RADIOFREQUENCY LABELS IN SURGICAL TREATMENT OF PATIENTS WITH POST-INFARCTION LEFT VENTRICULAR ANEURYSM AND VENTRICULAR TACHYCARDIA

To improve outcomes of surgical treatment of patients with post-infarction left ventricular aneurysms (LVA) and ventricular arrhythmias by means of radiofrequency ablation (RFA) and optimal excision of the damaged myocardium, 168 patients were examined and surgically treated. Before aneurysmectomy, the electrophysiological study with electro-anatomic CARTO reconstruction of the left ventricle (LV) was performed. The arrhythmogenic zones revealed were labeled using radiofrequency labels with the aid of ablative electrode (power of radiofrequency current: 45 W; irrigation with normal saline: 17 ml/min). During the operation, resection of the damaged endocardium was performed according to the radiofrequency labels. As the next step of the surgery, the LV endoventricular plastic repair was performed in accordance with the commonly accepted technique. Endocardectomy was performed in 74 patients of study group. The control group consisted of 94 patients with no endocardectomy performed. The patients of study and control groups aged 54.4±2.1 years and 56.2±1.6 years, respectively. All patients had a history of myocardial infarction complicated by LVA which occurred 3.7±0.9 years and 3.9±1.2 years before the surgery. In 130 patients of both groups, the aneurysm resection and LV reconstruction were carried out according to the Dor technique in 130 patients, using the modification by Menicanti in 38 patients. In 26 patients of both groups, the mitral annuloplasty was made. Aorto-coronary bypass grafting was performed in all subjects. One patient (1.4%) of study group died in hospital, the mortality in control group made up 6.4%. In 8 patients of the same group, ventricular arrhythmias in early post-operation period were detected. The late mortality (one year after surgery) was 4.1% in study group and 12.8% in control group. When analyzing the study data, subgroups of subjects in whom the electrophysiological study was performed post-operatively were additionally considered. Subgroup A consisted of 38 patients of study group, Subgroup B, of 32 patients of control group. In the Subgroup A subjects, an improvement of electrophysiological indices was revealed: areas of “electric scar” were located only in the endocardial patch, areas with the decreased potential totally disappeared, transition zones (0.5 1.5 mV) were local, without possibility of both development of re-entry and induction of ventricular tachycardia. In only one patient of Subgroup A with incomplete endocardectomy, monomorphic ventricular tachycardia was induced. In Group B, spontaneous episodes of ventricular tachycardia were documented in 5 cases; ventricular tachycardia was induced during the electrophysiological study in 7 cases (35% of subjects). In 11 ones of them, cardioverters-defibrillators were implanted. Thus, when treating surgically post-infarction LVA, endocardial, resection of scar and transition areas of LV is critical for preventing episodes of ventricular tachycardia. Endocardial electrophysiological study and electro-anatomic LV reconstruction permit one to reveal potential sites of the re-entry development. Radiofrequency labels made during the endocardial electrophysiological study permit one to locate precisely the damage area during the open-heart surgery to carry out endocardectomy in an optimal way.

coronary artery disease, myocardial infarction, left ventricular aneurysm, electro-anatomic mapping, endoventricular plastic repair

1. Бокерия Л. А., Федоров Г.Г. Хирургическое лечение больных с постинфарктными аневризмами сердца и сопутствующими тахиаритмиями // Грудная и сердечно-сосудистая хирургия. - 1994. - № 4. - С. 4 - 8.

2. Дор В., Сааб В., Кост П. и др. Пластика внутрижелудочковой заплатой с выключением пораженной межжелудочковой перегородки для восстановления ишемического повреждения левого желудочка: техника, результаты, показания, вытекающие более чем из 600 случаев // Грудная и сердечно-сосудистая хирургия. - 1997. - № 1. - С.13 - 19.

3. Braunwald E., Pfeffer М. А. Ventricular enlargement and remodeling following acute myocardial infarction: Mechanisms and management // Am. J. Cardiol. - 1991. - Vol. 68, № 14. - P. 1-6.

4. Di Donato M., Castelvecchio S., Kukulski N. et al. Surgical Ventricular Restoration: Left Ventricular Shape Influence on Cardiac Function, Clinical Status and Survival // Ann. Thorac. Surg. - 2009. - Vol. 87. - P. 455-461.

5. Di Donato M., Sabatier M., Dor V. et al. Ventricular arrhythmias after LV remodeling: surgical ventricular restoration or ICD? // Heart Fail. Rev. - 2005. - Vol. 9, № 4. - P. 299-306.

6. Dor V., Sabatier M., Montiglio F. et al. Endoventricular patch reconstruction of Ischemic failing ventricle: A single center with 20 years experience // Heart Fail. Rev. - 2004. - Vol. 9. - P. 269-286.

7. Faxon D.P., Myers W.O., McCabe C.H. et al. The influence of surgery on the natural history of angiographically documented left ventricular aneurysm: the Coronary Artery Surgery Study // Circulation. - 1986. - Vol. 74. - P. 110-118.

8. Kautzner J., Kirstein Pedersen A., Peichl P. Electro-anatomical mapping of the heart. - Remedica Publishing, 2006. - 160 c.

9. Marrouch N.F., Verna A., Wazni O. et al. Mode of initiation end ablation of ventricular fibrillation storms in patients with ischemic cardiomyopathy // J. Am. Coll. Cardiol. - 2004. - Vol. 43. - P. 1715 - 1720.

10. Menicanti L., Castelvecchio S., Ranucci M. et al. Surgical therapy for ischemic heart failure: Single-center experience with surgical anterior ventricular restoration // J. Thorac. Cardiovasc. Surg. - 2007. - Vol. 134. - P. 433 - 441.

11. Moran J.M. Postoperative Ventricular Arrhythmia // Ann. Thorac. Surg. - 1984. - Vol. 38. - P. 312 - 313.

12. Moss A.J., Zareba W., Hall W.J. Prophylactic Implantation of a Defibrillator in Patients with Myocardial Infraction and Reduced Ejection Fraction // N. Engl. J. Med. -2002. - Vol. 346. - P. 877-883.

13. Shipulin V, Kazakov V, Lezhnev A. et al. Morphological predictors and molecular markers of progressing postoperative remodeling of left ventricle in patients with ischemic cardiomyopathy // Front Lines of Thoracic Surgery / edited by Stefano Nazari. - Croatia: InTech, 2012. - P. 107-134.