Surgery for Ventricular Tachycardia in Patients Undergoing Left Ventricular Reconstruction by the Dor Procedure

Surgical ventricular reconstruction and intraoperative cryoablation in a patient with drug-refractory ventricular tachycardia and left ventricular thrombus: a case report

Background

Despite modern techniques for ablation of ventricular tachycardia (VT), the procedure faces challenges such as deep intramural substrates or inaccessibility of the pericardial space. We aim to present a case of successful surgical treatment of a patient with drug-refractory VT, an apical aneurysm, large left ventricular (LV) thrombus, and recurrent implantable cardioverter defibrillator (ICD) shocks following failed epicardial catheter ablation.

Case summary

A 67-year-old male with a history of ischaemic cardiomyopathy was brought to the emergency room after a syncope because of VT. The VT was terminated by an external cardioversion prior to admission. The ICD interrogation showed an episode of sustained monomorphic VT with eight appropriate but mostly ineffective ICD shocks. An echocardiogram revealed an apical aneurysm with a thrombus. Anticoagulation and antiarrhythmic drug therapy were initiated. Days later, the patient suffered recurrent episodes of sustained VTs, refractory to pharmacological therapy, and epicardial ablation; therefore, following aneurysmectomy and thrombus removal, a reconstruction of the LV and surgical endocardial cryoablation were performed. In addition, ICD extraction was done due to recurrent bacteraemia with Staphylococcus aureus. A subcutaneous ICD was later implanted. After surgery, the patient remained free of any VT episodes during 44 months of follow-up.

Conclusion

Combined surgical ventricular reconstruction and intraoperative cryoablation may be considered as an alternative, highly effective therapy in patients with drug-refractory VTs in the setting of a LV thrombus.

Surgical Ablation of Ventricular Tachycardia

Surgery for ventricular tachycardia (VT) is indicated in patients in whom pharmacotherapy or catheter ablation is ineffective or frequent VT attacks are not suppressed or with frequent activation of implantable cardioverter defibrillator. In ischemic VT, resection of fibrous endocardium combined with encircling cryothermia at the border between the infarcted and normal myocardium is performed. In surgery for VT associated with cardiomyopathy, close collaboration between the physician and surgeon is important and intraoperative mapping using electro-anatomic mapping system is helpful. In VT associated with cardiac tumors, cryothermia of the thinned subepicardial myocardium at the edge of the tumor is recommended in addition to resection of tumors.

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Congenital left ventricular diverticulum: A rare cause of cardiac arrhythmia

Congenital left ventricular diverticula are rare cardiac malformations that usually remain asymptomatic. However, life-threatening complications as ventricular arrhythmias, systemic embolism, spontaneous rupture and development of valvular regurgitation, are described. Diagnosis is based on excluding coronary artery disease, traumatic or inflammatory causes, and other underlying cardiomyopathies. Treatment is directed towards the potential complications, yielding mainly therapy of ventricular arrhythmia. Surgical resection is required for larger-sized congenital aneurysms with adverse hemodynamic effects. We present two cases of a left ventricular diverticulum causing cardiac arrhythmia which led to further surgical treatment.

Surgical procedure for targeting arrhythmogenic substrates in the treatment of ventricular tachycardia associated with cardiac tumors

BACKGROUND

Complete tumor resection is a standard strategy in the surgical treatment of ventricular tachycardia (VT) associated with cardiac tumors. Recently, an intraoperative electroanatomic mapping system (CARTO) has enabled surgeons to target the localized arrhythmogenic substrate for partial resection and/or cryoablation in nonresectable cardiac tumors.

OBJECTIVE

The purpose of this study was to evaluate the surgical procedures and late outcomes of the treatment of VT associated with cardiac tumors.

METHODS

We examined six patients (age 1-65 years) who had undergone surgical treatment of VT associated with cardiac tumors between 2010 and 2016. The 4 pathologies of the cardiac tumors were lipoma 2, fibroma 2, hemangioma 1, and lymphoma 1. Intraoperative epicardial mapping using CARTO was performed in 5 patients(80%). Surgical procedures and long-term outcomes were evaluated.

RESULTS

Arrhythmogenic substrates with abnormal electrograms, such as fractionated or late potential, were identified locally or circumferentially beside the tumor in every patient. Complete tumor resection with cryoablation was performed in 3 patients. Two patients underwent partial tumor resection with cryoablation. Cryoablation without tumor resection was performed in 1 patient. No mortality and morbidity occurred. Additional catheter ablation was required in 2 patients to treat occurrence of nonclinical VT and induction of clinical VT during hospital stay. Mean follow-up time was 90 ± 52.5 months. There was no recurrence of clinical VT.

CONCLUSION

The outcomes of surgical treatment of VT associated with cardiac tumors were excellent. Intraoperative CARTO mapping was beneficial to eliminate the VT substrates associated with nonresectable cardiac tumors.

Long-Term Survival and Echocardiographic Findings After Surgical Ventricular Restoration

BACKGROUND

This study investigates the long-term survival and durability of mitral procedures on patients undergoing surgical ventricular restoration.

METHODS

From 1992 to 2017, 109 patients underwent surgical ventricular restoration. Survival was determined from hospital records and the National Death Index. Preoperative demographics, clinical characteristics and features, operative technique, and follow-up echocardiography findings were analyzed using Cox regression and log-rank to determine variables influencing survival.

RESULTS

The mean age was 61.57 ± 12.81 years. There were 101 (93%) true and 8 (7%) pseudo-aneurysms. Concomitant surgeries included mitral valve (MV) repair (n = 40, 37%), MV replacement (n = 5, 5%), tricuspid valve repair (n = 4, 4%), aortic valve replacement (n = 3, 3%), coronary bypass grafting (n = 76, 70%; 1.6 ± 1.3 grafts), and ventricular septal defect closure (n = 5, 5%). Redo-sternotomies were performed in 12 patients (11%). Median duration of echocardiographic follow up was 2.9 years (interquartile range, 9.0) and was obtained in 59 patients (54%). Left ventricular ejection fraction improved from 28% ± 13% to 33% ± 16% (p = 0.011). Median duration of echocardiographic follow-up of MV repair was 3.6 years (interquartile range, 9.5). MV repair led to sustained improvements in mitral regurgitation (MR; p = 0.001) where only 2 (5%) experienced recurrence of moderate to severe MR. For patients who did not undergo an MV procedure there was no difference in preoperative and follow-up MR severity (p = 0.586). Median patient follow-up was 7.1 years (interquartile range, 8.5). Overall 5-, 10-, and 15-year survival rates were 71.9%, 48.1%, and 26.2%, respectively.

CONCLUSIONS

Surgical ventricular restoration was associated with sustained improvement in left ventricular ejection fraction with almost half surviving to 10 years postoperatively. For patients undergoing concomitant MV repair, the improvement in mitral competence is durable.

Sudden Cardiac Death in Patients With Ischemic Heart Failure Undergoing Coronary Artery Bypass Grafting: Results From the STICH Randomized Clinical Trial (Surgical Treatment for Ischemic Heart Failure)

BACKGROUND

The risk of sudden cardiac death (SCD) in patients with heart failure after coronary artery bypass graft surgery (CABG) has not been examined in a contemporary clinical trial of surgical revascularization. This analysis describes the incidence, timing, and clinical predictors of SCD after CABG.

METHODS

Patients enrolled in the STICH trial (Surgical Treatment of Ischemic Heart Failure) who underwent CABG with or without surgical ventricular reconstruction were included. We excluded patients with prior implantable cardioverter-defibrillator and those randomized only to medical therapy. The primary outcome was SCD as adjudicated by a blinded committee. A Cox model was used to examine and identify predictors of SCD. The Fine and Gray method was used to estimate the incidence of SCD accounting for the competing risk of other deaths.

RESULTS

Over a median follow-up of 46 months, 113 of 1411 patients who received CABG without (n = 934) or with (n = 477) surgical ventricular reconstruction had SCD; 311 died of other causes. The mean left ventricular ejection fraction at enrollment was 28±9%. The 5-year cumulative incidence of SCD was 8.5%. Patients who had SCD and those who did not die were younger and had fewer comorbid conditions than did those who died of causes other than SCD. In the first 30 days after CABG, SCD (n=5) accounted for 7% of all deaths. The numerically greatest monthly rate of SCD was in the 31- to 90-day time period. In a multivariable analysis including baseline demographics, risk factors, coronary anatomy, and left ventricular function, end-systolic volume index and B-type natriuretic peptide were most strongly associated with SCD.

CONCLUSIONS

The monthly risk of SCD shortly after CABG among patients with a low left ventricular ejection fraction is highest between the first and third months, suggesting that risk stratification for SCD should occur early in the postoperative period, particularly in patients with increased preoperative end-systolic volume index or B-type natriuretic peptide.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT0002359.

Aneurysm-related ischemic ventricular tachycardia: safety and efficacy of catheter ablation

Left ventricular aneurysm (LVA) postmyocardial infarction (MI) might be an arrhythmogenic substrate. We examined the safety and efficacy of catheter ablation of LVA-related ventricular tachycardia (VT).Thirty-three consecutive patients who underwent primary catheter ablation of ischemic VT were divided into LVA group (11 patients, mean age 61.9 years, 10 men) and none LVA group. Acute procedural outcomes, complications, and long-term outcomes were assessed.In LVA group, average number of induced VTs were 3.2 ± 2.6 (range 1-7), clinical VTs were located in the ventricular septum scar zone in 4 (36.4%) patients, acute success was achieved in 7 (63.6%) patients, partial success in 3 (27.3%) and failure in 1 patient, while none LVA group showing a statistically similar distribution of acute procedural outcomes (P = 0.52). There were no major or life-threatening complications. VT-free survival rate at median 19 (1-44) months follow-up was numerically but not significantly lower in LVA versus none LVA group (48.5% vs 62.8%, log-rank P = 0.40).Catheter ablation of ischemic VT in the presence of LVA appears feasible and effective, with about one-third of cases having septal ablation targets. Further studies are warranted.

Surgical cryoablation of drug resistant ventricular tachycardia and aneurysmectomy of postinfarction left ventricular aneurysm

Heart failure is usually associated with left ventricle remodelling, wall thickening, and worsening of the systolic function. Ventricular tachycardia is a common and a negative prognostic factor in patients with endocardial scarring following myocardial infarction and aneurysm formation. The authors present a case of a 51-year-old man with ischemic heart disease, who suffered myocardial infarction four years ago. The patient was admitted to the hospital with sustained ventricular tachycardia despite maximal pharmacotherapy and also underwent unsuccessful percutaneous radiofrequency ablation in the right ventricle. Transthoracic echocardiography revealed left ventricle dysfunction with ejection fraction of 25%, aneurysm of the apex of the left ventricle with thrombus formation inside the aneurysm. Surgical therapy consisted of the cryoablation applied at the transitional zone of the scar and viable tissue and the resection of the aneurysm. The patient remained free of any ventricular tachycardia four months later.

Surgical ventricular restoration to reverse left ventricular remodeling

Heart failure is one of the major health care issues in the Western world. An increasing number of patients are affected, leading to a high rate of hospitalization and high costs. Even with administration of the best available medical treatment, mortality remains high. The increase in left ventricular volume after a myocardial infarction is a component of the remodeling process. Surgical Ventricular Restoration (SVR) has been introduced as an optional therapeutic strategy to reduce left ventricular volume and restore heart geometry. So far, it has been established that SVR improves cardiac function, clinical status, and survival in patients with ischemic, dilated cardiomyopathy and heart failure. Since its first description , SVR has been refined in an effort to standardize the procedure and to optimize the results. This review will discuss the rationale behind surgical reversal of LV remodeling, the SVR technique, its impact on cardiac function and survival, and future expectations.

Hypertrophic cardiomyopathy with apical aneurysm: left ventricular reconstruction and cryoablation for ventricular tachycardia

This is a case study of a 58-year-old patient with hypertrophic cardiomyopathy, mid-ventricular obstruction, and apical aneurysm who had an episode of syncope due to ventricular tachycardia. Cardiovascular magnetic resonance imaging revealed asymmetrical left ventricular hypertrophy with mid-ventricular obstruction and an apical aneurysm. His coronary angiography was normal, and his ventricular tachycardia was induced by hypertrophic cardiomyopathy without ischemia. Apical aneurysmectomy, left ventricular reconstruction, and cryoablation at the rim of the aneurysm were performed. Fifteen days after the operation, an automatic implantable cardioverter-defibrillator was implanted. The postoperative course was uneventful, and ventricular tachyarrhythmia did not recur during 18 months of follow-up.

Surgical Ventricular Restoration: An Operation to Reverse Remodeling - Clinical Application (Part II)

The first part of the article dealt with the basic science behind the evolution of ventricular restoration procedures and the rationale for the use of novel surgical techniques. The second part describes the preoperative workup of patients in advanced heart failure, the core information required to determine the surgical approach and the essential principles and techniques of ventricular restoration. It then examines the effects of ventricular restorative procedures on pump function and clinical outcomes, the results of the worldwide experience with ventricular restoration and concludes with more recent advances in this field.

Hemodynamics at rest do not match clinical improvement after surgical ventricular restoration

OBJECTIVES

The aim was to study the change in cardiac index (CI) and pulmonary artery pressure (PAP) by intra-cardiac measurements after surgical ventricular restoration (SVR) in patients with left ventricular aneurysm and symptoms of heart failure. Aspects of functional improvement were analyzed as secondary outcomes.

DESIGN

Mean PAP and CI were obtained before and 6 months postoperatively in 22 patients who underwent SVR.

RESULTS

There were no significant changes in CI (2.3 vs. 2.4 L/min/m(2); p=0.91) or mean PAP (22 vs. 22 mmHg; p=0.64) at rest before and six months after surgery. Left ventricular ejection fraction improved from 25 to 38% (p<0.001). Before surgery 15 patients (68%) were in NYHA class III-IV and 6 months after the operation 19 (86%) patients were in NYHA class I-II (p<0.001).

CONCLUSIONS

Invasive hemodynamic measurements under resting conditions do not correspond well to the significant clinical improvement noted in these patients. Studies during exercise conditions are necessary to further evaluate this procedure.

Surgery for ventricular tachycardia and left ventricular aneurysm provides arrhythmia control

OBJECTIVES

Report long-term freedom from ventricular tachycardia (VT), survival, and causes of death in patients with left ventricular aneurysm and VT, who underwent a combined procedure for VT and surgical ventricular restoration (SVR).

DESIGN

The primary outcome measures VT, survival, and cause of death, were ascertained by review of patients' records, interrogation of implanted cardioverter-defibrillators and use of national registers.

RESULTS

Mean follow-up was 5.2 years. Overall survival was 62% at 5 years and 51% at 9 years. Freedom from spontaneous VT was 89%. In 32 patients who were non-inducible at postoperative testing, there was no occurrence of VT during a mean follow-up of 6.0 years. Causes of death were cardiac in 17 patients, and non-cardiac in 6 patients. No patient died from ventricular arrhythmia.

CONCLUSIONS

Direct surgery for VT combined with SVR resulted in a very low risk of late recurrence of VT and good long-term survival. Implantation of a cardioverter-defibrillator can safely be withheld in patients who are non-inducible on postoperative programmed electrical stimulation.

Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration: The Karolinska approach

This article presents a review on the efficacy of surgical ventricular restoration and direct surgery for ventricular tachycardia in patients with left ventricular aneurysm or dilated ischemic cardiomyopathy. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. A practical guide to the pre- and postoperative management of these patients is provided.

Edge-to-edge mitral repair without annuloplasty in combination with surgical ventricular restoration

BACKGROUND

Functional mitral regurgitation is common in ischemic dilated cardiomyopathy. Edge-to-edge repair is an option for correction and can be performed through the ventriculotomy during surgical ventricular restoration (SVR). This report describes the durability of the edge-to-edge repair without annuloplasty in combination with SVR.

METHODS

From March 1997 to July 2002, 31 patients with left ventricular aneurysm or ischemic dilated cardiomyopathy and functional ischemic mitral regurgitation grade II (n = 18), III (n = 10), and IV (n = 3) underwent SVR and edge-to-edge repair without annuloplasty with concomitant coronary artery bypass grafting. Long-term valve competence was assessed by echocardiography. Early and late survival and hospital readmission for heart failure were analyzed.

RESULTS

Early mortality was 5 (16%) of 31 patients. At 1, 3, and 5 years, actuarial survival was 77%, 55%, and 48%. The cumulative follow-up was 117 patient-years (4.5 years mean follow-up). Late echocardiograms performed at a mean of 3.1 years postoperatively showed patients had mitral regurgitation at grade 0 (n = 4), I (n = 10), II (n = 9), and III (n = 1). Two patients underwent reoperation owing to grade III-IV recurrent mitral regurgitation. Freedom from hospital readmission or cardiac death was 56% at 1 year and 48% at 3 years.

CONCLUSIONS

Combined mitral valve repair and SVR carries high operative risk and long-term prognosis is worse than after SVR alone. The edge-to-edge repair without annuloplasty for functional ischemic mitral regurgitation seems to be fairly durable in conjunction with SVR. To improve results a transventricular annuloplasty may be added.

Improved Health-Related Quality of Life and Functional Status After Surgical Ventricular Restoration

BACKGROUND

Surgical ventricular restoration (SVR) has been shown to improve hemodynamics and survival among patients with coronary artery disease, left ventricular aneurysm, and heart failure. The aim of this study was to investigate functional status and health-related quality of life after SVR.

METHODS

Over a period of 2 years beginning in March 2003, 23 patients with left ventricular aneurysm and depressed left ventricular function were included in a prospective study. Functional status and quality of life was analyzed preoperatively, 6 months postoperatively, and at late follow-up by assessment of New York Heart Association (NYHA) functional class, 6-minute walk test, and the Medical Outcome Study 36-Item Short Form.

RESULTS

There was no early mortality. Before surgery, 17 patients (74%) were in NYHA class III to IV; and 6 months after SVR, 20 patients (87%) were in NYHA class I to II (p < 0.001). At late follow-up, (mean, 22 months postoperatively), all patients alive (n = 20) were in NYHA class I to II. Mean 6-minute walk distance increased by 41 meters (p = 0.06) at 6 months postoperatively and by 57 meters (p = 0.03) at late follow-up. Quality of life, assessed by the physical component summary score of the Medical Outcome Study 36-Item Short Form, improved significantly (p = 0.04) at 6 months postoperatively. A significant and clinically relevant improvement in both physical aspects (+25%, p < 0.001) and mental aspects (+37%, p = 0.003) of quality of life was found at late follow-up.

CONCLUSIONS

Functional status and quality of life improved 6 months after SVR, and the improvement was sustained at late follow-up almost 2 years after surgery.

Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration

This article is a presentation of direct surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. Perioperative considerations and a short overview of the literature are presented.

Left ventricular reconstruction as an alternative to heart transplantation: a case report

A 57-year-old man with dilated cardiomyopathy was referred to our institution to be assessed for heart transplantation. He had symptoms of severe heart failure and left ventricular dysfunction. We proposed surgical ventricular restoration (the Dor procedure) as an alternative to heart transplantation. The patient underwent successful surgery and an uneventful postoperative course. Pre- and postoperative investigations are presented. One year after surgery, the patient is in good clinical and functional condition. This case illustrates that surgical ventricular restoration can be an alternative to heart transplantation.