or digitalis and quinidine, prevented tachyeardia in five patients and slowed it in one. Our cases suggest the following: (1) Recurrent supraventricular tachycardia in patients without the WPW syndrome may frequently be caused by a reciprocal mechanism. (2) The diagnosis of reciprocating tachycardia should be suspected when (a) the tachycardia recurs within minutes of its termination, (b) the o...

We studied transient entrainment and interruption of atrioventricular (AV) bypass pathway-type paroxysmal atrial tachycardia in 15 patients during overdrive pacing from selected atrial sites. Overdrive atrial pacing at less than a critically rapid rate for interruption transiently entrained the tachycardia. Transient entrainment was due to repeated early entrance of the wave front from the paci...

Focal right ventricular tachycardia is relatively uncommon. It usually arises from specific anatomic locations. A 59-year-old woman with a structurally normal heart and an automatic cardioverter-defibrillator implanted beforehand presented with drug-resistant incessant ventricular tachycardia for which 1786 anti-tachycardia pacing therapies and 119 shocks had been delivered. Electroanatomical m...

Four patients with myocardial dysfunction related to tachycardia underwent electrophysiological studies, which showed a re-entrant supraventricular tachycardia using an accessory atrioventricular connexion. Serial assessment of left ventricular function by echocardiography before and after control of the tachycardia indicated a variable degree of reversibility. Endomyocardial biopsy in two pati...

A case of sotalol-induced polymorphous ventricular tachycardia (torsade de pointes) is presented. The patient had moderately prolonged Q-T interval before medication with sotalol with further prolongation after application of this drug. Electrophysiological study during rechallenge with sotalol demonstrated a uniform ventricular tachycardia with a somewhat polymorphous onset; whether or not thi...

Objective: In ventricular arrhythmias, due to their free radical scavenging action, antioxidant agents are usually used in the treatment of cardiovascular disease. Since stress is considered as risk factor for increased mortality by causing malignant arrhythmias, the study was designed to evaluate the cardioprotective effects of ellagic acid (EA) on CaCl2-induced arrhythmias in rat stress model...

Background: Cardiac manifestations that occur in a majority of patients with organophosphate (OP) poisoning may range from innocuous electrocardiographic manifestations, such as sinus tachycardia, to life-threatening complications, including cardiogenic pulmonary edema and myocardial necrosis. In this study, we evaluated the various electrocardiographic manifestations in patients with OP pois...

A 45-year old man presents with stable monomorphic ventricular tachycardia. He had previously been diagnosed with idiopathic fascicular ventricular tachycardia. Intravenous flecainide results in termination of his tachycardia but unmasks a latent type 1 Brugada ECG pattern not seen on his resting ECG. We discuss his subsequent management and the need to consider an alternative diagnosis in indi...

The common atrioventricular nodal re-entry tachycardia is the most common form of paroxysmal supraventricular tachycardia. It starts frequently with a supraventricular ectopic beat that, on finding the fast pathway in refractory period, travels in the slow pathway as to appear as a prolongation of the PR interval on the ECG. In this study, we show a singular case of a common atrioventricular no...

A bout 15 years ago, Waldo and associates' first described that a tachycardia could be transiently accelerated to a faster rate by overdrive pacing without fundamentally altering the underlying tachycardia, a phenomenon they called transient entrainment. That first description of transient entrainment applied to atrial flutter but was soon extended to ectopic atrial tachycardias,2 atrioventricu...