Three mechanisms underlie the initiation and maintenance of ventricular tachycardia: automaticity, triggered activity, and reentry. As straightforward as these mechanisms are, assessing which mechanism is operative in a particular patient's ventricular tachycardia can be difficult. The optimal treatment strategy for ventricular tachycardia in a given patient can be influenced by the mechanism u...

Implantable antitachycardia devices suffer a high false-positive rate of delivery of therapy because current detection schemes based upon ventricular rate and rate variations are excessively sensitive at the cost of specificity. Several methods have been proposed for providing complementary information derived from morphologic analysis of intraventricular electrograms in order to increase speci...

I’ this issue of Chest (see page 24), James and MacLean present the pathologic findings in a 17-year-old male athlete with recurrent syncope, documented ventricular tachycardia, and sudden cardiac death. The patient’s brother had a somewhat similar history and also died suddenly. Pathologic examination in the present case revealed some fetal dispersion of the A-V node, a right-sided His bundle,...

BACKGROUND Conventional programmed ventricular stimulation protocols are inefficient compared with more recently proposed protocols. The purpose of the present study was to determine if additional efficiency could be derived from a 6-step programmed ventricular stimulation protocol that exclusively uses four extrastimuli. METHODS AND RESULTS The subjects were 209 consecutive patients with cor...

Electrophysiologic studies were performed in 172 consecutive patients for evaluation of documented sustained ventricular tachyarrhythmias. One hundred thirteen patients presented with sustained ventricular tachycardia that was hemodynamically stable, and 59 patients presented with cardiac arrest. Seventy-one patients without previously documented or suspected ventricular arrhythmias were also s...

In the differential diagnosis of broad-complex tachycardia, the most important decision is whether or not the tachycardia is ventricular, since this type carries the worst prognosis. However, the rules for a diagnosis of ventricular tachycardia are so complex that they are not satisfied in many cases, and the default diagnosis, supraventricular tachycardia, is erroneously accepted. We sought to...

A 51 year old woman with arrhythmogenic right ventricular dysplasia had two types of ventricular tachycardia--(a) a regular and sustained tachycardia and with normal frontal plane axis on electrocardiography and (b) an irregular non-sustained tachycardia with a leftward frontal plane axis. Changes in the QRS complex were sometimes seen during the sustained ventricular tachycardia. The clinical,...

Ventricular arrhythmias are important contributors to morbidity and mortality in patients with coronary artery disease. Ventricular fibrillation accounts for the majority of deaths occurring in the acute phase of ischemia, whereas sustained, monomorphic ventricular tachycardia due to reentry generated in the scar tissue develops most often in the setting of healed myocardial infarction, especia...

tachycardia, and reentrant left ventricular tachycardia) first described by Bernard Belhassen and colleagues in 1981. Belhassen ventricular tachycardia occurs more frequently in males 15 to 40 years old than in females of the same ages, and it may occur more commonly with exercise than at rest. Although approximately 90% of ventricular tachycardias occur in patients with anatomically abnormal h...

The ability of chronic bretylium tosylate treatment to prevent the induction of ventricular tachycardia was assessed in the conscious dog subjected to serial programmed ventricular stimulation on days 3-6 after acute myocardial infarction. In 34 untreated control dogs, programmed ventricular stimulation produced nonsustained ventricular tachycardia in 11 dogs (32%), sustained ventricular tachyc...