Relationship of the J Waves on 12-Lead Electrocardiogram and the Left Ventricular Epicardium

The purpose of this study was to evaluate the relationship of the J waves on 12-lead electrocardiogram (ECG) and the left ventricular epicardium. Methods and Results: Forty-seven patients with paroxysmal atrial fibrillation were studied. To analyze the epicardial electrograms in the basal inferior and inferolateral LV wall, unipolar electrograms (with 0.05- to 100-Hz filters) of the CS electrodes positioned from the ostium to the 2 o’clock position of CS were examined. The J waves in the inferior and/or lateral leads on 12-lead ECG were observed in 14 patients (early repolarization (ER) group) but not in 33 patients (non-ER group). In all of the 14 ER group patients, J wave on the CS unipolar electrograms was observed. In the other 33 non-ER group patients, J wave on the CS unipolar electrograms was also observed in 21 of them (100% versus 63.6%, P<0.01). In a 40 year-old, non-ER male patient with VT, we constructed an additional three-dimensional electroanatomic map of unipolar electrograms on the whole surface of the LV epicardium. The prominent J waves were observed at the basal inferior LV wall, which matched the location of the J waves detected on the CS electrodes. Conclusions: J wave on the epicardium is observed at the basal inferior LV wall, whether or not the J wave is on 12-lead ECG.