Results of nonguided subtotal endocardiectomy associated with left ventricular reconstruction in patients with ischemic ventricular arrhythmias

Surgery for Acquired Heart Disease

Results of nonguided subtotal endocardiectomy associated with left ventricular reconstruction in patients with ischemic ventricular arrhythmias We analyzed the effects of nonguided endocardiectomy in patients with ischemic ventricular arrhythmias who underwent reconstructive operations for postinfarction left ventricular aneurysm. A total of 106 patients among 287 consecutive patients had spontaneous or inducible ventricular tachycardia (49 spontaneous and 57 inducible). Cryotherapy was done in 67 patients and coronary revascularization was done in 98 %. Patients underwent complete hemodynamic study including programmed ventricular stimulation before and early after operation. Thirty-seven patients underwent hemodynamic evaluation after 1 year. The hospital mortality rate was 7.5 %. At early and late studies the mean ejection fraction was significantly increased. Ventricular tachycardia was no longer inducible in 92 % of patients after operation; only two patients had spontaneous ventricular tachycardia early after operation. At late study 10.8% of patients had inducible ventricular tachycardia and no spontaneous ventricular tachycardia was documented. AU surviving patients had clinical follow-up (mean 21.3 months, range 2 to 64 months). There were eight late deaths and no episodes of ventricular tachycardia or syncope that necessitated hospitalization. In conclusion, nonguided, extended endocardiectomy associated with left ventricular reconstruction is safe and effective in curing ischemic spontaneous and inducible ventricular tachycardia. (J THoRAc CARDIOVASC SURG 1994;107:1301-8) V. Dor, MD,a M. Sabatier, MD a (by invitation), F. Montiglio, MDa (by invitation), P. Rossi, MDa (by invitation), Monte Carlo, Monaco. A. Toso, MDb (by invitation), and M. Di Donato, MD b (by invitation), Florence, Italy

firing the past decade considerable advancement has been made in the treatment of patients with malignant ventricular arrhythmias. Treatment options include pharmacologic antiarrhythmic therapy, surgical treatment with guided and nonguided endocardial resection of the From the Centre Cardiothoracique de Monaco, Monte Carlo, Monaco; and the Department of Cardiology, University of Florence, Florence, Italyb Read at the Seventy-third Annual Meeting of The American Association for Thoracic Surgery, Chicago, Ill., April 25-28, 1993. Address for reprints: Vincent Dor, MD, Centre Cardiothoracique de Monaco, Av. D'Ostende II bis BP 223, 98004 Monaco Cedex. Copyright

1994 by Mosby-Year Book, Inc.

0022-5223/94 $3.00

+0

12/6/53447

arrhythmogenic sites.!" cryotherapy, and laser ablation. 5- 1O Blind aneurysmectomy alone, mainly if done with standard linear suture, has been reported to have a higher failure rate in resistant ventricular arrhythmias. ll . 12 More recently, the introduction of the automatic implantable cardioverter-defibrillator has been an important step forward for patients who have survived sudden death. Furthermore, the sole alternative for the treatment of malignant arrhythmias in patients with severely depressed left ventricular (LV) function whose surgical risk is considered extremely high is heart transplantation. Nowadays, despite all these clinical and surgical therapeutic interventions, the decision of how to manage ischemic malignant ventricular arrhythmias is still conI 301

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Table I. Clinical characteristics of the study group Total

In = 106) Age (yr) Delay from MI (mo) NYHA class In) I II III

IV

59 ± 8 48 ± 60 7 30 33 36

Anterior aneurysm: n = 97; posterior aneurysm: n = 9. MI. Myocardial infarction; NYHA. New York Heart Association.

troversial. It has to be mentioned that all these treatments are problematic inasmuch as in the majority of cases they are done in patients with coronary artery disease whose long-term prognosis depends not only on the presence or absence of ventricular arrhythmias, but also mainly on the underlying disease and on LV function. . In our center, a vast experience in reconstructive surgery for postinfarction LV aneurysm associated with complete myocardial revascularization has been developed since 1984, using the technique of endoventricular circular patch repair with septal exclusion.P'!" Our results have definitely demonstrated that this technique allows for achievement of significant improvement in LV function both at early and late hemodynamic evaluation, with a relatively low surgical risk even in patients with extremely severe LV dysfunction. 16 In the present paper we report the results of this kind of operation with associated subtotal nonguided endocardiectomy in patients with spontaneous or inducible VA who underwent endoventricular circular patch repair for postinfarction LV aneurysm and coronary artery disease. Methods Study patients. A series of 287 consecutive patients were treated by reconstructive operations comprising endoventricular circular patch repair and septal exclusion for postinfarction LV aneurysm between 1987 and 1992. Angina, congestive heart failure (CHF), or ventricular arrhythmia was the single indication for operation in 14%, 8%, and 3% of patients, respectively, whereas 75% of patients had multiple indications. One hundred six patients (99 men and 7 women, mean age 59 ± 8 years) who had spontaneous or inducible ventricular arrhythmias represent the study group. Clinical characteristics of the patients are given in Table I. Hemodynamic and electrophysiologic data were gathered for each patient in hemodynamic studies that included catheterization of the right and left sides of the heart and ventricular and coronary artery angiography. Cardiac output was measured by the thermodilution technique; ventricular volumes were calculated with the method of Chapman and associates." Global ejection fraction (EF) was calculated as EDV - ESV /

Table II. Total cases of ventricular arrhythmias in the study group Type of ventricular arrhythmia

n

Inducible VT Spontaneous and inducible VT Spontaneous VT (PVS contraindicated) Spontaneous VT, noninducible at PVS

57

Total

19 23 7 106

PVS. Programmed ventricular stimulation.

EDV X 100 (EDV, end-diastolic volume; ESV, end-systolic volume) and contractile EF (the EF of the nonaneurysmal portion of the LV) was calculated according to the method described by Kapelansky and associates.'? Preoperative programmed ventricular stimulation was done at the right ventricular apex and included pacing at two basic cycle lengths (600 and 500 msec) with up to two extra stimuli. Arrhythmia was considered inducible if monomorphic ventricular tachycardia (VT; VT rate zs 260 beats/min) lasting more than IS seconds was induced. Programmed ventricular stimulation was considered contraindicated if (I) EF was less than 20%, (2) intraventricular thrombi were present, or (3) left main coronary artery disease was detected. Twenty-three patients who had spontaneous VT did not undergo programmed ventricular stimulation before operation because it was contraindicated (Table II). Shortly after operation programmed ventricular stimulation and LV angiography were repeated in all except 2 survivors; 37 patients underwent hemodynamic study I year after operation by programmed ventricular stimulation, complete hemodynamic study, and bypass angiography. Postoperative programmed ventricular stimulation protocol was exactly the same as that before operation and any postoperatively induced sustained monomorphic VT was considered to be significant. Clinical follow-up was available in all surviving patients. The end points of the follow-up (obtained by telephone interview or by mailing a questionnaire) were mortality, syncope, or arrhythmias necessitating hospitalization. Surgical technique. The technique of endoventricular circular patch with septal exclusion has been described in detail in previous papers'
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septal scar with a septal hinge, is anchored inside the ventricle on contractile tissue, thus reducing the cavity circularly. Excluded external tissues are folded to reinforce suture line. Endocardiectomy was done in all patients; cryotherapy was also done in 67 of them. The indication for the use of cryosurgery is based on the judgment of the surgeon at the time of operation; when all of the surgical scar can be completely resected safely without damaging the mitral valve apparatus, no cryosurgery is used. However, unique to our procedure is that if the septal scar itself can be used as the LV aneurysm patch, it is essential to cryoablate the undetached base of this septal patch to electrically isolate it from the remainder of the heart. The decision to use the septal scar flap as a patch is based on the anatomy of the individual heart and therefore the use of cryosurgery varies from one patient to another. Bypass operation was done in 98% of patients . Mitral reconstruction or mitral replacement was done in all patients with posterior aneurysm. The mitral valve is replaced through the ventricular approach when we are obliged to resect the papillary muscle involved in the fibrotic scar, whether or not mitral insufficiency is present; the valve is repaired when preoperative mitral insufficiency and no need to resect the papillary muscle exist. Statistical analysis. Values are expressed as mean plus or minus the standard deviation. Paired t test , McNemar test, Mann- Whitney test, and the one-wa y analysis of variance were applied when indicated.

Results Eight patients (7.5%) died in the perioperative period (six of them died of refractory heart failure; one had massive intraaortic thrombosis 8 hours after operation; one had fatal cerebrovascular ischemia). Of the eight nonsurviving patients five had spontaneous VT and three had inducible nonclinical VT. Postoperative nonfatal complications occurred in 34 patients (32%): lowcardiac output occurred in 20, intraaortic balloon counterpulsation had to be used in 18, bleeding complications that necessitated blood transfusion were observed in 8, and renal failure occurred in 8. Two patients underwent heart transplantation (heterotopic heart transplantation) at 6 weeks and 6 months after operation for intractable heart failure, respectively. Hemodynamic parameters before, shortly after, and I year after operation are givenin Table III . EF was significantly increased both at early and late studies; mean pulmonaryartery pressure was decreased only early after operation. In patients who died in the perioperative period, baseline mean pulmonary artery pressure was significantlyhigher(31 ± I5versus 19 ± 9mmHg,p < 0.05) and EF lower (23% ± 10% versus 37% ± 13%, P < 0.001) than in survivors. Despite this finding, the hemodynamicresultsin the subgroup with baselinesevere pulmonary hypertension (mean pulmonary pressure 2: 30 mm Hg) were substantially positive (Table IV). At baselinethese patients had a higher end-diastolic

Fig. 1. Endocardial scar mobilization up to contractile muscle is shown.

volumeindex (139 ± 51 ml/rn? versus III ± 45 ml/rrr', p < 0.007) and a lower EF (29% ± 12% versus 38% ± 13%, P < 0.01) than those with normal pulmonary pressures,but the prevalenceof VT inducibilitywas not significantly different in patients with or without pulmonary hypertension. Table V reports the results of electrophysiologic study early after operation. VT was no longer inducible after operation in 92% of patients (88/96 patients who underwent postoperative programmed ventricular stimulation protocol). Three of the eight patients with postoperative inducible VT had inducible VT before operation (two of them had inducible-only VT). The other five patients had preoperative spontaneous VT and contraindications to programmed ventricular stimulation. Only two patients had spontaneous VT early after operation; they did not undergo programmedventricular stimulation because the presenceof postoperativespontaneous VT wasconsidered a surgical failure. All patients with postoperativespontaneous or inducible VT were discharged receiving amiodarone or mexiletine. The favorable results on ventricular arrhythmias were maintained at the l-year study (Table VI), when ventric-

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Table III. Hemodynamic parameters in the study group after 1 year Preop. EDVI

120 ± 60

Postop.

One year postop.

82 ± 23*

93 ± 27*

(ml/m-) EF (%) EFc (%) MPAP

32 ± II 45 ± II 19 ± 8

47 ± 11*

45 ± 14*

17 ± 6*

25 ± 14t

2.7 ± 0.63

2.6 ± 0.55

2.6 ± 0.56

n

Inducible VT Noninducible VT Spontaneous VT (PVS contraindicated) Perioperative deaths

(mm Hg) CI

Table V. Patients with early postoperative PVS (n = 96)

(Lyrnin/m') EDV/. End-diastolic volume index; EF. ejection fraction; EFc. contractile ejection fraction; M PAP, mean pulmonary artery pressure; C/, cardiac index.

Spontaneous VT Inducible VT

severe pulmonary hypertension (mean pulmonary artery pressure 30 mm Hg or greater; n = 18) MPAP (mm Hg) EF(%) EDVI (ml/m 2)

Preop.

Postop.

p Value

37 ± 6 29 ± 12 139 ± 51

24 ± 8 41 ± 7 83 ± 23

<0.001 <0.0001 <0.001

MPAP, Mean pulmonary artery pressure; EF, ejection fraction; EDV/, end-diastolic volume index.

ular arrhythmias was inducible in only 4 of 37 patients (3 inducible and 1 noninducible at the early follow-up). At clinical follow-up of all surviving patients (mean 21.3 months, range 2 to 64 months) neither ventricular arrhythmias nor syncope necessitating hospitalization was observed. Three patients died suddenly, four (one of whom had received total cardiac transplantation) died of progressive CHF, and one died of pulmonary embolism, for a total of eight late deaths. The three patients who had sudden death had noninducible VT at postoperative programmed ventricular stimulation; before operation one of them had inducible-only VT and two had spontaneous VT. Discussion In a vast review concerning the surgical treatment of ischemic VT, Cox 20 pointed out the several issues that still remain unresolved when the problem is approached: (I) indication for and contraindication to surgical treatment, (2) the importance of intraoperative mapping, (3) the type of surgical technique to be used, (4) the manner in which the surgical procedure is conducted, and (5) the role of the automatic implantable cardioverter-defibrillator. In the present paper we have tried to answer, at least in part, some of these questions.

88 2

92 2.0

8

7.5

Table VI. Patients with 1-year postoperative PVS (n = 37) n

Table IV. Hemodynamic parameters in patients with

8

PVS, Programmed ventricular stimulation.

•p < 0.00] versus preoperative study. t p < 0.00 I versus postoperative study.

%

8

Noninducible VT

%

o 4 33

10.8 89.2

PVS, Programmed ventricular stimulation.

Indications for operation. It has to be first pointed out that, in our series, patients underwent reconstructive operation for LV aneurysm and symptoms that, in the majority of cases, were angina and/or CHF (as evidenced by the high proportion of patients in New York Heart Association functional classes III and IV). Indication for intractable arrhythmias alone was low in our series and the incidence of spontaneous clinical VT was 18% when the overall number of patients (49/287) who underwent operation is considered. Thus comparison with other series, whose major indication for operation was intractable VT, appears difficult. In fact, most previous investigators reporting on the effects of a given surgical procedure for VT have confined their study group to those patients who had spontaneous documented VT. Because VT is a pathologic rhythm (that is, it cannot be induced in normal hearts as can ventricular fibrillation) we have treated inducible, nonclinical VT as a pathologic rhythm, and because LV aneurysms are frequently accompanied by this pathologic rhythm, we have actively searched for it in hopes of improving the long-term outlook for these patients by reducing the risk of late postoperative sudden death. In our study we chose a stimulation protocol with only two extrastimuli to avoid the risk of inducing clinical irrelevant arrhythmias; nevertheless, preoperative inducible-only VT was more prevalent in our patients than that reported by others 2 1- 23 ; in fact, 57 patients (38%) out of 150 who underwent preoperative programmed ventricular stimulation had inducible-only VT. This high frequency of nonclinical arrhythmias may have influenced the results. However, owing to the prognostic importance of VT inducibility after myo-

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cardial infarction-v" and to the poor prognostic value of persistent, postoperative VT inducibility in patients with clinical arrhythmias,n-3! we believe that patients with inducible-only VT and LV aneurysm should undergo endocardial excision inasmuch as we have demonstrated that even latent VT can be abolished in these patients and such a result is superior to leaving the patients vulnerable to postoperative VT, a problem that is known to be a harbinger of sudden death. As far as ventricular arrhythmias in posterior aneurysm is concerned, our results show that there are no differences in postoperative VT inducibility related to the site of the aneurysm. In fact, of the 10 patients with posterior aneurysm (among the 287 patients of the total group), 9 (90%) had preoperative spontaneous or inducible VT but only I patient had inducible-only VT and none had spontaneous VT after operation. In the present series we found that patients who died in the perioperative period had a significantly lower EF, thus confirming previous data. 28. 30. 31-33 On the contrary, we could not confirm any association between a poor systolic function of the nonaneurysmal LV portion and increased mortality: contractile EF, in fact was only marginally lower in nonsurvivors than in survivors (38% ± 8% versus 45% ± II %, not significant). However, the small number of deaths may have accounted for the lack of significance. Patients who died perioperativeIy had a much higher mean pulmonary pressure: as far as we know, this finding has not been reported in the major published series,20.28-30 perhaps because a complete hemodynamic study, including hemodynamics of the right side of the heart, is not routinely done. According to our data, we might therefore suggest that pulmonary hypertension and associated low EF can be regarded as relative contraindications for operation. On the contrary, because results have been good also in patients with an extremely severe LV dysfunction a low EF per se (EF ::s 20%) should not be considered a contraindication for LV reconstruction with endoventricular circular patch repair and associated endocardiectomy (Table VII). Guided versus nonguided endocardiectomy. The efficacy of map-guided endocardiectomy has been extensively proved. J. 2. 34-36 However, as has been discussed by Cox,20 intraoperative map-guided endocardiectomy is particularly useful to guide localized procedures- 34 but its benefit can be counterbalanced by "the wider excision of potentially arrhythmogenic tissue, that is accomplished by generalized procedures. . . ." Our technique consists of removing the visible endocardial scar and fibrosis and of applying cryoablation at the border of the lesion. Thus it is an extended, generalized, blind procedure done with total cardiac arrest and blood cold cardioplegia in the

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Table VII. Hemodynamic and electrophysiologic data in patients with extremely poor LV function (EF 20% or less) Preop. (n = 15)

EF(%) PAP (rnm Hg)

Spontaneous VT (n) Inducible VT (n)

15.8 ± 3.4 27.3 ± 9.4 II 4

Postop. (n = 13)

p Value

36.6 ± 8.1 22.9 ± 7.4

<0.0001 <0.001

o I

EJ. Ejection fraction; PAP. pulmonary artery pressure.

majority of cases. Nevertheless, Cox 20 has pointed out that surgical therapy for VT done in the normothermic beating heart gives better results. At present, however, no one technique in itself has proved its absolute superiority. In our series, the prevalence of postoperative VT inducibility was low in comparison with that of almost all the reported series.F: 29, 30 In particular, it was lower even in respect to the series that can be matched for number of patients and the type of operation.Fv? Our results were similar to those reported by the Duke-Barnes experience.i" This unusually low prevalence of postoperative VT inducibility cannot be ascribed to the type of operation, because our technique was different from that used by Cox. Most likely, it can be probably ascribed, apart from the extended endocardial resection, to the improved shape and geometry of the LV cavity achieved with endoventricular circular patch repair and to the complete myocardial revascularization that was done in the great majority of our patients. Nevertheless, there were eight patients in whom VT was still inducible after operation and this can be considered as surgical failure. Three of these patients had inducible VT before operation (two of them had inducible-only VT); the other five patients had spontaneous VT and contraindication to programmed ventricular stimulation, thus it is possible that they would have had inducible VT also before operation. Of these eight patients only one died of progressive heart failure 5 years after operation. VT inducibility was still low after I year (4/37 patients had inducible VT at the I-year programmed ventricular stimulation), and in patients followed up on clinical ground, no episodes of spontaneous VT were documented. As far as late survival is concerned, our results seem also encouraging, inasmuch as only three sudden deaths occurred among eight late deaths. Two patients who died suddenly had preoperative spontaneous VT and one had inducible-only VT. All three had no inducible VT at early follow-up examination. Thus 92% of patients with preoperative ventricular arrhythmias (excluding perioperative deaths) were alive at mean follow-up of 21.3 months.

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In our opinion, these are considerable results, even though data at longer follow-up are needed.

The role of the automaticimplantable cardioverterdefibrillator. The use of the automatic implantable cardioverter-defibrillator has gained increasing acceptance in the most recent period and, in the future, its use will further increase with technical improvement of the device. Our experience in this particular field is scant: in the present series, no patient received an automatic implantable cardioverter-defibrillator during or after operation and, in the two patients who had the device implanted before operation, it was removed when postoperative examination showed VT was not inducible. Some authors have recommended routine placement of cardioverter-defibrillator patches at the time of operation.t" Cox 20 suggests implanting such patches during operation if a guided procedure in the normothermic beating heart still results in inducible VT or if patients with extremely high risk for operation do not respond to amiodarone therapy. It has to be mentioned, however, that at present implantation of an automatic implantable cardioverter-defibrillator has several problems. First, it does not seem to unequivocally improve survival, because rates of sudden death and 5-year mortality rates of 1.5% to 2% per year and of 8% to 10%, respectively, have been reported-" 41; second, it is a palliative form oftherapy that can sometimes be even dangerous because of inadequate or inappropriate discharges of the device. In conclusion, extended, nonguided endocardiectomy with or without cryotherapy, associated with endoventricular circular patch repair and complete myocardial revascularization in patients with postinfarction LV aneurysm, depressed systolic function, and ischemic VT is safe and effective in curing spontaneous and inducible VT. The effects of this procedure on VT, as well as on the improvement in LV geometry and function, are still evident after I year. By preventing arrhythmias, reversing ischemia, and restoring LV geometry and shape toward normal, our aggressive approach appears to be an optimal treatment for patients whose ventricular arrhythmia is only one aspect of a complex clinical problem. REFERENCES 1. Josephson ME, Harken AH, Horowitz LN. Long-term results of endocardial resection for sustained ventricular tachycardia in coronary disease patients. Am Heart J 1982;104:51-7. 2. Josephson ME, Harken AH, Horowitz LN. Endocardial excision: a new surgical technique for the treatment of recurrent ventricular tachycardia. Circulation 1979;60: 1430-9. 3. Zee-Cheng CS, Kouchoukos NT, Connors JP, Rufty R. Treatment oflife-threatening ventricular arrhythmias with

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15. 16.

17.

18.

non guided surgery supported by electrophysiologic testing and drug therapy. J Am Coll Cardiol 1989;13:153-62. Sosa E, Jatene A, Kaeriyama JV, et al. Recurrent ventricular tachycardia associated with postinfarction aneurysm: results of left ventricular reconstruction. J THORAC CARDlOVASC SURG 1992;103:855-60. Ricks WB, Winkle RA, Shumway NG, Harrison DC. Surgical management of life threatening ventricular arrhythmias in patients with coronary artery disease. Circulation 1977;56:38-42. Garan H, Nguyen K, McGovern B, Buckley M, Ruskin IN. Perioperative and long-term results after electrophysiologically directed ventricular surgery for recurrent ventricular tachycardia. J Am Coll Cardiol 1986;8:201-9. Guiraudon G, Fontaine G, Frank R, et al. Encircling endocardial ventriculotomy: a new surgical treatment for life threatening ventricular tachycardia resistant to medical treatment following myocardial infarction. Ann Thorac Surg 1978;26:438-44. Mittleman RS, Candinas R, Dahlberg S, Salm TV, Moran JM, Huang SHS. Predictors of surgical mortality and long-term results of endocardial resection for drug-refractory ventricular tachycardia. Am Heart J 1992;124:122632. Caceres J, Akhtar M, Werner P, et al. Cryoablation of refractory sustained ventricular tachycardia due to coronary artery disease. Am J Cardiol 1989;63:296-30. Mickleborough LL, Mizuno S, Downar E, Gray Gc. Late results of operation for ventricular tachycardia. Ann Thorae Surg 1992;54:832-9. Mason JW, Stinson EB, Winkle RA, Oyer PE, Griffin JC, Ross DL. Relative efficacy of blind left ventricular aneurysm resection for the treatment of recurrent ventricular tachycardia. Am J Cardiol 1982;42:241-8. Sami M, Chaitman BR, Bourassa MG, Charpin D, Chabot M. Long-term follow-up of aneurysmectomy for recurrent ventricular tachycardia or fibrillation. Am Heart J 1978; 96:303-8. Dor V, Saab M, Coste P, Kornaszewska M, Montiglio F. Left ventricular aneurysm: a new surgical approach. Thorae Cardiovasc Surg 1989;37:11-9. Dor V, Bourlon F, Sabatier M, et al. La reconstruction du ventricule gauche par plastie circulaire endoventriculaire avec exclusion septale. Arch Mal Coeur 1990;83:1687-94. Dor V. Surgery for left ventricular aneurysm. Curr Opin Cardiol Curr Sci 1990;5:773-80. Di Donato M, Barletta G, Maioli M, et al. Early hemodynamic results of left ventricular reconstructive surgery for anterior wall left ventricular aneurysm. Am J CardioI1992; 69:886-90. Dor V, Sabatier M, Montiglio F, et al. Clinical, hemodynamic and electrophysiologic results of 200 left ventricular patch reconstruction for postinfarction left ventricular aneurysm. In: Proceedings of the Seventy-second Annual Meeting of The American Association for Thoracic Surgery, Los Angeles, 1992:82-3. Chapman CB, Baker 0, Reynolds J, Bonte FJ. Use of

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biplane cinefluorography for measurement of ventricular volume. Circulation 1958;18:1105-17. 19. Kapelanski DP, Al-Sadir J, Lamberti JJ, Anagnostopoulos CEo Ventriculographic feature predictive of surgical outcome for left ventricular aneurysm. Circulation 1978; 58:1167-74. 20. Cox JL. Patient selection criteria and results of surgery for refractory ischemic ventricular tachycardia. Circulation I989;79(Suppl):I 163-7. 21. Sulpizi AM, Friehling TD, Kowey PRo Value of electrophysiologic testing in patients with nonsustained ventricular tachycardia. Am J CardioI1987;59:841-5. 22. Santarelli P, Belloci F, Loperfido F, et al. Ventricular arrhythmia induced by programmed ventricular stimulation after acute myocardial infarction. Am J Cardiol 1985;55:391-4. 23. Woelfel A, Foster JR, Rowe WW, Jain A, Gettes LS. Induction of ventricular tachycardia in patients with left ventricular aneurysm and no history of arrhythmias. Am J Cardiol 1988;62:814-6. 24. Richards DA, Cody DV, Dennis AR, Russel PA, Young AA, Uther JB. Ventricular electrical instability: a predictor of death after myocardial infarction. Am J Cardiol 1983;51 :75-80. 25. Waspe LE, Seinfeld D, Ferrick A, Kim SG, Fischer JD. Prediction of sudden death and spontaneous ventricular tachycardia of survivors of complicated myocardial infarction:value of the response to programmed stimulation using a maximum of three ventricular extrastimuli. J Am Coli Cardiol 1985;5:1292-301. 26. RoyD, Marchand E, TherouxP, WatersDD, PelietierGB, Bourassa MG. Programmed ventricular stimulation in survivors of an acute myocardial infarction. Circulation 1985;72:487-94. 27. Miller JM, Kienzle MG, Harken AH, Josephson ME. Subendocardial resection for ventricular tachycardia: predictors of surgical success. Circulation 1984;70:624-31. 28. Ostermeyer J, Borggrefe M, Brethardt G, et al. Direct operations for the management of life-threatening ischemic ventricular tachycardia. J THORAC CARDIOVASC SURG 1987;94:848-61. 29. Swerdlow CD, Mason JW, Stinson EB, Oyer PE, Windle RA, Derby Gc. Results of operations for ventricular tachycardia in 105 patients. J THORAC CARDIOVASC SURG 1986;92:I05-13. 30. McGiffin DC, Kirklin JK, Plumb VJ, et a1. Relief of life threatening ventricular tachycardia and survival after direct operation. Circulation 1987;76:V93-103. 31. Miller JM, Marchlinski FE, Harken AH, Hargrove WC, Josephson ME. Subendocardial resection for sustained ventricular tachycardia in the early period after acute myocardial infarction. Am J Cardiol 1985;55:980-4. 32. Hammon JW Jr, Primm KR, Smith RF, et al. Indications for different modes of surgical therapy in medically refractory ventricular arrhythmias. Ann Surg 1986;203:679-84. 33. Hargrove WC III, Miller JM, Vassallo JA, Josephson ME. Improved results in the operative management of ventric-

Dor et al.

34.

35.

36.

37.

38.

39.

40.

41.

I 307

ular tachycardia related to inferior wall infarction. J THORAC CARDIOVASC SURG 1986;92:726-32. Ostermeyer J, Breithardt G, Borggrefe M, Godehardt E, Seipel L, Bircks W. Surgical treatment of ventricular tachycardias: complete versus partial encircling endocardial ventriculotomy. J THORAC CARDIOVASC SURG 1984; 87:517-25. Wiener I, Mindich D, Pitchon R. Determinants of ventricular tachycardia in patients with ventricular aneurysm: results of intraoperative epicardial and endocardial mapping. Circulation 1982;65:856-61. Horowitz LN, Harken AH, Kastor JA, Josephson ME. Ventricular resection guided by epicardial and endocardial mapping for treatment of recurrent ventricular tachycardia. N Engl J Med 1980;302:589-93. Moran JM, Kehoe RF, Loeb JM, Lichtenthal PR, Sanders JH Jr, Michaelis LL. Extended endocardial resection for the treatment of ventricular tachycardia and ventricular fibrillation. Ann Thorac Surg 1982;34:538-52. Krafchek J, Lawrey GM, Roberts R, Magro SA, Wyndham CR. Surgical ablation of ventricular tachycardia: improved results with a map-directed regional approach. Circulation 1986;73:1239-47. Kron IL, Lerman BB, Di MarcoJP. Extendedsubendocardial resection: a surgical approach to ventricular tachyarrhythmias that cannot be mapped intraoperatively. J THORAC CARDIOVASC SURG 1985;90:586-91. Platia EV, Griffith LS, Watkins L Jr, et al. Treatment of malignant ventricular arrhythmias with endocardial resection and implantation of the automatic cardioverter defibrillator. N Engl J Med 1986;314:213-6. Mirowski M. The automatic implantable cardioverter defibrillator: an overview. J Am Coli Cardiol 1985;6: 461-6.

Discussion Dr. Lynda L. Mickleborough (Toronto, Ontario, Canada). Dr. Dor, you have made it clear that remodeling the LV and resection of the aneurysm in these patients does something to improve the prevalence of arrhythmias during follow-up. I agree entirely with this conclusion. I have three questions. I wonder whether this series is truly comparable with results obtained in most map-directed series for VT control. The two criteria for entry of patients into these series would be the spontaneous occurrence of symptomatic arrhythmias in addition to inducibility of arrhythmias at the time of preoperative electrophysiologic testing. It was not clear to me how many of the patients in your series met both these inclusion criteria. Do you think there could be any possible negative effect of extensive endocardial excision as used in your approach? In particular, how many of your patients required postoperative pacing because of inadequate ventricular rate? Finally, how do you decide which of your patients gets cryoablation in addition to excision of the endocardial scar? Dr. William W. Angell (Tampa, Fla.). We seem to have switched over almost completely to defibrillator implantation for patients with VT syndromes, particularly in that group of

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Dar et at.

patients in whom revascularization is not an essential component of the surgical procedure. I wonder if Dr. Dor could tell us what his present indication is for the use of a defibrillator and whether his group is still using endocardiectomy as the primary modality for the treatment of VT. Dr. G. Hossein Almassi (Milwaukee, Wis.). I was intrigued by the fact that these investigators are using the autogenous scar tissue as a patch for ventricular reconstruction. Would you not be concerned about the fate of this patch in the long term in terms of its expansion and the creation of the same problem that was there to begin with, namely, an aneurysm underneath the closure line? Dr. Dor. Dr. Mickleborough, I mentioned in our last table that, among these 106 patients, we had 49 with spontaneous sustained VT and 57 with inducible sustained VT. In terms of prognosis, however, the final evolution of this second category was almost the same as the first with 35% risk of sudden death. This method is therefore a good way to cure spontaneous and inducible VT. As far as pacing is concerned, we had no need for permanent pacing in this series. Sometimes we have to use temporary pac~ ing, mainly according to the type of cardioplegia used. Concerning cryoablation, because we started using it in 1989,

The Journal of Thoracic and Cardiovascular Surgery May 1994

there was no use of cryoablation in the series from 1987 to 1989. We used cryoablation to try to achieve 100% success, but its use did not change the statistics, which is the reason we say that we are not sure whether cryoablation gives more benefit than endocardiectomy, ventricular reconstruction, and total revascularization of the infarcted area. Dr. Angell, we have never used a defibrillator in addition to operation and, in the two patients fitted with the device before radical operation, we removed the defibrillator once we were sure that at the I-year follow-up they no longer had VT. Maybe we are wrong, but we think it is a nice way to eliminate this very heavy material in a patient who hopes to lead a normal life without any trouble. To answer our colleagues from Milwaukee, we talked last year about the autogenous patch. It is true that we started this technique in 1988 and, in all our patients followed up after I month and I year, we have not seen any disturbances or any evolution with this type of fibrous material. However, the future might show us at the 5-year follow-up examination that we are wrong and we will then go back to the artificial tissue patch. But, again, for pure septal scar, it is elegant and fast to use this autogenous tissue to rebuild the normal ventricle and for the moment we will continue to do so.

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