Discrimination between physiologic and pathologic left ventricular dilatation.

The identification of certain cardiovascular disease in athletes may constitute the basis for disqualification from competition in an effort to minimize the risk of sudden cardiac death. The aim of this study was to assess diastolic and systolic parameters measured by tissue Doppler imaging in endurance veteran athletes who had prominent cardiac dilatation and patients with idiopathic dilated cardiomyopathy in order to determine whether these variables might differentiate each other.

A review of levosimendan in the treatment of heart failure.

Heart failure is a relatively important public health problem due to its increasing incidence, poor prognosis, and frequent need of re-hospitalization. Intravenous positive inotropic agents play an important role in treating acute decompensation of patients with heart failure due to left ventricular systolic dysfunction. Although frequently used, the inotropic agents beta-adrenergic agonists and phosphodiesterase inhibitors seem effective for improving symptoms in the short term; it has been shown that they increase morbidity and mortality by elevating intracellular cyclic adenosine monophosphate (cAMP) and calcium levels. Levosimendan is a new positive inotropic agent having ATP-dependent potassium-channel-opening and calcium-sensitizing effects. In studies on its effects without increasing intracellular calcium concentrations and on its effects that depend on available intracellular calcium levels, it has been shown to have favorable characteristics different from those of current inotropic agents, which exert their effects by increasing calcium concentrations. This study aims to review other important studies about levosimendan by revealing the underlying mechanisms of its activity, efficiency, and safety.

Aortic elastic properties and left ventricular diastolic dysfunction in patients with obstructive sleep apnea.

Although the responsible mechanisms are not yet fully known, obstructive sleep apnea is associated with an increased risk for cardiovascular disease and events. The aorta is not only a conduit delivering blood to the tissues but is also an important modulator of the entire cardiovascular system, its elastic properties also affecting left ventricular function and coronary blood flow. The aim of this study was to determine left ventricular diastolic function and aortic elastic properties in patients with obstructive sleep apnea syndrome. Fourteen male patients with obstructive sleep apnea and 14 age- and body mass index-matched healthy male controls took part in the study as a control group. All subjects underwent echocardiographic examination; left ventricular cavity dimension, standard and tissue Doppler parameters, and aortic diameter (3 cm above aortic valve) at systole and diastole were measured. While the aortic stiffness index in patients with obstructive sleep apnea was significantly higher than that of the control group (4.5 +/- 0.3 vs 2.1 +/- 0.1, P = 0.001), the aortic distensibility index was found to be lower in this group compared with controls (2.4 +/- 1.2 vs 3.9 +/- 1.5 cm2 dynes(-1) 10(-6), P = 0.009). Furthermore, peak velocity of myocardial systolic wave and peak velocities of myocardial diastolic waves in sleep apnea patients were lower than in controls. There was an association between aortic stiffness and the apnea hypopnea index (coefficient = 0.49, P = 0.002). We also found an inverse correlation between peak velocity of myocardial diastolic wave and aortic stiffness (coefficient = -0.43, P = 0.003), using multiple linear regression. Increased aortic stiffness that is associated with the severity of disease in patients with obstructive sleep apnea may lead to diastolic dysfunction of the left ventricle.

Endothelial flow-mediated dilatation and exercise capacity in highly trained endurance athletes.

Brachial artery ultrasound during reactive hyperemia is a noninvasive method of assessing peripheral endothelium-dependent vasodilatation. Aerobic exercise has the potential to improve local endothelial function. We sought to analyze the effects of regular aerobic training on brachial artery endothelial function in endurance athletes. We studied diameter and blood flow of the brachial artery in 32 endurance male athletes and 30 healthy male subjects. In the same subjects flow-mediated dilatation of the brachial artery was recorded by inducing an ischemia through a forearm arterial occluding cuff. Maximal oxygen consumption was significantly higher in the athletes group than in the controls (61.24 +/- 5.43 vs 44.49 +/- 2.68 ml/kg/min, p < 0.001). Flow-mediated dilatation of the brachial artery induced by forearm arterial occlusion in athletes was also higher than that of the control subjects (17.1 +/- 2.3 vs 11.2 +/- 1.7, p=0.002). Furthermore, there was an association between flow-mediated dilatation and VO2max (r=0.69, p < 0.001). Baseline measurements of the diameter and the blood flow volume of the brachial artery were similar in both groups. During reactive hyperemia period, the percent of the changes of endothelial diameters and flow were significantly higher in athletes than in controls. Higher flow-mediated dilatation levels in athletes reflect better vascular adaptation to habitual aerobic exercise.