Surgical Cryoablation Research Articles

Lesion durability found during mandated percutaneous catheter ablation after surgical cryo-ablation for treatment of non-paroxysmal atrial fibrillation

ObjectivesCurrent recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation.MethodsPatients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol.ResultsWe analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS).ConclusionsThe effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.

Cryoablation Catheter Used in the Surgical Treatment of Atrial Fibrillation May Treat Chest Tube Pain: Engin Technique.

Postoperative pain after cardiac surgery plays an important role in the patient's recovery process. In particular, pain at the chest tube site can negatively affect the comfort and recovery of these patients. Effective pain control minimizes the risk of many complications. Oral and intravenous analgesics, epidural anesthesia, paravertebral block, and intercostal nerve blockade are used in chest tube pain control. We routinely use the surgical cryoablation method in the presence of atrial fibrillation in the preoperative period of cardiac surgery in our clinic. Here we aimed to describe our method of using the cryoablation catheter for intercostal nerve blockade.

Electrophysiological study prior to planned pulmonary valve replacement in patients with repaired tetralogy of Fallot.

Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However, risk stratifying remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) with or without subsequent ablation in patients with rTOF planned for pulmonary valve replacement (PVR). We included all consecutive patients with rTOF referred to our institution from 2010 to 2018 aged ≥18 years for PVR. Right ventricular (RV) voltage maps were acquired and PVS was performed from two different sites at baseline, and if non-inducible under isoproterenol. Catheter and/or surgical ablation was performed when patients were inducible or when slow conduction was present in anatomical isthmuses (AIs). Postablation PVS was undertaken to guide implantable cardioverter-defibrillator (ICD) implantation. Seventy-seven patients (36.2 ± 14.3 years old, 71% male) were included. Eighteen were inducible. In 28 patients (17 inducible, 11 non-inducible but with slow conduction) ablation was performed. Five had catheter ablation, surgical cryoablation in 9, both techniques in 14. ICDs were implanted in five patients. During a follow-up of 74 ± 40 months, no sudden cardiac death occurred. Three patients experienced sustained VAs, all were inducible during the initial EP study. Two of them had an ICD (low ejection fraction for one and important risk factor for arrhythmia for the second). No VAs were reported in the non-inducible group (p < .001). Preoperative EPS can help identifying patients with rTOF at risk for VAs, providing an opportunity for targeted ablation and may improve decision-making regarding ICD implantation.

Systematic Electrophysiological Study Prior to Pulmonary Valve Replacement in Tetralogy of Fallot: A Prospective Multicenter Study.

Ventricular arrhythmias and sudden death are recognized complications in tetralogy of Fallot. Electrophysiological studies (EPS) before pulmonary valve replacement (PVR), the most common reintervention in tetralogy of Fallot, could potentially inform therapy to improve arrhythmic outcomes. A prospective multicenter study was conducted to systematically assess EPS with programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR from January 2020 to December 2021. A standardized stimulation protocol was used across all centers. A total of 120 patients were enrolled, mean age 39.2±14.5 years, 53.3% males. Sustained ventricular tachycardia was induced in 27 (22.5%) patients. When identifiable, the critical isthmus most commonly implicated (ie, in 90.0%) was between the ventricular septal defect patch and pulmonary annulus. Factors independently associated with inducible ventricular tachycardia were history of atrial arrhythmia (OR, 8.56 [95% CI, 2.43-34.73]) and pulmonary annulus diameter >26 mm (OR, 5.05 [95% CI, 1.47-21.69]). The EPS led to a substantial change in management in 23 (19.2%) cases: 18 (15.0%) had catheter ablation, 3 (2.5%) surgical cryoablation during PVR, and 9 (7.5%) defibrillator implantation. Repeat EPS 5.1 (4.8-6.2) months after PVR was negative in 8 of 9 (88.9%) patients. No patient experienced a sustained ventricular arrhythmia during 13 (6.1-20.1) months of follow-up. Systematically performing programmed ventricular stimulation in patients with tetralogy of Fallot referred for PVR yields a high rate of inducible ventricular tachycardia and carries the potential to alter management. It remains to be determined whether a standardized treatment approach based on the results of EPS will translate into improved outcomes. URL: https://www. gov; Unique identifier: NCT04205461.

PO-04-150 ATRIAL TACHYCARDIA IN PATIENTS WITH REPAIRED TETRALOGY OF FALLOT: ITS CHARACTERISTICS AND THE EFFICACY OF CATHETER ABLATION

With advanced surgical techniques and patient care, many patients with repaired tetralogy of Fallot (TOF) have extended life expectancy. However, longevity is often complicated by tachyarrhythmias. In this study, we focused on atrial tachycardias (AT), its characteristics, and the effectiveness of catheter ablation. Seventy-seven patients with repaired TOF, who are treated and followed at the University of Tsukuba Hospital, were included. The patients were divided into patients with AT and without. Various clinical parameters were evaluated and compared between the two groups. Electrophysiological and electro-anatomic data were studied in patients who had AT and underwent catheter ablation. The mean age was 34± 12 years old, and 55% were females. Twenty-three patients had AT (30%). The patients with AT were older than those without AT (40± 12 vs 31± 11; P= 0.003), the left ventricular ejection fraction was lower (58± 6 vs 62± 5; P=0.006), the right atrial (RA) area (cm2) was larger (29± 14 vs 15± 5; P<0.001), the left atrial (LA) area (cm2) was also larger (19± 3 vs 16± 4; P<0.001), the RA to LA ratio was higher (1.5 vs 1; P<0.001), had a lower tricuspid annular plane systolic excursion (16± 4 vs 18± 4; P= 0.032), and a higher prevalence of restrictive physiology (35% vs 9%; P= 0.007), respectively. These parameters were obtained during maintained sinus rhythm in all patients. Twenty patients underwent catheter ablation, in which 30 AT were ablated. Low voltage area in RA was recognized in all patients using 3D electro-anatomic mappings. The mechanism of AT was intra-atrial reentrant tachycardia revolving around RA atriotomy scar from the previous surgery in 13 AT (43%), cavotricuspid isthmus dependent in 12 AT (40%), and focal activity in the remaining 5 AT (17%). After a median follow-up of 27 months, only three patients had AT recurrence. However, in one patient, the recurrent AT could not be suppressed by endocardial ablation and was successfully treated by surgical cryoablation done during pulmonary valve replacement. The patients with AT had biventricular dysfunction and larger bi-atrial size compared with those without AT. Additionally, regardless of AT mechanism, catheter ablation was an effective treatment modality in the majority of the patients.

PO-05-097 FIRST REPORT OF CRYOABLATION OF NON-PAPILLARY MUSCLE PVCS UNDER DIRECT VISUALIZATION DURING MV REPAIR: INTER-LEAFLET TRIANGLE AND THE AORTO-MITRAL CONTINUITY

Up to 60% of patients with mitral valve prolapse (MVP) have premature ventricular contractions (PVC), usually of papillary muscle (PM) origin. However, one-third of PVCs are of non-PM origin, from areas exposed to annular stress forces. We have previously demonstrated the feasibility of intraoperative cryoablation of PM PVCs under direct visualization during mitral valve (MV) repair. To our knowledge, this is the first report of a similar approach for non-PM PVCs. We present two cases of visually-guided surgical cryoablation of non-PM PVCs at the time of elective MV repair. Both were guided by ECG morphology criteria and hybrid PET/MRI imaging pre-operatively. n/a Case 1 (Figure): 73 year old female with degenerative MVP, severe MR and frequent PVCs (27%). There were two PVC morphologies: the dominant PVC was suggestive of interleaflet triangle (ILT) origin (abrupt V3 transition), and the less frequent PVC was consistent with postero-medial PM origin. Hybrid PET-MRI demonstrated focal uptake of FDG in the LV summit region just under the aortic valve. The patient underwent an uncomplicated MV repair, TV repair and cryoablation of the ILT (open endocardial retrograde approach) and then the posterior PM. Follow up TTE showed normal MV and aortic leaflets function without regurgitation or stenosis. An event monitor at 2 months post-op revealed a PVC burden of 2% (off drugs). Case 2: 76 year old male with degenerative MVP, severe mitral regurgitation (MR) and frequent symptomatic PVCs (24%), suggestive of an aortomitral continuity (AMC) origin. Simultaneous cardiac 18F FDG-PET and MRI with LGE imaging demonstrated focal uptake of FDG in the AMC region, no LGE was detected. The patient underwent an uncomplicated MV repair, TV repair and cryoablation of the AMC. The cryo-application was performed on the atrial side of the mitral annulus with forward pressure to reach the ventricular myocardium. There were no PVCs during post-op monitoring and a 6-month follow-up monitor revealed a PVC burden of 1% (off drugs). Surgical cryoablation of non-PM PVCs under direct visualization at the time of MV surgery, using standard ECG criteria and pre-op Hybrid PET-MRI imaging, is feasible. Further studies are needed to determine the safety and effectiveness of adjunctive PVC cryoablation at the time of MV surgery.

110 ANEURYSMECTOMY AND SURGICAL ABLATION: WHEN?

Abstract A 60-year-old man with a previous myocardial infarction was admitted to our ICU for acute pulmonary edema in the context of an acute antero-lateral non-ST elevation myocardial infarction. Echocardiography showed severe left ventricular (LV) dilatation with extensive wall motion abnormalities, large apical aneurysm and severe systolic dysfunction. Coronary angiography showed a triple-vessel disease with proximal occlusion of the left anterior descending artery. During the hospitalization, multiple episodes of drug-resistant monomorphic ventricular tachycardias occurred, requiring repeated DC Shock. After Heart Team discussion, the patient underwent coronary artery bypass grafting, LV restoration according to the procedure described by Guilmet and surgical cryoablation. The Guilmet septoexclusion is indicated when the interventricular septum is more involved than the free wall. After aneurysm incision, cryolesions were applied at the septum and at the transitional zone of the scar and viable tissue. Thus, the anterior free wall was sewn obliquely to the septum. Finally, the edges of the incision, anterior and septal, were sewn together to assure a definitive hemostasis (overcoat technique). After surgery, an implantable cardioverter-defibrillator was implanted in secondary prevention. The postoperative course and subsequent cardiological follow-up were characterized by a gradual clinical improvement with mild increasing in LV function and reduction in ventricular arrhythmias. Nowadays, combined aneurysmectomy and endocardial ablation are rarely performed, but should be considered in patients with LV aneurysm who manifest drug-resistant ventricular arrhythmias. Encircling cryoablation in a remodelled ventricle is safe and effective in reducing ventricular arrhythmias which are a negative prognostic factor.

Cryoablation of Papillary Muscles at Surgery for Malignant Ventricular Arrhythmias Due to Mitral Valve Prolapse.

Mitral valve prolapse (MVP) is relatively common condition and while generally benign a small subset of patient suffers from malignant ventricular arrhythmias (MVA) and sudden cardiac death (SCD). We report three cases of mitral valve prolapse, mitral regurgitation and malignant ventricular arrhythmias refractory to medical therapy, who had surgical cryoablation at the time of surgery on the mitral valve. During a follow-up period ranging from 3 to 11 years all three patients have remained free of ventricular arrhythmias and cryoablation lesions targeting the base of the papillary muscles have not caused any detrimental effect on the valve function. Surgical cryoablation of papillary muscles as described in this article should be considered in MVP who suffer from MVA, aborted SCD or frequent ventricular ectopics likely to cause LV dysfunction.

PO-699-06 ELECTROPHYSIOLOGICAL STUDY PRIOR TO PLANNED PULMONARY VALVE REPLACEMENTIN PATIENTS WITH SURGICALLY REPAIRED TETRALOGY OF FALLOT

Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However risk stratification remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) during electrophysiological studies (EPS), with or without subsequent ablation, in patients with rTOF planned for pulmonary valve replacement (PVR). All consecutive patients aged ≥18 years with rTOF referred to our institute from 2010 to 2018 for PVR were included. Right ventricular (RV) voltage maps were created and PVS performed from two different sites (apex and infundibulum), including with isoproterenol if the patient was not inducible at baseline. Catheter or surgical cryoablation was performed when patients were inducible or when anatomical isthmuses (AIs) were judged to have the potential to sustain reentrant VAs. Post-operative EPS was undertaken to guide decisions regarding implantable cardioverter-defibrillator (ICD) implantation if patients required surgical cryoablation to complete linear lesions or in cases of persistent inducibility after catheter ablation. 77 patients (36,2 +/- 14,3 years old, 71% male) were included. 18 were inducible and 22 % needed isoproterenol infusion for inducibility. Ablation was performed in 28 patients (17 inducible, 11 non-inducible with slow conduction isthmuses). 5 patients were inducible after catheter ablation, they benefited from surgical cryoablation at the time of PVR and a repeated EPS 3 months post surgery. No patients were inducible at the repeated EPS. ICDs were implanted in five patients: four inducible and one non inducible. During a follow-up of 51 +/- 35 months, 3 patients in the inducible group experienced sustained VAs (two treated by ICD shock) versus none in the non-inducible group (p<0,001). Performing systematic EPS prior to PVR can help stratifying the arrhythmic risk in the repaired TOF population. Identification of pathological isthmuses involved in reentrant VT allows targeted ablation. In our report preemptive ablation in non inducible patients with slow conducting AI seem to be safe. Finally, our protocol can guide ICD implantation.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Successful surgical resection plus surgical cryoablation for the treatment of a large left ventricular fibroma

Residual tumor mass after large cardiac fibroma resection carries long-term risk, but cryoablation is useful during surgery to remove such tissue. Here, we present a case of a large cardiac fibroma of the posterior wall of the left ventricle, discovered during long-term, episodic ventricular tachycardia. Resection with cryoablation completely removed the tumor, eliminating postoperative, distant ventricular arrhythmias.

Percutaneous ablation of renal tumors versus surgical ablation and partial nephrectomy: Medicare trends and reimbursement cost comparison from 2010 to 2018.

The purpose of this study is to analyze trends in Medicare volume and reimbursement for percutaneous and surgical ablation as well as laparoscopic and open partial nephrectomy for treatment of small renal tumors from 2010 to 2018. Claims from the Medicare Part B Physician/Supplier Procedure Summary from 2010 to 2018 were extracted using CPT codes for percutaneous and surgical renal ablation and surgical and laparoscopic partial nephrectomy. Facility reimbursement and relative value units (RVUs) were obtained using the Centers for Medicare & Medicaid Services physician fee schedule look-up tool. Volume of percutaneous ablation increased from 2539 to 4571 procedures (80.0%). Specifically, percutaneous cryoablation became the dominant technique, increasing from 1434 to 2981 procedures (107.9%). Overall, volume of partial nephrectomy also increased by 40.4%, driven by an increase in laparoscopic partial nephrectomy from 3227 to 7770 procedures (140.8%) with a decrease in open partial nephrectomy from 3489 to 1661 (- 52.4%). Volume of surgical ablations also decreased 72.7% from 1260 to 344 procedures. In 2018, reimbursement was $358.56 for percutaneous radiofrequency ablation, $481.32 for percutaneous cryoablation, $1216.43 for surgical radiofrequency ablation, $1269.35 for surgical cryoablation, $1381.67 for open partial nephrectomy, and $1552.66 for laparoscopic partial nephrectomy. There has been a trend toward minimally invasive techniques for treatment of small renal tumors among Medicare patients. Laparoscopic partial nephrectomy has become the dominant treatment. In the setting of evidence showing comparable outcomes with surgery as well as lower costs to insurers, the volume of percutaneous ablation has also markedly increased.

B-PO05-168 BEDSIDE PERCUTANEOUS SYMPATHETIC BLOCK IS SAFE AND EFFECTIVE IN REFRACTORY ELECTRICAL STORM AS A BRIDGE TO ADVANCED THERAPIES

Patients with electrical storm (ES) who fail standard medical and interventional therapies have a high mortality rate and are difficult to bridge to definitive therapies. Bedside, ultrasound-guided percutaneous sympathetic block (PSB) can stabilize these patients in the acute setting. To describe the outcomes of patients with electrical storm (ES), in whom PSB was used to bridge them to advanced therapies. Retrospective study of consecutive ES patients undergoing bedside ultrasound-guided PSB between 1/2017-3/2020 at our institution. Of the 19 PSB patients in ES, the majority were male (89.5%) with average age of 66.5±6.0 years and left ventricular ejection fraction (LVEF) 28± 10%. There was underlying ischemic cardiomyopathy in 52%. Catheter ablation was performed in 47.3% prior to PSB with average 1.1±1.4 ablations with 2.5±0.48 adjunctive anti-arrhythmia medications. The ventricular arrhythmia (VA) was monomorphic in 70% with cycle length 250-490ms. Despite intubation and mechanical ventilation in 47% of these patients, the majority were in ES (94%) the day of procedure. After PSB, no ventricular arrhythmia recurred in eight patients (42%). There was a significant decrease in amount of VA (4.4±2.5 vs. 2.2± 3.5 episodes P= 0.019) and number of patients with ES the day before and after procedure 18 vs. 16 patients P=0.00001. Minor reversible side effects were noted in 21% and no significant bleeding was reported despite all patients being on anticoagulants or antiplatelet agents. Follow up was 4.5±5 months: 5 patients died, one referred to hospice, 5 had heart transplant and 3 underwent surgical sympathetic denervation. Four patients underwent coronary revascularization, 2 were treated with immunosuppression, 2 underwent stereotactic body radiation therapy, 1 surgical cryoablation, one AAI pacing, 2 LVAD and 1 needle catheter ablation. Fifteen patients survived admission and 13 (86%) were free of any arrhythmia during follow up. PSB with continue infusion is a safe and effective beside procedure in patients who have exhausted conventional therapy and can offer a rescue bridge to facilitate advanced treatments.

The Impact of Surgical Posterior Nasal Nerve Cryoablation on Symptoms and Disease-Specific Quality of Life in Patients With Chronic Rhinitis.

Preliminary data have demonstrated long-term efficacy of posterior nasal nerve (PNN) cryoablation in reducing rhinitis symptoms for patients with allergic rhinitis (AR) and nonallergic rhinitis (NAR). We sought to evaluate the impact of procedural cryoablation of the PNN on quality of life (QOL) in patients with AR and NAR. Adult patients undergoing PNN cryoablation for AR or NAR after appropriate medical therapy were included for analysis. Demographics, medical therapies, baseline rhinitis symptom (total nasal symptom score [TNSS]), and disease-specific QOL (mini-rhinoconjunctivitis quality of life questionnaire [mini-RQLQ]) were recorded. The Wilcoxon signed-rank test was used to test for significant changes in baseline test scores posttreatment. Absolute and relative improvement in outcomes was determined for each participant. Secondary outcomes were assessed with univariate and multivariate analyses. Fourteen patients were enrolled with a mean follow-up of 16.5 weeks. The TNSS and mini-RQLQ scores significantly improved after PNN cryoablation (median δs [interquartile range]: -4 [3] and -1.61 [1.08], respectively; both P = .0002). The minimal clinically important difference for the TNSS and mini-RQLQ was obtained in 92.9% of patients in each category. Relative mean percentage (%) improvement after PNN cryoablation in the TNSS and mini-RQLQ was 40.7% and 40.5% (standard deviation = 24.9 and 29.5, respectively), respectively, for all patients. Patients with NAR (n = 10) reported mean improvement of 41.3% (29.1) as measured by the TNSS and 49.6% (25.9) by mini-RQLQ. Patients with AR reported mean percentage improvement in TNSS and mini-RQLQ scores of 39.5% (12.1) and 24.6% (28.5), respectively. Patients who had been prescribed a nasal anticholinergic for management prior to PNN cryoablation had statistically significantly increased improvement in mini-RQLQ scores from pre- to post-procedure (P = .0387). Surgical cryoablation of the PNN significantly improves both symptoms and disease-specific QOL in majority of patients with AR and NAR.

Early outcomes of usage of cryoFORM® probe for cryomaze procedure in congenital heart surgery.

This study aimed to evaluate the early outcomes of patients who underwent a concomitant therapeutic maze procedure for congenital heart surgery. Between 2019 and 2020, eight patients underwent surgical cryoablation by using the same type of cryoablation probe. Three patients had atrial flutter, two had Wolf-Parkinson-White syndrome, two intra-atrial reentrant tachycardia, and one had atrial fibrillation. Four patients underwent electrophysiological study. Preoperatively, one patient was on 3, two were on 2, five were on 1 antiarrhythmic drug. Six patients underwent right atrial maze and two underwent bilateral atrial maze. Five out of six right atrial maze patients underwent right atrial reduction. Nine different lesion sets were used. Some of the lesions were combined and applied as one lesion. In Ebstein's anomaly patients, the lesion from coronary sinus to displaced tricuspid annulus was delicately performed. The single ventricle patient with heterotaxy had junctional rhythm at the time of discharge and was the only patient who experienced atrial extrasystoles 2 months after discharge. Seven of the eight patients were on sinus rhythm. No patient needed permanent pacemaker placement. Cryomaze procedure can be applied in congenital heart diseases with acceptable arrhythmia-free rates by selecting the appropriate materials and suitable lesion sets. The application of cryomaze in heterotaxy patients can be challenging due to differences in the conduction system and complex anatomy. Consensus with the electrophysiology team about the choice of the right-left or biatrial maze procedure is mandatory for operational success.

Long-term therapeutic effect of Fontan conversion with an extracardiac conduit.

The aim of this study was to identify the long-term therapeutic effect of total cavopulmonary connection (TCPC) conversion with an extracardiac conduit. Between 1991 and 2014, 36 patients underwent TCPC conversion with an extracardiac conduit. Half of these patients were diagnosed with tricuspid atresia or its variant. The left ventricle was dominant in 26 patients (72.2%). Median age at conversion and interval from initial Fontan operation to conversion were 24.1 years (interquartile range 18.9-29.2) and 17.8 years (15.4-20.9), respectively. Surgical cryoablation was concomitantly performed in 32 patients (88.9%). Cardiac catheter examination was performed preoperatively (36 patients, 100%) and at 1 year (31 patients, 86%), 5 years (25 patients, 69%) and 10 years (13 patients, 36%) after TCPC conversion. Symptom-limited treadmill exercise with expired gas analysis was performed preoperatively (32 patients, 88.9%) and at 1 year (27 patients, 75.0%), 5 years (20 patients, 55.6%) and 10 years (12 patients, 33.3%) after conversion. All patients received follow-up; the mean follow-up period was 8.2 ± 4.8 years. Actuarial survival rate, protein-losing enteropathy-free survival rate and rate of survival with sinus rhythm maintenance at 10 years were 79.2%, 67.8% and 48.5%, respectively. The survival curve declined steeply when the duration of Fontan circulation exceeded 25 years. New cases of protein-losing enteropathy developed postoperatively in 2 patients. Permanent pacemakers were implanted in 12 patients (33%), but atrial tachyarrhythmia was not sustained in any of the remaining patients. Pulmonary arterial pressure (11.0 ± 3.1 to 9.5 ± 3.6 mmHg, P = 0.003), pulmonary vascular resistance (2.1 ± 0.7 to 1.3 ± 0.5 WU/m2, P < 0.0001) and cardiac index (2.0 ± 0.3 to 2.9 ± 0.6 l/min/m2, P < 0.0001) significantly improved from preoperative evaluation to 1 year after the conversion, and these improvements were maintained during the entire follow-up period. Peak oxygen uptake remained unchanged from the preoperative evaluation (49.7 ± 11.5% predicted) to 1 year (52.5 ± 12.0%), 5 years (56.2 ± 9.6%) and 10 years (51.2 ± 9.4%) after conversion (P = 0.19). Owing to its anti-arrhythmic effect and Fontan pathway recruitment effect, TCPC conversion with an extracardiac conduit prevented the natural decline of exercise tolerance that is seen in classic Fontan patients.

Is programmed electrical stimulation mandatory for recognition of ventricular arrhythmogenicity in heart failure?

Ischemic cardiomyopathy often presents with advanced heart failure necessitating an intensive multidisciplinary approach to management. These patients constitute a very difficult population presenting with angina and ventricular tachyarrhythmias sometimes presenting as sudden cardiac death. In those patients presenting with spontaneous ventricular tachyarrhythmias, treatment with automated intracardiac defibrillator implantation has a significant mortality benefit. In patients with significant left ventricular (LV) dilatation and a left ventricular ejection fraction ≤ 30%, guidelines state that device implantation should be preceded by programmed electrical stimulation, which demonstrates inducible ventricular tachyarrhythmia. The treatment options for patients with moderate LV dilatation and ejection fraction ≥ 30% is individualized. Devices have their associated problems. Radiofrequency ablation has mixed results. Surgical cryoablation when performed concomitantly with surgical ventricular restoration has shown promising results. But, this option remains isolated to patients eligible for surgical ventricular restoration. Programmed electrical stimulation for inducibility of ventricular tachyarrhythmias in these patients also has a questionable role. The need for programmed electrical stimulation prior to cryoablation also seems highly individualized. In this review, we discuss the mechanisms of ischemic ventricular tachyarrhythmias and treatment options in heart failure. The mechanisms of ventricular arrhythmogenesis in ischemic cardiomyopathy help in formulating novel technical modifications for cryoablation when performed concomitantly with surgical ventricular restoration.

Characteristics of ventricular tachycardia and long-term treatment outcome in patients with dilated cardiomyopathy complicated by lamin A/C gene mutations

BackgroundDilated cardiomyopathy caused by lamin A/C gene (LMNA) mutation is complicated with atrioventricular (AV) conduction disturbances, malignant ventricular arrhythmias, and progressive severe heart failure. Radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) has been reported to be challenging due to the high recurrence rate in patients with LMNA-related cardiomyopathy. However, electrophysiological and histopathological characteristics of VT substrate remain to be fully elucidated. Methods and resultsWe experienced 6 familial patients with LMNA-related cardiomyopathy in 3 pedigrees (6 males, 43.7±4.5 [SD] years). All patients had first VT attack at 50±6.6 [SD] years of age, and 4 underwent RFCA for incessant VT. Their electrocardiograms during VT showed similar QRS morphologies, characterized by an inferior axis, SR pattern in aVR, and QS pattern in aVL, suggesting the origin of the basal anterior ventricle. Indeed, the VTs had multiple exits around the basal anterior ventricular septum in all RFCA cases. Although we performed multiple RFCA procedures including epicardial ablation and surgical cryoablation, all cases experienced VT recurrences in 4.5±6.4 [SD] months after last procedure. All patients developed end-stage heart failure with frequent VT events, and died at 59.5±3.6 years of age (severe heart failure in 5 and lung disease in 1). In three autopsy cases with RFCA, fibrofatty degeneration was noted in the AV node. In addition, in the deep basal ventricular septum, inhomogenous fibrotic degenerated tissue was noted beyond the reach of RF lesions. ConclusionsThese results demonstrate that patients with LMNA-related cardiomyopathy are characterized by VTs refractory to RFCA probably because of the deep intramural focus at the basal ventricular septum, resulting in poor prognosis with progressive severe heart failure despite all available optimized therapies. Thus, we should consider heart transplantation in their early 50s when several VT events begin to occur.

Guidance of Intra-Operative Ventricular Tachycardia Ablation during LVAD Implantation with Pre-operative Cardiac MRI

Introduction Ventricular tachycardia (VT) is common in ischemic cardiomyopathy (ICM). Ablation maybe required to reduce ICD shocks and improve the quality of life. Preoperative VT mapping is an invasive electrophysiologic study prior to the surgery which heart failure patients may not tolerate. Substrate modification is usually done in an open epicardial approach during LVAD implantation. Non-invasive mapping techniques have not been described before. In this case pre-operative cardiac magnetic resonance (CMR) imaging was used to plan VT scar mapping and guide intra-operative cryoablation that was done while performing LVAD implantation. Case Report 69-year-old man with ICM (ejection fraction of 23%) and biventricular cardioverter-defibrillator (ICD). He has history of VT, four ablations, and on mexiletine and amiodarone. He had VT-related syncope terminated with anti-tachycardia pacing (ATP). ICD interrogation showed 15 appropriate shocks and >100 ATP therapies since the device implantation 6 months prior. In hospital he had slow monomorphic VT (slow cycle length 650 msec) with left bundle-branch morphology and superior axis positive in AVR. Milrinone was started for cardiogenic shock (cardiac index of 1.81 L/min/m2). He was not a transplant candidate so he was scheduled for destination therapy LVAD. Before the procedure he had sustained monomorphic VTs refractory to ATP requiring ICD shock. Cardiac MRI showed large chronic infarct with marked remodeling and transmural delayed enhancement in the inferoseptal, inferior, and inferolateral segments at the base a mid-ventricular portions of the left ventricle (LV) extending into the inferior aspect of the apical LV. Six myocardial segments equivalent was involved with transmural infarct. We decided to do an intra-operative VT ablation during LVAD implantation. Intraoperatively the LVAD ring was anchored to the apex with sutures. LV incision was made, and cryoablation of the inferoseptal towards inferolateral wall was performed using Cryo3 cryoICE catheter. Corresponding to the scar on MRI ablation lesions were created and the lesions were overlapping (from 3 to 9 o'clock position). The incision site was also cryoablated with a total of ten cryoablations. Conclusion This is the first case to use cardiac MRI for preoperative VT mapping and did correspond to the lesions seen intra-operatively. This is a novel non-invasive mapping tool for heart failure patients undergoing surgical cryoablation . At 1 month follow up the patient has had 68 episodes of non-sustained VT, and 8 episodes of VT, successfully treated with ATP.

Application of cryoablation for the treatment of atrial fibrillation in patients undergoing cardiac surgery: Our mid-term results.

In this study, we aimed to present mid-term results of concomitant argon-based cryoablation in patients undergoing cardiac surgery. Between August 2014 and May 2016, 33 patients (17 males, 16 females; mean age 63.9 years; range 45 to 82 years) underwent the Maze procedure using cryoablation for the treatment of atrial fibrillation during a concomitant open cardiac operation. Robot-assisted procedures were used in 12 patients. Biatrial or isolated left atrial ablation was performed according to the underlying pathology. The rhythm assessment with 12-lead electrocardiography and 24-hour Holter, and recordings of atrial fibrillation-related medications, stroke or other thromboembolic events were evaluated by the cardiologist at 3 and 12 months postoperatively. Thirty patients (90.9%) were in sinus rhythm and three (9.1%) were in atrial fibrillation at the time of discharge. Cryoablation failed in three patients (n=2, 8.3% in isolated left atrial and n=1, 11.1% in biatrial group) following the operation in the mid-term. Among the patients, there was no in-hospital mortality and no major postoperative complications such as stroke, sepsis, renal failure requiring dialysis, and prolonged respiratory failure. Concomitant surgical cryoablation is an effective method for the treatment of atrial fibrillation, when performed concomitantly with other cardiac surgical procedures and results in very low atrial fibrillation recurrence, even in robotic surgery.

Novel approaches for the treatment of ventricular tachycardia.

Ventricular tachycardia (VT) is a crucial cause of sudden cardiac death (SCD) and a primary cause of mortality and morbidity in patients with structural cardiac disease. VT includes clinical disorders varying from benign to life-threatening. Most life-threatening episodes are correlated with coronary artery disease, but the risk of SCD varies in certain populations, with various underlying heart conditions, specific family history, and genetic variants. The targets of VT management are symptom alleviation, improved quality of life, reduced implantable cardioverter defibrillator shocks, prevention of reduction of left ventricular function, reduced risk of SCD, and improved overall survival. Antiarrhythmic drug therapy and endocardial catheter ablation remains the cornerstone of guideline-endorsed VT treatment strategies in patients with structural cardiac abnormalities. Novel strategies such as epicardial ablation, surgical cryoablation, transcoronary alcohol ablation, pre-procedural imaging, and stereotactic ablative radiotherapy are an appealing area of research. In this review, we gathered all recent advances in innovative therapies as well as experimental evidence focusing on different aspects of VT treatment that could be significant for future favorable clinical applications.