Epicardial Approach Research Articles

Abstract 12974: Successful VT Ablation Utilising Intracoronary Gelatin Sponge Injection

Introduction: We report two cases of recurrent ventricular tachycardia (VT) successfully treated by intra-coronary Gelatin sponge embolization where initial endocardial ablation was unsuccessful and epicardial approaches were unfavourable. Case Histories: (1) A 75-year-old male with Inferior STEMI who underwent PCI to oRPDA developed VT storm that required DCCV 11 times. The VT was hemodynamically unstable, hence only substrate modification was performed. He still had recurrent episodes of VT and a second ablation attempt localised VT circuit breakout to the infero-apical septum, but ablation was unsuccessful due to a deep intramural circuit. Epicardial ablation was not attempted due to a 1cm pericardial effusion after the first procedure. Unipolar signals from selective wiring of the distal rPDA with a percutaneous coronary intervention guidewire and microcatheter showed early local electrograms. 5ml of Gelatin sponge injection was injected after a 5x2mm coil failed to occlude the distal rPDA. Post occlusion, VT was not inducible with double ventricular extra-stimuli. He has been VT free for 5 months (2) A 41-year-old female with dilated cardiomyopathy, previous left ventricular assist device and revision was admitted for VT storm. The VT map identified earliest activation with far-field pre-systolic potentials at the baso-lateral LV segment. Pre-systolic far field ventricular EGMs were also seen in the adjacent coronary sinus, consistent with a likely epicardial exit site of the VT. Endocardial ablation failed, and epicardial access was not feasible due to adhesions. Coronary angiography revealed a small calibre non dominant left circumflex artery supplying the VT exit site. Cold saline injection down the mLCX terminated the VT and the vessel was occluded with 5 ml of Gelatin sponge. VT was subsequently not inducible. Discussion & Conclusion: Critical portions of VT circuits may course epicardially or intramurally 3 , limiting successful endocardial catheter ablation. Epicardial access was risky. Coronary vessel embolization using coils 4 and ethanol 5 have been performed. Use of absorbable Gelatin sponge has been described in managing coronary perforation 6 , but to the best of our knowledge these are the first cases of its use in VT ablation.

Catheter ablation for ventricular tachycardia in Chagas disease

Abstract Background Chagas disease (ChD) is a major cause of non-ischemic cardiomyopathy (NICM) in Latin America and is becoming more frequent in other parts of the world, especially due to immigration movements. Ventricular Tachycardia (VT) is more common in this type of NICM than others, and finding an effective treatment strategy still is a challenge. Catheter ablation is an option, but there is poor data regarding its efficacy and safety. Purpose Evaluate the outcomes after VT catheter ablation in ChD patients. Methods Data were collected by VT studies reports and patient record analysis, including comorbidities and clinical status at baseline and on follow-up. We analyzed all-cause mortality, one-year VT recurrence rate and procedure related major complications. Results Between January 2013 and December 2018, 157 catheter ablation procedures in 121 ChD patients were performed in our institution. The mean follow-up time was 22.6±22.1 (mean ± SD) months. Overall post procedure mortality was 33.1%, and mean survival time was 51.2 months (95% CI: 44.8–58. NYHA functional class (p=0.022), ejection fraction (p=0.020) and immediate ablation result (p 0.002) were predictors of all-cause mortality in the follow-up. Clinical VT inducibility after ablation was a predictor of VT recurrence at one year (p=0.04). An epicardial approach was performed in 125 (79%) procedures, and accidental right ventricle (RV) puncture occurred in 23 (18.4%), in which open-chest surgery for bleeding hemostasis was necessary in 4 procedures (3.2%). Conclusion Mortality and recurrence rates in ChD patients after VT ablation were high, and correlated with heart failure severity. Epicardial approach is often necessary in this subset of patients. There was a correlation between immediate ablation results and recurrence. Kaplan-Meier of cumulative survival Funding Acknowledgement Type of funding source: None

Paroxysmal and persistent atrial fibrillation; does the clinical classification match the substrate?

Abstract Background/Introduction The classification of atrial fibrillation (AF) currently is based on clinical characteristics, however classifying underlying electropathology would assist in selecting appropriate therapy. In this study, we measured atrial conduction parameters in sinus rhythm (SR) using an intra-operative high resolution epicardial mapping approach in paroxysmal (PAF) and persistent AF (persAF) patients. Purpose To study whether the clinical classification is related to the amount and severity of conduction disorders in SR. Methods We included 47 PAF and 24 persAF patients for intra-operative measurements of SR at the right atrium (RA), Bachmann's Bundle (BB), the left atrium (LA) and the pulmonary vein area (PV). Various conduction parameters were calculated, including number of continuous conduction delay and block (cCDCB) lines, total activation time (TAT), and orientation of conduction block (CB) lines at BB. Results After adjustment for confounders, only TAT of BB was significantly longer in persAF patients, 75 [53–92] ms vs 55 [40–76] ms. This can be attributed to more CB line parts orientated perpendicular to the conduction direction and a higher number of cCDCB lines. Other conduction characteristics at BB and other atrial areas showed no difference between PAF and persAF patients. Conclusion(s) Patients with persAF have a longer activation time at BB compared to patients with PAF. Other conduction parameters show significant overlap between these groups at BB and in other atrial areas, suggesting that, in SR, the clinical classification does not match the arrhythmogenic substrate. Funding Acknowledgement Type of funding source: None

16-month outcomes following hybrid ablation for long-standing persistent atrial fibrillation in patients with dilated atria

Abstract Introduction Although catheter ablation therapy is a well-established treatment for cardiac dysrhythmias, the success rates for longstanding, persistent AF with dilated atria remain unsatisfactory. The minimally invasive hybrid technology is a novel form of therapy. Methods A prospective, single-center UK study to evaluate the hybrid ablation technique for patients with longstanding (>1 year) persistent AF and dilated atria. Stage 1 was a minimally invasive epicardial approach for ablation of the posterior wall of left atrium (LA) and pulmonary veins (PVs). Stage 2 was a transcatheter approach via the femoral veins to isolate the endocardial aspect of the PVs +/− posterior wall. Occasionally, the sequence of the stages was reversed. Results Forty-one patients were enrolled for the study with a mean follow-up for 16±9 months. Mean age was 65±9 years and the mean BMI was 32±7. Males constituted 75% of the study cohort. Mean LA size was 48±7 mm and mean left ventricular ejection fraction (LVEF) was 51.9%, although 51.6% of patients had impaired LVSF (LVEF below 55%). 87.8% CI (0.7–0.9) of patients remained in sinus rhythm (SR) without repeat ablation, whereas only 12.2% CI (0.04–0.02) had redeveloped persistent AF. Although numerically different, there was no statistically significant difference in maintaining SR between patients with severely dilated LA (>50 mm) and those without (70% vs. 90%, respectively; z=−1.39, p=0.165). Major perioperative complications during stage 1 ablation were low, with IVC injury in 1 patient and a mild stroke in 1 patient. Median LOS was 1 day (1–4 days) and there was no 30-day mortality after stage 1. Conclusions The hybrid ablation therapy has a conversion rate from longstanding persistent AF to SR of 87.8% at a mean follow-up of 16±9 months, without repeat ablation. LOS was short, with very few complications and no peri-operative mortality. The hybrid approach appears to be very encouraging for a condition with otherwise low success rates by conventional endocardial techniques alone. Funding Acknowledgement Type of funding source: None

Percutaneous epicardial approach for LAA ligation

The left atrial appendage (LAA) is believed to be a source for thrombus formation and an ancillary structure involved in the initiation and maintenance of atrial fibrillation (AF). LAA ligation has been proposed as adjunctive therapy for the treatment of AF. This study will determine the feasibility of a percutaneous epicardial approach for LAA ligation. The pericardium of 5 dogs was accessed via percutaneous subxyphoid approach. A 20F epicardial cannula was inserted into the pericardial space and contrast-injected to visualize the LAA. Under fluoroscopic guidance, a suction cup catheter was inserted and attached to the LAA. A 12F snare device was inserted over the vacuum cup to ligate the LAA. The closure of the LAA was verified with LA angiography, in the first 2 dogs, and ICE in all 5 animals. All animals were sacrificed for post hoc assessment of LAA closure. All 5 dogs underwent successful epicardial suture ligation of the LAA. In the first 2 dogs, LA angiography demonstrated complete closure of the LAA. All dogs underwent gross examination of the LAA. Post hoc assessment was notable for a small well-circumscribed hematoma on the LAA, consistent with point of suction cup attachment, as well as complete closure of the entire LAA. No laceration or perforation was noted on the LAA. Exclusion of the LAA via a novel percutaneous epicardial-only approach was successful without complications. This demonstrates the feasibility of this technique in an animal model, and may provide an effective approach for epicardial-only LAA exclusion in humans.

The 'double transition': a novel electrocardiogram sign to discriminate posteroseptal accessory pathways ablated from the right endocardium from those requiring a left-sided or epicardial coronary venous approach.

The precise localization of manifest posteroseptal accessory pathways (APs) often poses diagnostic challenges considering that a small area may encompass AP that may be ablated from the right or left endocardium, or epicardially within the coronary sinus (CS). We sought to explore whether the QRS transition pattern in the precordial lead may help to discriminate the necessary ablation approach. Consecutive patients who underwent a successful ablation of a single manifest AP over a 5-year period were included. Standard 12-lead electrocardiograms were reviewed. A total of 273 patients were identified. Mean age was 31 ± 15 years and 62% were male. Of the 110 identified posteroseptal AP, 64 were ablated from the right endocardium, 33 from the left endocardium, and 13 inside the CS. While a normal precordial QRS transition was most often observed, a subset of 33 patients presented an atypical 'double transition' pattern which specifically identified right endocardial AP. The combination of a q wave in V1 with a proportion of the positive QRS component in V1 < V2 > V3, predicted a right endocardial AP with a 100% specificity. In case of a positive QRS sum in V2, this 'double transition' pattern predicted a posteroseptal right endocardial AP with 99.5% specificity and 44% sensitivity. The positive predictive value was 97%. The only false positive was a midseptal AP. In the case of a negative or isoelectric QRS sum in V2, APs were located more laterally on the tricuspid annulus. The combination of a q wave in V1 with a double QRS transition pattern in the precordial leads is highly specific of a right endocardial AP and rules out the need for CS or left-sided mapping.

Perioperative Imaging to Guide Epicardial Mapping and Ablation.

Accessing the epicardial space without a sternotomy or a surgical pericardial window to treat ventricular arrhythmias in Chagas disease became a medical necessity in South America. Since the introduction of the dry percutaneous epicardial access approach, epicardial access has been standard procedure for management of ventricular arrhythmias in ischemic and nonischemic cardiomyopathies and atrioventricular accessory pathways after failed conventional endocardial ablation. Understanding the epicardial space and neighboring structures has become an important subject of teachings in electrophysiology. The evolution of complex ablation procedures to treat atrial and ventricular arrhythmias and device interventions to prevent cardioembolic stroke requires thorough understanding of pericardial anatomy.

Epicardial Ablation Complications.

The percutaneous epicardial approach has become an adjunctive tool for electrophysiologists to treat disparate cardiac arrhythmias, including accessory pathways, atrial tachycardia, and particularly ventricular tachycardia. This novel technique prompted a strong impulse to perform epicardial access as an alternative strategy for pacing and defibrillation, left atrial appendage exclusion, heart failure with preserved ejection fraction, and genetically engineered tissue delivery. However, because of the incremental risk of major complications compared with stand-alone endocardial ablation, it is still practiced in a limited number of highly experienced centers across the world.

Acute and mid-term outcome of ethanol infusion of vein of Marshall for the treatment of perimitral flutter.

We hypothesized that an epicardial approach using ethanol infusion in the vein of Marshall (EIVOM) may improve the result of ablation for perimitral flutter (PMF). We studied 103 consecutive patients with PMF undergoing high-resolution mapping. The first 71 were treated with radiofrequency (RF) ablation alone (RF-group), and the next 32 underwent EIVOM followed by RF on the endocardial and epicardial mitral isthmus (EIVOM/RF-group). Contact force was not measured during ablation. Acute and 1-year outcomes were compared. Flutter termination rates were similar between the RF-group (63/71, 88.7%) and EIVOM/RF-group (31/32, 96.8%, P = 0.27). Atrial tachycardia (AT) terminated with EIVOM alone in 22/32 (68.6%) in the EIVOM/RF-group. Bidirectional block of mitral isthmus was always achieved in the EIVOM/RF-group, but significantly less frequently achieved in the RF-group (62/71, 87.3%; P = 0.05). Median RF duration for AT termination/conversion was shorter [0 (0-6) s in the EIVOM/RF-group than 312 (55-610) s in the RF-group, P < 0.0001], as well as for mitral isthmus block in the EIVOM/RF-group [246 (0-663) s] than in the RF-group [900 (525-1310) s, P < 0.0001]. Pericardial effusion was observed in 1/32 (3.2%) in EIVOM/RF-group and 5/71 (7.0%) in RF-group (P = 0.66); two in RF-group required drainage and one of them developed subsequent ischaemic stroke. One-year follow-up demonstrated fewer recurrences in the EIVOM/RF-group [6/32 (18.8%)] than in the RF-group [29/71 (40.8%), P = 0.04]. By multivariate analysis, only EIVOM was significantly associated with less AT recurrence (hazard ratio = 0.35, P = 0.018). Ethanol infusion in the vein of Marshall may reduce RF duration required for PMF termination as well as for mitral isthmus block without severe complications, and the mid-term outcome may be improved by this approach.

Outcome of cardiac tamponades in interventional electrophysiology.

The aim of this study was to analyse tamponades following electrophysiological procedures regarding frequency and mortality in a high-volume centre and to identify independent predictors for severe tamponades. We performed a retrospective study on 34982 consecutive patients undergoing diagnostic electrophysiological studies or catheter ablation of cardiac arrhythmias. The combined endpoint was defined as severe tamponade. Criteria for severe tamponade included surgical repair, repeat pericardiocentesis, cardiopulmonary resuscitation, intrahospital death or death during follow-up, and thrombo-embolic events or complications due to therapeutic management. Multivariate analysis was performed to identify independent predictors for severe tamponade. A total of 226 tamponades were identified. Overall frequency of tamponades was 0.6%. Procedures requiring epicardial approach had the highest rate of tamponades (9.4%). Twenty-nine patients with tamponade underwent surgery (12.8% of all tamponades and 21.4% of tamponades during epicardial procedures). Overall tamponade-related mortality was 0.03% (9 deaths). Fifty-six patients (24.8%) experienced severe tamponade. Independent risk factors for severe tamponades were endocardial ablation of ventricular tachycardia, epicardial approach, balloon device ablation, high aspiration volume during pericardiocentesis and structural heart disease. The frequency of tamponades is strongly dependent on the type of procedure performed. Overall tamponade-related mortality was low but significantly higher in patients undergoing epicardial procedures. Surgical backup should be considered for patients undergoing complex ventricular tachycardia ablation and left atrial ablation procedures.

Endocardial and endo-epicardial substrate mapping and ablation of ventricular arrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy

Purpose: to compare epicardial and endocardial surface area of local abnormal ventricular activity (LAVA) and low voltage zone (LVZ) and effectiveness of endocardial versus combined endo-epicardial ablation of ventricular arrhythmias in ARVC patients.Methods: a prospective observational “case-control” study comprised 20 patients with ARVC and ventricular arrhythmias referred to catheter ablation. The study group with epicardial approach (EPI group) comprised 10 patients with sustained VT, who signed informed consent for the epicardial access. The control group (ENDO group) comprised 10 patients with sustained VT or frequent symptomatic premature ventricular contractions (PVC). Electroanatomical voltage mapping and LAVA ablation was performed.Results: the patient mean age was 41.4±13.8 years, 70% males; 90% patients in the EPI group had sustained VT, 50% - in the ENDO group. In the EPI group the endocardial unipolar low voltage zone area (LVZ) significantly prevailed over the bipolar endocardial LVZ area: 75.4 cm2 [IQR: 23.2; 211.9] vs 6.7 cm2 [IQR: 4.4; 35.5] (Р=0.009). In the ENDO group the LVZ area on unipolar map had a trend toward the prevalence over the bipolar area, but was not statistically different: 12.7 cm2 (IQR: 0; 46.3) vs 3.65 cm2 (IQR: 0; 46.3) (Р&gt;0.05). The epicardial bipolar LVZ area prevailed over unipolar epicardial LVZ area: 65.3 cm2 [IQR: 55.6; 91.3] vs 6.7 cm2 [IQR: 4.4; 35.3] (Р=0.005). Non-inducibility of any ventricular arrhythmia was achieved in 90% of EPI patients and in 80% of ENDO cases. The median follow-up period was 22.3±10.5 months. During a mean follow-up period freedom of ventricular arrhythmia recurrence was 70% in the EPI group and 100% in the control group (Р&gt;0.05).Conclusion: Although there was a significant difference in bipolar LVZ areas between endo- and epicardial maps, our series showed that endocardial only ablation is an effective strategy in ventricular arrhythmia management in ARVC patients.

P355Complete non-inducibility after radiofrequency ablation for electrical storm improves survival rates

Abstract Background Electric storm is a life threatening condition, that can complicate multiple cardiac pathologies and is associated with high mortality. Catheter ablation has been shown to reduce ventricular tachycardia (VT) burden in patients with electrical storm but the optimal procedural endpoint and the therapeutic particularities required by different etiologies are still under debate. Purpose Our objective was to determine if there are any periprocedural factors that influence midterm outcomes. We also sought if there were any significant differences between the results for ischemic and nonischemic patients. Methods The study included 66 consecutive patients, mean age 60 years, 82% males, treated for electrical storm in our center with endocardial/endo-epicardial radiofrequncy catheter ablation (with or without remote magnetic navigation). Acute success was defined as elimination of the clinical tachycardia with complete non-inducibility (including ventricular fibrillation) or non-inducibility for monomorphic VT with programmed ventricular stimulation using up to 4 extrastimuli. Mean follow-up duration was 9.4 months and the type of recurrence was catalogued in 3 categories: initial VT (isolated), electric storm and other sustained VT. Results The overall acute success rate was 93%, complete non-inducibility was achieved in 64.5% and non-inducibility for monomorphic VT in 87.5% of the cases. Epicardial approach was used in 44% of the non-ischemic cases vs 10.5% of the ischemic ones (p = 0.005). There were no significant differences between complete noninducibility rates and recurrence/death rates of the ischemic vs nonischemic groups. Among the variables analysed for predicting noninducibility, only two reached statistical significance: mean QRS duration of the clinical tachycardia (160 ± 32 ms vs 240 ± 63.3ms, p = 0.02) and shortest RS complex (124 ± 14.7 ms vs 210 ± 12ms, p = 0.02). Recurrent ventricular arrhythmia occurred in 25% of the patients during follow up, from which: 27.2 % initial VT (isolated), 36.4% electric storm and 36.4% other sustained VT. Death rate was 10.6% (7 patients). Kaplan Meier plot showed that the lot with complete noninducibility after programmed ventricular stimulation had better survival rates (p = 0.01). Conclusions Ablative therapy had a good acute success rate, without significant differences between ischemic and noninschemic patients in our study. Complete noninducibility after programmed ventricular stimulation after ablation was associated with better survival rates. Unsuccessfull ablation is a predictor of inhospital death of these patients.

Ablation of Ventricular Arrhythmias From the Left Ventricular Apex in Patients Without Ischemic Heart Disease.

This study aimed to characterize the incidence, clinical characteristics, and electrocardiographic and electrophysiologic features of LVA VA in the absence of CAD and to describe the experience with catheter ablation (CA) in this group. The left ventricular apex (LVA) is a well-described source of ventricular arrhythmias (VAs) in patients with coronary artery disease (CAD) and history of apical infarction but is a rare source of VA in the absence of CAD. Patients referred for CA of VA at our institution were retrospectively reviewed, and those with LVA VA in the absence of CAD were identified. Of 3,710 consecutive patients undergoing VA ablation, CA of LVA VA was performed in 24 patients (20 with monomorphic ventricular tachycardia, 4 with premature ventricular contractions or nonsustained ventricular tachycardia; 18 men; mean age: 54 ± 15 years). These cases comprised 10 of 35 (29%) hypertrophic cardiomyopathy, 9 of 789 (1.2%) nonischemic cardiomyopathy, and 5 of 1,432 (0.4%) idiopathic VA ablation procedures. VA QRS morphology was predominantly right bundle with slurred upstroke and right superior frontal plane axis with precordial transition≤V3. Epicardial ablation was performed in 14 of 24 (58%). After a median of 1 procedure (range 1 to 4) at this institution and median follow-up of 47months (range 0-176), VA recurred in 1 patient (4%). LVA VA in the absence of CAD is unusual and may occur in patients with hypertrophic cardiomyopathy or nonischemic cardiomyopathy or, rarely, in the absence of structural heart disease. It can be recognized by characteristic ECG features. CA of LVA VA is challenging; multiple procedures, including epicardial approaches, may be required to achieve VA control over long-term follow-up.

QTc dispersion as a novel marker in identifying patients requiring an epicardial approach for ablation of scar mediated ventricular tachycardia

IntroductionEpicardial exit sites of ventricular tachycardia (VT) are frequently encountered during VT ablation requiring an epicardial ablation approach for successful elimination of VT. We sought to assess the utility of repolarization markers in identifying individuals requiring an epicardial ablation approach in addition to an endocardial approach. Methods32 patients who underwent successful ablation for scar mediated VT were included in the study. Fourteen patients who required a combined endocardial and epicardial VT ablation were defined as epicardial VT group (Epi) whereas 18 patients who were successfully ablated from the endocardium alone constituted the endocardial VT group (Endo). Repolarization markers during sinus rhythm were compared between the two groups. ResultsA higher QTc max and QTc dispersion were seen in the Epi group compared to Endo group (479 ± 34 vs 449 ± 20, p = 0.008 and 63 ± 13 vs 38 ± 8, p = 0.001, respectively). Ts-p and Ts-p/Tp-e were higher in the Epi group (166 ± 23 vs 143 ± 23, p = 0.008 and 1.55 ± 0.26 vs 1.3 ± 0.21, p < 0.005). On multivariate regression, QTc dispersion was an independent predictor of the need for an epicardial approach to ablation. A QTc dispersion more than 51.5 msec identified individuals requiring a combined epicardial and endocardial approach to ablation with a sensitivity of 92.9% and a specificity of 100%. ConclusionsPatients requiring an epicardial ablation have a higher QTc dispersion. A value greater than 51.5 msec reliably differentiates between the two groups with high sensitivity and specificity.

SURGICAL VERSUS TRANSVENOUS PACING OUTCOMES IN ADULT CONGENITAL HEART DISEASE

Adults with congenital heart disease (ACHD) often require cardiac implantable electronic devices (CIED). To date, there is no data comparing transvenous (TV) or epicardial (EPI) approaches in an exclusively adult population. A retrospective review was performed for all CIED implants at the Ahmanson

Role of the Left Atrial Appendage in Systemic Homeostasis, Arrhythmogenesis, and Beyond.

The left atrial appendage (LAA) affects body homeostasis via atrial natriuretic peptide and the renin-angiotensin-aldosterone system and plays an important role in atrial compliance. Approximately 90% of clots in nonvalvular atrial fibrillation (AF) are formed in the LAA. AF is the most common sustained cardiac arrhythmia and is frequently associated with stroke. Because anticoagulation for stroke prophylaxis carries a higher bleeding risk, LAA closure via epicardial and endocardial approaches has gained popularity and is being increasingly pursued for arrhythmogenic, homeostatic, and stroke-reduction benefits. This review discusses the homeostatic role of the LAA and its involvement in arrhythmogenesis and thrombus formation.

Modulation of SERCA in Patients with Persistent Atrial Fibrillation Treated by Epicardial Thoracoscopic Ablation: The CAMAF Study.

Objectives: To evaluate atrial fibrillation (AF) recurrence and Sarcoplasmic Endoplasmic Reticulum Calcium ATPase (SERCA) levels in patients treated by epicardial thoracoscopic ablation for persistent AF. Background: Reduced levels of SERCA have been reported in the peripheral blood cells of patients with AF. We hypothesize that SERCA levels can predict the response to epicardial ablation. Methods: We designed a prospective, multicenter, observational study to recruit, from October 2014 to June 2016, patients with persistent AF receiving an epicardial thoracoscopic pulmonary vein isolation. Results: We enrolled 27 patients. Responders (n = 15) did not present AF recurrence after epicardial ablation at one-year follow-up; these patients displayed a marked remodeling of the left atrium, with a significant reduction of inflammatory cytokines, B type natriuretic peptide (BNP), and increased levels of SERCA compared to baseline and to nonresponders (p < 0.05). Furthermore, mean AF duration (Heart rate (HR) 1.235 (1.037–1.471), p < 0.05), Left atrium volume (LAV) (HR 1.755 (1.126–2.738), p < 0.05), BNP (HR 1.945 (1.895–1.999), p < 0.05), and SERCA (HR 1.763 (1.167–2.663), p < 0.05) were predictive of AF recurrence. Conclusions: Our data indicate for the first time that baseline values of SERCA in patients with persistent AF might be predictive of failure to epicardial ablative approach. Intriguingly, epicardial ablation was associated with increased levels of SERCA in responders. Therefore, SERCA might be an innovative therapeutic target to improve the response to epicardial ablative treatments.

High-Density Grid Catheter forDetailedMappingofSinusRhythm and Scar-Related Ventricular Tachycardia: Comparison With a Linear Duodecapolar Catheter.

This study aimed to evaluate the feasibility and accuracy of using a novel grid mapping catheter during scar-related ventricular tachycardia (VT) ablation. Ultra-high-density (UHD) mapping improves identification of local abnormal ventricular activities (LAVAs) and characterization of scar substrates. Consecutive patients underwent endocardial and/or epicardial ablation guided by a HD grid mapping catheter. A linear duodecapolar catheter was used in the initial cases for systematic correlation. Isochronal late activation mapping was performed during sinus rhythm to identify deceleration zones, and activation mapping of VT was performed when tolerated. In 38 patients, 51 electroanatomic maps (left ventricle: 26, epicardium: 21, right ventricle: 4) were created using a grid catheter. LAVAs were identified in 98% of cases and deceleration zones were observed in 86%. High-frequency electrograms with diastolic activation were identified during 44 sustained monomorphic VTs, and the critical isthmus was colocalized to deceleration zones during sinus rhythm in 96% of cases. In 17 cases that underwent sequential mapping with both grid and linear catheters, the low voltage area detected using the grid (HD wave) was significantly smaller, with ratios of 0.61 (<0.5mV) and 0.81 (<1.5mV) relative to the duodecapolar catheter. VT ablation guided by a novel HD grid catheter is safe and feasible for clinical use in human scar-related VT via both endocardial and epicardial approaches. Automated selection of larger bipolar amplitudes among orthogonal pairs consistently displayed smaller low voltage areas than a previously validated linear catheter.

Impact of the inflammation on the outcomes of catheter ablation of drug-refractory ventricular tachycardia in cardiac sarcoidosis.

Catheter ablation (CA) of ventricular tachycardia (VT) in cardiac sarcoidosis (CS) has been reported with varying success. However, there is a scarcity of data on the outcomes of CA based on ongoing inflammation. We hypothesized that the response to VT ablation depends upon the stage of the disease. Between July 2004 and December 2018, 24 patients of CS presented with drug-refractory VT at CARE Hospital (Hyderabad) and the University of Minnesota (Minneapolis, MN). Patients were classified into two groups based on cardiac magnetic resonance imaging and positron emission tomography: (a) inflammatory phase, (b) scar phase. All patients underwent 3D electro-anatomic mapping guided CA. The clinical VT was ablated in all but one patient. In 16 patients (66.6%), both the clinical and nonclinical VTs were ablated (complete success), while in seven patients (29.1%) nonclinical VTs was still inducible. In patients with inflammation (group A), complete success for VT ablation was achieved in 10 out of 17 (58.8%). In patients without inflammation (group B), complete success was achieved in six out of seven patients (85.7%). Eleven patients (45.8%) had a recurrence of VT. Among patients in the inflammatory phase (group A): 10 out of 17 patients had a recurrence of VT, while only one out of seven patients in the scar phase (group B) had VT recurrence over a mean follow-up of 5.7 ± 3.9 years. Epicardial ablation was performed in 10 (41.6%) patients. CA of drug-refractory VT in CS is effective, often requiring the epicardial approach. Incomplete success and recurrence of VT werehigher in the inflammatory phase of the disease.

The influence of epicardial and endocardial use of cryoenergy on the completeness of lesions in surgical ablation of atrial fibrillation.

IntroductionCryoenergy is the most commonly used method of lesion formation in patients who have undergone surgical ablation of atrial fibrillation. Despite frequent use, the clinical effect of cryoenergy in endocardial and epicardial approaches is unknown.AimTo compare the effect of various cryoenergy applications on the postoperative incidence of sinus rhythm and completeness of lesions performed.Material and methodsA total of 55 patients underwent concomitant atrial fibrillation surgical ablation using cryoenergy under various conditions: epicardially during cardiac arrest, epicardially on beating heart, and endocardially. In the postoperative period, patients were invited to attend an electrophysiological examination to assess the completeness of surgical ablation lesions and, if necessary, to complete catheter ablation.ResultsTwenty-four patients underwent epicardial ablation on the arrested heart (group 1), 12 patients underwent epicardial ablation on the beating heart (group 2), and 19 patients underwent endocardial ablation (group 3). In the electrophysiological examination, sinus rhythm was present in 71% vs. 83% vs. 89% of patients, respectively. The completeness of pulmonary vein isolation was confirmed in 31% vs. 25% vs. 95% of patients, complete box lesions in 15% vs. 0% vs. 79% of patients, respectively.ConclusionsDespite the similar clinical effect of surgical ablation in all three approaches, the morphologically most effective use of cryoenergy is endocardial ablation. This approach has a very good result. Our findings further support the endocardial use of cryoenergy during surgical ablation of atrial fibrillation.