Catheter ablation of the atrial end of the slow pathway using radiofrequency current, guided by ASP potentials, can eliminate AVNRT with very little risk of atrioventricular block.

Saline irrigation maintains a low electrode-tissue interface temperature during radiofrequency application at high power, which prevents an impedance rise and produces deeper and larger lesions. A higher temperature in the tissue (3.5 mm deep) than at the electrode-tissue interface indicates that direct resistive heating occurred deeper

Radiofrequency current is highly effective in ablating accessory pathways, with low morbidity and no mortality.

A simple ECG algorithm identifies accessory pathway ablation site in Wolff-Parkinson-White syndrome. A truly negative delta wave in lead II predicts ablation within the coronary venous system.

These findings support the hypothesis that ILVT originates from the Purkinje network of the left posterior fascicle. A P potential can be recorded at the posteroapical left ventricular septum during ILVT, and ablation is successful at the site recording the earliest P potential. Pace mapping with similar QRS is not specific due to capture of the Purkinje fiber network at a site remote from the origin of the tachycardia.

Right atriofascicular APs consist of two components. The proximal component is located at the lateral, anterolateral, or posterolateral tricuspid annulus, does not generate an AP potential recordable by catheter electrodes, and is responsible for the decremental conduction properties. The "distal" component extends from the tricuspid annulus to the distal right bundle branch at the apical right ventricular free wall and generates a large, high-frequency AP potential that accurately identifies a site for ablation.

INCE THE ORIGINAL OBSERVAtions that Greenland Eskimos eating a diet high in omega-3 polyunsaturated fats (PUFAs) from sea mammals and fish had an unexpectedly low risk of cardiac death, 1,2 multiple lines of evidence have suggested that omega-3 PUFAs have antiarrhythmic properties. Four randomized clinical trials 3-6 have shown that dietary changes or supplements to increase omega-3 PUFA intake result in a reduced risk of sudden death without a consistent change in risk of myocardial infarction. To test the hy

(1) The EVR forms a line of fixed conduction block between the IVC and the CS; (2) the EVR and the TA provide boundaries for the AFL reentrant circuit; and (3) verification of a complete line of block between the TA and the EVR is a more reliable criterion for long-term ablation success.