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Introduction: While cardiac sarcoidosis (CS) carries a risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD), risk stratification of patients with CS and preserved left ventricular/right ventricular (LV/RV) systolic function remains challenging. We sought to evaluate the role of electrophysiologic testing and programmed electrical stimulation of the ventricle (EPS) in patients with suspected CS with preserved ventricular function. Methods: One hundred twenty consecutive patients with biopsy‐proven extracardiac sarcoidosis and preserved LV/RV systolic function underwent EPS. All patients had either probable CS defined by an abnormal cardiac positron emission tomography or cardiac magnetic resonance imaging, or possible CS with normal advanced imaging but abnormal echocardiogram (ECG), SAECG, Holter, or clinical factors. Patients were followed for 4.5 ± 2.6 years for SCD and VAs. Results: Seven of 120 patients (6%) had inducible ventricular tachycardia (VT) with EPS and received an implantable cardioverter defibrillator (ICD). Three patients (43%) with positive EPS later had ICD therapies for VAs. Kaplan‐Meier analysis stratified by EPS demonstrated a significant difference in freedom from VAs and SCD (P = 0.009), though this finding was driven entirely by patients within the cohort with probable CS (P = 0.018, n = 69). One patient with possible CS and negative EPS had unrecognized progression of the disease and unexplained death with evidence of CS at autopsy. Conclusions: EPS is useful in the risk stratification of patients with probable CS with preserved LV and RV function. A positive EPS was associated with VAs. While a negative EPS appeared to confer low risk, close follow‐up is needed as EPS cannot predict fatal VAs related to new cardiac involvement or disease progression. [ABSTRACT FROM AUTHOR]

A 62‐year‐old man was referred to our institution for high‐density, symptomatic premature ventricular contractions (PVCs) with resultant decrease in left ventricular (LV) function having failed prior ablation attempts. Successful, durable ablation of the patient's mid‐myocardial PVC arising from the LV summit region was achieved through the proximal great cardiac vein with ablation depth augmented by use of half‐normal saline irrigant. Though standard ablation of ventricular arrhythmias using normal saline irrigation from the coronary venous system has been well‐reported, this may be of limited value in addressing mid‐myocardial sites of origin. This novel case describes the safe use of cooled radiofrequency ablation with use of half‐normal saline irrigant from the distal coronary sinus as an option to address complex sites of PVC origin such as the LV summit. [ABSTRACT FROM AUTHOR]

Introduction: Multiple ablations are often necessary to manage ventricular arrhythmias (VAs) in nonischemic cardiomyopathy (NICM) patients. We assessed characteristics and outcomes and role of adjunctive, nonstandard ablation in repeat VA ablation (RAbl) in NICM. Methods and results: Consecutive NICM patients undergoing RAbl were analyzed, with characteristics of the last VA ablations compared between those undergoing 1 versus multiple‐repeat ablations (1‐RAbl vs. >1RAbl), and between those with or without midmyocardial substrate (MMS). VA‐free survival was compared. Eighty‐eight patients underwent 124 RAbl, 26 with > 1RAbl, and 26 with MMS. 1‐RAbl and > 1‐RAbl groups were similar in age (57 ± 16 vs. 57 ± 17 years; P = 0.92), males (76% vs. 69%; P = 0.60), LVEF (40 ± 17% vs. 40 ± 18%; P = 0.96), and amiodarone use (31% vs. 46%, P = 0.22). One‐year VA freedom between 1‐RAbl vs. > 1RAbl was similar (82% vs. 80%; P = 0.81); adjunctive ablation was utilized more in >1RAbl (31% vs. 11%, P = 0.02), and complication rates were higher (27% vs. 7%, P = 0.01), most due to septal substrate and anticipated heart block. >1‐RAbl patients had more MMS (62% vs. 16%, P < 0.01). Although MMS was associated with worse VA‐free survival after 1‐RAbl (43% vs. 69%, P = 0.01), when >1RAbl was performed, more often with nonstandard ablation, VA‐free survival was comparable to non‐MMS patients (85% vs. 81%; P = 0.69). More RAbls were required in MMS versus non‐MMS patients (2.00 ± 0.98 vs. 1.16 ± 0.37; P < 0.001). Conclusion: For NICM patients with recurrent, refractory VAs despite previous ablation, effective arrhythmia control can safely be achieved with subsequent ablation, although >1 repeat procedure with adjunctive ablation is often required, especially with MMS. [ABSTRACT FROM AUTHOR]

Background: Bipolar radiofrequency ablation (bRFA) has been used to create larger ablation lesions and to treat refractory arrhythmias. However, little is known about optimal bRFA settings.Objective: The purpose of this study was to evaluate various bRFA settings, including active and ground catheter tip orientation and use of variable active and ground catheters during bRFA.Methods: Two ablation catheters, 1 active and 1 ground, were oriented across from each other, with viable bovine myocardium in between. The catheter tips were placed in various combinations perpendicular or parallel to the myocardium. The active catheter was either a 3.5-mm externally irrigated or 8-mm tip, and the ground catheter was either a 4-mm, 3.5-mm irrigated, or 8-mm tip. Retrospective analysis was undertaken for all bRFA performed at University of Colorado.Results: The largest and deepest lesions were produced using irrigated active and ground tips, oriented perpendicularly. In 14 cases (10 patients) of bRFA for ventricular tachycardia and premature ventricular complexes, acute success was achieved in 13 of 14 procedures. Long-term success was achieved in 7 of 10 patients, but 3 patients required multiple bRFA ablations.Conclusion: Active and ground catheter tip orientation and type are important determinants of lesion sizes during bRFA. The largest and deepest lesions, without a higher incidence of steam pops, were achieved using 2 irrigated catheters. As the largest published series to date, bRFA ablation can be performed safely and effectively in humans. Larger studies are necessary to better evaluate bRFA efficacy and safety. [ABSTRACT FROM AUTHOR]

Exercise-induced syncope should alert clinicians to the possibility of LQTS and must be distinguished from other malignant causes of syncope such as hypertrophic cardiomyopathy, catecholaminergic ventricular tachycardia, and arrhythmogenic right ventricular cardiomyopathy. Emerging genotype-phenotype links have connected mutations resulting in LQTS with risk of developing atrial fibrillation and cardiomyopathy. [ABSTRACT FROM AUTHOR]

Background Premature ventricular complexes (PVCs) and ventricular tachycardia (VT) are associated with persistent symptoms and ventricular dysfunction. Approved medical therapies have undesirable side effects and proarrhythmic liability. Ranolazine is a novel antianginal that preferentially blocks the late sodium current. This current is enhanced among patients with cardiomyopathy; a promising target population for ranolazine. The utility of ranolazine, however, for ventricular arrhythmia suppression has not been well characterized. Objectives We sought to determine the effectiveness of ranolazine for suppression of ventricular ectopy, particularly in the setting of ventricular dysfunction where enhanced efficacy might be expected. Methods We retrospectively evaluated eight patients (six with >10% PVC burden and two with incessant VT) treated with ranolazine. Arrhythmia frequency was evaluated by continuous monitoring before and after ranolazine initiation and the correlation between ventricular function and reduction in PVC burden was assessed. Results Among six patients with PVCs, ranolazine resulted in a median decrease in PVC burden of 60.2% (P = 0.06). In two cases of apparent PVC-induced cardiomyopathy, normalization of ventricular function was observed. A significant, inverse correlation between baseline ejection fraction and percentage reduction in PVCs was observed (rho = −0.89, P = 0.02). In two patients treated for incessant VT despite Class III antiarrhythmic therapy, ranolazine eliminated VT and prevented recurrent defibrillator therapy. Conclusions Although not approved for this indication, ranolazine appears effective for symptomatic ventricular arrhythmias. The reduction in PVC burden was greatest among individuals with reduced ventricular function, perhaps due to enhanced late sodium current associated with cardiomyopathy. A confirmatory prospective trial seems warranted. [ABSTRACT FROM AUTHOR]

Endocardial Electrograms in Epicardial VT/PVCs Introduction While most ventricular arrhythmias (VA) can be ablated successfully using an endocardial (endo) approach, epicardial (epi) mapping and ablation is sometimes required. There may be suggestive clues on the surface electrocardiogram; however, identification of an epi origin of VA with certainty remains problematic. Methods and Results All patients referred for ablation of ventricular tachycardia or frequent ventricular ectopy from June 2007 to July 2011 were evaluated. Patients with completed endo and epi electroanatomical activation maps of an epi VA were included (n = 10). Bipolar electrograms (EGMs) in the area of earliest endo activation were analyzed and compared to the area of early epi activation. An EGM component was characterized as far field if it was monophasic and there was inability to capture. We identified 3 characteristics from endo mapping that consistently indicated need for epi ablation: (1) Diffusely early activation (>2 cm2 region of sites with equally earliest activation within 10 milliseconds). (2) Sequence of a far-field EGM followed by a near-field EGM in the region of earliest endo activation. (3) Inability to capture the far-field component of the earliest EGM (stim-QRS < egm-QRS time) or reproduce morphological features of the VA complex with stimulation at the earliest endo site of activation. Conclusions The presence of a diffusely early area of activation and inability to capture a far-field endo EGM indicates that epi ablation may be needed to eliminate a VA. [ABSTRACT FROM AUTHOR]

ICD Shocks in Cardiac Sarcoidosis. Background: An implantable cardioverter defibrillator (ICD) is indicated for some patients with cardiac sarcoidosis (CS) for prevention of sudden death. However, there are little data regarding the event rates of ICD therapies in these patients. We sought to identify the incidence and characteristics of ICD therapies in this patient population. Methods: We performed a cohort study of patients with ICDs at 3 institutions. Cases were those patients with CS and an ICD implanted for primary or secondary prevention of sudden death. Additionally, we included a comparison with historical controls of ICD therapy rates reported in clinical trials evaluating the ICD for primary and secondary prevention of sudden death. Results: Of the 112 CS subjects identified, 36 (32.1%) received appropriate therapies for ventricular tachyarrhythmias (VT) over a mean follow-up period of 29.2 months. VT storm (>3 episodes in 24 hours) occurred in 16 (14.2%) CS subjects. Inappropriate therapies occurred in 13 CS subjects (11.6%). Covariates associated with appropriate ICD therapies included left ventricular ejection fraction (LVEF) <55% (OR 6.52 [95% CI 2.43-17.5]), right ventricular dysfunction (OR 6.73 [95% CI 2.69-16.8]), and symptomatic heart failure (OR 4.33 [95% CI 1.86-10.1]). Conclusions: In our cohort of patients with CS and ICDs, almost one-third receive appropriate therapies. This may be due to a myocardial inflammatory process leading to increased triggered activity and subsequent scarring leading to reentrant tachyarrhythmias. Adjusted predictors of ICD therapies in this population include left or right ventricular dysfunction. (J Cardiovasc Electrophysiol, Vol. 23, pp. 925-929, September 2012) [ABSTRACT FROM AUTHOR]

Background: Ventricular tachycardia (VT) ablation is often avoided in patients with advanced heart failure (HF) and this group of patients is often excluded from research trials. Objective: To evaluate VT recurrence rates among patients with severe HF and VT treated with ablation (Abl) versus medications (Med) alone. Methods: We performed a retrospective analysis of patients presenting to a tertiary referral hospital between 2006 and 2017 with ventricular tachycardia and severe heart failure (New York Heart Association functional Class IV or any Interagency Registry for Mechanically Assisted Circulatory Support score) for whom electrophysiology consult was requested. Baseline characteristics and VT recurrence were compared based on method of arrhythmia treatment. Results: Of 129 patients, 47% underwent ablation while 53% were managed medically. In this cohort, mean age was 60 ± 12 years, 84% were males, ischemic cardiomyopathy was present in 55%, mean LVEF was 24±12%, and 77% had a preexisting ICD.One-year mortality was 23%, 40% of whom were treated with Abl versus 60% with Med, p=0.196. Abl patients were more likely to have an ICD prior to presentation (85% vs 69%, p=0.037) and had shorter length of hospital stay (14±16 vs 21±16 days, p=0.021) compared to Med patients. Other baseline characteristics were not significantly different between groups. Abl patients overall had better VT-free survival compared to those treated with medications alone (OR 0.36, 95% CI [0.18, 0.80], Figure). Conclusions: Ablation of ventricular arrhythmia even in patients with severe heart failure is associated with decreased length of hospitalization and improved VT-free survival compared to medical therapy alone. These findings warrant additional, prospective study to verify and possibly improve management of this high-risk group of patients. [ABSTRACT FROM AUTHOR]

Background: Ventricular tachycardia (VT) is common in patients with severe heart failure (HF). Objective: We sought to determine whether early recurrence of VT is associated with worse survival. Methods: We performed retrospective analysis of patients presenting to a tertiary referral hospital between 2006-2017 with VT and severe HF (defined as New York Heart Association functional Class IV or any Interagency Registry for Mechanically Assisted Circulatory Support score) for whom electrophysiology consultation was requested. A comparison was made in baseline characteristics and outcomes between those with early VT recurrence (within 30 days of initial consult) and those without early VT recurrence. Results: Of 129 patients, 47% underwent ablation while 53% were managed medically. Mean age was 60±12 years, 84% were males, ischemic cardiomyopathy was present in 55%, mean LVEF was 24±12%, and 77% had a preexisting ICD. Early recurrence of VT was observed in 25 patients (19%). Those with early recurrence had lower mean LVEF (20±7% vs 25±12%, p =0.032), were less likely to have an ICD prior to presentation (56% vs 82%, p =0.015), were more likely to have been treated with only medications (80% vs 20%, p =0.003), had greater in-hospital mortality (28% vs 5%, p =0.002) and experienced a longer hospitalization (23±19 vs 17±16 days), compared to those without early recurrence. There was no significant difference in other baseline characteristics between groups. Patients with early recurrence had significantly worse 1-year survival 56% vs 82% (Figure), with OR 3.5, 95% CI [1.3,8.9]. Conclusion: Early VT recurrence among patients with severe heart failure is associated with increased mortality within the year following presentation. VT ablation should be considered to help mitigate risk of early recurrence and associated morbidity in such patients. [ABSTRACT FROM AUTHOR]