Operation for recurrent ventricular tachycardia

Surgical therapy of ventricular arrhythmias

Since the advent of implantable cardioverters/defibrillators (ICD) and percutaneous ablation, surgery for the treatment of ventricular arrhythmia has decreased tremendously. Nevertheless, surgical treatment of ventricular arrhythmias is still required, especially for cases where ICD discharge occurs very frequently or in patients with other indications for surgery. The choice of surgical therapy may range from radiofrequency- or cryoablation of a single focus (identified either intra- operatively or percutaneously) to more extensive surgical procedures such as surgical ventricular reconstruction with endocardial resection or even resection of the right ventricle and the creation of a cavo-pulmonary circulation for malignant arrhythmias and right ventricular failure in patients with arrhythmogenic right ventricular dysplasia. However, the choice of surgical procedure should be made based on the pathomechanism of the arrhythmia. This is important because any incision in the left or right ventricle or percutaneous ablation may also be the cause for ventricular arrhythmia. In this short review we will describe the most common underlying substrates for ventricular arrhythmia, indications for surgery, the techniques used for treatment and the results achieved. We will conclude that for most cases of patients with ventricular arrhythmia undergoing surgery, ischemia and the presence of a scar after myocardial infarction is the underlying cause and revascularization plus surgical ventricular reconstruction with endocardial resection may be the best treatment option.

Intra-coronary guidewire mapping–A novel technique to guide ablation of human ventricular tachycardia

HYPOTHESIS

Endocardial catheter ablation of ventricular tachycardia (VT) may fail if originating from epicardial or intramural locations. We hypothesized that mapping could be achieved using an angioplasty guidewire in the coronary circulation, to guide trans-coronary ablation.

METHODS AND RESULTS

Six patients (2 male), 64 +/- 14 years and previously unsuccessful endocardial VT ablation were studied. Using ECG and existing endocardial mapping data, a coronary artery supplying the predicted VT origin was selected. A 0.014-in angioplasty guidewire was advanced into branches of the artery and connected to an amplifier to record unipolar signals against an indifferent electrode within the inferior vena cava. An uninflated angioplasty balloon was advanced over the wire such that only the distal 5 mm was used for mapping. One VT per patient was mapped (CL 348 +/- 102.1 ms). Diastolic potentials were recorded from all (77.7 +/- 43.8 ms pre-QRS onset) and concealed entrainment demonstrated in 3. Pacemapping during sinus rhythm was used in the remainder due to failure of entrainment (n = 2) or degeneration to VF (n = 1). Following branch identification, cold saline injection causing VT termination was used for further confirmation. Five VTs were ablated using intra-coronary ethanol injection via the central lumen of the inflated over the wire balloon. The other was ablated using radiofrequency energy in a coronary vein adjacent to the target artery, which was too small for an angioplasty balloon. No complications or recurrence of ablated VT was seen over 19 +/- 17 months of follow up.

CONCLUSIONS

Intracoronary guidewire mapping is a novel method of electrophysiological epicardial mapping to help guide trans-coronary VT ablation.

Effect of coronary artery bypass grafting and aneurysmectomy on QT dispersion in moderate or severe left ventricular dysfunction

BACKGROUND

The aim of the study was to evaluate the effect that coronary artery bypass grafting (CABG) and aneurysmectomy in the same session have on QT dispersion (QTd) in moderate or severe left ventricular dysfunction.

METHODS

Forty-four patients underwent QT interval analyses before and 1 month after aneurysmectomy and CABG. QT interval and QTd were corrected for heart rate using the square root formula of Bazett (QTCB), the cubic root formula of Fridericia (QTCF), and the linear formula of Sagie et al (QT CS ).

RESULTS

The mean pre- and postsurgery QTd results were 65.29 +/- 29.25 and 51.76 +/- 18.49 milliseconds, respectively; the corresponding findings for QT CF were 68.06 +/- 31.26 and 55.16 +/- 24.56 milliseconds; and the corresponding findings for QT CS were 66.53 +/- 32.22 and 51.10 +/- 18.29 milliseconds. With these 3 methods, the postoperative findings were significantly lower than the preoperative findings ( P < .05 for all). In contrast, the opposite was true with the QT CB method (preoperative 71.1 +/- 65.80 vs postoperative 76.43 +/- 7.96 milliseconds, P < .05).

CONCLUSION

The study showed that based on the methods of Fridericia (QT CF ) and Sagie et al (QT CS ), QT intervals are significantly decreased after CABG and aneurysmectomy.

Long-Term Outcomes After Cryoablation for Ventricular Tachycardia During Surgical Treatment of Anterior Ventricular Aneurysms

Intraoperative map-guided procedures have been widely advocated as the best surgical strategy for the treatment of ventricular tachycardia (VT), though favorable results have been reported with subendocardial resection without mapping. This study examined the very long-term results of encircling cryoablation without mapping during surgery for anterior left ventricular aneurysm complicated by VT. Between 1985 and 2003, this procedure was performed in 52 patients, 7 of whom (13.7%) were operated within 1 month of anterior myocardial infarction. Their mean age was 64.4 +/- 8.3 years and mean left ventricular ejection fraction was 31.7%+/- 9.5%. The overall hospital mortality was 1.9%. At 14 years, 86% of patients (95% CI: 75.4-96.6) were free from VT or sudden death. An implantable defibrillator was implanted in five patients (9.6%) during follow-up. The 14-year overall survival was 51.4% (95% CI: 33.8-72.4), and two patients (3.8%) underwent cardiac transplantation during follow-up. The main cause of late death was congestive heart failure in eight patients (40.0%). Favorable long-term results can be achieved with encircling cryoablation without mapping in patients undergoing surgery for anterior left ventricular aneurysm complicated by VT.

Sequential map-guided endocardial resection for ventricular tachycardia improves outcome

OBJECTIVE

Surgery for ventricular tachycardias late after myocardial infarction is frequently associated with high mortality including sudden death, and arrhythmia recurrences. We examined our results of sequential map-guided endocardial resection at normothermia in patients with ventricular tachyarrhythmias late after myocardial infarction to assess the efficacy of this technique as well as the early and long-term outcome.

METHODS

From 1995 to 1999, 22 patients underwent normothermic sequential map-guided endocardial resection for ventricular tachyarrhythmias late after myocardial infarction. Mean age was 61.2+/-6.5 years and left ventricular ejection fraction 32.5+/-8.7%. Adjunctive procedures included endoventricular patch repair of left ventricular aneurysm in 21 patients, coronary artery bypass grafting in 15 patients, and mitral valve replacement in one patient. Inducibility of ventricular tachycardia was evaluated postoperatively and patients were treated with sotalol or defibrillator implantation.

RESULTS

The intraoperative number of inducible different ventricular tachycardia morphologies was 4.0+/-2.7. More than one mapping-resection sequence was needed in ten patients. In only one patient, sustained ventricular tachycardia was induced postoperatively, sotalol was not tolerated and a defibrillator was implanted. Five patients with inducible non-sustained ventricular tachycardia became non-inducible while on sotalol. There was one operative death (4.5%). During a median follow-up of 26 (1--62) months, there were neither cardiac deaths nor ventricular tachycardia recurrences. Two patients died from non-cardiac causes. Cumulative probability of survival at 5 years was 0.83+/-0.09.

CONCLUSIONS

Sequential map-guided endocardial resection at normothermia was associated with low operative mortality and low postoperative inducibility of sustained ventricular tachycardia. The selected therapeutic approach resulted in freedom of arrhythmia recurrence and cardiac mortality including sudden death, during long-term follow-up.

Cryothermal ablation: mechanism of tissue injury and current experience in the treatment of tachyarrhythmias

Cryosurgery has been an integral part of the surgical management of cardiac arrhythmias since the late 1970s. With the recent development of intravenous cryocatheters, the use of cryothermy in the treatment of cardiac arrhythmias will increase in the near future. The following discussion includes a detailed consideration of the mode of tissue injury associated with cryothermy and a comprehensive review of cryosurgery in the management of a variety of cardiac arrhythmias. Cryosurgical management of supraventricular and ventricular tachycardias has proven to be both safe and effective. Cryothermal tissue injury is distinguished from hyperthermic injury by the preservation of basic underlying tissue architecture and minimal thrombus formation. Such differences will be particularly important in settings requiring extensive lesion formation, such as catheter-based maze procedures for the treatment of atrial fibrillation.

Identifying patients at low risk of death from cardiac failure after operation for postinfarct ventricular tachycardia

BACKGROUND

In unselected patients, cardiac failure accounted for most deaths after antiarrhythmic operation (ER) for postinfarction ventricular tachycardia (VT). This study aimed to determine whether patients at low risk of this outcome could be predicted from a retrospective analysis of variables from 100 consecutive ER patients.

METHODS

Thirteen variables suggested by other researchers as predictive of outcome were analyzed. At the time of study, ER was the only therapy available for drug refractory VT.

RESULTS

Only emergency ER, wall motion score less than 3 and Killip classification were significantly related to death from cardiac failure. The lack of correlation between emergency ER and variables of ER timing, VT less than 24 hours of ER or VT type implies that the need for emergency ER is also related to ventricular dysfunction. Multivariate analysis identified a group at particularly low risk of death with a specificity of 95%.

CONCLUSIONS

Patients at low risk of death after ER can be identified prospectively. In the implantable cardioverter defibrillator era, elective ER is best reserved for such patients. Emergency ER may still be justified in younger patients without comorbidity who will die of VT without it.

Long-term results of visually guided left ventricular reconstruction as single therapy to treat ventricular tachycardia associated with postinfarction anteroseptal aneurysm

INTRODUCTION

Postinfarction ventricular tachycardia (VT), anteroseptal aneurysm, and ventricular dysfunction are commonly associated and predict a poor long-term prognosis. Surgical left ventricular reconstruction, which includes double plication of the anterior and septal wall, can improve ventricular function. This article analyzes the long-term efficacy of such a procedure to control recurrence of VT in a group of 50 consecutive patients.

METHODS AND RESULTS

The study group consisted of 50 consecutive patients operated on between December 1986 and December 1994. The group comprised 44 men and 6 women. The mean age was 56+/-11 years. All patients had spontaneous VT following an anterior myocardial infarction. Twenty-five patients had two or more episodes of VT (eight presented as cardiac arrest, nine as syncope). Coronary artery disease was limited to the left anterior descending artery in 27 patients. An anteroseptal aneurysm was present in 49 patients. All patients had VT induced by programmed ventricular stimulation before surgery, and left ventricular reconstruction was performed without intraoperative mapping in all cases. Total mortality, VT recurrence, and sudden death rate were the endpoints of the study. In-hospital mortality was 8%. Postoperative left ventricular ejection fraction improved from 0.38 to 0.50 (P<0.05). Only two patients had postoperative inducible VT. Overall survival, VT recurrence rate, and sudden death rate were 73%, 12%, and 10%, respectively, after a median follow-up period of 6.25 years (0 to 8 years).

CONCLUSION

Visually guided left ventricular reconstruction with septal and anterior wall plicature can be utilized effectively to treat recurrent VT associated with postinfarction anteroseptal aneurysm.

Large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction: long-term outcome

OBJECTIVE

Map-guided procedures have been the accepted standard for ventricular tachycardia surgery. However, promising results of visually guided resections without mapping have been reported. The goal of this study was to evaluate the efficacy of large encircling cryoablation without mapping for ventricular tachycardia after anterior myocardial infarction.

METHODS

Between 1985 and 1996, this procedure, along with aneurysmectomy, was performed on 38 patients for malignant ventricular tachycardia. The mean interval between the operation and myocardial infarction was 59.2 months; 7 patients (18.4%) were operated on within 1 month of myocardial infarction. The mean patient age was 62.1 +/-7.3 years and the mean left ventricular ejection fraction was 29.0% +/-7.2%.

RESULTS

Hospital mortality was 2.6% (1 patient). The electrical success rate based on postoperative electrophysiologic studies was 94.5%. Overall electrical success rate was 89.1%. Freedom from ventricular tachycardia was 77% (95% CI 61%-94%) at both 5 and 7 years. Freedom from sudden cardiac death was 91% (95% CI 80%-100%) at both 5 and 7 years, with overall actuarial survivals at 5 and 7 years of 63% (95% CI 47%-80%) and 42% (95% CI 22%-63%), respectively. The main cause of late death was congestive heart failure in 62.6% of these patients.

CONCLUSIONS

One can achieve good results without intraoperative mapping in the treatment of patients with ventricular tachycardia after anterior myocardial infarction by using large encircling cryoablation.

Left ventricular aneurysmectomy; comparison between two techniques; early and late results

OBJECTIVE

The aim of the present study was to evaluate early and late results of two different surgical techniques for left ventricular aneurysms repair. The conventional aneurysmectomy and direct closure of the ventricular wall and the endoventricular patch plasty.

METHODS

We retrospectively reviewed 118 patients operated on for postinfarction left ventricular aneurysm from 1981 to 1994. Eighty-seven patients (Group A) were operated upon between 1981 and 1991 with the conventional technique and 31 patients (Group B) between 1992 and 1994 with the endoventricular patch plasty technique. Preoperative clinical, hemodynamic and echocardiographic evaluation with operative procedures and early postoperative results of all patients are reported. We also analyzed results of late clinical and echocardiographic controls of 34 patients of Group A and all patients of Group B after a mean follow-up of 42 and 28 months, respectively.

RESULTS

Mean number of by-pass grafts was 1.9 in Group A and 2.6 in Group B (P = 0.01). The left anterior descending coronary artery was revascularized in 27 patients of Group A (34.6%) and 26 of Group B (89.7%) (P < 0.001); the left internal mammary artery was used in seven patients of Group A (8.9%) and 24 of Group B (82.8%) (P < 0.001). Hospital mortality in Group A was 10.3% (9/87), in Group B there was no hospital mortality (P > 0.05). Thirty-two patients of Group A (36.8%) and 3 of Group B (9.7%) suffered of low cardiac output syndrome (P = 0.01). At late control, improvements observed in NYHA and CCS classes, left ventricular ejection fraction (all P < 0.001 in both groups versus preoperative values) and left ventricular end-diastolic diameter (P > 0.05 in Group A and P < 0.001 in Group B) proved to be statistically higher in patients of Group B.

CONCLUSIONS

Endoventricular patch plasty associated with a complete myocardial revascularization, in particular of the anterior descending coronary, and a larger use of the internal mammary artery, permits, by means of reconstruction of the left ventricular geometry, a better outcome for patients undergoing left ventricular aneurysmectomy.

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.