Encircling endocardial cryoablation for ventricular tachycardia after myocardial infarction: experience with 33 patients

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Surgical Endoepicardial Linear Ablation for Ventricular Tachycardia With Postinfarction Left Ventricular Aneurysm

This retrospective study evaluated the feasibility of surgical endoepicardial linear ablation for ventricular tachycardia in patients with postinfarction left ventricular aneurysm. Sixty-four patients with multivessel coronary artery disease and left ventricular aneurysm but no mural thrombosis of the aneurysm or valve disease were treated at our institution from March 2012 through July 2015. All underwent off-pump coronary artery bypass grafting and left ventricular aneurysm repair by linear plication. Twenty-three patients (35.9%) had ventricular tachycardia and underwent surgical endoepicardial linear ablation on the beating heart guided by epicardial substrate mapping with the Carto 3 system. The remaining 41 patients (64.1%) composed the no-ablation group. The effectiveness of surgical linear ablation in the ablation group was evaluated. Safety and clinical outcomes were evaluated and compared between the groups. The ventricular tachycardia recurrence rate in the ablation group was 17.4% in the immediate postoperative period and 23.8% at last follow-up (39 ± 21 mo). Early (<30-d) mortality rates were 8.7% in the ablation group and 4.9% in the no-ablation group (P=0.41); the respective late mortality rates were 19.1% and 18% (P=0.70). Multivariate Cox regression analysis indicated that preoperatively poor left ventricular function was an independent risk factor for early and late death in both groups. The groups were similar in terms of the need for postoperative mechanical circulatory support, intensive care unit stay, and cumulative survival rate. We conclude that, for carefully selected candidates, surgical endoepicardial linear ablation combined with off-pump coronary artery bypass grafting and left ventricular aneurysm linear plication is a feasible treatment for ventricular tachycardia with postinfarction left ventricular aneurysm.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Surgical linear ablation for ventricular tachycardia with postinfarction ventricular aneurysm

BACKGROUND

Left ventricular aneurysm (LVA) might be an arrhythmogenic substrate. Endocardiectomy and cryoablation for ventricular tachycardia (VT) with LVA can cause extensive myocardial damage. We aimed to evaluate the feasibility of surgical radial linear ablation for VT with LVA guided by electrophysiological mapping.

MATERIALS AND METHODS

Porcine models of VT with LVA were developed. Endocardial and epicardial substrate mapping during sinus rhythm were performed under thoracotomy. Surgical radial linear ablation was achieved by a bipolar radiofrequency ablation device. Outcomes, including procedural success and acute freedom of VT, were analyzed.

RESULTS

Fifteen of 20 pigs developed LVA in a 6-wk survival period. A total of 28 sustained monomorphic VTs were initiated in 13 of 15 pigs (86.67%). The number of potential points captured from the endocardium and epicardium were 319 ± 45 and 358 ± 52 per animal, respectively. The ablative targets containing abnormal potentials were located largely on the border zone of LVA. Eight linear lesions from core to border zone of LVA were achieved per animal in a radial and even manner continuously, and ablation was repeated three times to transect border zone. The acute freedom of VT was 84.62%, P < 0.05.

CONCLUSIONS

Surgical linear endo-epicardial ablation seemed to be feasible in a porcine model with VT and LVA.

Catheter Ablation of Multiple Unstable Macroreentrant Tachycardia Within the Right Atrium Free Wall in Patients Without Previous Cardiac Surgery

Background— Macroreentrant atrial tachycardia (AT) involving the right atrial free wall (RAFW) has been reported in patients without atriotomy. Catheter ablation of these ATs remains challenging due to the multiple morphologies of ATs with unstable reentrant circuits in some patients. The purpose of this study was to clarify the electrophysiological characteristics of these ATs and attempt the novel approach for catheter ablation.

Methods and Results— Electrophysiological study and catheter ablation were performed in 17 patients (14 men; 71 [quartile 1, 67; quartile 3, 76] years) with reentrant ATs originating from the RAFW using 3D mapping. All patients had no history of cardiac surgery. Clinical ATs with stable cycle length and atrial activation were identified in 11 patients (group A). All ATs were successfully ablated. In the remaining 6 patients, clinical tachycardia continuously changed, with a different cycle length and P-wave morphology and atrial activation sequence during mapping or entrainment study (group B). A complete isolation of the RAFW was attempted in group B. After complete isolation was achieved in 5 of 6 patients, ATs were not induced in these 6 patients. The number of previous failed catheter ablations and induced ATs were higher in group B than in group A. During 31 (19; 37) months of follow-up, AT recurrence developed in 27% patients from group A and 33% from group B.

Conclusions— Multiple and unstable macroreentrant ATs from the RAFW can occur in patients without a history of cardiac surgery. The RAFW isolation has the potential to abolish all ATs.

Off-Pump Positioning of a Conventional Aortic Valve Prosthesis through the Left Ventricular Apex with the Universal Cardiac Introducer under Sole Ultrasound Guidance, in the Pig

Objective

To test an alternative to catheter and open-heart techniques, by documenting the feasibility of implanting an unmodified mechanical aortic valve (AoV) in the off pump, beating heart using the universal cardiac introducer (UCI) attached to the left ventricular (LV) apex.

Methods

In six pigs, the LV apex was exposed by a median sternotomy. The UCI was attached to the apex. A 12-mm punching tool (punch), introduced through the UCI, was used to create a cylindrical opening through the apex. Then, the AoV, secured to a holder, was introduced into the LV, using transesophageal echocardiographic, guided through the apical LV opening, navigated into the LV outflow tract, and positioned within the aortic annulus. Trans-esophageal echocardiographic guidance was useful for navigation and positioning by superimposing the aortic annulus and prosthetic ring while Doppler imaging verified preserved prosthetic function and absence of perivalvular leaks. The valve function and hemodynamics were observed before termination for macroscopic evaluation.

Results

The punch produced a clean opening without fragmentation or myocardial embolization. During advancement of the mechanical AoV, there were no arrhythmias, mitral valve dysfunctions, evidence of myocardial ischemia, or hemodynamic instability. The AoVs were well seated over the annulus, without obstructing the coronaries or contact with the conduction system. The ring of AoVs was well circumscribed by the aortic annulus.

Conclusions

This study documented the feasibility of positioning a mechanical AoV on the closed, beating heart. These results should encourage the development of adjunct technologies to deliver current tissue or mechanical AoV with minimal side effects.

Endoaneurysmorrhaphy and cryoablation for postinfarction left ventricular aneurysm with ventricular tachycardia

BACKGROUND

Early reperfusion in the acute phase of myocardial infarction and better medical treatment of consequent heart failure and tachyarrhythmia have decreased the incidence of massive myocardial infarction, left ventricular (LV) aneurysm and also postinfarction-sustained ventricular tachycardia (VT). However, for a number of patients, surgical ablation combined with aneurysm resection and myocardial revascularization remains a possible curative procedure. In this study, the efficacy of endoaneurysmorrhaphy and cryoablation was evaluated in patients with postinfarction LV aneurysm with VT.

METHODS

The medical records of 9 patients who underwent LV endoaneurysmorrhaphy and cryoablation for VT at Taipei Veterans General Hospital between January 1995 and August 2005 were reviewed retrospectively.

RESULTS

There were 8 men and 1 woman, with a mean age of 69.7 years (range, 52-77 years). Preoperative VT and LV aneurysm were found in all patients, who underwent extensive cryoablation at the transitional zone of scar and viable tissue without intraoperative mapping and LV remodeling with prosthetic patch. Associated procedure included coronary artery bypass grafting in 8 patients. During follow-up, no surgical or in hospital mortality were noted. There was 1 late sudden death at home 1.7 months after the operation. No recurrent VT was detected, and all patients showed improvement in New York Heart Association functional class (mean, 2.33 vs.1.67; p=0.025) and LV ejection fraction (mean, 26.3% vs.34.1%; p=0.021).

CONCLUSION

In patients suffering from postinfarction LV aneurysm complicated with VT, combining cryoablation and endoaneurysmorrhaphy offers good arrhythmia control and clinical outcome.

Acute and long-term outcome of transvenous cryothermal catheter ablation of supraventricular arrhythmias involving the perinodal region

OBJECTIVE

Cryoenergy is a new valuable treatment option to perform ablation close to the atrioventricular (AV) node in the cure of supraventricular tachycardias because of its favourable properties, such as the possibility of creating reversible lesions. The aim of this study was to report our experience on the effectiveness and safety of catheter cryoablation performed in "critical areas" to treat a large cohort of patients with supraventricular arrhythmias.

METHODS

One hundred and thirty-one patients suffering from supraventricular tachycardias underwent catheter cryoablation using a 7F catheter. Eighty-seven patients presented with AV nodal re-entrant tachycardia (AVNRT), 39 had accessory pathways (APs) either manifest or concealed (15 midseptal, 24 parahissian), three had ectopic right atrial tachycardia (AT), and two patients had a permanent junctional reciprocating tachycardia (PJRT). When the optimal parameters were recorded, ice mapping at -30 degrees C was performed for 80 s to validate the ablation site. If the expected result occurred, cryoablation was carried out by lowering the temperature to -75 degrees C for 4 min.

RESULTS

In two patients cryoablation was not performed because of technical reasons. Cryoablation was acutely successful in 84 out of 85 patients with AVNRT, in 37 of 39 with APs and in all patients with AT and PJRT. No complications occurred in any patient. Transient AV conduction impairment occurred in seven patients with midseptal APs and in two patients with AVNRT. In particular, in these patients no late permanent AV block was observed at follow-up. At a mean follow-up of 27 +/- 12.9 months, clinical success rate was 87%.

CONCLUSIONS

Cryoablation is a safe and effective technique with a high success rate in the long term. It may be particularly useful when performing ablation close to the AV node or His bundle owing to the possibility of validating the ablation site with ice mapping, which creates only a reversible lesion, mainly in the midseptal APs.

Ventricular arrhythmias after LV remodelling: surgical ventricular restoration or ICD?

Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular stimulation (PVS) to evaluate surgical ventricular restoration (SVR) that excludes scar and lower ventricular volume alters the early and late arrhythmia process without ICD utilization.

METHODS

Clinical and hemodynamic results before and after SVR in post-infarction patients, are compared to contrast spontaneous and/or inducible ventricular tachycardia to patients without arrhythmias. Study arrhythmia groups included: Spontaneous in 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia: Inducible in 105 patients without clinical ventricular arrhythmias but PVS inducible ventricular tachycardia; and No arrhythmias in 190 patients without spontaneous or PVS inducible ventricular tachycardia.

RESULTS

Preoperative LV end systolic volume index helped define preoperative arrythmia potential: Spontaneous > 120/m(2), inducible > 100 ml/m(2), and none < 100ml/m(2). Overall operative mortality rate was 7.6% (29/382). Sudden cardiac death rate was 2.5% causing 18.7% of all deaths. Surgical management reduced inducible ventricular tachycardia, from 41% preoperatively (144/352) to 8% (26/307) at early study, and 8% (14/177) one year later. Cardiac mortality was low at 5-years and not different between groups, despite use of only one late ICD device.

CONCLUSIONS

Favorable electrical success rate and low mortality always included volume reduction to interrupt functional re-entry circuits, but also added endocardiectomy, cryoablation, CABG and mitral repair when needed. Overall SVR findings show volume and shape alteration limits ventricular arrhythmias that impair prognosis, and suggests ICD devices are not needed.

Short- and long-term success of substrate-based mapping and ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia

BACKGROUND

Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia (ARVD). Substrate-based mapping and ablation may overcome these limitations. We report the results and success of substrate-based VT ablation in ARVD.

METHODS AND RESULTS

Twenty-two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/changing VT morphologies (n=14), nonsustained VT (n=10), or hemodynamic intolerance (n=5). Sinus rhythm CARTO mapping was performed to define areas of "scar" (<0.5 mV) and "abnormal" myocardium (0.5 to 1.5 mV). Ablation was performed in "abnormal" regions, targeting sites with good pace maps compared with the induced VT(s). Linear lesions were created in these areas to (1) connect the scar/abnormal region to a valve continuity or other scar or (2) encircle the scar/abnormal region. Eighteen patients had implanted cardioverter defibrillators, 15 had implanted cardioverter defibrillator therapies, and 7 had sustained VT (6 with syncope). VTs (3+/-2 per patient) were induced (cycle length, 339+/-94 ms), and scar was identified in all patients. Scar areas were related to the tricuspid annulus, proximal right ventricular outflow tract, and anterior/inferior-apical walls. Lesions connected abnormal regions to the annulus (n=12) or other scars (n=4) and/or encircled abnormal regions (n=13). Per patient, a mean of 38+/-22 radiofrequency lesions was applied. Short-term success was achieved in 18 patients (82%). VT recurred in 23%, 27%, and 47% of patients after 1, 2, and 3 years' follow-up, respectively.

CONCLUSIONS

Substrate-based ablation of VT in ARVD can achieve a good short-term success rate. However, recurrences become increasingly common during long-term follow-up.

Relationship Between Successful Ablation Sites and the Scar Border Zone Defined by Substrate Mapping for Ventricular Tachycardia Post-Myocardial Infarction

INTRODUCTION

It is unknown if identification of scar border zones by electroanatomical mapping correlates with successful ablation sites determined from mapping during ventricular tachycardia (VT) post-myocardial infarction (MI). We sought to assess the relationship between successful ablation sites of hemodynamically stable post-MI VTs determined by mapping during VT with the scar border zone defined in sinus rhythm.

METHODS AND RESULTS

Forty-six patients presenting with hemodynamically stable, mappable monomorphic VT post-MI and who had at least one such VT successfully ablated were prospectively included in the study. In each patient, VT was ablated by targeting regions during VT that exhibited early activation, +/- isolated mid-diastolic potentials, and concealed entrainment suggesting a critical isthmus site. Prior to ablation, a detailed sinus-rhythm CARTO voltage map of the left ventricle was obtained. A voltage <0.5 mV defined dense scar. Successful VT ablation sites were registered on the sinus voltage map to assess their relationship to the scar border zone. Of the 86 VTs, 68% were successfully ablated at sites in the endocardial border zone. The remaining VTs had ablation sites within the scar in (18%), in normal myocardium (4%), and on the epicardial surface (10%). There were no significant differences in VT recurrence amongst the different groups.

CONCLUSION

Successful ablation sites of hemodynamically stable, monomorphic VTs post-MI are often located in the scar border zone as defined by substrate voltage mapping. However, in a sizable minority, ablation sites are located within endocardial scar, epicardially, and even in normal myocardium.

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

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

Safety and efficacy of cryoablation of accessory pathways adjacent to the normal conduction system

Cryoablation of Septal Accessory Pathways.

INTRODUCTION

Catheter ablation has become a routine treatment for patients with Wolff-Parkinson-White syndrome because of its low risk and high efficacy; however, radiofrequency ablation in the septum close to the AV node or His bundle still carries a definite risk for AV block. Cryoenergy catheter ablation has recently become available. This technique has specific features, such as the ability to create reversible loss of function to predict the effects of ablation (ice mapping) and the adherence of the catheter tip to the endocardium with freezing, which avoids the risk for dislodgment. Both of these characteristics may minimize the risk of complications. The aim of this study was to analyze the effectiveness and safety of catheter cryoablation in 20 patients with para-Hisian or midseptal accessory pathways (AP).

METHODS AND RESULTS

Eleven patients with para-Hisian and 9 patients with midseptal AP underwent catheter cryoablation. Ice mapping at -30 degrees C was performed to ascertain the disappearance of AP conduction and the absence of impairment of AV nodal conduction. If the expected result was obtained, cryoablation was performed by lowering the temperature to -75 degrees C for 4 minutes in order to create a permanent lesion. Cryoablation was successful in all patients using a mean of 1.2 +/- 0.4 applications. Recurrences occurred in 4 patients (20%) who underwent a second successful cryoablation session. No complications were observed.

CONCLUSION

Cryoablation appears to be a safe and effective technique for ablation of APs close to the AV node or His bundle because of the ability to predict the acute effects of ablation with ice mapping before creation of an irreversible lesion.

Short-term results of substrate mapping and radiofrequency ablation of ischemic ventricular tachycardia using a saline-irrigated catheter

OBJECTIVES

We evaluated the safety and acute procedural efficacy of a combined electrophysiologic and anatomic approach to ablation of all inducible ventricular tachycardias (VT) during sinus rhythm using an irrigated radiofrequency (RF) ablation catheter.

BACKGROUND

Ventricular tachycardia associated with chronic myocardial infarction (MI) is frequently hemodynamically intolerable and associated with multiple electrocardiographic morphologies. Because traditional mapping techniques are contingent on hemodynamic stability for adequate VT mapping, VT ablation therapy for many patients has been disappointing.

METHODS

High-density electroanatomic mapping was performed during either sinus rhythm in 11 consecutive patients with a history of MI and ventricular arrhythmias. The RF ablation was performed using an irrigated-tip ablation catheter. All inducible VTs were targeted for catheter ablation during sinus rhythm.

RESULTS

The RF ablation lesions were placed in a linear fashion traversing the border zones of infarcted and normal tissue (mean of 3.4 linear lesions/patient). With this strategy, the target VT was eliminated in 9 of 11 patients (82%). Furthermore, when targeting all inducible monomorphic VTs, complete procedural success was achieved in 7 of 11 patients (64%). During the follow-up period (mean 13.1 +/- 1.9 weeks), spontaneous VT was only noted in the two patients with no acute procedural benefit.

CONCLUSIONS

By identifying potentially arrhythmogenic tissue during sinus rhythm, substrate mapping can guide the ablation of a majority of inducible VTs using an irrigated RF ablation catheter. This emerging therapeutic paradigm may be considered in the management of patients with multiple hemodynamically unstable monomorphic VTs.

[Role of coronary artery revascularization and aneurysmectomy in ventricular arrhythmias in the chronic phase of myocardial infarction]

INTRODUCTION AND OBJECTIVES

The influence of coronary artery revascularization on the control of ventricular arrhythmias in patients with chronic myocardial infarction is uncertain. However, ablation of the arrhythmogenic circuit in these patients by aneurysm resection is useful for controlling ventricular arrhythmias. We made a prospective analysis of our clinical strategy in patients who were candidates for coronary artery revascularization and/or aneurysmectomy to determine its influence on the recurrence of ventricular arrhythmias.

PATIENTS AND METHOD

Prospective study of 17 consecutive patients with chronic myocardial infarction and ventricular arrhythmias unrelated with an acute ischemic event, who had coronary artery disease and/or ventricular aneurysm susceptible to aggressive treatment. We evaluated our clinical strategy and the recurrence of ventricular arrhythmias during a mean follow-up period of 33.64 months.

RESULTS

Two groups of patients were studied: patients with ventricular aneurysm (group I: 12 patients) and patients without ventricular aneurysm (group II: 5 patients). Seven patients of group I underwent endoaneurysmorrhaphy and endocardial resection (4 of these patients had associated revascularization procedures). Three patients were not candidates for aneurysmectomy or revascularization procedures. Two patients underwent only revascularization procedures. All the patients in group II were revascularized. The patients who underwent aneurysmectomy did not have recurrence of arrhythmias. In 5 of the 6 patients who underwent programmed electrophysiological stimulation after aneurysmectomy, no sustained arrhythmia could be induced. Patients who were only revascularized had a high rate of recurrence of ventricular arrhythmias (57%), which were inducible after revascularization.

CONCLUSION

Aneurysmectomy and endocardial resection constituted, in our experience, an effective tool for controlling ventricular arrhythmias associated with left ventricular aneurysm. Coronary artery revascularization in patients with ventricular arrhythmias and chronic myocardial infarction probably does not prevent the recurrence of ventricular arrhythmias.

Surgical ventricular restoration in patients with postinfarction coronary artery disease: effectiveness on spontaneous and inducible ventricular tachycardia

Surgical ventricular reconstruction (SVR) involves resection of scar, septal exclusion, cavity reduction by endoventricular patch, and complete coronary grafting. At the Cardiothoracic Centre of Monaco, ventricular stimulation (PVS) is performed before SVR, unless contraindicated. In patients with spontaneous and/or inducible ventricular arrhythmias, nonguided endocardiectomy and cryosurgery are added. We report clinical and hemodynamic results after SVR in postinfarction patients, to compare management of patients with spontaneous and/or inducible ventricular tachycardia, with those without arrhythmias. The 3 subsets were: Group A, 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia (Spontaneous); Group B, 105 patients without clinical ventricular arrhythmias but with inducible ventricular tachycardia at PVS (Inducible); and Group C, 190 patients without spontaneous arrhythmias and not inducible ventricular tachycardia at PVS (No arrhythmias). Overall surgical mortality rate was 7.6% (29 of 382). Sudden death mortality was only 18.7% of all deaths. Surgical management caused marked reduction of inducible ventricular tachycardia, from 144 of 352 inducible ventricular tachycardia before surgery (41%), to 26 of 307 (8%) at early study, and 14 of 177 (8%) one year later. Cardiac mortality was low at 5 years, and not different among groups; this indicates that the surgical procedure limits the ventricular arrhythmias that normally impair prognosis in postinfarction dilated cardiomyopathy. We believe the favorable electrical success rate and low mortality are not linked to one aspect of the surgical procedure, but to an integrated approach that relieves ischemia (coronary bypass graft), and reduces left ventricular volumes (SVR) to improve pump function, and nonguided endocardiectomy plus cryoablation, to interrupt functional reentry circuits.

Intraoperative computerized mapping of ventricular tachycardia: differences between anterior and inferior myocardial infarctions

INTRODUCTION

Although direct ventricular tachycardia (VT) surgery has been shown to be effective for treatment of inferior myocardial infarction (MI), the differences in the arrhythmia substrates compared to anterior MI have not been systematically delineated. We sought to compare operative procedures and VT substrates between anterior and inferior MI locations.

METHODS AND RESULTS

Computerized mapping was performed in 30 patients with a 128-electrode system using epicardial sock and transatrial left ventricular endocardial balloon arrays, followed by combined endocardial resection and cryoablation. At surgery, there were 51 and 34 different VTs in 18 patients with anterior MI and 12 patients with inferior MI, respectively. The proportion of aneurysms was lower in inferior MI (25% vs 78%, P = 0.008). Total activation times accounted for 65% +/- 23% and 50% +/- 22% of the VT cycle length in anterior and inferior infarcts, respectively (P = 0.005). Complete superficial reentry was identified in 12 VTs related to anterior infarcts and in only two VTs associated with inferior infarction (P = 0.038). Involvement of papillary muscles occurred in two patients with inferior MI. Patients with inferior infarcts received more cryolesions and required epicardial cryolesions or mitral valve replacement more frequently, and their operative mortality was greater (2/12 vs 0/18). Noninducibility rate (89.3%) and 2-year survival (76% +/- 8%) did not differ according to infarct location.

CONCLUSION

VT associated with inferior MI can be ablated successfully; however, the substrate is more complex, with frequent participation of intramural layers rendering the ablative procedure more difficult.

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

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

Malignant ventricular arrhythmias revealing anomalous origin of the left coronary artery from the pulmonary artery in two adults

We report two cases of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), revealed by malignant ventricular arrhythmias in adult patients. A two coronary system was re-established in both patients, and cryotherapy was performed on one of the patients who, in addition, presented ventricular aneurysm triggering ventricular tachycardia.

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

INTRODUCTION

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

METHODS AND RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Combined radiofrequency ablation-cooling catheter for reversible cryothermal mapping and ablation

Reversible cryothermal mapping of cardiac arrhythmias has been performed intraoperatively. However, a steerable cooling catheter for reversible mapping has not yet been developed. We therefore developed and tested a cooling system consisting of a -15 degrees C hypertonic saline reservoir and a 7F steerable catheter also capable of radiofrequency (RF) ablation. Using excised ovine hearts placed in a 37 degrees C circulating saline bath, we measured the temperatures at depths of 0 mm, 1 mm, and 2 mm. The temperature after 90 seconds of cooling was 16.5 +/- 2.1 degrees C at 0 mm compared to 23.9 +/- 4.1 degrees C at 1 mm and 31.1 +/- 3.9 degrees C at 2 mm depth (p < 0.01). These data suggest that a 7F steerable combined RF ablation-cooling catheter may achieve temperatures suitable for mapping arrhythmias such as atrial tachycardias and right ventricular outflow tract tachycardias. Further enhancements to achieve lower temperatures at depth may be needed to reversibly map other arrhythmias such as left ventricular tachycardias.

Perioperative and long-term results with mapping-guided subendocardial resection and left ventricular endoaneurysmorrhaphy

BACKGROUND

Surgical ablation of the arrhythmogenic focus in patients with life-threatening ventricular tachyarrhythmias can be curative. However, the surgical techniques have been plagued by a high perioperative mortality rate (averaging approximately 12%). Reconstruction of the left ventricle may reduce mortality.

METHODS AND RESULTS

Reconstruction of the left ventricle with a pericardial patch, or endoaneurysmorrhaphy, was performed with mapping-guided subendocardial resection for recurrent ventricular tachycardia in 25 patients over a 5-year period. Postoperatively, electrophysiological studies were conducted to assess the results of surgery, which were further evaluated during long-term follow-up with survival analyses. The study included 25 patients, 60 +/- 9 years of age, with coronary artery disease, discrete left ventricle aneurysms, and malignant ventricular tacharrhythmias. Left ventricular ejection fraction was 24 +/- 6% preoperatively. Left ventricular endocardial mapping, endocardial resection, and endoaneurysmorrhaphy were performed in all patients. There was no operative or postoperative (30-day) mortality. Postoperative ventricular tachycardia was induced in 2 of the 25 patients (8%); left ventricular function increased to 32 +/- 9% (range, 19% to 52%). At a mean follow-up of 37 +/- 16 months (range, 6 to 65 months), there had been 6 deaths, including 1 sudden cardiac death, 2 congestive heart failure deaths, and 3 noncardiac deaths. Analysis of multiple variables failed to identify predictors of postoperative inducibility, sudden cardiac death, cardiac death, or total mortality.

CONCLUSIONS

Endoaneurysmorrhaphy with a pericardial patch combined with mapping-guided subendocardial resection frequently cures recurrent ventricular tachycardia with low operative mortality and improvement of ventricular function. Long-term follow-up demonstrates low sudden cardiac death rates.