View clinical trials related to Myocardial Stunning.
Filter by:The purpose of this study is to investigate the effect of percutaneous coronary intervention (PCI) on myocardial viability in coronary artery disease patients with single coronary total occlusion (CTO) lesions.
Chronic kidney disease (CKD) is linked to elevated mortality rate, and cardiovascular disease is the main cause related to this outcome. The cardiovascular mortality among patients on conventional hemodialysis (CHD) is high, achieving up to 30 times more risk of death when comparing to individuals of same age on general population. Congestive heart failure can develop in 25% to 50% of patients, leading to a worse prognosis. CKD patients present anatomic and functional abnormalities on peripheral bed vases and also cardiovascular abnormalities that can cause myocardial ischemia. This last usually is transitory and lead to left ventricular dysfunction that can persist even after the end of dialysis session despite normal coronary perfusion. The prolonged dysfunction is called myocardial stunning (MS). Patients on CHD are subject to hemodynamic instability, myocardial ischemia and development of regional abnormalities of myocardial wall (ARPM´s). MS induced by intradialytic ischemia is a complication that can be minimized by applying techniques associated to more stability during the CHD, as cool dialysate or increasing the length of the therapy. The goal of the present study is to evaluate the behavior of cardiovascular system (trough hemodynamic performance during CHD, accessing MS by echocardiography technique, and biomarkers associated to MS). Finally, the investigators aimed to investigate the role of two different dialysate calcium concentration (2,5 and 3,5 mEq/l) in the genesis of MS during CHD. The elucidation of pathogenesis of MS during CHD might help us modified hemodialysis technique in order to prevent MS, and reduce the high cardiovascular mortality among CKD patients.
Until now it has been assumed that regular endurance training has a positive influence on cardiac function and that the positive effect increases with increasing intensity. However, little is known about the effects of intense endurance stress on the heart. According to current knowledge repeated exposure to strenuous endurance activity may lead to minor but possibly irreversible damage to the heart with resultant scarring of the heart's muscle. Within this study we attempt to find out by different analytical methods - in particular magnetic resonance imaging (MRI) and ultrasound of the heart - to what extent the heart muscle is affected by an intense endurance exercise, i.e. the "Jungfrau-Marathon", and which changes can possibly be found. Due to repeated measurements we will obtain further information on the short-term course of possible changes. Hypotheses: A single bout of prolonged strenuous exercise (PSE) leads to transient alteration in cardiac function accompanied by the appearance of biomarkers for myocardial damage.
Viability assessment remains a clinical challenge in patient with coronary artery disease and left ventricular dysfunction. Several imaging modalities are available for evaluating myocardial viability, based either on perfusion or on contractile reserve analysis. Briefly, perfusion analysis is highly sensitive and contractile reserve highly specific. A combined analysis of both perfusion and contractile reserve has been proposed to improve the diagnostic accuracy in patient referred for a revascularization procedure. However, the value of this combined analysis has not been validated in unselected patients referred for viability assessment. The patients enrolled in the study will undergo a nitrate enhanced rest gated SPECT using a Tc-99m labeled tracer (sestamibi or tetrofosmine) followed by a second gated SPECT acquired during a low-dose dobutamine infusion (10 mcg/kg/mn). All patients will have a 6-month clinical and imaging follow-up, including physical examination and a nitrate enhanced rest gated SPECT using the same radiopharmaceutical. All treatments received during this 6-month period will be recorded, including medical therapy and coronary revascularization (angioplasty, stenting and CABG). Finally, the value of baseline perfusion and contractile reserve analysis in predicting left ventricular ejection fraction changes at 6-month follow-up will be evaluated.