Identification of unusual reentry circuit sites of nonischemic ventricular outflow tract tachycardia.

Background: Reentrant ventricular outflow tract (OT) tachycardia is rare in patients with nonischemic heart disease. The mechanism of ventricular tachycardia (VT) arising from the region of the aortic sinus of Valsalva (ASOV) is usually focal, rather than reentrant. Consequently, less is known about reentrant circuits in the OT and the aortic sinuses.

Reentrant ventricular tachycardia originating in the right ventricular outflow tract: slow conduction identified by right coronary artery ostium pacing.

A case of reentrant ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) is described. An electrophysiological study revealed that programmed stimulation from the right ventricle apex induced 2 types of VT with similar left bundle branch block configuration and inferior axis. Yet, VT cycle length (CL) was different; one was stable, sustained VT with a CL of 360 ms and the other was hemodynamically intolerable VT with a CL of 330 ms.

Clinical study of the acute effects of intravenous nifekalant on the defibrillation threshold in patients with persistent and paroxysmal atrial fibrillation.

Background: Antiarrhythmic agents are considered to have significant effects on the defibrillation energy requirement, so this study investigated the effects of nifekalant on defibrillation.

Methods And Results: Forty-two patients with persistent atrial fibrillation (AF) underwent electrical cardioversion via intracardiac electrode catheters prior to and after the intravenous administration of nifekalant. The success rate of the defibrillation and change in the defibrillation threshold using sequential incremental defibrillation energy deliveries was investigated.

Reversible ischemic neurological deficit (RIND) due to exercise testing for the diagnosis of angina pectoris.

A 57 year old Japanese male with chest oppression due to exercise is presented. This symptom was likely due to effort angina pectoris. Master's double two-step test revealed ischemic ST segment depression on the electrocardiogram, thus, a Tl201 myocardial stress imaging test using a bicycle ergometer was undertaken.