| ǥ :
|
ȣ - 500264 314 |
| Epicardial conduction property of aortic cusp origin premature ventricular contractions and their ablation outcomes |
| 고려의대¹, 세종병원², 인제의대³, Utah Valley Medical Center⁴ |
| 신승용¹, 박희남¹, 김진석¹, 임홍의¹, 이현수¹, 박상원², 남궁준³, 최종일¹, 신성희¹, Chun Hwang², 김영훈¹ |
BACKGROUND: Ventricular arrhythmias originated from left ventricular outflow tract (LVOT), aortic cusp (AC), or non-AC LV epicardium are difficult to localize by surface ECG. We hypothesized that the arrhythmogenic foci at AC exit to the epicardial surface through preferential conduction.
METHODS and RESULTS: Nine patients (M:F=4:5, 41.8±11.9 years old) with Ventricular tachycardia (VT) or frequent premature ventricular contractions (PVC) originated from LVOT or AS were studied for radiofrequency catheter ablation (RFCA). We performed activation mapping at anterior interventricular vein (AIV), AC, and anterior mitral annulus (AMA), simultaneously. The distances between the earliest activation sites and adjacent catheters and conduction intervals were measured at RAO 45° and LAO 45°. The conduction velocities between the successful ablation site to epicardial (AIV) and endocardial earliest activation site (AMA) were calculated by triangular algebra. Results: 1. Successful ablation sites were above left coronary cusp (LCC) in 7 patients, above right coronary cusp (RCC) in 1 patient, and beneath LCC in 1 patient. The median number of RFCA was 1.0±2.7, and the time to elimination of arrhythmia was 4.5±2.6 sec. 2. Surface ECG showed QRS width 150.0±20.7ms, maximal depolarization time (MDT) 89.9±15.5ms, and the ratio of MDT over QRS 59.7±6.1% indicating epicardial foci. PVC from LCC had rS or S waves in lead I, and those from RCC had R waves in lead I. Seven patients with LCC origin showed R or RS waves in V1 whereas one patient with LCC origin and one patient with RCC origin showed rS in V1. 3. The conduction velocities between successful ablation site on the AC to epicardial earliest activation site (AIV: 1.69±0.75 m/s) was faster than that to the endocardial earliest activation site (AMA: 0.80±0.39 m/s, p<0.05). 4. At 5.8±4.4 months of follow-up, one patient who was treated by low power RFCA (20W, 50C°) recurred PVC in Holter recording.
CONCLUSION: Majority of ventricular arrhythmias from AC originated from the above LCC and had faster conduction velocity to the epicardial side of AIV than to the endocardial side of AMA, suggesting preferential conduction from AC to LV epicardium.
|
|
|
|
|
