Cardiac repolarisation indices are associated with oxygen consumption during maximal exercise test in highly-trained cross-country skiers.

The objective of this study was to test the vectorelectrocardiographic T-wave characteristics for their associations with oxygen consumption (VO) and physical performance during a maximal cardiopulmonary exercise test (CPET) in highly trained cross-country skiers. Male highly trained cross-country skiers ( = 30) performed the maximal CPET on the bicycle ergospirometric "Oxycon Pro" system with simultaneous oxygen consumption (VO) and electrocardiogram recording. The measurements were done at rest; the stage preceding anaerobic threshold (preAnT); peak load; and recovery.

Formation of a border ischemic zone depends on plasma potassium concentration.

Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal border under [K] variation. Sixty-four-lead epicardial mapping was performed in 26 rats ([K] 2.

Action potential morphology affects T-wave symmetry (simulation study).

Background: Assessing T-wave symmetry in addition to QT subintervals measurements can provide novel independent data about ventricular repolarization abnormalities linked with arrhythmogenesis. However, the causes of the changes of T-wave symmetry are not completely understood. In silico studies showed that the more symmetrical T-waves were associated with shorter action potential duration (APD) and larger dispersion of ventricular repolarization (DOR).

Terminal T-wave inversion predicts reperfusion tachyarrhythmias in STEMI.

Introduction: A reliable electrocardiographic predictor of ventricular fibrillation (VF) in patients with ST elevation myocardial infarction (STEMI) is lacking so far. Previous experimental/simulation study suggested a terminal T-wave inversion (TTWI) in ischemia-related ECG leads corresponding to anterior infarct localization as an independent predictor of reperfusion VF (rVF). This T-wave characteristic has never been tested as a rVF predictor in clinical settings.

Dispersion of ventricular repolarization: Temporal and spatial.

Repolarization heterogeneity (RH) is an intrinsic property of ventricular myocardium and the reason for T-wave formation on electrocardiogram (ECG). Exceeding the physiologically based RH level is associated with appearance of life-threatening ventricular arrhythmias and sudden cardiac death. In this regard, an accurate and comprehensive evaluation of the degree of RH parameters is of importance for assessment of heart state and arrhythmic risk.