2. Case Report
A 50-year-old man with a history of MI experienced intermittent VT over 10 times in the previous month, and his cardiac function was grade IV, according to NYHA heart failure class. Antiarrhythmic drugs were ineffective. Approximately 70%–80% proximal stenosis was diagnosed by coronary angiography in the left anterior descending branch (LAD), with ejection fraction (EF) 31%; left ventricular end-diastolic diameter (LVEDD), 62 mm; left atrium (LA), 50 mm; and LVA, 61 × 25 mm. Electrocardiogram showed that VT originated from the left ventricle. The left ventricle and right ventricle were reconstructed by the CARTO system. 10-pole IBI CS electrodes were implanted into the right femoral vein. VT was prone to recurrence after right ventricle apex (RVA) S1 300 ms stimulation. One VT was LBBB (CL=250ms), and the other VT was RBBB (CL=460ms). VT activation and voltage mapping were conducted under the guidance of CartoSound. The two VTs were all LVA-related reentry. There were significant delayed potentials at the junction between the edge of the LVA and the normal myocardium and in the center of the VA. The first type of LBBB VT was related to the internal reentry of LVA, and the second type of RBBB VT was related to the reentry of normal myocardial junction between the edge of LVA and the left ventricular anterior wall. The above two reentries and all delayed potentials in the interior and edge of LVA were ablated to disappear by unipolar RFCA (Figure 1 ). VT could not be induced by RVA stimulations. Three days later, VT the same as original VT, recurred approximately 20–40 times a day, all requiring electro-cardioversion.
CABG was performed via the great saphenous vein (GSV) to the LAD under beating-heart cardiopulmonary bypass. The LVA (approximately 80 × 40 mm) was opened for removing mural thrombus (about 10g) in LVA, and scattered scars in LVA was approximately 20 mm. Then bipolar RFCA clamps (AtriCure, USA) with eight ablation lines ablated LVA from center to the surrounding myocardium according to the anatomical position of real heart corresponding original CARTO. Also, one ablation line passed through the isthmus of the reentrant circuit of refractory VT. Linear closure was performed with clamping using 2-0 Prolene sutures to repair the LVA (Figures 2) .
There were no post-procedural complications. Holter monitoring showed one ventricular premature beat (VPB), 0 VT, and 594 supraventricular tachycardias (SVTs). A beta-blocker was prescribed as an antiarrhythmic drug at discharge. One year later, Holter monitoring showed 2443 VPBs, one VT (ventricular triple rhythm), and 0 SVT. The EF measured 33%; LVEDD, 59 mm; and LA, 38 mm. Coronary CT showed GSV-LAD patency. Cardiac function was restored to grade I. The patient provided written informed consent for publication of this case report.
The requirement for ethical approval was waived as this is a case report. All procedures were performed per the ethical standards of the institutional and/or national research committee.