Category: ECG / Electrophysiology

Extrinsic sinus nodal dysfunction: Extrinsic sinus mechanisms of sinus node dysfunction could be drug effects or due to autonomic influences.

Sinus arrest / sinus pause occurs when sinus node’s principal pacemaker cells fail to fire. A pause should be more than 1.5 times the basic cycle length.

Potential hazards of using MRI with Pacemakers: MRI uses a very strong magnetic field which could be deleterious to the implanted cardiac pacemaker in various ways. Mechanical forces

ECG demonstrating Left bundle branch block.

Radiofrequency catheter ablation of AVNRT: Slow pathway ablation for AVNRT - Posterior approach, Fast pathway ablation for AVNRT - Anterior approach.

Potential complications of catheter ablation of AVRT: complications of vascular access and catheter manipulation, complications of delivery of RF energy.

Efficacy and success rate of ablation of AVRT: efficacy 89-99%, overall recurrence of conduction after successful ablation 7% .

Ablation of atrioventricular reentrant tachycardia (AVRT)

Radiofrequency catheter ablation of SVT: use of an electrode catheter to destroy small areas of myocardial tissue or conduction system, or both, that are critical to the

Cryothermal ablation of supraventricular tachycardia requires special equipment for cooling the cryocatheter.