Paroxysmal supraventricular tachycardia (SVT) is commonly produced by two mechanisms: atrial reentry via an A-V nodal pathway or a rapid firing ectopic focus. Studies in the experimental animal and in human beings with sustained SVT have sbown that the site for reentry appears to be the upper A-V junction. This report documents an unusual site d reentry in a patient with recurrent SVT. Progress...

We present a case of a 37-year-old female who complained of frequent palpitations caused by an atrial tachycardia and atrial premature contractions. Angiography revealed that the coronary sinus was occluded at the ostium and connected to a persistent left superior vena cava. An electrophysiological study and three-dimensional mapping revealed that the origin of the atrial tachycardia and atrial...

To evaluate the clinical response of five children with automatic atrial tachycardia (AA T) and associated cardiomyopathy to arrhythmia control, we compared pretreatment and posttreatment 24hour ECG heart rates, cardiothoracic ratio by chest radiograph, and echocardiographic measures of ventricular ,function. Two children were treated with amiodarone, two with surgical excision and cryoablation...

Antiarrhythmic therapy can have a key role in prolonging the lives of patients with most common atrial tachyarrhythmias such as atrial flutter (AFL) or atrial fibrillation (AF). The optimal use of antiarrhytmic drug therapy depends in part on understanding the underlying mechanisms of AFL and AF and pharmacodynamis of each antiarrhythmic drug. Currently, there is a large body of experimental an...

BACKGROUND Successful ablation of ectopic beats originating from the pulmonary veins (PV) could eliminate paroxysmal atrial fibrillation (PAF). However, information about the structure of the PV in patients with PAF that is initiated by PV ectopic beats has not been reported. METHODS AND RESULTS We studied the morphology of the PVs and measured their diameters in 3 groups of patients. Group I...

Sofosbuvir is an antiviral drug that entirely revolutionized the treatment of hepatitis C. This drug has an Iranian commercial brand, which is known as Ledibiox. Several adverse events have been reported with this drug, including syncope, pancolitis, and exacerbated pulmonary arterial hypertension; however, arrhythmia rarely has been described through the literature. Here, we report a 40-year-o...

After recovery from acetylstrophanthidin-induced ventricular tachycardia, a repetitive ventricular response (RVR) following a single diastolic stimulus could be elicited for 22 minutes. With atrial pacing at the maximum ventricular follow rate, RVR was obtainable for 70 minutes. A pause in pacing also evoked a ventricular ectopic beat; however, this persisted for only 27 minutes. The minimum he...

BACKGROUND The superior vena cava (SVC) has cardiac musculature extending from the right atrium. However, no previous study in humans has given details regarding the ectopic foci that initiate paroxysmal atrial fibrillation (PAF), which may originate from the SVC. METHODS AND RESULTS A total of 130 patients with frequent attacks of PAF initiated by ectopic beats were included. Eight patients ...

Conversion of the atriopulmonary Fontan to a total cavopulmonary extracardiac connection with concomitant arrhythmia surgery and pacemaker placement is a safe and efficacious procedure for this patient population. From 1994 to 2007 a total of 118 patients have undergone this procedure with one (0.8%) early and nine (7.6%) late deaths. During the course of our experience with Fontan conversion o...

Whether or not the atrium plays an essential role in initiating and/or sustaining atrioventricular (A-V) nodal re-entrant tachycardia was evaluated in eight patients. In all eight patients, the atrium could be rendered refractory to retrograde atrial echoes during the tachycardia without interrupting the arrhythmia. This was accomplished by introducing atrial premature depolarizations prior to ...