INTRODUCTION Vectorcardiography (VCG) may have predictive value in Tetralogy of Fallot (TOF) patients undergoing ventricular arrhythmia inducibility (VAI) electrophysiology studies (EPs). MATERIALS AND METHODS Blinded, retrospective analyses of 37 adult TOF patients undergoing EPs prior to pulmonary valve replacements were performed (21 female, median age 37years). VAI was evaluated from EPs ...

Ventricular arrhythmia is a well-known cause of syncopal attacks and sudden cardiac death in humans. Ventricular repolarization (VR) is the most unstable phase in cardiac electrical activity and its regulation depends on the coordinated activity in multiple ion channels. Several physiological factors such as heart rate (HR), autonomic nervous system (ANS) activity, gender and age influence the ...

Elevated ventricular repolarization lability is believed to be linked to the risk of ventricular tachycardia/ventricular fibrillation. However, ventricular repolarization is a complex electrical phenomenon, and abnormalities in ventricular repolarization are not completely understood. To evaluate repolarization lability, vectorcardiography (VCG) is an alternative approach where the electrocardi...

To test modified Newtonian dynamics (MOND) on galactic scales, we study six strong gravitational lensing early-type galaxies from the CASTLES sample. Comparing the total mass (from lensing) with the stellar mass content (from a comparison of photometry and stellar population synthesis), we conclude that strong gravitational lensing on galactic scales requires a significant amount of dark matter...

The polarcardiographic responses to exercise in normal men, young and middle-aged, have been compared with those of men who show ischemic responses on the electrocardiogram. Changes in the ST-vectors are the most significant. These changes have been reduced to a single numerical quantity based on the spatial magnitude of the vector at the end of the QRS complex and the spatial direction of a ve...