We report a 26-year-old woman with frequent episodes of palpitation and dizziness. Resting electrocardiography showed no evidence of ventricular preexcitation. During electrophysiologic study, a concealed right posteroseptal accessory pathway was detected and orthodromic atrioventricular reentrant tachycardia incorporating this pathway as a retrograde limb was reproducibly induced. After succes...

Four patients with paroxysmal supraventricular tachycardia have been studied using programmed electrical stimulation of the heart and intracardiae recordings. One patient had an atrioventricular (A-V) junctional tachycardia, possibly due to a rapidly discharging protected ectopic focus, and three patients had anomalous atrioventricular connections. The ECG recordings in all four patients showed...

A 75-year-old man underwent an electrophysiologic procedure because of recurrent palpitations and documented tachycardia. At baseline, there was sinus rhythm with right bundle branch block. Programmed stimulation demonstrated anterograde dual AV nodal physiology. A regular, long RP tachycardia with a cycle length of 540 msec and inverted P waves in the inferior leads was induced by atrial overd...

A 34-year-old woman with a long history of paroxysmal supraventricular tachycardia underwent an electrophysiologic procedure. The baseline sinus cycle length, atrial-His (AH), and His-ventricular (HV) intervals were 720, 70, and 50 msec, respectively. A narrow-QRS complex tachycardia was induced by ventricular pacing at a cycle length of 380 msec (Fig. 1). The tachycardia cycle length was 400 m...

To study recurrent ventricular tachycardia in the late phase or myocardial infarction (MI), transmural anteroapical infarcts were created by ligation of the left anterior descending (LAD) coronary artery in 25 dogs. Twenty dogs survived LAD ligation and underwent an open-chest electrophysiologic study an average of 20 days after MI. Programmed electrical stimulation was carried out using the ex...

The approach to successful ablation of arrhythmias is based on elucidating the underlying mechanism and relative dimensions of the tachycardia circuit. Activation mapping readily distinguishes macroreentry from focal arrhythmias, the latter of which have centrifugal spread. When macroreentrant atrial tachycardia is suspected, entrainment maneuvers with atrial overdrive pacing at various anatomi...

OBJECTIVE To report experience with radiofrequency catheter ablation of fascicular tachycardia including two cases of the rare type of this arrhythmia which arises from the anterior fascicle of the left bundle branch. DESIGN Review of results of radiofrequency ablation in nine consecutive patients presenting with fascicular tachycardia. SETTING Regional cardiac centre. INTERVENTION Percut...

Catheter ablation of ventricular tachycardia was successfully performed in a patient with dilated cardiomyopathy (ejection fraction 38%) and a long history of repetitive palpitations. Holter monitoring showed ventricular tachycardia that had a left bundle branch block QRS configuration with inferior axis deviation and was present for about one third of the daytime hours. At electrophysiological...

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...

Two patients who presented by scalar ECG with an A-V junctional tachycardia were demonstrated during an electrophysiologic evaluation to have an atrial tachycardia without P waves in the surface ECG. Case 1 had an atrial tachycardia that conducted through the A-V node with a Wenckebach block. Atrial activity was recorded only from the proximal portion of the coronary sinus and from right atrial...