined, and the cause of brain death was noted.

Impact of postprandial variation in triglyceridemia on low-density lipoprotein particle size.

The fasting atherogenic dyslipidemia of visceral obesity, which includes the presence of small, dense low-density lipoprotein (LDL) particles, is predictive of an increased risk of coronary heart disease (CHD). It has also been suggested that progression of atherosclerosis may be accelerated in the presence of postprandial hyperlipidemia independently from the fasting dyslipidemic state. Studies have shown that the best predictor of postprandial hyperlipidemia and of the small, dense LDL phenotype is fasting triglyceride (TG) concentration.

Hydrogen peroxide modulates the Kv1.5 channel expressed in a mammalian cell line.

Reactive oxygen species have been implicated in different types of cardiac arrhythmias including human atrial fibrillation. Kv1.5, the presumed molecular correlate of I(Kur), is an important determinant of human atrial repolarization.

Effect of atorvastatin on exercise-induced myocardial ischemia in patients with stable angina pectoris.

To investigate whether marked and sustained lipid-lowering in subjects with stable angina pectoris and dyslipidemia reduces exercise-induced myocardial ischemia, 17 subjects were treated with dose-adjusted atorvastatin over 1 year and underwent serial evaluation of exercise electrocardiographic ischemic parameters, serum biomarkers, and brachial artery endothelial function. Endothelial function improved progressively and C-reactive protein, P-selectin, and tissue plasminogen activator inhibitor levels decreased, but there was no decrease in exercise electrocardiographic ischemia.

Contribution of apo CIII reduction to the greater effect of 12-week micronized fenofibrate than atorvastatin therapy on triglyceride levels and LDL size in dyslipidemic patients.

Background: Apolipoprotein (apo) CIII plays an important role in the catabolism of triglyceride-rich lipoproteins as it is a potent inhibitor of lipoprotein lipase (LPL). A low LPL activity has been simultaneously associated with hypertriglyceridemia, low HDL cholesterol and with small LDL particles.

Aim: To compare the effects of a 12-week treatment with micronized fenofibrate (200 mg) versus atorvastatin (10 mg) on apo CIII and lipoprotein-lipid levels including LDL size.

Potential contribution of metformin to the management of cardiovascular disease risk in patients with abdominal obesity, the metabolic syndrome and type 2 diabetes.

With an evolving landscape of a growing number of obese and/or type 2 diabetic patients in our affluent population, the metabolic syndrome has become a major issue because of its impact on cardiovascular disease risk. In this regard, although it is appropriate to aim at a better glycaemic control in type 2 diabetic patients, hyperglycaemia does not appear to be the main culprit responsible for the markedly increased cardiovascular disease risk in this population. Rather, studies have suggested that a cluster of metabolic abnormalities, which includes an atherogenic dyslipidaemic state, an impaired glucose/insulin homeostasis, and a pro-thrombotic and inflammatory profile, substantially increases the risk of coronary heart disease in type 2 diabetic patients in a manner which is partly independent of glycaemic control.

Determinants of stroke after coronary artery bypass grafting.

Objectives: Cerebrovascular accidents (CVA) after CABG are deleterious complications whose prevention remains poorly defined. The aim of this study was to identify the determinants for CVA after CABG.

Methods: Nine thousand nine hundred and sixteen patients underwent CABG at our institution from January 1992 to June 2002.

Impact of valve prosthesis-patient mismatch on short-term mortality after aortic valve replacement.

Background: The prosthesis used for aortic valve replacement (AVR) can be too small in relation to body size, thus causing valve prosthesis-patient mismatch (PPM) and abnormally high transvalvular pressure gradients. This study examined if there is a relation between PPM and short-term mortality after operation.

Methods And Results: The indexed valve effective orifice area (EOA) was estimated for each type and size of prosthesis being implanted in 1266 consecutive patients and used to define PPM as not clinically significant if >0.

Does moderate mitral regurgitation impact early or mid-term clinical outcome in patients undergoing isolated aortic valve replacement for aortic stenosis?

Objective: The early and mid-term impact of functional mitral regurgitation (MR) in patients undergoing isolated aortic valve replacement (AVR) for aortic stenosis remains unresolved.

Method: Through our institutional databank, using a case-match study, we identified 58 patients with MR grades 0-1 and 58 patients with MR grades 2-3 (patients matched for sex, age, ejection fraction (EF), NYHA, diabetes, and CVA). Data were collected prospectively (mean duration of follow-up: 3.

[Treatment of obesity: the need to target attention on high-risk patients characterized by abdominal obesity].

Abdominal obesity is associated with metabolic abnormalities, increasing the risk of type 2 diabetes and coronary artery disease (CAD). The Quebec Cardiovascular Survey demonstrated that the atherogenic metabolic triad (AMT) present in abdominally obese (AO) males increases the risk of CAD 20-fold over the course of 5 years. An early detection algorithm was developed to identify individuals presenting these atherogenic abnormalities.

Myocardial infarction in a young woman secondary to a rupture of a noncoronary sinus of Valsalva aneurysm without coronary artery disease.

A 22-year-old woman presented with sudden onset of chest pain. Echocardiography showed a ruptured aneurysm of the noncoronary sinus of Valsalva in the right atrium. Slight ST segment depression was observed on initial electrocardiography (ECG).

Modulation of L-type Ca2+ channels in neonatal rat heart by a novel Ca2+ channel agonist.

L-type Ca2+ channels are essential in triggering the intracellular Ca2+ release and contraction in heart cells. In this study, we used patch clamp technique to compare the effect of two pure enantiomers of L-type Ca2+ channel agonists: (+)-CGP 48506 and the dihydropyridine (+)-SDZ-202 791 in cardiomyocytes from rats 2-5 days old. The predominant Ca2+ current activated by standard step pulses in these myocytes was L-type Ca2+ current.

Left ventricular longitudinal shortening in patients with aortic stenosis: relationship with symptomatic status.

Background And Aim Of The Study: Symptomatic status in aortic stenosis is not always related to hemodynamic severity as estimated by the aortic valve effective orifice area (AVA), and other factors may be involved. It has been seen previously that, whilst ejection fraction is preserved, left ventricular (LV) longitudinal shortening may be selectively decreased in aortic stenosis, and hypothesized that this might be a marker of subendocardial ischemia as subendocardial myocardial fibers are oriented longitudinally. The present study examined the possible relationship between LV longitudinal shortening and symptoms in patients with aortic stenosis.

What induces the warm-up ischemia/angina phenomenon: exercise or myocardial ischemia?

Background: The relation of the warm-up ischemia phenomenon to the presence and intensity of initial myocardial ischemia is unclear. We sought to determine whether the warm-up ischemia phenomenon requires initial myocardial ischemia or can be induced by exercise without ischemia and whether there is a relation between the intensity of initial ischemia and the attenuation of ischemia on reexercise.

Methods And Results: Twelve subjects with exertional myocardial ischemia performed 2 exercise ECG tests (1 and 2) at a +/-10-minute interval on 3 occasions (A, B, C) 1 month apart.

Rescue therapy with methylene blue in systemic inflammatory response syndrome after cardiac surgery.

Severe unresponsive vasoplegia syndrome following cardiopulmonary bypass is rare. The authors report a case of severe vasoplegia, unresponsive to conventional treatment three days following cardiopulmonary bypass. A single intravenous bolus (2 mg/kg) of methylene blue was administered with normalization of the peripheral resistance.

Prevalence of metabolic alterations predictive of cardiovascular disease risk in the Québec population.

Background: It is well established that cardiovascular diseases (CVD) are the most important cause of morbidity and mortality in North America and in industrialized countries. Furthermore, the presence of CVD risk factors is widespread in Canada, and two-thirds of adult Canadians present at least one traditional risk factor for CVD.

Objective: To quantify the prevalence of metabolic alterations predictive of an increased risk of CVD in a representative sample of the Québec population.

Is the gender difference in LDL size explained by the metabolic complications of visceral obesity?

Background: Several studies have reported a significant gender difference in low-density lipoprotein (LDL) size, with men being characterized by smaller, denser LDL particles than women, and it has been suggested that the contribution of the greater accumulation of visceral adipose tissue in men compared with women may be a factor potentially contributing to the gender difference in LDL heterogeneity.

Materials And Methods: We measured LDL particle size by 2-16% nondenaturing polyacrylamide gradient gel electrophoresis in 299 men and 231 women in whom visceral adipose tissue accumulation was measured by computed tomography. A fasting plasma lipoprotein-lipid profile was also obtained in all subjects.

Role of specific cytochrome P450 enzymes in the N-oxidation of the antiarrhythmic agent mexiletine.

1. Mexiletine is extensively metabolized in man by C- and N-oxidation and the aim of the present study was to characterize major cytochrome P450 enzyme(s) involved in the formation of N-hydroxymexiletine. 2.

Mitral annulus velocities by Doppler tissue imaging: practical implications with regard to preload alterations, sample position, and normal values.

Because it appears to be less affected by changes in preload, mitral annulus Doppler tissue imaging (DTI) has been proposed as an alternate mean of identifying pseudonormal patterns of left ventricular filling. We thus studied the practical implications of DTI in 40 patients classified according to the Canadian Consensus on Diastolic Function (9 control participants, 9 with impaired relaxation, and 22 pseudonormal participants). Using DTI, the early diastolic velocity (Ea) was the most reproducible parameter whereas the late diastolic velocity (Aa) and Ea/Aa ratio varied significantly.

Ethanol protects against lysophosphatidylcholine-induced uncoupling of cardiac cell pairs.

Moderate alcohol consumption is related to a reduction in cardiovascular deaths. Lysophosphatidylcholine (LPC) produces arrhythmias similar to those induced by ischemia most likely due to its uncoupling properties. We assessed effects of LPC in the presence of ethanol in cardiac myocyte pairs using the double whole-cell voltage-clamp technique.

Independent contribution of left ventricular ejection time to the mean gradient in aortic stenosis.

Background And Aims Of The Study: Transvalvular mean pressure gradients (MPG) are important in the evaluation of aortic stenosis, but surprisingly they often differ in patients having similar valve effective orifice area (EOA) and stroke volume (SV). The study aim was to determine if these differences could be explained by variations in left ventricular ejection time (LVET).

Methods: A pulse duplicator system with a constant SV of 75 ml and incremental increases of LVET from 250 to 450 ms was used to measure MPG by Doppler echocardiography in three fixed stenoses (0.

Hemodynamic performance at rest and during exercise after aortic valve replacement: comparison of pulmonary autografts versus aortic homografts.

Background: The Ross procedure and aortic homografts have both been shown to have superior hemodynamic performance after valve replacement, but there have been few comparisons.

Methods: Sequential Doppler echocardiograms were performed up to 5 years after aortic valve replacement in 132 patients with the Ross procedure and 111 patients with an aortic homograft (AH). Measurements included assessment of valvular regurgitation and calculations of valve effective orifice area (EOA) and mean transvalvular gradients; the same measurements were also performed at the level of the pulmonary homograft in the Ross patients as well as during maximum exercise in 20 Ross patients and 14 AH patients.