BACKGROUND Exercise gated single-photon emission computed tomography (SPECT) using technetium-99m (99mTc)-sestamibi evaluates both myocardial perfusion during stress and wall motion >30 min after the stress, which has the potential to assess not only exercise-induced myocardial ischemia but also the development of myocardial stunning. METHODS AND RESULTS To evaluate the incidence of post-stre...

Stress-induced cardiomyopathy, in contrast to acute myocardial infarction, is a type of heart failure characterized by reversible left ventricular dysfunction. Cardiac imaging primarily reveals ventricle stunning, 81.7% which apical type. Emotional or psychological stress usually precedes the onset stress-induced increasingly being recognized as unique neurogenic stunning disease. To distinguis...

While coronary thrombolytic therapy in clinical practice is well established for acute myocardial infarction, the injury associated with reperfusion ("reperfusion injury") is still under intense investigation regarding its nature and the strategy for its prevention. Reperfusion injury has been defined as cell injury caused by reperfusion itself, in contradistinction to cell injury caused by the...

This study was undertaken to elucidate whether cal-adrenoceptor activity is beneficial to contractile dysfunction during reperfusion after a brief period of ischemia (stunned myocardium) in 54 open-chest dogs. Contractile dysfunction assessed by fractional shortening (FS) was observed 3 hours after the onset of reperfusion following 15 minutes of complete occlusion of the left anterior descendi...

Among the numerous mechanisms proposed for myocardial stunning, three appear to be more plausible: 1) generation of oxygen radicals, 2) calcium overload, and 3) excitation-contraction uncoupling. First, the evidence for a pathogenetic role of oxygen-derived free radicals in myocardial stunning is overwhelming. In the setting of a single 15-minute coronary occlusion, mitigation of stunning by an...

Brief myocardial ischemia of less than 20 min duration, followed by reperfusion, is known to cause transient contractile dysfunction, often termed myocardial stunning. Tagged magnetic resonance imaging offers a noninvasive method that can be used to quantify this regional mechanical dysfunction in stunned myocardium. To this end, a closed-chest canine model of myocardial stunning was created by...

Prominent T-wave inversions are well recognized electrocardiographic signs that can occur in acute myocardial infarction (AMI). However, the giant negative T waves may be associated with myocardial stunning without AMI.This case report describes 2 patients without AMI who developed rare giant T-wave inversions measuring up to 35 mm in depth and QT prolongation after admission to hospital. While...

Introduction: Cardiovascular disease (CVD) has been well documented as the leading cause of death in the general population worldwide. Physical activity is a modifiable factor in the development and progression of CVD reducing its incidence by 42-44% and reducing mortality and hospital admissions. The presence of chronic kidney disease (CKD), and the recurrence of cumulative circulatory stress ...

There is no evidence regarding the effect of stunning on maximization of regional myocardial external work (EW) or efficiency of energy transfer (EET) in relation to regional afterload (end-systolic stress, sigma(es)). To that end, we studied these relationships in both the left anterior descending coronary artery (LADCA) and left circumflex coronary artery regions in anesthetized, open-chest p...

To test the hypothesis that persistent myocardial stunning can lead to hibernating myocardium, 13 pigs were chronically instrumented, and persistent stunning was induced regionally by 6 repetitive episodes of 90-minute coronary stenosis (CS) (30% reduction in baseline coronary blood flow [CBF]) followed by full reperfusion every 12 hours. During the 1st CS, CBF fell from 43+/-2 to 31+/-2 mL/min...