Homogeneity of recovery time protects against arrhythmias whereas dispersion of recovery time is arrhythmogenic. A single surface electrocardiographic QT interval gives no information on recovery time dispersion but the difference between the maximum and minimum body surface QT interval may be relevant. This hypothesis was tested by measuring the dispersion of the corrected QT interval (QTc) in...

A 10-year-old boy with varicella developed syncopal episodes caused by runs of self-terminating ventricular tachycardia and ventricular fibrillation. These arrhythmias were thought to be caused by varicella myocarditis and were resistant to most common antiarrhythmic agents. Continuous electrocardiographic recording and analysis proved extremely useful in the management of this case. Mexiletine...

PRELIMINARY STUDIES " suggested that the capacity of a drug to suppress ventricular arrhythmia might be inherent in a chemical structure which does not possess certain actions previously associated with antiarrhythmic activity, e.g., elevation of electric threshold, depression of conduction, and local anesthesia. Ambonestyl, 2-diethylaminoethyl-isonicotinamide,* (MC 4112), was found to be a com...

Encainide is a new agent for treating ventricular arrhythmias. We attempted long-term oral therapy with encainide in 38 patients with recurrent, strikingly drug-refractory ventricular tachycardia. The usual daily dose of encainide ws 150-250 mg divided into four or six doses. The mean period until withdrawal of encainide or the date of follow-up was 4.2 months. Encainide completely eliminated r...

To determine if enflurane has different effects on myocardial sensitivity to adrenaline than those previously reported for halothane, we have studied the enflurane-adrenaline interaction in isolated canine trabeculae using doses of adrenaline necessary to produce slow responses (adrenaline threshold for the development of slow responses, ATSR) as an indicator. The preparations were depolarized ...

Myocytes overlying a zone of infarction form the primary substrate for serious reentrant ventricular arrhythmias. In vitro and in vivo studies suggest that antiarrhythmic agents affect Na+ channels of cells from the epicardial border zone (EBZ) of the 5-day infarcted heart differently than they affect those of normal muscle. However, the mechanisms responsible for this difference remain unclear...

In cardiac patients, life-threatening tachyarrhythmia is often precipitated by abnormal changes in ventricular repolarization and refractoriness. Repolarization abnormalities typically evolve as a consequence of impaired function of outward K+ currents in cardiac myocytes, which may be caused by genetic defects or result from various acquired pathophysiological conditions, including electrical ...

Objective(s): Electrical inhomogeneity between ischemic and non ischemic myocardium is the basis of arrhythmia which occurs following coronary artery occlusion. The leakage of potassium from the ischemic region to the non ischemic region is very effective in the generation of these arrhythmias. The aim of this study is to research the effect of ATP-dependent potassium (KATP) channel blocker (gl...

background: increased heart rate is a normal physiological adaptation occurring during pregnancy. some women have severe tachycardia requiring medical attention. aim of this study is to determine the number of women with benign symptomatic palpitations who receive treatment. method: we performed a retrospective chart review of all women who were referred to our obstetric-medicine clinic for eva...

Atrial fibrillation (AF) is a prevalent condition particularly amongst the elderly, which contributes to both morbidity and mortality. The burden of disease has lead to significant increases in health care utilization and cost in recent years. Treatment of Atrial fibrillation consists of either a rate or rhythm control strategy. Rhythm control is achieved using medical management and/or cathete...