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Background: Dofetilide is a class III antiarrhythmic agent approved for the treatment of atrial fibrillation and atrial flutter. Given the efficacy of other class III agents, it has been used off‐label for the treatment of premature ventricular complexes (PVCs) and ventricular tachycardias (VTs). Objective: The purpose of this study was to determine the efficacy and safety of dofetilide for ventricular arrythmias (VAs). Methods: In this retrospective cohort study, 81 patients (59 men; age = 60 ± 14 years; LVEF = 0.34 ± 0.16) were admitted for dofetilide initiation to treat PVCs (29), VTs (42) or both (10). A ≥ 80% decrease in PVC burden was defined as a satisfactory response. An ICD was present in 72 patients (89%). Another antiarrhythmic was previously used in 50 patients (62%). Prior catheter ablation had been performed in 33 patients (41%). Results: During intitiation, dofetilide was discontinued in 12 patients (15%) due to QT prolongation (8) and inefficacy to suppress VAs (4). Among the 32 patients with PVCs who successfully started dofetilide, the mean PVC burden decreased from 20 ± 10% to 8 ± 8% at a median follow‐up of 2.6 months (p <.001). PVC burden was reduced by ≥80% in only 11/32 patients (34%). During 7 ± 1 years of follow‐up, 41/69 patients (59%) continued to have VAs and received appropriate ICD therapies for monomorphic VTs (35) and polymorphic VT/VF (6) at a median of 8.0 (IQR 2.6–33.2) months. Dofetilide had to be discontinued in 50/69 patients (72%) due to inefficacy or intolerance. The composite outcome of VT/VF recurrence, heart transplantation, or death occurred in 6/12 patients (50%) without dofetilide and 49/69 patients (71%) with dofetilide. The event free survival was similar between patients treated with and without dofetilide (log‐rank p =.55). Conclusions: Treatment with dofetilide was associated with a decrease in PVCs, however clinically significant suppression occurred in a minority of patients. Dofetilide failed to suppress the occurrence of VTs in a majority of patients. [ABSTRACT FROM AUTHOR]

Introduction: Bicuspid aortic valves (BAV) are the most common congenital heart defects and the extent of ventricular arrhythmias (VA) in patients with BAV is unclear. The objective of this study is to describe VAs and late gadolinium enhancement cardiac magnetic resonance imaging (LGE‐CMR) in patients with BAV. Methods: A total of 19 patients with BAV (18 males, age: 58 ± 13 years) were referred for VA ablation procedures. Ten patients had BAVs at the time of ablation, nine patients had prior aortic valve replacement for a BAV. All but one patient had LGE‐CMR and all patients underwent programmed ventricular stimulation at the time of the ablation. Results: Frequent PVCs were the targeted VAs in 17/19 patients and VT in 2/19 patients. Monomorphic ventricular tachycardia (VT) was inducible in 6 patients. A total of 15 VTs were inducible (2.5 ± 1.0 VTs per patient with a mean cycle length of 322 ± 83 msec). LGE was present in 13 patients. Patients with inducible VT had larger borderzone and core scar compared to non‐inducible patients (7.8 ± 2.1 cm3 vs. 2.5 ± 3.1 cm3 and 5.1 ± 2.6 cm3 vs. 1.9 ± 3.0 cm3, p‐value <.05 for both). PVCs and VTs were mapped to the periaortic valve area in 12 patients and 4 patients, respectively. The PVC burden was reduced from 27 ± 13 to 3 ± 6 (p <.001) and the ejection fraction improved from 49 ± 13% to 55 ± 9% (p =.005). Conclusions: VAs in patients with BAV often originate from the perivalvular area and patients often have LGE and inducible VT. LGE may be due to ventricular remodeling secondary to the presence of BAV and harbors the arrhythmogenic substrate for VT. [ABSTRACT FROM AUTHOR]

This document is a letter published in the Journal of Interventional Cardiac Electrophysiology. The letter discusses the safety and hemodynamic implications of using transseptal access for ventricular tachycardia (VT) ablation in patients with left ventricular assist devices (LVADs). The study included 15 patients who underwent VT ablation procedures with transseptal access. The results showed that transseptal access was straightforward and complications were infrequent. Post-procedure evaluations did not show any significant shunting or persistent atrial septal defects. The study suggests that transseptal access for VT ablation in LVAD patients is generally safe and prophylactic atrial septal defect closure is unnecessary. [Extracted from the article]

Background: Programed ventricular stimulation (PVS) is a risk stratification tool in patients at risk for adverse arrhythmia outcomes. Patients with negative PVS may yet be at risk for adverse arrhythmia‐related events, particularly in the presence of symptomatic ventricular arrhythmias (VA). Objective: To investigate the long‐term outcomes of real‐world patients with symptomatic VA without indication for device therapy and negative PVS, and to examine the role of cardiac scaring on arrhythmia recurrence. Methods: Patients with symptomatic VA, and late gadolinium enhancement cardiac magnetic resonance imaging (LGE‐CMR), and negative PVS testing were included. All patients underwent placement of implantable cardiac monitors (ICM). Survival analysis was performed to investigate the impact of LGE‐CMR findings on survival free from adverse arrhythmic events. Results: Seventy‐eight patients were included (age 60 ± 14 years, women n = 36 (46%), ejection fraction 57 ± 9%, cardiomyopathy n = 26 (33%), mitral valve prolapse [MVP] n = 9 (12%), positive LGE‐CMR scar n = 49 (62%), history of syncope n = 23 (29%)) including patients with primarily premature ventricular contractions (n = 21) or nonsustained VA (n = 57). Patients were followed for 1.6 ± 1.5 years during which 14 patients (18%) experienced VA requiring treatment (n = 14) or syncope due to bradycardia (n = 2). Four/9 patients (44%) with MVP experienced VA (n = 3) or syncope (n = 1). Baseline characteristics between those with and without adverse events were similar (p > 0.05); however, the presence of cardiac scar on LGE‐CMR was independently associated with an increased risk of adverse events (hazard ratio: 5.6 95% confidence interval: [1.2–27], p = 0.03, log‐rank p = 0.03). Conclusions: In a real‐world cohort with long‐term follow‐up, adverse arrhythmic outcomes occurred in 18% of patients with symptomatic VA despite negative PVS, and this risk was significantly greater in patients with positive DE‐CMR scar. Long term‐monitoring, including the use of ICM, may be appropriate in these patients. [ABSTRACT FROM AUTHOR]

This article discusses the incidence of post-implant ventricular arrhythmias (VAs) in patients with left ventricular assist devices (LVADs). The study compared the HeartMate 3 (HM3) LVAD to other LVAD types and found that patients with HM3 implants were less likely to experience VAs. The reduction in VAs may be attributed to the HM3 device's pulsitility and fully magnetically levitated rotor. The study suggests that device type and flow technology may play a role in reducing the negative effects of LVAD implantation. However, further research is needed to fully understand the mechanisms behind this reduction. [Extracted from the article]

Introduction: Variants of cardiomyopathy genes in patients with nonischemic cardiomyopathy (NICM) generate various phenotypes of cardiac scar and delayed enhancement cardiac magnetic resonance (DE‐CMR) imaging which may impact ventricular tachycardia (VT) management. Methods: The objective was to compare the findings of cardiomyopathy genetic testing on DE‐CMR imaging and long‐term outcomes among patients with NICM undergoing VT ablation procedures. Image phenotyping and genotyping were performed in a consecutive series of patients referred for VT ablation and correlated to survival free of VT. Scar depth index (SDI) (% of scar at 0‐3 mm, 3‐5 mm and >5 mm projected on the closest endocardial surface) was determined. Results: Forty‐three patients were included (11 women, 55 ± 14 years, ejection fraction (EF) 45 ± 16%) and were followed for 3.4 ± 2.9 years. Pathogenic variants (PV) were identified in 16 patients (37%) in the following genes: LMNA (n = 5), TTN (n = 5), DSP (n = 2), AMLS1 (n = 1), MYBPC3 (n = 1), PLN (n = 1), and SCN5A (n = 1). A ring‐like septal scar (RLSS) pattern was more often seen in patients with pathogenic variants (66% vs 15%, p =.001). RLSS was associated with deeper seated scars (SDI >5 mm 30.6 ± 22.6% vs 12.4 ± 16.2%, p =.005), and increased VT recurrence (HR 5.7 95% CI[1.8‐18.4], p =.003). After adjustment for age, sex, EF, and total scar burden, the presence of a PV remained independently associated with worse outcomes (HR 4.7 95% CI[1.22‐18.0], p =.02). Conclusions: Preprocedural genotyping and scar phenotyping is beneficial to identify patients with a favorable procedural outcome. Some PVs are associated with an intramural, deeper seated scar phenotype and have an increase of VT recurrence after ablation. [ABSTRACT FROM AUTHOR]

Background: Frequent premature ventricular complexes (PVCs) can cause PVC-induced cardiomyopathy. The value of PVC ablation in patients with preserved left ventricular function in the low–normal range (ejection fraction: 50–55%) is not established. Strain analysis has been used to estimate changes in left ventricular function beyond assessment of the ejection fraction (EF). Longitudinal strain has been proposed as a method to detect changes over time in the setting of frequent asymptomatic premature ventricular complexes and preserved left ventricular (LV) function. A decrease in strain may be evidence of PVC-induced cardiomyopathy. Objective: In this study, we assessed the role of PVC ablation in patients with low–normal EF and the effect on EF and myocardial strain before and after PVC ablation. Methods: A total of 70 consecutive patients with either low–normal EF (0.5–<0.55, n = 35) or high–normal EF (≥0.55; n = 35), using available imaging and Holter data, were referred for ablation due to frequent PVCs. EF and longitudinal strain were assessed pre- and post-ablation. Results: There was a significant increase in EF (53.2 ± 0.4% to 58.3 ± 0.5%, p < 0.001) and improvement in longitudinal strain (−15.2 ± 3.3 to −16.6 ± 3, p = 0.007) post-ablation in patients with low–normal EF and successful ablation. There was no change in EF or longitudinal strain in patients with high–normal EF and a successful ablation pre- vs. post-ablation. Conclusions: Patients with frequent PVCs and low–normal LV EF compared to patients with frequent PVCs and high–normal LV EF have evidence of PVC-induced cardiomyopathy and may benefit from ablation despite a preserved left ventricular EF. [ABSTRACT FROM AUTHOR]

Introduction: Thromboembolic events after catheter ablation of ventricular tachycardia (VT) can result in significant morbidity. Thromboembolic prophylaxis after catheter ablation can be achieved by the use of antiplatelet agents, vitamin K antagonists, or direct oral anticoagulants (DOACs). The relative safety and efficacy of these modes of prophylaxis are uncertain. We sought to compare the outcomes of patients who received warfarin or DOACs for thromboembolic prophylaxis after catheter ablation of VT. Methods and Results: Anticoagulation with DOACS was started after left ventricular VT ablation in a series of 42 consecutive patients with structural heart disease (67 ± 11 years, 3 women, ejection fraction 32 ± 14%). Duration of hospital stay, bleeding episodes, and thromboembolic events were compared to a historic consecutive group of patients (n = 38, 65 ± 13 years, 14 women, ejection fraction 36 ± 13%) in whom anticoagulation with a formerly described protocol of heparin and vitamin K antagonist was used after VT ablation procedures. Hospital stay was significantly shorter in the group where DOACs were used as compared to vitamin K antagonists (3.3 ± 1.8 vs. 5.0 ± 2.5 days postablation; p = 0.001) without an increase of bleeding or thromboembolic events. Conclusion: Anticoagulation with DOACs is safe and shortens hospital stay in patients with structural heart disease undergoing left ventricular VT ablation procedures. [ABSTRACT FROM AUTHOR]

Introduction: Transseptal puncture (TSP) is routinely performed for left atrial ablation procedures. The use of a three‐dimensional (3D) mapping system or intracardiac echocardiography (ICE) is useful in localizing the fossa ovalis and reducing fluoroscopy use. We aimed to compare the safety and efficacy between 3D mapping system‐guided TSP and ICE‐guided TSP techniques. Methods: We conducted a prospective observational study of patients undergoing TSP for left atrial catheter ablation procedures (mostly atrial fibrillation ablation). Propensity scoring was used to match patients undergoing 3D‐guided TSP with patients undergoing ICE‐guided TSP. Logistic regression was used to compare the clinical data, procedural data, fluoroscopy time, success rate, and complications between the groups. Results: Sixty‐five patients underwent 3D‐guided TSP, and 151 propensity score‐matched patients underwent ICE‐guided TSP. The TSP success rate was 100% in both the 3D‐guided and ICE‐guided groups. Median needle time was 4.00 min (interquartile range [IQR]: 2.57–5.08) in patients with 3D‐guided TSP compared to 4.02 min (IQR: 2.83–6.95) in those with ICE‐guided TSP (p =.22). Mean fluoroscopy time was 0.2 min (IQR: 0.1–0.4) in patients with 3D‐guided TSP compared to 1.2 min (IQR: 0.7–2.2) in those with ICE‐guided TSP (p <.001). There were no complications related to TSP in both group. Conclusions: Three‐dimensional mapping‐guided TSP is as safe and effective as ICE‐guided TSP without additional cost. [ABSTRACT FROM AUTHOR]

With the increasing literature demonstrating benefits of catheter ablation for ventricular tachycardia (VT), the number of patients undergoing VT ablation has increased dramatically. As VT ablation is being performed more routinely, operators must be aware of potential complications of VT ablation. This review delves deeper into the practice of VT ablation with a focus on periprocedural complications. [ABSTRACT FROM AUTHOR]

Of the patients with VA recurrence who had been discharged on amiodarone after LVAD, 12 had stopped amiodarone prior to their first VA. Given the support of catheter ablation in non-LVAD population, larger prospective trials on the benefits of catheter ablation in LVAD patients would be helpful to guide optimal management in this challenging patient population. Furthermore, many patients with LVADs continue to have recurrence of VAs, and recurrent ICD therapies can cause significant morbidity and lower quality of life in LVAD patients. [Extracted from the article]

Introduction: Monitored anesthesia care (MAC) or general anesthesia (GA) can be used during catheter ablation (CA) of atrial fibrillation (AF). However, each approach may have advantages and disadvantages with variability in operator preferences. The optimal approach has not been well established. The purpose of this study was to compare procedural efficacy, safety, clinical outcomes, and cost of CA for AF performed with MAC versus GA. Methods: The study population consisted of 810 consecutive patients (mean age: 63 ± 10 years, paroxysmal AF: 48%) who underwent a first CA for AF. All patients completed a preprocedural evaluation by the anesthesiologists. Among the 810 patients, MAC was used in 534 (66%) and GA in 276 (34%). Ten patients (1.5%) had to convert to GA during the CA. Results: Although the total anesthesia care was longer with GA particularly in patients with persistent AF, CA was shorter by 5 min with GA than MAC (p < 0.01). Prevalence of perioperative complications was similar between the two groups (4% vs. 4%, p = 0.89). There was no atrioesophageal fistula with either approach. GA was associated with a small, ~7% increase in total charges due to longer anesthesia care. During 43 ± 17 months of follow‐up after a single ablation procedure, 271/534 patients (51%) in the MAC and 129/276 (47%) patients in the GA groups were in sinus rhythm without concomitant antiarrhythmic drug therapy (p = 0.28). Conclusion: With the participation of an anesthesiologist, and proper preoperative assessment, CA of AF using GA or MAC has similar efficacy and safety. [ABSTRACT FROM AUTHOR]

Introduction: Ventricular tachycardia (VT) in structurally normal hearts or nonischemic cardiomyopathy can originate from the aortic sinuses of Valsalva (SoV). It is unknown whether VT can originate from the SoVs in patients with prior myocardial infarction (MI). Objective: To evaluate the prevalence, arrhythmogenic substrate, and ablation outcomes of postinfarction VT originating from the SoVs. Methods: Among 217 consecutive patients with postinfarction VT undergoing ablation, we identified 13 (6%) patients who had ≥1 VT mapped in a SoV. Control groups of 13 patients with idiopathic SoV VT and 13 postinfarction patients without SoV VT were included. Results: In the study group, 17 VTs were mapped in a SoV (right n = 5, left‐right commissure n = 6, left n = 6). SoV VT target sites had low bipolar voltage during sinus rhythm [median 0.42 (IQR: 0.16–0.53) mV] which was significantly lower than target sites in patients with idiopathic SoV VTs [median 1.02 (IQR: 0.89–1.52) mV; p <.001]. An area of endocardial low voltage was found below the aortic valve in all patients with postinfarction SoV VTs compared to 9 (69%) of the patients in the postinfarction control group without SoV VT (p =.02). Morphology characteristics of postinfarction SoV VTs differed from idiopathic SoV VTs. None of the postinfarction SoV VTs were inducible after ablation and none recurred after a median follow‐up of 14 months. Conclusion: In patients with prior MI, VT can be targeted in an aortic SoV. The SoVs should be routinely investigated in postinfarction patients with inferior axis VT and an area of low voltage below the aortic valve. [ABSTRACT FROM AUTHOR]

Background: Focal ventricular arrhythmias (VAs) originating from the intramural myocardium of the basal septum are difficult to localize and ablate. Proximal septal veins emptying into the great cardiac vein can reach close to the origin of intramural arrhythmias. Objective: To assess characteristics of proximal septal coronary veins in patients with intramural VAs. Methods and Results: Among 84 consecutive patients with intramural VAs, 29 patients (age 60 ± 11years, 16 males, ejection fraction 47 ± 13%) underwent preprocedural cardiac computed tomographic angiography (CTA). In 14 of these patients, the intramural site of origin (SOO) was identified with multipolar catheters. The intramural SOO could not be accessed with mapping catheters in the other 15 patients while mapping the coronary venous system. The CTA identified sizable proximal septal veins in all patients in whom the SOO could be accessed with mapping catheters. In the patients in whom the intramural SOO was not identified, the proximal septal veins were often either small (<2 mm at the branching site) or non‐existent (n = 9, p =.001). The proximal septal veins in patients in whom the SOO was identified were larger than in the patients in whom the SOO could not be identified (3.0 ± 0.6 mm vs. 2.1 ± 0.9 mm, p =.01). Conclusions: Preprocedural imaging with CTAs can be beneficial in identifying the anatomy of proximal septal coronary veins that allow adequate mapping of patients with suspected intramural VAs. [ABSTRACT FROM AUTHOR]

Introduction: Cardiac resynchronization therapy (CRT) and left ventricular assist devices (LVAD) improve outcomes in heart failure patients. Early ventricular arrhythmias (VA) are common after LVAD and are associated with increased mortality. The association between left ventricular pacing (LVP) with CRT and VAs in the early post‐LVAD period remains unclear. Methods: This was a retrospective study of all patients undergoing LVAD implantation from 1/2016 to 12/2019. Patients were divided into those with CRT and active LVP (CRT‐LVP) immediately post‐LVAD implant versus those without CRT‐LVP. Implantable cardiac defibrillator electrograms were reviewed and early VAs were defined as sustained ventricular tachycardia (VT)/ventricular fibrillation occurring within 30 days of LVAD implantation. Results: Of 186 included patients (mean age 53 years, 75% male, mean body mass index 28), 72 had CRT devices, 63 of whom had LV pacing enabled after LVAD implant (CRT‐LVP group). Patients with CRT‐LVP were more likely to have VA in the early postoperative period (21% vs. 4%; p =.0001). All 9 patients with CRT in whom LVP was disabled had no early VA. Among those with early VA, patients with CRT‐LVP were more likely to have monomorphic VT (77% vs. 40%; p =.07). In multiple logistic regression, CRT‐LVP pacing remained an independent predictor of early VA after adjustment for history of VA and AF. Conclusions: Patients with CRT‐LVP after LVAD implant had a higher incidence of early VA (specifically monomorphic VT). Epicardial LV pacing may be proarrhythmic in the early postoperative period after LVAD. [ABSTRACT FROM AUTHOR]

Background: Intramural ventricular arrhythmias (VAs) can originate in patients with or without structural heart disease. Electrogram (EGM) recordings from intramural sources of VA have not been described thoroughly. Objective: We hypothesized that the presence of scar may be linked to the site of origin (SOO) of focal, intramural VAs. Methods: In a series of 21 patients (age: 55 ± 11 years, 12 women, mean ejection fraction 43 ± 14%) in whom the SOO of intramural VAs was identified, we analyzed bipolar EGM characteristics at the SOO and compared the findings with the endocardial breakout site. The patients were from a pool of 86 patients with intramural VAs referred for ablation. Results: In 16/21 patients intramural scarring was detected by cardiac magnetic resonance (CMR) imaging In patients in whom the intramural SOO was reached, intramural bipolar EGMs showed a lower voltage and had broader EGMs compared to the endocardial breakout sites (0.97 ± 0.56 vs. 2.28 ± 0.15 mV, p =.001; and 122.3 ± 31.6 vs. 96.5 ± 26.3 ms, p <.01). All intramural sampled sites at the SOO had either low voltage or broad abnormal EGMs. The activation time was significantly earlier at the intramural SOO than at breakout sites (−36.2 ± 11.8 vs. −23.2 ± 9.1 ms, p <.0001). Conclusions: Sites of origin of intramural VAs with scar by CMR display EGM characteristics of scarring, supporting that scar tissue localizes to the SOO of intramural outflow tract arrhythmias in some patients. Scarring identified by CMR may be helpful in planning ablation procedures in patients with suspected intramural VAs. [ABSTRACT FROM AUTHOR]

Background: Late gadolinium enhancement cardiac magnetic resonance (LGE‐CMR) imaging distinguishes between intrinsic postinfarction scar and radiofrequency ablation lesion related scar (dark core lesions [DCLs]) in patients with prior ventricular tachycardia (VT) ablation procedures. Objective: To combine LGE‐CMR and electroanatomic mapping data to describe the relationship between DCLs and recurrent VT among patients undergoing repeat ablations for postinfarction VT. Methods: Consecutive patients with repeat ablation for postinfarct VT with LGE‐CMR before the repeat procedures were studied. Prior ablation procedures and implantable cardiac defibrillator electrograms were analyzed to determine new versus previously documented VT. DCLs were identified on preprocedure LGE‐CMR and registered to electroanatomic maps. A control group of patients undergoing repeat ablation procedures without imaging was included. Results: Nineteen study patients and 14 control patients were followed for 2.6 (1.6–5.6) years (31 [94%] men, age 65.8 ± 8.4 years, ejection fraction 24.7 ± 10.3, p > 0.10 for all). DCLs corresponded to unexcitable tissue during repeat procedures (area 22.4 ± 15.1 vs. 22.9 ± 16.8 cm3, correlation coefficient =.93). Most VT target sites (39/50 [78%]) were in close proximity (<1 cm) to DCLs. Most DCL related VTs 32/39 (82%) were new VTs. Patients with LGE‐CMR imaging incorporated into their ablation procedures had improved 24‐month survival from VT (64% vs. 38%, log rank p < 0.02). Conclusion: LGE‐MRI can identify prior ablation lesions corresponding to nonexcitable tissue during repeat ablation procedures for postinfarction VT. VT target sites are often located in close proximity to the DCL area that may function as a fixed border for reentry circuits. Registration of DCL from prior ablation may facilitate repeat ablation procedures. [ABSTRACT FROM AUTHOR]

Introduction: Quinidine is an effective therapy for a subset of polymorphic ventricular tachycardia and ventricular fibrillation (VF) syndromes; however, the efficacy of quinidine in scar‐related monomorphic ventricular tachycardia (MMVT) is unclear. Methods and Results: Between 2009 and 2020 a single VT referral center, a total of 23 patients with MMVT and structural heart disease (age 66.7 ± 10.9, 20 males, 15 with ischemic cardiomyopathy, mean LVEF 22.2 ± 12.3%, 9 with left ventricular assist device [LVAD]) were treated with quinidine (14 quinidine gluconate; 996 ± 321 mg, 8 quinidine sulfate; 1062 ± 588 mg). Quinidine was used in combination with other antiarrhythmics (AAD) in 19 (13 also on amiodarone). All patients previously failed >1 AAD (amiodarone 100%, mexiletine 73%, sotalol 32%, other 32%) and eight had prior ablations (median of 1.5). Quinidine was initiated in the setting of VT storm despite AADs (6), inability to tolerate other AADs (4), or recurrent VT(12). Ventricular arrhythmias recurred despite quinidine in 13 (59%) patients at a median of 26 (4–240) days after quinidine initiation. In patients with recurrent MMVT, VT cycle length increased from 359 to 434 ms (p =.02). Six (27.3%) patients remained on quinidine at 1 year with recurrence of ventricular arrhythmias in all. The following adverse effects were seen: gastrointestinal side effects (6), QT prolongation (2), rash (1), thrombocytopenia (1), neurologic side effects (1). One patient discontinued due to cost. Conclusion: Quinidine therapy has limited tolerability and long‐term efficacy when used in the management of amiodarone‐refractory scar‐related MMVT. [ABSTRACT FROM AUTHOR]

Background: Sarcoidosis is an inflammatory disease characterized by the formation of granulomas, which involve the heart in up to 25% of patients. Cardiac sarcoidosis can lead to life threatening arrhythmias and heart failure. While corticosteroids have been used as a treatment for over 50 years, they are associated with hypertension, diabetes, and weight gain, further increasing cardiovascular risk. Interleukin-1 (IL-1) is the prototypical proinflammatory cytokine that works to activate the nuclear transcription factor NF-kB, one of the targets of glucocorticoids. IL-1 also plays an important role also in the pathophysiology of heart disease including atherosclerosis, myocardial infarction, and myocarditis.Methods: Building on a network of research collaborators developed in the Cardiac Sarcoidosis Consortium, we will investigate the feasibility and tolerability of treatment of CS with anakinra at two National Institute of Health Clinical and Translational Science Award (CTSA) hubs with expertise in cardiac sarcoidosis. In this pilot study, up to 28 patients with cardiac sarcoidosis will be recruited to compare the administration of an IL-1 blocker, anakinra, 100 mg daily on top of standard of care versus standard of care only for 28 days and followed for 180 days. Utilizing surrogate endpoints of changes in systemic inflammatory biomarkers and cardiac imaging, we aim to determine whether IL-1 blockade with anakinra can combat systemic and cardiac inflammation in patients with cardiac sarcoidosis.Discussion: The current trial demonstrates an innovative collaborative approach to clinical trial development in a rare, understudied disease that disproportionately affects females and minorities. Trial Registration The trial was registered prospectively with ClinicalTrials.gov on July 12, 2019, identifier NCT04017936. [ABSTRACT FROM AUTHOR]

Introduction: In patients with structural heart disease presenting with ventricular tachycardia (VT), detection of ventricular thrombi and subsequent management can be challenging. This study aimed to assess the value of multimodality imaging with cardiac magnetic resonance imaging (CMR), contrast‐enhanced transthoracic echocardiography (TTE), and computed tomography (CT) for thrombus detection as well as a management algorithm geared towards anticoagulation and deferred ablation for patients referred for VT ablation. Methods and results: A total of 154 consecutive patients referred for VT ablation underwent preprocedural multimodality imaging with CMR, CT, and TTE. In 9 patients (6%) a new ventricular thrombus was detected and anticoagulation was initiated. Thrombi were detected by CMR in nine patients, by CT in seven patients, and by TTE in two patients. Five patients eventually underwent endocardial VT ablation procedures 6.0 ± 2.0 months after initiation of anticoagulation with one patient also requiring an epicardial approach. Two patients died while on anticoagulation, unrelated to ventricular arrhythmia. Four of five patients were rendered non‐inducible and no testing was performed in 1/5 patients. Areas containing left ventricular thrombi were non‐excitable with pacing. Six of thirty‐two inducible VTs were mapped in close vicinity of ventricular thrombi. No clinical embolic events occurred during the ablation procedures. Conclusions: Ventricular thrombus was detected in 6% of consecutive patients with structural heart disease undergoing VT ablation. CMR was the most sensitive modality, while contrast‐enhanced TTE failed to detect the majority of thrombi. Anticoagulation followed by ablation can be safely and successfully performed in patients with ventricular thrombi. [ABSTRACT FROM AUTHOR]

Cardiovascular magnetic resonance (CMR) is a proven imaging modality for informing diagnosis and prognosis, guiding therapeutic decisions, and risk stratifying surgical intervention. Patients with a cardiac implantable electronic device (CIED) would be expected to derive particular benefit from CMR given high prevalence of cardiomyopathy and arrhythmia. While several guidelines have been published over the last 16 years, it is important to recognize that both the CIED and CMR technologies, as well as our knowledge in MR safety, have evolved rapidly during that period. Given increasing utilization of CIED over the past decades, there is an unmet need to establish a consensus statement that integrates latest evidence concerning MR safety and CIED and CMR technologies. While experienced centers currently perform CMR in CIED patients, broad availability of CMR in this population is lacking, partially due to limited availability of resources for programming devices and appropriate monitoring, but also related to knowledge gaps regarding the risk-benefit ratio of CMR in this growing population. To address the knowledge gaps, this SCMR Expert Consensus Statement integrates consensus guidelines, primary data, and opinions from experts across disparate fields towards the shared goal of informing evidenced-based decision-making regarding the risk-benefit ratio of CMR for patients with CIEDs. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) is a risk factor for atrial fibrillation (AF). The effect of antidiabetic medications on AF or the outcomes of catheter ablation (CA) has not been well described. We sought to determine whether metformin treatment is associated with a lower risk of atrial arrhythmias after CA in patients with DM and AF. Methods and Results: A first CA was performed in 271 consecutive patients with DM and AF (age: 65 ± 9 years, women: 34%; and paroxysmal AF: 51%). At a median of 13 months after CA (interquartile range: 6–30), 100/182 patients (55%) treated with metformin remained in sinus rhythm without antiarrhythmic drug therapy, compared with 36/89 patients (40%) not receiving metformin (p =.03). There was a significant association between metformin therapy and freedom from recurrent atrial arrhythmias after CA in multivariable Cox hazards models (hazard ratio [HR]: 0.66; ±95% confidence interval [CI]: 0.44–0.98; p =.04) that adjusted for age, sex, body mass index, AF type (paroxysmal vs. nonparoxysmal), antiarrhythmic medication, obstructive sleep apnea, chronic kidney disease, coronary artery disease, left ventricular ejection fraction, and left atrial diameter. A Cox model that also incorporated other antidiabetic agents and fasting blood glucose demonstrated a similar reduction in the risk of recurrent atrial arrhythmias with metformin treatment (HR: 0.63; ±95% CI: 0.42–0.96; p =.03). Conclusions: In patients with DM, treatment with metformin appears to be independently associated with a significant reduction in the risk of recurrent atrial arrhythmias after CA for AF. Whether this effect is due to glycemic control or pleiotropic effects on electroanatomical mechanisms of AF remains to be determined. [ABSTRACT FROM AUTHOR]

Background: Lead damage is a complication caused by lead manipulation or heating damage from conventional electrocautery (EC) after cardiovascular implantable electronic device (CIED) replacement. Application of electrical plasma (PEAK PlasmaBlade) is a new technology that reportedly reduces this risk. Objectives: This study was designed to compare the effect of EC versus PEAK PlasmaBlade on lead parameters and complications after generator replacement procedures. Methods: We retrospectively studied 410 consecutive patients (840 leads) who underwent CIED replacement using EC (EC group) and 410 consecutive patients (824 leads) using PEAK PlasmaBlade (PlamaBlade group). Pacing lead impedance, incidence of lead damage, and complications were compared between both groups. Results: Lead impedance increased in 393 leads (46.8%) in the EC group versus 282 leads (34.2%) in the PlasmaBlade group (p <.01) with average percent changes of 6.7% and 4.0% (p <.01), respectively. Lead impedance decreased in 438 leads (52.1%) in the EC group versus 507 leads (61.5%) in the PlasmaBlade group (p <.01) with average percent changes of −5.7% and −7.1% (p <.01), respectively. Lead damage requiring lead revision occurred in five leads (0.6%) or after five procedures (1.2%) in the EC group compared to three leads (0.4%, p =.50) or after three procedures (0.7%, p =.48) in the PlasmaBlade group. There were no significant differences in the procedural‐related complications between the EC group (nine patients, 2.2%) and the PlasmaBlade group (five patients, 1.2%, p =.28). Conclusion: Conventional electrocautery can potentially damage lead insulations. However, this study shows that when used carefully electrocautery is as safe as the PEAK PlasmaBlade™. [ABSTRACT FROM AUTHOR]

This article discusses the use of cardiac magnetic resonance (CMR) imaging to identify arrhythmogenic substrates in patients with non-ischemic cardiomyopathy (NICM) undergoing ventricular tachycardia (VT) ablation procedures. The study compared CMR strain imaging to electroanatomic mapping (EAM) data and late-gadolinium-enhanced CMR (LGE-CMR) to assess its clinical utility. The results showed that CMR strain imaging had better agreement with EAM in identifying abnormal segments, compared to LGE-CMR. However, LGE-CMR still offers advantages such as 3D reconstructions of scar location and depth. Further research is needed to improve strain assessment and determine the optimal combination of imaging parameters for VT ablation procedures in NICM patients. [Extracted from the article]

Introduction: Left ventricular noncompaction (LVNC) is associated with ventricular arrhythmias (VA) including premature ventricular complexes, and ventricular tachycardia (VT). The value of imaging with delayed enhancement cardiac magnetic resonance (DE‐CMR) and programmed ventricular stimulation (PVS) for risk stratification in patients with VA and LVNC is unknown. The purpose of this study was to determine whether DE‐CMR and PVS are beneficial for risk stratification and whether CMR helps to identify VA target sites. Methods and Results: Consecutive patients with LVNC undergoing ablation for VAs were included, all patients had preprocedure DE‐CMR. A total of 23 patients (7 women, 46 ± 14 years, ejection fraction 35 ± 14) were included and followed for 2.9 ± 2.2 years. DE‐CMR scar was present in 12/23 patients (52%). PVS was performed in 20/23 patients, 8/10 patients (80%) with scar were inducible for VT compared to 0/10 (0%) patients without scar (p <.001). VA target sites in patients with scarring were located adjacent to areas of scarring in all but 1 patient and ablation was successful in 15/23 patients (65%). Patients with scar had worse survival free of VT than those without scar (log rank p =.01) and patients with inducible VT had worse survival free of VT than those who were noninducible (log rank p <.001). Conclusions: The presence of CMR defined scar in patients with LVNC was associated with inducible VT and worse outcomes. Inducibility for VT was associated with VT recurrence. Furthermore, CMR is beneficial in localizing the arrhythmogenic substrate in LVNC and therefore can aid in procedural planning. [ABSTRACT FROM AUTHOR]

Catheter ablation is an effective treatment method for ventricular arrhythmias (VAs). These arrhythmias can often be mapped and targeted with ablation from the left and right ventricular endocardium. However, in some situations the VA site of origin or substrate may be intramural or epicardial in nature. In these cases, the coronary venous system (CVS) provides an effective vantage point for mapping and ablation. This review highlights situations in which CVS mapping may be helpful and discusses techniques for CVS mapping and ablation. [ABSTRACT FROM AUTHOR]

The authors comment on a study published within the issue which examined the safety and efficacy outcomes of premature ventricular complexes (PVC) and ventricular tachycardia (VT) ablation among patients with prior mitral valve (MV) surgery. Topics covered include several issues identified by the study that can make catheter ablation more complicated and challenging, the strengths and limitations of the study, and the study's clinical implications.

Aims: Catheter ablation is an effective treatment for post-infarction ventricular tachycardia (VT). However, some patients may experience a worsened arrhythmia phenotype after ablation. We aimed to determine the prevalence and prognostic impact of arrhythmia exacerbation (AE) after post-infarction VT ablation.Methods and Results: A total of 1187 consecutive patients (93% men, median age 68 years, median ejection fraction 30%) who underwent post-infarction VT ablation at six centres were included. Arrhythmia exacerbation was defined as post-ablation VT storm or incessant VT in patients without prior similar events. During follow-up (median 717 days), 426 (36%) patients experienced VT recurrence. Events qualifying as AE occurred in 67 patients (6%). Median times to VT recurrence with and without AE were 238 [interquartile range (IQR) 35-640] days and 135 (IQR 22-521) days, respectively (P = 0.25). Almost half of the patients (46%) who experienced AE experienced it within 6 months of the index procedure. Patients with AE had had longer ablation times during the ablation procedures compared to the rest of the patients (median 42 vs. 34 min, P = 0.02). Among patients with VT recurrence, the risk of death or heart transplantation was significantly higher in patients with than without AE (hazard ratio 1.99, 95% CI 1.28-3.10; P = 0.002) after adjusting for age, gender, ejection fraction, cardiac resynchronization therapy, post-ablation non-inducibility, and post-ablation amiodarone use.Conclusion: Arrhythmia exacerbation after ablation of infarct-related VT is infrequent but is independently associated with an adverse long-term outcome among patients who experience a VT recurrence. The mechanisms and mitigation strategies of AE after catheter ablation require further investigation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aims: Cardiac sarcoidosis (CS) is a known cause of ventricular tachycardia (VT). However, an arrhythmogenic presentation may not prompt immediate comprehensive evaluation. We aimed to assess the diagnostic and disease course of patients with arrhythmogenic cardiac sarcoidosis (ACS).Methods and Results: From the Leiden VT-ablation-registry, consecutive patients with CS as underlying aetiology were retrospectively included. Data on clinical presentation, time-to-diagnosis, cardiac function, and clinical outcomes were collected. Patients were divided in early (<6 months from first cardiac presentation) and late diagnosis. After exclusion of patients with known causes of non-ischaemic cardiomyopathy (NICM), 15 (12%) out of 129 patients with idiopathic NICM were ultimately diagnosed with CS and included. Five patients were diagnosed early; all had early presentation with VTs. Ten patients had a late diagnosis with a median delay of 24 (IQR 15-44) months, despite presentation with VT (n = 5) and atrioventricular block (n = 4). In 6 of 10 patients, reason for suspicion of ACS was the electroanatomical scar pattern. In patients with early diagnosis, immunosuppressive therapy was immediately initiated with stable cardiac function during follow-up. Adversely, in 7 of 10 patients with late diagnosis, cardiac function deteriorated before diagnosis, and in only one cardiac function recovered with immunosuppressive therapy. Six (40%) patients died (five of six with late diagnosis).Conclusion: Arrhythmogenic cardiac sarcoidosis is an important differential diagnosis in NICM patients referred for VT ablation. Importantly, the diagnosis is frequently delayed, which leads to a severe disease course, including irreversible cardiac dysfunction and death. Early recognition, which can be facilitated by electroanatomical mapping, is crucial. [ABSTRACT FROM AUTHOR]

Background: Implanted defibrillators are capable of recording activity data based on company‐specific proprietary algorithms. This study aimed to determine the prognostic significance of baseline and decline in device‐derived activity level across different device companies in the real world. Methods: We performed a retrospective cohort study of patients (n = 280) who underwent a defibrillator implantation (Boston, Medtronic, St. Jude, and Biotronik) for primary prevention at the University of Michigan from 2014 to 2016. Graphical data obtained from device interrogations were retrospectively converted to numerical data. The activity level averaged over a month from a week postimplantation was used as baseline. Subsequent weekly average activity levels (SALs) were standardized to this baseline. SAL below 59.4% was used as a threshold to group patients. All‐cause mortality and death/heart failure were the primary end‐points of this study. Results: Fifty‐six patients died in this study. On average, they experienced a 50% decline in SAL prior to death. Patients (n = 129) who dropped their SAL below threshold were more likely to be older, male, diabetic, and have more symptomatic heart failure. They also had a significantly increased risk of heart failure/death (hazard ratio [HR] 3.6, 95% confidence interval [95% CI] 2.3‐5.8, P <.0001) or death (HR 4.2, 95% CI 2.2‐7.7, P <.0001) compared to those who had sustained activity levels. Lower baseline activity level was also associated with significantly increased risk of heart failure/death and death. Conclusion: Significant decline in device‐derived activity level and low baseline activity level are associated with increased mortality and heart failure in patients with an ICD for primary prevention. [ABSTRACT FROM AUTHOR]

Introduction: Intramural scarring is a risk factor for sudden cardiac death. The objective of this study was to determine the value of scar quantification for risk stratification in patients with nonischemic cardiomyopathy (NICM) undergoing ablation procedures for ventricular arrhythmias (VA). Methods and Results: Cardiac late gadolinium‐enhanced magnetic resonance imaging was performed in patients with NICM referred for ablation of premature ventricular complexes or ventricular tachycardia (VT). Only patients with intramural delayed enhancement were included. Scar volume was measured and correlated with immediate and long‐term outcomes. Receiver operator curves, Wilcoxon signed‐rank testing, and logistic regression were used to compare patient characteristics. The study consisted of 99 patients (74 males, mean age: 59.6 [54.0‐68.1] years, ejection fraction [EF]: 46.0 [35.0‐60.0]%). Patients without clinical VT or inducible VT had smaller total and core scar size compared to patients with a history of VT or inducible VT (total scar 1.12 [0.74‐1.79] cm3 vs 7.45 [4.16‐12.21] cm3, P <.001). A total scar volume of greater than or equal to 2.78 cm3 was associated with inducibility of VT (AUC 0.94, 95% CI [0.89‐0.98], sensitivity 85%, specificity 90%). Scar volume was associated with VT inducibility independent of a prior history of VT or the preprocedure EF (adjusted OR 1.67 [1.24‐2.24]/cm3, P <.01). Conclusion: Quantification of scar size in patients with intramural scarring is useful for risk stratification in patients with NICM and VA independent of the EF or a prior history of VT. Scar characteristics of patients without a history of VT who have inducible VT are similar to patients with a history of VT. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: The endpoint for radiofrequency catheter ablation (RFA) of cavo-tricuspid isthmus (CTI)-dependent atrial flutter (AFL) is complete conduction block along the CTI. The purpose of this study is to evaluate the utility of the temporal relationship between the P wave and the local atrial electrograms in determining complete CTI block.Methods: RFA of CTI was performed in 125 patients (age 63 ± 11 years). During pacing from the coronary sinus (CS), the intervals from the peak of the P wave (Ppeak) in lead V1 to the second component of the local atrial electrogram (A2) along the ablation line (Ppeak-A2) and from the end of the P wave (Pend) to A2 (Pend-A2) were investigated before and after complete block in the first 100 patients (training set). In the next 25 patients (validation set), Ppeak-A2 and Pend-A2 intervals were prospectively assessed to determine CTI block.Results: The mean Ppeak-A2 and Pend-A2 immediately before complete block were - 15±24 and - 39±23 ms compared to 49 ± 17 and 21 ± 16 ms after CTI block (P < 0.0001). Ppeak-A2 ≥ 20 ms and Pend-A2 ≥ 0 ms predicted CTI block with 98% sensitivity and 95% specificity and 96% sensitivity and 100% specificity, respectively. In the validation set, the positive and negative predictive values of Ppeak-A2 ≥ 20 ms or Pend-A2 ≥ 0 ms were 100 and 96%, respectively. The diagnostic accuracy was 98%.Conclusions: During pacing from the CS, the temporal relationship between the P wave in lead V1 and A2 is a simple and reliable indicator of complete block during RFA of CTI-AFL. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Ablation in the left ventricle (LV) is associated with a risk of thromboembolism. There are limited data on the use of specific thromboembolic prophylaxis strategies postablation. We aimed to evaluate a thromboembolic prophylaxis protocol after ventricular tachycardia (VT) ablation. Methods and results: The index procedures of 217 patients undergoing ablation for infarct‐related VT with open irrigated‐tip catheters were included. Patients with large LV endocardial ablation area (>3 cm between ablation lesions) were started on low‐dose, slowly escalating unfractionated heparin (UFH) infusion 8 hours after access hemostasis, followed by 3 months of anticoagulation. Patients with less extensive ablation were treated only with antiplatelet agents postablation. Postablation bridging anticoagulation was used in 181 (83%) patients. Of them, 11 (6%) patients experienced bleeding events (1 required endovascular intervention) and 1 (0.6%) experienced lower extremity arterial embolism requiring vascular surgery. Systemic anticoagulation was prescribed in 190 (89%) of 214 patients discharged from the hospital (warfarin in 98%), while the rest received single‐ or dual‐antiplatelet therapy alone. Patients treated with an anticoagulant had significantly longer radiofrequency time compared to patients treated with antiplatelet agents only. One (0.5%) of the patients treated with oral anticoagulation experienced major bleeding 2 weeks postablation. No thromboembolic events were documented in either the anticoagulation or the “antiplatelet only” group postdischarge. Conclusion: A slowly escalating bridging regimen of UFH, followed by 3 months of oral anticoagulation, is associated with low thromboembolic and bleeding risks after infarct‐related VT ablation. In the absence of extensive ablation, antiplatelet therapy alone is reasonable. [ABSTRACT FROM AUTHOR]

Abstract: Background: Myocardial wall thickness (WT) in patients with a prior myocardial infarction has been used to indicate scarring. However, the correlation of WT with sites critical to ventricular tachycardia (VT) has not been previously investigated. The purpose of this study was to correlate electroanatomic mapping data obtained during VT ablation with WT determined by cardiac computed tomography (CT). Methods and results: Cardiac CTs were performed in 15 consecutive patients (mean age 63 ± 10 years, 86% male, left ventricular ejection fraction 27 ± 12%) with a prior infarct referred for VT ablation. The CTs were registered to the electroanatomic maps obtained during the mapping procedure. Pacing was performed throughout the scar at sites with fractionated electrograms and isolated potentials. Ablation sites were identified by pace‐mapping or entrainment‐mapping and these sites were correlated with WT. Bipolar and unipolar voltage amplitude and bipolar electrogram width correlated with WT (correlation coefficient: 0.63, 0.65, and 0.41, respectively, P < 0.001). Ablation target sites were identified for 58 of 113 inducible VTs. The ablation target sites were located on CT‐defined ridges (WT: 4.2 ± 1.2 mm) bordered by areas of thinning (WT: 2.6 ± 1.1 mm, P < 0.0001) in 14 of 15 patients. Ablation targets were found on ridges in 49 of 58 VTs (84%) for which target sites were identified. A total of 70 ridges were localized in the 15 patients. VT became noninducible postablation in 11 of 15 patients (73%). Conclusion: WT measured by CT identifies ridges of myocardial tissue that often are critical for postinfarction VT and that can be appropriate target sites for ablation. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Although noninferiority of cryoballoon ablation (CBA) and radiofrequency catheter ablation for antral pulmonary vein isolation (APVI) has been reported in patients with paroxysmal atrial fibrillation (PAF), it is not clear whether contact force sensing (CF‐RFA) and CBA with the second‐generation catheter have similar procedural costs and long‐term outcomes. The objective of this study is to compare the long‐term efficacy and cost implications of CBA and CF‐RFA in patients with PAF. Methods and results: A first APVI was performed in 146 consecutive patients (age: 63 ± 10 years, men: 95 [65%], left atrial diameter: 42 ± 6 mm) with PAF using CBA (71) or CF‐RFA (75). Clinical outcomes and procedural costs were compared. The mean procedure time was significantly shorter with CBA than with CF‐RFA (98 ± 39 vs. 158 ± 47 minutes, P < 0.0001). Despite a higher equipment cost in the CBA than the CF‐RFA group, the total procedure cost was similar between the two groups (P = 0.26), primarily driven by a shorter procedure duration that resulted in a lower anesthesia cost. At 25 ± 5 months after a single ablation procedure, 51 patients (72%) in the CBA, and 55 patients (73%) in the CF‐RFA groups remained free from atrial arrhythmias without antiarrhythmic drug therapy (P = 0.84). Conclusions: The procedure duration was approximately 60 minutes shorter with CBA than CF‐RFA. The procedural costs were similar with both approaches. At 2 years after a single procedure, CBA and CF‐RFA have similar single‐procedure efficacies of 72–73%. [ABSTRACT FROM AUTHOR]

Purpose of Review: The aim of this review is to describe predictors and therapeutic principles for PVC-induced cardiomyopathy. Recent Findings: PVC-induced cardiomyopathy is a treatable condition resulting in a reversible form of cardiomyopathy. Summary: PVC-induced cardiomyopathy has only recently been recognized as an entity that causes a reversible form of cardiomyopathy. The mechanism of development of PVC-induced cardiomyopathy has not yet been elucidated, although dyssynchrony appears to play a major role. Multiple factors have been described that are independently associated with PVC-induced cardiomyopathy. Predictors of PVC-induced cardiomyopathy include PVC prevalence, epicardial origin, male gender, longer symptom duration and asymptomatic status, presence of interpolated PVCs, lack of circadian variability, and a broader PVC-QRS width. In the presence of cardiomyopathy, work-up for structural heart disease and its etiology should be performed, followed by aggressive attempts at PVC reduction. There is evidence that ablation therapy is superior to medical therapy for frequent PVCs, but treatment decisions need to be individualized depending on the patients symptoms, PVC prevalence, PVC origin, patients comorbidities, and patient preference. The potential of sudden cardiac death associated with the presence of structural heart disease needs to be recognized, and appropriate risk stratification is mandatory. [ABSTRACT FROM AUTHOR]

Aims: Magnetic resonance imaging (MRI) has been reported to be safe in patients with cardiac implantable electronic devices (CIED) provided a specific protocol is followed. The objective of this study was to assess whether this is also true for patients excluded from published protocols.Methods and Results: A total of 160 MRIs were obtained in 142 consecutive patients with CIEDs [106 patients had an implantable cardioverter defibrillator (ICD) and 36 had a pacemaker implanted] using an adapted, pre-specified protocol. A cardiac MRI was performed in 95 patients, and a spinal/brain MRI was performed in 47 patients. Forty-six patients (32%) had either abandoned leads (n = 10), and/or were pacemaker dependent with an implanted ICD (n = 19), had recently implanted CIEDs (n = 1), and/or had a CIED device with battery depletion (n = 2), and/or a component of the CIED was recalled or on advisory (n = 32). No major complications occurred. Some device parameters changed slightly, but significantly, right after or at 1-week post-MRI without requiring any reprogramming. In one patient with an ICD on advisory, the pacing rate changed inexplicably during one of his two MRIs from 90 to 50 b.p.m.Conclusion: Using a pre-specified protocol, cardiac and non-cardiac MRIs were performed in CIED patients with pacemaker dependency, abandoned leads, or depleted batteries without occurrence of major adverse events. Patients with devices on advisory need to be monitored carefully during MRI, especially if they are pacemaker dependent. [ABSTRACT FROM AUTHOR]