Perioperative and long-term results with mapping-guided subendocardial resection and left ventricular endoaneurysmorrhaphy

BACKGROUND

Surgical ablation of the arrhythmogenic focus in patients with life-threatening ventricular tachyarrhythmias can be curative. However, the surgical techniques have been plagued by a high perioperative mortality rate (averaging approximately 12%). Reconstruction of the left ventricle may reduce mortality.

METHODS AND RESULTS

Reconstruction of the left ventricle with a pericardial patch, or endoaneurysmorrhaphy, was performed with mapping-guided subendocardial resection for recurrent ventricular tachycardia in 25 patients over a 5-year period. Postoperatively, electrophysiological studies were conducted to assess the results of surgery, which were further evaluated during long-term follow-up with survival analyses. The study included 25 patients, 60 +/- 9 years of age, with coronary artery disease, discrete left ventricle aneurysms, and malignant ventricular tacharrhythmias. Left ventricular ejection fraction was 24 +/- 6% preoperatively. Left ventricular endocardial mapping, endocardial resection, and endoaneurysmorrhaphy were performed in all patients. There was no operative or postoperative (30-day) mortality. Postoperative ventricular tachycardia was induced in 2 of the 25 patients (8%); left ventricular function increased to 32 +/- 9% (range, 19% to 52%). At a mean follow-up of 37 +/- 16 months (range, 6 to 65 months), there had been 6 deaths, including 1 sudden cardiac death, 2 congestive heart failure deaths, and 3 noncardiac deaths. Analysis of multiple variables failed to identify predictors of postoperative inducibility, sudden cardiac death, cardiac death, or total mortality.

CONCLUSIONS

Endoaneurysmorrhaphy with a pericardial patch combined with mapping-guided subendocardial resection frequently cures recurrent ventricular tachycardia with low operative mortality and improvement of ventricular function. Long-term follow-up demonstrates low sudden cardiac death rates.

Why is catheter ablation less successful than surgery for treating ventricular tachycardia that results from coronary artery disease?

Nearly 80% of patients with coronary artery disease who have map-directed surgery for control of ventricular tachycardias require no drug therapy to prevent recurrences, while fewer than 50% of patients undergoing catheter ablation have similar outcomes. Catheter ablation will fail if arrhythmogenic sites are incompletely ablated by lesions that are too small or too far away from the reentrant pathway or if all arrhythmogenic sites are not identified. The underlying assumptions used to guide site selection are that: (a) ventricular tachycardias arise from reentrant mechanisms; (b) monomorphic ventricular tachycardias with similar QRS morphologies arise from the same pathway; (c) the ventricular tachycardia initiated during the procedure represents the patient's spontaneous arrhythmia; (d) the endocardial site that should be ablated can be identified from cardiac activation maps produced during induced ventricular tachycardia or from ancillary techniques; and (e) the patient has only one or two reentrant pathways. Relying on incorrect assumptions may account for the difference in success rates. Patients may have similar appearing ventricular tachycardias that arise from different pathways, and the entire thin layer of viable tissue between the infarct and the endocardium may contain many reentrant pathways. Some ventricular tachycardias may arise from the myocardium away from the endocardium, while others may arise from the epicardium. Small lesions may not be large enough to eliminate all possible reentrant pathways. Catheter ablation may be less successful because the lesions are inadequate, the assumptions guiding the selection of arrhythmogenic tissue are incorrect, or all arrhythmogenic sites are not identified. The primary reason catheter ablation is less successful than surgery in the treatment of ventricular tachycardias is that catheter ablation does not ablate as much tissue as is removed by surgery. The success rate of catheter ablation probably can be improved if the amount of tissue ablated is increased.

Value of body surface mapping in localizing the site of origin of ventricular tachycardia in patients with previous myocardial infarction

OBJECTIVES

This study examined the performance of the 62-lead body surface electrocardiogram (ECG) in identifying the site of origin of ventricular tachycardia in patients with a previous myocardial infarction.

BACKGROUND

Because the accuracy of ECG localization of ventricular tachycardia using standard 12-lead recordings is restricted to the identification of rather large ventricular areas, application of multiple torso lead recordings may augment the resolving power of the surface ECG and result in more discrete localization of arrhythmogenic foci.

METHODS

Thirty-two patients were selected for electrophysiologically guided ablative therapy for drug-resistant postinfarction ventricular tachycardia. In these patients, QRS integral maps of distinct monomorphic ventricular tachycardia configurations were correlated with a previously generated infarct-specific reference data base of paced QRS integral maps. Each paced pattern in the data base corresponded with ectopic endocardial impulse formation at 1 of 18 or 22 discrete segments of the left ventricle with a previous anterior or inferior myocardial infarction, respectively. Electrocardiographic localization was compared with the results obtained during intraoperative or catheter endocardial activation sequence mapping.

RESULTS

Body surface mapping was performed during 101 distinct ventricular tachycardia configurations. Compared with the activation mapping data that were acquired in 64 of 101 ventricular tachycardias, body surface mapping identified the correct segment of origin in 40 (62%) of 64 tachycardias, a segment adjacent to the segment where the arrhythmia actually originated in 19 (30%) of 64 tachycardias and a segment disparate from the actual segment of origin in 5 (8%) of 64 tachycardias. With respect to infarct location, the segment of origin was correctly identified in 28 (60%) of 47 ventricular tachycardias in patients with anterior, 7 (70%) of 10 tachycardias in patients with inferior and 5 (71%) of 7 tachycardias in patients with combined anterior and inferior myocardial infarction.

CONCLUSIONS

This study shows that body surface mapping enables precise localization of the origin of postinfarction ventricular tachycardia in 62% and regional approximation in 30% of tachycardias. The multiple-lead ECG may be used to guide and shorten catheter-based mapping procedures during ventricular tachycardia and to provide relevant information on the origin of tachycardias that cannot be mapped with conventional single-site mapping techniques because of unfavorable characteristics.

Comparison of the usefulness of the implantable cardioverter-defibrillator and subendocardial resection in patients with sustained ventricular arrhythmias and poor regional wall motion associated with coronary artery disease

The implantable cardioverter-defibrillator (ICD) and subendocardial resection are effective forms of therapy for sustained ventricular arrhythmias associated with coronary artery disease in selected patients. The relative efficacy of these 2 treatments in equivalently matched patients is not known. A regional wall motion score has been shown to be a powerful predictor of long-term outcome after both ICD implantation and subendocardial resection. This study retrospectively analyzed the long-term outcome of patients with coronary artery disease and ventricular arrhythmias treated during the same period with an ICD (n = 53) or by subendocardial resection (n = 65). Treatment outcomes were compared in subgroups determined by preoperative regional wall motion scores of either < or = 16 or > 16%. The 3-year cardiac mortality of the 2 therapies was not significantly different among patients with a wall motion score of > 16% (0% ICD vs 11% endocardial resection) or of < or = 16% (41% ICD vs 35% endocardial resection). Similarly, the 3-year sudden cardiac death mortality was similar among patients with a score of > 16% (0% for both ICD and endocardial resection) or of < or = 16% (9% ICD vs 14% endocardial resection, p = NS). At 24 months after hospital discharge, the percentage of patients who were in New York Heart Association functional class I or II was similar among patients with a wall motion score of > 16% (75% ICD vs 86% endocardial resection, p = NS) or with a wall motion score of < or = 16% (26% ICD vs 45% endocardial resection, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Drugs, surgery, cardioverter defibrillator: a decision based on the clinical problem

These three therapeutic options are the basis of sudden cardiac death prevention: antiarrhythmic drugs, surgery, and automatic implantable cardioverter defibrillator. Each of these treatments has specific favorable and unfavorable indications. Antiarrhythmic drugs are mainly limited by the low therapeutic profile, proarrhythmic effects, complex pharmacokinetics and pharmacodynamics, possible negative inotropic effects, and the possible change of the organic substratum. Arrhythmia surgery may be limited by the need of a highly trained center, by a relatively high perioperative mortality (up to 15%), and by limited electrophysiological and clinical indications. The implantable cardioverter defibrillator is an expensive tool with a theoretically wide range of clinical indications, with already proven efficacy in converting ventricular fibrillation to sinus rhythm but with unproven efficacy on prolonging survival because of a lack of controlled trials (which, we must admit, is also true for drugs and surgery). The results of the ongoing multicenter trials on this item will clarify this clinical point. The choice among these different therapeutic options is mainly based on hemodynamic status (ejection fraction), feasibility of a surgical treatment, and the electrophysiological characteristics of the ventricular arrhythmia.