JACC Vol. 14. No I July l9e37-41 37

lectrophysiological~y guided endocardial rese come a well accept ative drug-resistant ven tacb localized endocardial resection tive than simple aneMrysmectomy (2.3) or cQ~o~a~y bypass surgery, ventricular tachycardia may persist patients after operation (4). The recurrence after localized endocardial resection may re of programmed electrical stimulation and activation mapping to define the extent of the electrophysiologic disorder accu- rately, rather than represent a failure of surgical tecb~~ique. Lack of sensitivity and specificity of programmed electrical stimulation and the recurrence of ventricular tachycardia after localized endocardial resection have caused our insti- tution to adopt a more aggressive approach to the ablation of these arrhythmias. In this report, we review our experience with complete endocardial resection for sustained drug resistant ventricular tachycardia.

From the Departments of Surgery, Medicine and Anaesthesia. Dalhousie University, Halifax, Nova Scotia, Canada. This study was supported in part by a grant from the Medical Research Council and from the New Brunswick Heart and Stroke Foundation, New Brunswick, Canada.

Manuscript received July 26. 1989: revised manuscript received January 24. 1990. accepted February 21. 1990.

-for Roderick W. Landymore. MD, Room 3065. R.C. Dickson Centre, Victoria General Hospital, Halifax, Nova Scotia. Canada B3H 2Y9.

01990 by the American College of _ardioiogy

demonstrated the presence of a well ned anterior aneu- rysm in 18 of the 26 patients. The re had hypokinesia or akinesia of the region involved by the prior infarction; six of these patients had abnormalities of the anterior wall and two had abnormalities of the posterior wall. Preoperative ejection fraction ranged from 10% to 59% (mean 29%). Coronary angiography demonstrated the pres- ence of occlusive coronary artery disease requiring concom- itant c bypass surgery in 14 patients.

Ele iologic ~v~~u~~~~~. Programmed electrical stimulation was carried out before operation in all patients. Single, double and triple ventricu duced at various cycle lengths at of the right ventricle. Programmed electrical stimulation was used not only to confirm the diagnosis of sustained ventric- ular tachycardia, but also to assess the efficacy of drug therapy. A mean of 3.5 + 2 drug interventions had failed to control the ventricular arrhythmia in each patient before

07351097/%%3.50

38 LANDYMORE ET AL. SURGERY FOR DRUG-RESISTANT TACHYCARDIA

SAW Vol. 16. ko. t

Table 1. Clinical Features of 26 Patients

Ai3e (yr) M/F (no.) Frior infarction (no.)

C3 mo. >3 mo.

LVA (IN EF (%I >70% comnw stenosis (no.)

42-16 W? l9l7

II 15 1 l&59 129) l-3 ( 1.8)

Numbers in parentheses are mean dues. EF = ejection fraction; F = female; LVA = left ventricular aneurysm: M = male.

endoc~i~ resection was recommended. ~eope~tive pro- grammed electricat stimulation elicited from 1 to 3 mapho- iiogically distinct ventricular tachycardias per patient (mean r SD 2 & 0.7). In 11 patients the tachycardia had a right bundle branch configuration, in I3 it had a left bundle branch ~o~g~~ion; 2 patients had a poiymo~hic ta~hycardia. The cycle length of the tachycardias ranged from 250 to 470 ms (mean 297).

All patients underwent electrophysiologic evaluation within 7 to 10 days postoperatively, with the exception of the three patients in the series who had died within the first 3 weeks after e~~~i~ excision. The ~sto~~tive electro- physiologic protocol was identical to the preoperative pro- tocol already described.

Surgleal prowlure. Myocardial preservation was pro- vided with a combination of systemic cooling to 25T, topical cooling and ~~s~loid c~iople~a. My~~di~ tempem- ture was monitored and maintained within a range of lo” to 15°C. Coronary artery bypass surgery was performed after cardioplegic arrest was initiated. Endocardial resection was then carried out after a ventriculotomy was made through the left vent&ular aneurysm or the infarction scar. A11 visibly scarred endo~~dium was excised pond the entire circumference of the infarction, with the excision extending approximately 1 cm above the visual demarcation between endocardial scar and normal muscle. The endocardial scar frequently involved the papillary muscles; in this situation, the papillary muscle was partly or completely detached and replated. The septum was patched in the last 19 patients with a Gore-Tex patch to prevent a postoperative ventricular se@ defect. (The septal patch was routinely employed after our experience with the seventh patient in this series, who developed spontaneous perforation of the ventricular sep- tum after extended septal end~~j~ resection.) The ven- tricle was then closed with felt and mattress sutures of o polypropelene.

SUstica~ analysis. Results are reported as the arithmetic mean value SL: SD. Statistical comparisons were made with the chi-square test.

Results Twenty-six patients underwent complete endocardial re-

section. Resection was performed through a well defined

anterior vent~c~~ aneu~sm in 18 patients incision in the estimation scar (6 anterior wall, wall) in the remaining 8 patients. Papillary muscle surgery was required in 23 patients. The anterior papillary muscle was partially or completely detached in 21 patients and the poste- fior ~1~ muscle in I7 patients. Fou~e~n patients aqua

surgery, receiving two grafts per paGent. Three patients (12%) died within 30 days

reskction. One woman with sustained drug- resistant ventricular tachycardia, co and chronic re;~~! ftilure ~~~e~e~t do~di~ resection. Four hours developed a spontaneous peroration of the vent~~Mlar sep turn. The defect was recognized immediately by the pres- ence of a murmur, hemodynamic instability and a step-up in the right-sided oxygen saturation values. She was returned to the operating room and found to have a small ve~t~cular septal defect. Three weeks after the repair, she developed a further spontaneous septal perforation in a different region of the ventricular septum and again underwent repair of the defect. She never fully recovered from the operation and eventually died from renal failure.

The second death ~curred in a maa utmost a left ventricular aneurysm and with an ejection fraction of 17%. Endocardial resection and three vessel aortocoronary by- pass surgery was performed uneventfully. Although this patient was weaned from cardiopulmonary bypass with low dose dobutamine, his cardiac function continued to deterio- rate and he died 3 weeks after the ovation with renal failure and low cardiac output. A third patient with an qjection fraction of 24% underwent single aortocoronary bypass grafting and complete endocardial resection through an infarction scar. Low cardiac output that did not respond to conventions therapy develo~d after the p~edure, and the patient died I week after o~ration,

A~ythR~ a&r end~a~d~~~ resection. There were no episodes of spontaneous ventricular tachycardia or fibrilla- tion after endocardial resection. However, postoperative programmed electrical stimulation elicited ventricular tachy- cardia in one patient. He was treated with p~~namide, an antia~hythmic agent that had no therapeutic benelit before operation, but that controlled his electrophysiologically in- duced postoperative nonclinical arrhythmia. He returned 1 year later because of side effects from the drug; procaina- mide administ~tion was di~ontinued, and he unde~ent repeat pro~mmed electrical stimulation that failed to dem- onstrate any verttricular arrhythmias. He was discharged on no medication and is now free of ventricular tachycardia 78 months after the original operation.

~~~~0~0~~. Th ivors of endoc~di~ resection II foi~owed up 6 to 92 months (mean 43). There have been five late deaths (19% mortality rate). One patient, admitted to the hospital 4 months after endocardial resection with massive pulmonary embolism, died in right heart failure. The second patient died

4.5 years after the initial end~ardiai resection.

of dug-resistant venteicul~ tachycardia was in 1979 (5). ~x~e~e~ce has &own that localiz resection is far superior to nonelectrophysiologicaiiy guided proc~u~s ~2,3,~~, aitho vent~cular a~hythm~as may persist in 30% of patients. ler et al. (4) recently described 100 consecutive patients who underwent electrophysiologi- tally guided localized endocardial resection for drug- resistant ventricuiar tachycardia. The tachycardia was con- trolled in 60% of patients with surgery alone and in 73% with a combination of surgery and antiarrhythmic drug therapy. In the remainder of this group, either spontaneous clinical ~rhythmias occurred ~sto~eratively or the arrhytbmia could be induced with programmed eiect~cal stimuiatio~. Brodman et al. (7) reported early results in 22 patients unde~oing elect~physiologica~ly guided localized endocar- dial resection. Ventricular tachy~a~ia was controlled with a combination of endocardial resection and antiarrhythmic drug therapy in 68% of the survivor. Jason et al. (2) described 33 patients who underwent electrophysiologically guided surgery. Ventricular tachycardia occurred spontane- ously in 24% of patients and was inducible in a other 6%

ing in ~~% of patients.

recise emdoc~rdial loca~i2atio~

ventricular sites are present in 64% of patients whose condition does not improve after vocalized e~doc$rdia~ re- section and that 47% of these patients have multiple path- ways. Their clinical observations surest that there may be multiple anatomic sites that contain the electrophysioiogic substrate necessary to generate these malignant ~rr~ytb- mias. ~ni~l studies ff3-15) super this conceit and have shown that the electroanatomic substrate is located in the border zone between the infarct scar and healthy myocar- dium. This zone surrounds the infarct and consists of ische- mic myocardium interdigitating with in healthy myocardium. The cells not only but also are di~erent electro~hysiologically refractoriness and the rate at which an i propagated. Therefore, it is not the complexity of the electroa~ physiologic testing may fail to electrophysiologic disorder.

sa~strate, electric the extent of the

al resectbm. The extent of endocardial resection appears to be related to the ultimate success of the ovation, ~rafchek et al. (12) reported that vent~cular

40 LANDYMORE ET AL. SURGERY FOR DRUG-RESISTANT TACHYCARDIA

JACC Vol. 16. No. I July 199&37-41

tachyc~dia recurred in 3 of 8 patients after l~ali~d en- docardial resection, and in 1 of 24 patients who had under- gone a more extensive regional endocardial resection: all 4 patients who had nonelectrophysiologically guided complete endocardia) resection have had no further arrhythmias. Moran et at. (11) described 40 patients who unde~ent complete endocardial resection with excision of all visible endocardial scar. Ventricular tachycardia was induced in only 3 of 36 survivors (99% surgical cure tate). Kron et al. (16) reported their experience with 33 patients undergoing endocardial resection, including I? who unde~ent localized elect~physiolo~c~ly guided endocardial resection. Ven- tricular tachycardia was induced in five patients after oper- ation, and two patients had spontaneous clinical arrhyth- mias. There was one late sudden death, and one patient had recurrent ventricular tachycardia. Seven patients underwent complete endocardial resection because of unsuccessful int~o~~tive mapping. Postoperative programmed electri- cal stimulation failed to elicit ventricular tachycardia in these patients, and all patients are free from clinical arrhythmias.

Our experience with complete endocardial resection com- plements the results reported from institutions that have employed more extensive end~ardial resection. All our patients who underwent complete endocardial resection are free from ventricular arrhythmias and require no antiar- rhythmic drug therapy. Our findings combined with the data from other centers (I 1,12,17) strongly suggest that complete endocardial resection is superior to a localized procedure because it removes a much larger mass of tissue and, therefore, may ablate multiple ventricular foci that are present but not identified by electrophysiologic mapping.

Arrhythmias originating from the mitral valve. Encircling endocardial resection with complete removal of endocardial scar o&en required ope~tion on the subvalvul~ ~p~tus of the mitral valve. The papillary muscles of the mitral valve are frequently involved with infarct scar and thus may be the origin of malignant ventricular arrhythmias. Some surgeons (18,19) have employed mitral valve replacement when there is extensive involvement of the papillary muscles. whereas others U2,16) have utilized cryothe~py in this situation, Mitral valve replacement places the patient at risk from all the complications of prosthetic heart valves, while the efficacy of cryoablation has yet to be established. Krafchek et al. (20) utilized cryoablation in four patients, Spontaneous ventricular tachycardia necessitating repeat cryosu~ery oc- curred 4 days after c~otherapy in one patient: complete heart block developed in another patient after application of a cryolesion to the upper part of the septum. Kron et al. (16) applied a cryolesion to the base of a papillary muscle that was extensively involved with endocardial scar. The cryole-

@Sly resulted in severe mitral regurgitation that fii ;81 valve replacement.

e perform endocardial resection in the region of the PaPi)hQ’ mwks in almost all of our patients, Frequently, the resection requires partial detachment and reimplantation

of the papillary muscles. This technique was o~g~~al~y described by Carpentier et al. (21) in France and has not resulted in significant postoperative mitral insufficiency in our experience. A single patient in our series did require mitral valve replacement for mitral insufficiency, but the regurgita~on occurred 4.5 years after the initial e~d~~di~ resection and was related to generalized ventriculnr dilation. Ultimately, this patient required cardiac transplantation for unrelenting congestive heart failure.

vent a posto~rati earlier experience in one patient who deve~o~d multiple defects after an extensive septal endocardial resection. Spon- taneous ventricular septal defects (7,ll) are a weU recognized complication of such extensive resection (7, I 1). To prevent this complicati~, we routinely patch the septum in all ~tients requiring extensive septal e~d~~dial resection. me believe that the septal patch is justified, because we cannot predict which patients will develop spontaneous perforation of the septum and because reoperation for septal perforation after endocardial resection in this seriously ill g undoubt~ly increase the pejorative mo use of prosthetic material within the vent to promote thromboembolism, we have not observed any morbidity associated with the use of the patch in our series. One of our patients with a patch died 3 weeks after operation from low cardiac output. Autopsy demonst~ted that the entire septum was covered with p~ud~~o~elium, making it virtu- ally impossible to identify the site of the septal patch. This observation indicates that the patch rapidly becomes covered, and this should reduce the risk of thrombus formation.

jollity after endued ~~~io~. The operative mor- tality rae associated with localized or extended end~ial resection is higher than that associated with ao~~o~n~y bypass surgery or single valve replacement, but approaches that reported after simple aneurysmectomy. Reported peri- operative mortality rates (22-25) after aneurysm resection range from 12% to 2l%, with the greatest morality being observed in those patients with poor left vent~cular function and congestive heart failure. The reported operative mortal- ity rates (7,12,16) after endocardial resection of 12% to 18% compare favorably with our early operative mortality rate of 12% and are comparable with the mortality rate after simple aneurysmectomy.

Death after endocardial resection is frequently related to postoperative low cardiac output and most often occurs in patients with very low ejection fraction. Our early experi- ence suggests that patients with a low ejection fraction and without a left ventricular aneurysm have a much higher mo~~ity rate than do patients with a low eject on with a well defined left ventricular aneurysm (p finding that complements the observations of Moran et ;I’f (1 I). The presence of a large aneurysm permits access to the ventricle. and resection of the aneurysm usually improves

JACC Vol. 16. No. I duly wm37-41

docardial resection t

nce the reliability of preope ophysiolog~c evaluation so t

owever, until these tee

resection offers the best overall surgical complete ablation of drug-resistant ventricular This approach is particularly reco~~eaded in a well defined anterior ventricular aneurysm.

I. Wetstein L, Landymore R. Herre J. Current status of surgery for ventricular tachyarrhythmias. Surg Clin North Am 1986:65:571-T :.

2. Mason J. Stinson E, Winkle R. et al. Surgery for ventricular tachycardia: efficacy of left ventricular aneurysm resection compared with operalion guided by electrical activation mapping. Circulation 1982:65:1148-54.

3. Boneil de Soyza N. Murphy ML. Bissett J. Kane J. Doherty J. Venlric- ular arrhythmia in chronic stable angina pectoris with surgical or medical treatment. Ann Intern Med !979:89: 10-4.

4. Miller JM, Kienzle MG, Harken AH, Josephson ME. Subendocardial resection for ventricular tachycardia: predictors of surgical success. p:,-..I&:,.- ,oP”.,,,.6,4_3l ~,,%.“,ruIYI‘ IJUT,,“. * .

S. Harken A, Josephson M. Horowitz LN. Surgical endocardial resection for the treatment of malignant ventricular tachycardia. Ann Surg 1979: 190:456-&O.

6. Tabry LF. Geha AS, Hammond CL. Baue AE. Effect of surgery on ventricular tachyarrhythmias associated with coronary arterial occlusive disease. Circulation 1978:58(suppl 1):1-166-70.

7. Brodman R. Fisher JD, Johnston DR. et al. Results of electrophysiolog- ically-guided operations for drug-resistant recurrent ventricular tachycar- dia and ventricular fibrillation due to coronary artery disease. J Thorac Cardiovasc Surg 1984:87:431-8.

iCarl I.. Do I_. Yrol rrent on the induch:~ 0

terman J. tricular tat

of high a. Am J

9. . Slevenson W. Pro~~a~~e~ electrical stimulation with ~ife-l~rea~e~i~~ ventricular arrhylbmias. What

is the significance of induced arrhyt&mias and what is the correct stimuiatroa protocol’! Uirculaiitin IL85::2:i-7.

IO. Kim S. Seiden S. Malob J. Waspe L. Fisher 9. Discordance between ambuh~ory monitoring and programmed stimulation in assessing of mexiietine in patients with venlricular tachycardia. Am !986:Ii?:l4-Y.

II.

I?.

F. Loch J. Lichtenthal PR. Sanders JH Jr, Michaelis LL. Extended endocardial reseclion for the trealtnent of ventricular lachycardia and ventricular fihrillalion. Ann Thorac Surg I98!:34:538-52.

Krafchek J. Laurie G. Roberts R. Magro S. Wyndham C. Surgical ablation of venlricular tachycardia: improved results with a map-directed regional approach. Circulation 19#6:73:123Y-47.

13. El-Sherif N. Scherlag B. LazLara K. Hope R. I&entrant ventricular arrhythmias in the iate myocardial infarction period. 1. Conduction characteristics in the infarction zone. Circulation 1977:55:689-702.

14. Spear JF. Michelson EL. Moore EN. Excitability of cells within a mottled infarct of dogs susceptible to sustained ventricular lachyarrhythmlas. J Am Coil Cardiol 1983:1:1099-I IO.

15. Wetstein L. Michelson EL. Simson . et al. increased interphase between normoxic and ischemic tissue as the cause for re-entrant ven- tricular tachyarrhythmias. J Surg Res 1982:33:5?6-34.

16. Kron 1. Lerman R. DiMarco J. Extended subendocardial resection: a surgical approach lo ventricular tachyarrhylhmias lhal cannol be mapped intraoperatively. J Thorac Cardiovasc Surg 1985:90:586-91.

17. Landymore R. Kinley CE. Gardner M. Encircling endocardial resection with complete removal of endocardial scar without intraoperative map- ping for the ablation of drug-resistant ventricular tachycardia. J Thorac Cardiovasc Surg 1985:89: 18-24.

18. Moran JM. Kehoe RF. Lorb JM. el al. The role of papillary muscle resection and mitral valve replacement in the cantrol of refractory venlricular arrhythmia. Circulation 1983:68(suppl 111:11-154-60.

19.

20.

21.

22.

23.

24.

7i

lvey T. Brady 6. Misbach 6. Green HL. Surgical management of refractory venlricular arrhythmias in patients with prior inferior myocar- dial infarction. J Thorac Cardiovasc Surg 1985:89:369-77.

Krafchek 9. Lawric G. Wyndham C. Cryoablation of arrhythmias from the interventricular septum: initial experience with a new bivenlricular approach. J Thorac Cardiovasc Surg 1986:91:419-27.

Carpentier A. Relland J. DeLoche A. et al. Conservative management of the prolapsed mitral valve. Ann Thorac Surg 1978:26:294-302.

Brawley R. Magovern G, Gott V. Donahoo J. Gardner T. Watkins L. Left ventricular aneurysmectomy: faclors influencing postoperalive resulls. J Thorac Cardiovasc Surg 1983:85:712-7.

Burton N. Stinson E. Oyer P. Shumway N. Left VentriCdar aneurysm: preoperative risk factors and long-term postoperative resulls. J Thorn Cardiovasc Surg 1979:77:65-75.

Skinner J. Rasak C. Kongtahworn C, et al Nalural history of sur&iCallY treated ventricular aneurysm. Ann Thorac Surg 1984:38:42-5.

La. Glearchyk A. Lemole 6. Spagna P. Left ventricular aneurysm: ten years’ experience in surgical treatment of 244 cases. Improved clinical status, hemodynamics and long-term longevity. 3 Thorac Cardiovasc Suq 1984; 88:544-53.

26. Mickleborough L, Harris L. Downar E. Gray G. A new inlraoperative approach for endocardial mapping of ventricular tachycardia. J Thorac Cardiovasc Surg 1988:95:271-80.