View clinical trials related to Myocardial Stunning.
Filter by:Incomplete recovery from ischemia causes stunned myocardium. Ischemia may be due to coronary artery disease or aortic cross-clamping during surgery. Stunning leads to myocardial dysfunction. It has been suggested that the mechanism responsible for the contractile depression in stunned myocardium is a decreased sensitivity of the myofibrils to calcium. Levosimendan is a calcium sensitizer, which has been shown to improve the function of stunned myocardium without obvious impairment of diastolic function. Systemic vasodilation and need of vasoconstrictive medication is usually apparent after administration of levosimendan. Colucci et al have demonstrated that with intracoronary administration of milrinone, another inodilator, systemic vasodilation could be excluded. If this is true with levosimendan, it may be possible to improve left ventricular hypo/dyskinesia without afterload reduction by adding levosimendan into cardioplegia solution. The investigators hypotize that levosimendan, delivered together with cardioplegia, can improve LV dysfunction after opening of aortic cross-clamp in patients undergoing aortic valve and coronary artery bypass operation. Our primary endpoint is a change in cardiac output 15 min after separation from cardiopulmonary bypass compared to the baseline. Secondary endpoints are a change in LV ejection fraction from baseline to 5 min after sternal closure and cTnT/CK-MB on the first postoperative morning.
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.
There is increasing interest in myocardial abnormalities following central nervous system events, such as subarachnoid hemorrhage (SAH). These cardiac abnormalities include ECG changes, decreased cardiac output, decreased blood pressure, specific cardiac enzyme elevations, and segmental wall motion abnormalities (SWMA). Interestingly, wall motion abnormalities and ECG changes have shown to be reversible, and therefore the dysfunction has been described as neurogenic myocardial stunning. The pathophysiology of cardiac dysfunction following SAH has not yet been fully elucidated. Many reports (mainly case reports) have been published, but so far no study has investigated the frequency of these abnormalities in a prospective manner, have correlated the occurrence of the different cardiac abnormalities, and have assessed which clinical variables can predict cardiac dysfunction. And only a limited number of studies have related neurological outcome with cardiac dysfunction.