Introduction Focal atrial tachycardia (AT) mechanisms include enhanced automaticity and triggered activity. Autonomically mediated focal atrial arrhythmias (AT or atrial fibrillation [AF]) are rare. Adrenergic stimulation such as exercise or stress can initiate focal atrial arrhythmias by enhancing automaticity, whereas vagal nerve arrhythmogenicity is associated with reentry and early afterdep...

Focal atrial tachycardias arise preferentially from specific locations within the atria. Careful analysis of the P wave can provide useful information about the chamber and likely site of origin within that chamber. Macro-reentrant atrial flutter also tends to occur over a limited number of potential circuits. In this case, the ECG usually gives a guide to the chamber of origin, but unless it s...

Apatient with dilated cardiomyopathy and aborted sudden death was admitted for repeated shocks from his Guidant Ventak Prizm dual chamber implantable cardioverterdefibrillator (ICD). Interrogation of stored events over the last six months revealed 46 episodes at a rate of 140/min, interpreted as ventricular tachycardia (VT). These were usually interrupted by programmed overdrive ventricular pac...

Fragments of Holter monitoring a 64-year-old patient with paroxysms supraventricular tachycardia are presented, atrial ectopic activity during is recorded, which does not interrupt the tachycardia, but changes sequence RR intervals. The possibility remote analysis data 3-day patient’s electrocardiogram in 12-channel provided.

A 44-year old lady underwent electrophysiology study for recurrent palpitations and documented narrow QRS regular tachycardia. The baseline ECG showed subtle preexcitation that was easily manifest on atrial pacing. The retrograde atrial activation sequence during ventricular pacing was eccentric suggesting retrograde conduction over the accessory pathway. A regular narrow QRS tachycardia with c...

BACKGROUND We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciproc...

Ablation of cavotricuspid ishtmus flutter and atrial tachycardia in a complex substrate has never been reported using remote navigation via superior approach. Venous access was obtained via right internal jugular for ablation and left subclavian for duodecapolar catheter placement into the coronary sinus. In a posttransplant patient presenting with both regular and irregular tachycardia, both c...

A woman underwent bilateral lung transplantation for pulmonary fibrosis in June of 2013. The early postoperative period was complicated by continuous atrial arrhythmias that proved unresponsive to antiarrhythmic agents (propafenon and bisoprolol). Therefore, in February 2014, we performed an electrophysiological study after adequate antibiotic and antimycotic prophylaxis. During the procedure, ...

Case Presentation A 34-year-old man with a 10-year history of paroxysmal supraventricular tachycardia underwent an electiophysiologic procedure. A narrowQRS complex tachycardia with a cycle length of 260 to 280 msec reproducibly was induced by right atrial overdrive pacing. At times there was a 1:1 relationship between the atrium and ventricle (Fig. 1), and at other times there was Mobitz I sec...

BACKGROUND Radiofrequency ablation (RFA) for atrioventricular nodal reentrant tachycardia appears to reduce atrial tachycardia, which might relate to parasympathetic denervation at cardiac ganglionated plexuses. METHODS AND RESULTS Compared to 7 control canines without RFA, in 14 canines, RFA at the bottom of Koch's triangle attenuated vagal stimulation-induced effective refractory periods pr...