Endocardial Resection Research Articles

Linear left ventricular aneurysmectomy: Modern imaging studies reveal improved morphology and function

It remains uncertain whether left ventricular aneurysmectomy (LVA) improves ventricular function and whether LVA improves or distorts left ventricular contour. we applied the powerful imaging techniques of multiple-gated acquisition scanning, intraoperative transesophageal echocardiography, and magnetic resonance imaging to assess functional and morphologic changes after LVA in 75 consecutive patients undergoing LVA by conventional resection and linear closure. fifty-two patients (69%) underwent concomitant coronary artery bypass grafting, 25 (33%) had directed endocardial resection, and 4 (5%) had valve replacement. the hospital mortality rate was 6.7% ( 5 / 75 ). Actu arial survival rates were 86%, 80%, and 64% at 1 year, 2 years, and 5 years, respectively. Mean anginal class improved from 3.49 to 1.24 ( p < 0.0001). Mean congestive heart failure class improved from 3.04 to 1.70 ( p < 0.0001). by multiplegated acquisition scan (48 patients), mean ejection fraction improved from 0.25 preoperatively to 0.33 postoperatively ( p < 0.0001). intraoperative transesophageal echocardiography (28 Patients) revealed no cases of distortion and demonstrated normalization of left ventricular contour in 69% of patients. Mean wall motion score improved from 16.4 to 18.8 ( p < 0.001). Mean crosssectional area of the left ventricle decreased from 18.7 cm 2 to 12.8 cm 2 ( p < 0.006). Magnetic resonance imaging confirmed normalization of left ventricular contour without distortion. We conclude that linear LVA is clinically effective and objectively improves left ventricular morphology and function. On this basis, we have extended application of LVA to include patients with at least moderate-sized aneurysms undergoing coronary artery bypass grafting, despite the absence of traditional indications of arrhythmia, embolism, and frank congestive heart failure.

Electrophysiologic testing in patients who respond acutely to intravenous amiodarone for incessant ventricular tachyarrhythmias

The outcome of patients who receive intravenous amiodarone for suppression of incessant ventricular tachyarrhythmia has not been studied conclusively. We conducteda prospective study in which all patients who responded acutely to intravenous amiodarone and went on to receive a subsequent oral loading dose were subjected to electrophysiologictesting before hospital discharge to determine whether additional or alternative therapy would be required. Among 18 patients (17 with ischemic heart disease) who entered the protocol, 16 had a clinical response to intravenous amiodarone alone (12 patients) or in combination withe another antiarrhythmic drug (4 patients) and survived to study. Of these, 10 had monomorphic ventricular tachycardia (VT) when first seen, five had polymorphous VT or ventricular fibrillation (VF), and three had both. In seven patients sustained monomorphic VT was inducible (group 1), and in nine it was not (group 2). The only clinical factor that distinguished group 1 from group 2 was age (group 1 > group 2). Five patients in group 1 and one in group 2 received an implantable cardioverter defibrillator; one patient in group 1 had a successful endocardial resection. During a mean follow-up period of 11 months, four patients in group 1 have had appropriate implantable cardioverter defibrillator discharges, whereas only one patient in group 2 has had a clinical event (sudden death). We conclude that intravenous amiodarone is a highly effective drug used alone or in combination to suppress spontaneous incessant VT/VF. Predischarge electrophysiologic testing, even in patients who have polymorphous VT, has predictive value over and above the observed clinical response. These preliminary results favor predischarge testing and aggressive device treatment in this cohort.

Outcome of endocardial resection in 33 patients with coronary artery disease: Correlation with ventricular tachycardia morphology

The results in 33 patients with ventricular tachycardia (VT) treated by endocardial resection were reviewed, with special emphasis on the presence of single or multiple morphologies preoperatively and intraoperatively. Multiple VT morphologies were induced in 16 patients and a single VT morphology was induced in the remaining 17. Intraoperative programmed stimulation failed to induce VT in eight patients and visually-directed endocardial resection was performed. The remaining patients underwent map-guided resection. The surgical success rate did not correlate with any morphologic characteristics of the VT, such as bundle branch block pattern or axis. In addition, concordance of VT morphologies preoperatively and intraoperatively before resection did not correlate with the surgical success rate. However, patients in whom multiple morphologies of VT were induced intraoperatively had a significantly higher success rate (100%) compared with those patients in whom only a single morphology was induced intraoperatively (50%, p < 0.05). Long-term follow-up was maintained in 26 patients. Ventricular tachycardia recurred in two patients and VF recurred in two others who did not have inducible VT 1 week after endocardial resection. In conclusion, neither the preoperative morphologic characteristics of VT nor discordance between the morphologies of VT induced preoperatively and in the operating room influenced the outcome of endocardial resection. However, the surgical success rate is higher when multiple morphologies of VT are inducible in the operating room than when only one VT morphology is inducible.

Predictors of surgical mortality and long-term results of endocardial resection for drug-refractory ventricular tachycardia

The results of surgical therapy performed in 51 consecutive patients with ventricular tachycardia were reviewed to determine short- and long-term predictors of success of such therapy in preventing recurrences of life-threatening ventricular arrhythmias. Of 41 patients (80%) who survived surgery, 40 had postoperative programmed stimulation and, of these patients, 78% ( n = 31) had no inducible ventricular tachycardia on no antiarrhythmic therapy. This group had a very low incidence of arrhythmia recurrence, with only one nonfatal episode of ventricular tachycardia after a mean follow-up of 41 ± 30 months. In contrast, two of the nine patients (22%) who had inducible arrhythmias postoperatively had cardiac arrest ( p = 0.12). Multivariate analysis identified two significant predictors of perioperative mortality in our patients: increased duration of cardiopulmonary bypass time and increased baseline pulmonary capillary wedge pressure. It is concluded that (1) patients who do not have inducible ventricular tachycardia after arrhythmia surgery have a very low incidence of recurrent arrhythmia and (2) prolonged time of cardiopulmonary bypass and increased pulmonary capillary wedge pressure are predictive of perioperative mortality.

Dose a posterior aneurysm increase the risk of endocardial resection?

The bias has been that the ideal anatomic circumstance for endocardial resection is the anterior left ventricular location. Posterior left ventricular aneurysms have been thought to be problematic to map and more difficult to close, and possibly to have a different substrate for ventricular tachycardia. To address this problem, we retrospectively reviewed the cases of 110 consecutive patients who underwent sequential endocardial resection for ventricular tachycardia between 1983 and 1991. Ninety-six patients had an anterior aneurysm, and 14 patients had a posterior aneurysm or infarct. Operative survival and 5-year survival were very similar between the two groups ( p = not significant). A positive postoperative electrophysiological study was present in 11% of the anterior group versus 14% of the posterior group ( p = not significant). There was a significantly greater incidence of mitral valve replacement in the posterior group, and we believe this was most likely due to frequent localization of the arrhythmia to the papillary muscle. Otherwise, patients with a posterior aneurysm or infarct had surgical results equivalent to those in patients with an anterior location. As long as there is a discrete aneurysm or infarct, endocardial resection is a safe and effective therapeutic procedure for ventricular tachycardia.

Cellular and Clinical Electrophysiology of Verapamil‐Sensitive Ventricular Tachycardias

Verapamil‐Sensitive Ventricular Tachycardias. Ventricular tachycardia (VT) due to reentry is often associated with organic structural heart disease, such as coronary artery disease with previous myocardiai infarction, and primary or secondary cardiomyopathy. Treatment of this form of VT generally requires the use of potent antiarrhythmic drugs such as procainamide, quinidine, and amiodarone, or nonpharmacologic interventions such as endocardial resection and implantation of cardioverter defibrillators. Some forms of VT, typically occurring in younger patients and not associated with structural heart disease, may be due to a mechanism other than reentry and may be terminated or prevented by Ca2+ channel or beta blockers. Because these tachycardias are often so effectively treated with these rather benign agents, all patients with sustained VT undergoing an electrophysiologic study should be carefully evaluated to rule out the possibility of having these forms of VT. These tachycardias may be induced by treadmill exercise testing, programmed electrical stimulation, and/or catecbolamine infusion. While it appears that the mechanisms of these tachycardias may be caused by triggered activity related to afterdepolarizations or enhanced automaticity, there is evidence that some may in fact be due to reentry involving Ca2+‐dependent slow conduction. The cellular mechanisms of triggered activity and enbanced automaticity, and their relation to clinical ventricular arrhythmias, are discussed. (J Cardiovasc Electrophysiol, Vol. 3. pp. 500–514 October 1992)

Long-term surgical results in sudden death syndrome associated with cardiac dysfunction after myocardial infarction.

To evaluate the surgical results in patients with inducible ventricular tachyarrhythmias due to coronary disease and left ventricular dysfunction, the authors reviewed their experience in 170 patients who had survived one or more cardiac arrests after myocardial infarction and were unresponsive to drug therapy based on electrophysiologic studies (EPS). There were nine operative deaths (5%). Based on intraoperative EPS, surgical remodeling of left ventricular dysfunction (aneurysm resection, infarct debulking, and septal reinforcement) with map-guided cryoablation and coronary artery bypass graft was performed in 34 patients (group A), and left ventricular remodeling and coronary artery bypass graft without guided endocardial resection was performed in 25 patients (group B). Forty-three patients (group C) had coronary artery bypass graft with implantation of an automatic implantable cardioverter defibrillator (AICD). Group D (68 patients) received AICD only. After operation, based on EPS results, four patients in group A (12%) and three patients in Group B (15%) required AICD implantation. Overall survival at 6 years was 65%, 48%, 85%, and 58% in patient groups A, B, C, and D, respectively (p = not significant). During follow-up in group A patients, none died suddenly and none needed AICD. In group B, two patients required AICD 3 and 5 years later, and five patients died suddenly. The incidence of sudden death was 2.3%/patient/year and 3.5%/patient/year after AICD implantation (groups C and D). At 6 years, cardiac-event-free survival was 80% and 70% for groups A and B and 38% and 24% for groups C and D, respectively (p less than 0.001). Patients receiving map-guided ablative procedures had significantly improved cardiac-event-free survival rates.

Surgical Outcome for "Normal" Coronary Ventricular Tachyarrhythmias

Analyses of 75 surgically treated patients for potential life-threatening ven tricular tachyarrhythmias demonstrate a distinct subset of patients with "nor mal" coronary ventricular tachyarrhythmias. This subset of 10 patients (Group A) was compared with the remaining 65 patients (Group B), who had intra luminally obstructed and ischemic lesions. The etiologies for Group A patients included 4 hypertrophic cardiomyopathies, 4 dynamic intramyocardial muscle bridges, and 2 congenital aneurysms or diverticula. The localized arrhythmic foci for Group A were all preoperatively or intraoperatively determined as com pared with only 33 of 65 (51 %, p &lt; 0.05) in Group B. While the specific types of surgical intervention for the two groups were seemingly identical (ie, revascu larization, endocardial resection, aneurysmectomy and reconstruction, and/or insertion of automatic internal cardiac defibrillators), the mortality rates were significantly different (mortality A vs B: early 0/10 vs 5/65, p &lt; 0.05 and late 0/ 10 vs 4/60, p &lt; 0.05). All Group A patients underwent repeated studies demon strating maintained ventricular function, in contrast to Group B patients, who exhibited severe ventricular impairment (7/60, p &lt; 0.05). In summary, "normal" coronary ventricular tachyarrhythmias are found in a distinctive subset of patients. Their different etiologies result in better out comes from direct operation, and hence, these patients should be managed with this important premise. Indirect or non-operative approaches should not be used in place of these potential cures.

Time to first pulse after automatic implantable cardioverter defibrillator implantation

Should automatic implantable cardioverter defibrillator (AICD) power sources be explanted and discontinued if they have not pulsed during the first generator life? We have followed 59 patients an average of 23 months (range, 3 days to 8.4 years) after AICD implantation. The indication for AICD implantation was based on clinical dysrhythmia, history of sudden death, and findings at electrophysiologic study. Thirty-eight of 59 patients (64%) had experienced sudden death and 52 / 58 (90%) were inducible at electrophysiologic study. Excluding 5 inappropriate pulsing episodes, 31 of 59 patients (53%) had 235 pulses (range, 1 to 36; median, 2 pulses). The time to first pulse after implantation ranged from 1 day to 3.5 years with a median time of 2 months. In 6 patients, the first pulsing occurred later than 1 year after AICD implantation. Fifteen generators demonstrating impending power source failure have been replaced in 11 patients. Power source depletion occurred at an average of 24.1 months (range, 8 to 40 months). In 3 patients, the first pulsing occurred after generator depletion and replacement. By univariate analysis, none of 13 variables (sex, age, cardiac disease process, functional class, previous myocardial infarction, sudden death history, ejection fraction, type of dysrhythmia, inducibility with electrophysiologic testing, number of extra stimuli required for induction, left ventricular aneurysm resection, endocardial resection, or concomitant operation) was found to be a predictor of pulsing ( p > 0.05). We conclude that the majority of patients with pulses after AICD implantation will have them during the first 6 months. However, in this group of patients at high risk for sudden death by ventricular dysrhythmia, absence of pulsing during the first battery life does not justify explantation and discontinuance of AICD back-up.

Continuing experience with the automatic implantable cardioverter defibrillator

The automatic implantable cardioverter defibrillator (AICD) is now used commonly in the management of malignant ventricular arrhythmias. Its use may obviate the need for antiarrhythmic drugs or endocardial resection. We reviewed our continuing experience with the AICD to determine its safety and efficacy. Since June 1987, 102 patients (mean age: 63 years) who survived out-of-hospital ventricular fibrillation or hemodynamically unstable ventricular tachycardia not associated with acute myocardial infarction underwent implantation of an AICD. There were three operative deaths and nine complications. Eighty-nine patients are alive. No patient has experienced sudden cardiac death. Forty-two patients (43%) have had 1 or more AICD discharges associated with symptoms of cardiac arrest. During AICD implantation, it appears preferable to configure lead placement by individual patient characteristics rather than by a rigid protocol. The relative safety and efficacy of the AICD support its use as an alternative to toxic medications or more dangerous endocardial resection in suboptimal candidates.

Results of electrophysiologic testing and long-term prognosis in patients with coronary artery disease and aborted sudden death

The purpose of this study was to evaluate the results of electrophysiologic testing and the long-term prognosis of 56 patients with coronary artery disease who presented with aborted sudden death unrelated to acute myocardial infarction. The mean age of the patients was 62 ± 8 years (± standard deviation) and 48 were men. The mean left ventricular ejection fraction was 0.34 ± 0.16. During the baseline electrophysiology test, sustained monomorphic ventricular tachycardia (VT) was inducible in 22 patients who then underwent electropharmacologic testing: 11 patients were treated with antiarrhythmic drugs that suppressed the induction of VT or resulted in the VT becoming hemodynamically stable; 10 patients who failed drug testing received an automatic implantable cardioverter/defibrillator (AICD); one patient underwent endocardial resection. Among 34 patients who did not have inducible sustained VT, a precipitant of cardiac arrest (severe ischemia, proarrhythmia) was identified and was corrected in 9 of 34. An AICD was recommended in the remaining 25 patients; however, nine patients refused and were treated empirically with antiarrhythmic drugs. The mean follow-up was 22 ± 12 months. The 2-year actuarial incidence of sudden death was 31% in patients who were treated with drugs based on the results of electropharmacologic testing, 26% in patients who were treated with antiarrhythmic drugs on an empiric basis, 0% among patients in whom a correctable etiology for the cardiac arrest was identified, and 9% among patients who underwent implantation of an AICD. The 3-year actuarial incidence of sudden death among the 20 patients treated with antiarrhythmic drugs was 53%, compared with 9% among the 26 patients who underwent AICD implantation ( p = 0.03). In conclusion, antiarrhythmic therapy, whether guided by electrophysiologic testing or administered on an empiric basis, is associated with a high incidence of recurrent sudden death in patients with coronary artery disease and aborted sudden death. Implantation of an AICD may be advisable in all patients with coronary artery disease and aborted sudden death in whom a correctable precipitant cannot be identified.

The influence of preoperative shock on outcome in sequential endocardial resection for ventricular tachycardia

Sequential endocardial resection was used in 92 consecutive patients to treat ventricular tachycardia. All patients had coronary artery disease with previous myocardial infarction. All patients had repeated cycles of mapping and resection of arrhythmogenic foci in the normothermic beating heart until ventricular tachycardia was no longer inducible. Eighty-six patients (93%) survived to hospital discharge. The survival rate in patients normotensive at the time of operation was 98% and in patients in shock at the time of operation, 43%. By Cox regression analysis, preoperative shock was the significant predictor (p less than 0.001) of operative mortality. Seventy-four of the 86 operative survivors (86%) had no sustained ventricular tachycardia at initial postoperative electrophysiologic study when receiving no antiarrhythmic drugs. Eighty-three of the 86 operative survivors (97%) had no sustained ventricular tachycardia at final postoperative electrophysiologic study when using antiarrhythmic drugs as needed. After a median follow-up of 21 months (range 1 to 79 months) there were 4 sudden cardiac deaths, 12 other cardiac deaths, and 3 noncardiac deaths. There were no documented nonfatal episodes of sustained monomorphic ventricular tachycardia after hospital discharge. Use of the sequential endocardial resection technique is effective in curing ventricular tachycardia with low operative morbidity and mortality.

Surgical Treatment of Postinfarct Ventricular Tachycardia—Seven Years of Experience

The results of surgery for postischemic drug-resistant ventricular arrhythmias (VA) are still controversial. The operative mortality in the literature ranges between 10% and 40% because of selection of patients. The authors reviewed their experience at Freeman Hospital where all patients with drug-refractory ventricular tachycardia (VT) or ventricular fibrillation (VF) underwent surgical treatment regardless of left ventricular function (LVF) and of time from infarction and operation. Between March, 1981, and March, 1988, 65 patients [53 men, 12 women aged thirteen to seventy-five years (mean fifty-four)] underwent surgery. All of them had a previous myocardial infarct (MI). Mean preoperative ejection fraction was 28% ± 11, and 32 % had single-vessel, 44 % double-vessel, and 24% triple-vessel disease. In 16 surgical treatment was undertaken on an emergency basis. All had intraoperative mapping based on activation sequence or, when this was not possible (noninducible VT/VF), on analysis of fragmented potentials. LV endocardial resection was performed in 64 patients. Heart transplant (HTx) was necessary in 1. Associated procedures were aneurysmectomy in 40 patients (62%), multiple cryoablation in 13 (20%), encircling ventriculotomy in 8 (12%), right ventricular endocardial resection in 1, coronary artery bypass grafting in 43 (66%), mitral valve replacement in 5 (8%), and closure of postinfarct ventricular septal defect (VSD) in 2. The operative mortality was 26% (17 patients}. The main cause of death was left ventricular failure, 13 (20%). The mortality was higher in patients with previous anterior MI 15/49 (31%) and in emergency operations 9/16 (56%). The follow-up ranged between four and forty months (mean twenty-two months) with 6 late deaths (2 arrhythmia related). In 11 patients (17%) postoperative arrhythmic episodes were observed, but only in 6 (5 drug controlled, 1 without therapy) was there recurrence of preoperative arrhythmia. Surgery for life-threatening VA allows good long-term results for relief of arrhythmias. Perioperative mortality is still high in unselected patients; it depends mainly on the preoperative LVF. HTx in cases with very depressed LVF is an option, but in the majority of patients in this group it was contraindicated.

Long-term outcome of laser ablation alone or in combination with endocardial resection in ventricular tachycardia

Long-term outcome of laser ablation alone or in combination with endocardial resection in ventricular tachycardia

Operative Management of Symptomatic MB

The relationships between coronary myocardial bridging (MB) and clinical symptoms have been controversial. Five young male patients underwent testing for symptomatic MB, manifested as angina with evidence of ischemia or sudden death. Preoperative testing included atrial stimulation studies for evidence of lactate extraction and serial cardiac catheterization. Positive lactate production and/or extensive milking (&gt;90%) of the proximal left anerior descending artery (LAD) were documented in 4 patients, who were, therefore, treated surgically by supra-arterial myotomy. Associated intraoperative mapping and endocardial resection were required for significant anterior aneurysm and scars. Postopera tive studies demonstrated resolution of the milking and/or intracoronary gradi ents. The remaining patient had recurrent sudden death, but negative lactate study, and was treated by automatic internal cardiac defibrillator (AICD). Symptomatic young patients can present with pathologic compression of the proximal LAD from extensive MB. Complete supra-arterial myotomies were successful treatments. Other adjunctive surgical procedures: (1) mapping, (2) endocardial resection, and/or (3) AICD, were based on their preoperative stress testing and intraoperative findings.

Surgical intervention for drug-resistant ventricular tachycardia

EndocardiaL resection was required in 26 patients with sustained drug-resistant ventricular tachycardia. The early mortality rate (within 30 days after operation) was 12%. Two deaths were the result of low cardiac output, and the third death was related to recurrent ventricular septal defect after septal endocardial resection. The survivors of endocardial resection were followed up from 6 to 92 months (mean 43). There were no recurrences of ventricular arrhythmias, and patients did not require antiarrhythmic drug therapy. The late mortality rate after endocardial resection was 19%. There were two late cardiac-related deaths (unrelated to arrhythmias) and three late deaths from noncardiac causes.Complete endocardial resection successfully ablates drug-resistant ventricular tachycardia, but is associated with an increased perioperative mortality rate in those patients who have severely depressed left ventricular function without a well defined left ventricular aneurysm.

Surgical Ablation of Ventricular Tachycardia in the Normothermic Heart

Nineteen patients with ventricular tachycardia were subjected to surgery using a normothermic map-guided approach. Surgical ablation was performed by endocardial resection and cryoablation. Eleven patients had multiple distinct morphologies, and eight patients needed concomitant coronary artery bypass surgery. Seventeen patients survived the perioperative period, and all but one patient had a successful surgical ablation of all documented morphologies. Ventricular tachycardia surgery can be accomplished with the sequential map-guided approach on the normothermic beating heart, and in this era of the implantable defibrillator should remain a mainstay of the surgical treatment for ventricular tachycardia.

Surgery for ventricular arrhythmia

Years of frustration of cardiac surgeons attempting to control intractable ventricular arrhythmia finally ended when the team of Harken, Josephson, and Horowitz performed electrophysiologically directed left ventricular endocardial resection and reported their early results 10 years ago. The scientific background for this break-through is reviewed and some subsequent modulations of their procedure are described. The current status of arrhythmia surgery since the advent of the automatic internal cardioverter-defibrillator is described: the two methodologies are complementary not competitive.

Right ventricular endomyocardial fibrosis diagnosis and management.

The clinical course, noninvasive and invasive diagnostic findings in 4 patients (pt) with endomyocardial fibrosis are reported. All patients (16-50 years) were in functional class III-IV (NYHA). Central venous pressure with large a- and v-waves was elevated in all; liver enlargement and peripheral edema were also noticed in all pts, and ascites in 3. An apical 2/6 systolic murmur was present in 2, and a right parasternal pansystolic murmur 2-4/6 with positive Carvallo's sign in all pts. ECG was non-specific and chest x ray showed right atrial enlargement in every case. A right-sided diastolic plateau which was higher than left ventricular end-diastolic pressure was present in all pts. Echo-, angiocardiography and computed tomography of the heart revealed obliteration of the right ventricular cavity, predominantly localized at the apex. Two pts who underwent endocardial resection and tricuspid valve replacement are alive and well after 9 and 8 years, respectively. One pt died early in the postoperative period and one died waiting for surgical therapy. In conclusion, echo-, angiocardiography and computed tomographic findings are diagnostic. A satisfactory differentiation from other cardiac disorders with restrictive hemodynamics and right-sided heart failure is possible.

Evolving patterns in the surgical treatment of malignant ventricular tachyarrhythmias

The advent of the automatic implantable cardioverter defibrillator (AICD), generally viewed as a safe and effective intervention, has in some measure discouraged the use of electrophysiologically directed endocardial resection for intractable ventricular arrhythmias. We reviewed the records of 127 patients undergoing either AICD procedures or resection over a 6-year period. Thirty-day mortality was 5.6% ( 5 / 89 patients) for all AICD procedures, 10.7% ( 3 / 28 ) for AICD placement plus coronary artery bypass grafting, and 11.8% ( 4 / 34 ) for resection. These mortality figures are not significantly different. Patients undergoing resection were less likely to require antiarrhythmic agents than patients given an AICD (33% versus 61%). Survival at 2 years was 78% in the resection group and 72% in the AICD group. Survival at 4 years was still 78% in the resection group. Only 1 late sudden death occurred in the AICD group and none in the resection group. We conclude that resection continues to be a valuable alternative, offering a greater overall benefit at only slightly increased risk.