Pacing maneuvers from the aortic cusps: A useful technique during ablation of focal arrhythmias arising from the aortic root.

BACKGROUND: The ablation of arrhythmias arising near the His-bundle region in the non-coronary aortic cusp (NCAC) is challenging. Among the aortic sinuses of Valsalva, the NCAC is located between the right atrium and the left atrium. For this reason, pacing from the NCAC should result in atrial capture while pacing from the right and left coronary cusps (LCC) may result in ventricular capture. The objective of this study is to prove that atrial capture during pacing from the sinuses of Valsalva may be used to confirm a correct position in the non-coronary cusp. METHODS: A total of 30 patients with structurally normal heart undergoing left sided ablation procedures, underwent electrophysiological study of the aortic cusps. Each of the aortic valve cusps was paced with increasing outputs and analyzed offline to determine their unique electrocardiographic characteristics. RESULTS: In the NCAC, we obtained an atrial capture in 29 out of 30 patients (96.6%). The atrial capture was highly specific for a position in the NCAC (p < .001). The median output required to capture from the cusp was 10 mA (range 5-25 mA) at a pulse width of 2 ms. In the right coronary cusp (RCC) and LCC, we obtained ventricular capture in all patients (100%). The median output required to capture from the cusp was 10 mA (range 10-25 mA) in RCC and 25 mA (range 10-25 mA) in LCC at a pulse width of 2 ms. CONCLUSIONS: Atrial capture during a pacemapping from the aortic cusps can be considered proof of a correct position in NCAC.

Multicentre experience with the second-generation subcutaneous implantable cardioverter defibrillator and the intermuscular two-incision implantation technique.

INTRODUCTION: The recently developed second-generation subcutaneous implantable cardioverter defibrillator (S-ICD) and the intermuscular two-incision implantation technique demonstrate potential favorable features that reduce inappropriate shocks and complications. However, data concerning large patient populations are lacking. The aim of this multicentre prospective study was to evaluate the safety and outcome of second-generation S-ICD using the intermuscular two-incision technique in a large population study. METHODS AND RESULTS: The study population included 101 consecutive patients (75% male; mean age, 45 ± 13 years) who received second-generation S-ICD (EMBLEM; Boston Scientific, Marlborough, MA) implantation using the intermuscular two-incision technique as an alternative to the standard implantation technique. Twenty nine (29%) patients were implanted for secondary prevention. Twenty four (24%) patients had a previously implanted transvenous ICD. All patients were implanted without any procedure-related complications. Defibrillation testing was performed in 80 (79%) patients, and ventricular tachycardia was successfully converted at less than or equal to 65 J in 98.75% (79/80) of patients without pulse generator adjustments. During a median follow-up of 21 ± 10 months, no complications requiring surgical revision or local or systemic device-related infections were observed. Ten patients (9.9%) received appropriate and successful shocks for ventricular arrhythmias. Three (2.9%) patients experienced inappropriate shocks due to oversensing the cardiac signal (n = 1), noncardiac signal (n = 1), and a combination of both cardiac and noncardiac signals (n = 1), with one patient requiring device explantation. No patients required device explantation due to antitachycardia pacing indications. CONCLUSIONS: According to our multicentre study, second-generation S-ICD implanted with the intermuscular two-incision technique is an available safe combination and appears to be associated with a low risk of complications, such as inappropriate shocks.

Safety and efficacy of the new bidirectional rotational Evolution® mechanical lead extraction sheath: results from a multicentre Italian registry.

Aims: The aim of this prospective multicentre study is to evaluate safety and efficacy of the new bidirectional rotational mechanical lead extraction (LE) sheath (Evolution RL, Cook Medical, USA) in chronically implanted leads (>1-year-old leads). Methods and results: Between September 2013 and June 2016, a total of 238 leads in 124 consecutive patients were removed by using the new Evolution RL rotational mechanical sheath. Indications for LE were cardiac device infection in 63 (50.8%) cases, lead malfunction in 41 (33.1%), upgrade in 1 (0.8%) case and for other reasons in the remaining 19 cases (15.3%). Ninety-one leads (38.2%) were implantable cardioverter defibrillator leads (81 dual coil vs. 10 single coil), 38 (16%) right ventricular leads, 86 (36.1%) right atrial leads, and 23 (9.7%) coronary sinus leads. The mean implant duration was 92.2 ± 52.9 months (range 12-336). 91.6% of the leads (218/238) were extracted completely with the Evolution RL alone, with the complete success rate rising to 98.7% (235/238 leads) with combined use of a snare. Overall clinical success rate was 100%. No Evolution sheath-related complications were noted. There were no deaths or major complications. Five minor complications (4%) were encountered. In cases of companion leads no wrapping or lead damage were observed. Conclusion: On the basis of our prospective multicentre study, the new hand-powered bidirectional rotational mechanical LE sheath is an effective and safe tool for the extraction of chronically implanted leads without major complications and lead wrapping or lead damage.

Contiguity Between Ablation Lesions and Strict Catheter Stability Settings Assessed by VISITAGTM Module Improve Clinical Outcomes of Paroxysmal Atrial Fibrillation Ablation　- Results From the VISITALY Study.

BACKGROUND: Our aim was to evaluate the clinical outcome of paroxysmal atrial fibrillation (AF) ablation with contact force technology, using an automated lesion tagging system (VISITAGTM module) with strict criteria of catheter stability.Methods and Results:We enrolled 200 consecutive patients who underwent pulmonary vein isolation (PVI) in 11 centers and were followed up for 12 months. The stability setting was within 3 mm for ≥10 s and for ≥15 s in 47% and 53% of patients, respectively. A mean of 67.2±21.9 VISITAGs was acquired. Freedom from atrial tachyarrhythmias at follow-up was 77.5% (155/200), and the contiguity between lesions was associated with a higher chronic success rate (96% vs. 77.1%; log-rank P=0.036). Radiofrequency (RF), fluoroscopy times, and recurrence rates at the 12-month follow-up were significantly lower than in a comparison group of 80 patients without VISITAGTM module (42.7±14.5 vs. 50.9±23.6 min; P=0.032; 11.6±7.8 vs. 18.4±12.8 min; P=0.003 and 22.5% vs. 41.2%; P=0.02). Two major complications (1 cardiac tamponade and 1 minor stroke) were observed only in the control group. CONCLUSIONS: Paroxysmal AF ablation with contact force technology and strict criteria of stability using the VISITAG module was a safe procedure, associated with an improvement in efficiency and a reduction of atrial tachyarrhythmia recurrence at the 12-month follow-up compared with manual annotation. Contiguity between lesions seemed to enhance effectiveness outcomes.

Intermuscular Two-Incision Technique for Subcutaneous Implantable Cardioverter Defibrillator Implantation: Results from a Multicenter Registry.

BACKGROUND: The traditional technique for subcutaneous implantable cardioverter defibrillator (S-ICD) implantation, which involves three incisions and a subcutaneous pocket, is associated with possible complications, including inappropriate interventions. The aim of this prospective multicenter study was to evaluate the efficacy and safety of an alternative intermuscular two-incision technique for S-ICD implantation. METHODS: The study population included 36 consecutive patients (75% male, mean age 44 ± 12 years [range 20-69]) who underwent S-ICD implantation using the intermuscular two-incision technique. This technique avoids the superior parasternal incision for the lead placement and consists of creating an intermuscular pocket between the anterior surface of the serratus anterior and the posterior surface of the latissimus dorsi muscles instead of a subcutaneous pocket. RESULTS: All patients were successfully implanted in the absence of any procedure-related complications with a successful 65-J standard polarity defibrillation threshold testing, except in one, who received a second successful shock after pocket revision. During a mean follow-up of 10 months (range 3-30), no complications requiring surgical revision were observed. At device interrogation, stable sensing without interferences was observed in all patients. Two patients (5.5%) experienced appropriate and successful shock on ventricular fibrillation and in four patients (11%), a total of seven nonsustained self-terminated ventricular tachycardias were correctly detected. No inappropriate interventions were observed. CONCLUSIONS: Our experience suggests that the two-incision intermuscular technique is a safe and efficacious alternative to the current technique for S-ICD implantation that may help reducing complications including inappropriate interventions and offer a better cosmetic outcome, especially in thin individuals.

Reduction of inappropriate anti-tachycardia pacing therapies and shocks by a novel suite of detection algorithms in heart failure patients with cardiac resynchronization therapy defibrillators: a historical comparison of a prospective database.

AIMS: Implantable cardioverter defibrillators improve survival of patients at risk for ventricular arrhythmias, but inappropriate shocks occur in up to 30% of patients and have been associated with worse quality of life and prognosis. In heart failure patients with cardiac resynchronization therapy defibrillators (CRT-Ds), we evaluated whether a new generation of detection and discrimination algorithms reduces inappropriate shocks. METHODS AND RESULTS: We analysed 1983 Medtronic CRT-D patients (80% male, 67 ± 10 years), 1368 with standard devices (Control CRT-D) and 615 with new generation devices (New CRT-D). Expert electrophysiologists reviewed and classified the electrograms of all device-detected ventricular tachycardia/fibrillation episodes. Total follow-up was 3751 patients-years. Incidence of inappropriate shocks at 1 year was 2.8% [95% confidence interval (CI) = 2.0-3.5] in Control CRT-D and 0.9% (CI = 0.4-2.2) in New CRT-D (hazard ratio = 0.37, CI = 0.21-0.66, P < 0.001). In New CRT-D, inappropriate shocks were reduced by 77% [incidence rate ratio (IRR) = 0.23, CI = 0.16-0.35, P < 0.001] and inappropriate anti-tachycardia pacing by 81% (IRR = 0.19, CI = 0.11-0.335, P < 0.001). Annual rate per 100 patient-years for appropriate VF detections was 3.0 (CI = 2.1-4.2) in New CRT-D and 3.2 (CI = 2.1-5.0) in Control CRT-D (P = 0.68), for syncope was 0.4 (CI = 0.2-0.9) in New CRT-D and 0.7 (CI = 0.5-1.0) in Control CRT-D (P = 0.266), and for death was 1.0 (CI = 0.6-1.6) in New CRT-D and 3.5 (CI = 3.0-4.1) in Control CRT-D (P < 0.001). CONCLUSION: Detection and discrimination algorithms used in new generation CRT-D significantly reduced inappropriate shocks when compared with standard CRT-D. This result, with no compromise on VF sensitivity or risk of syncope, has important implications for patients' quality of life and prognosis.

Asystole detected by implantable loop recorders: true or false?

We report a case of a false asystole detected by an implantable loop recorder a few days after its implantation. In the discussion section we try to give some hints to help cardiac electrophysiologists in distinguish true from false asystoles, in order to avoid unuseful and potentially dangerous implantations of pacemakers.

Comparison of Oral Procainamide and Mexiletine Treatment of Recurrent and Refractory Ventricular Tachyarrhythmias.

Background: Antiarrhythmic therapy for recurrent ventricular arrhythmias (VAs) in patients having undergone catheter ablation and in whom amiodarone and/or beta-blockers were ineffective or contraindicated is a controversial issue. Purpose: The present study sought to compare the efficacy and tolerability of oral procainamide and mexiletine in patients with recurrent ventricular arrhythmias when the standard therapy strategy failed. Methods: All patients with an implantable cardioverter defibrillator (ICD) treated with oral procainamide or mexiletine for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in two cardiology divisions between January 2010 and January 2020 were enrolled. Patients were divided into group A (oral procainamide) and group B (mexiletine) and the two groups were compared to each other. The primary endpoint was the efficacy of therapy; the secondary endpoint was the discontinuation of therapy. All events that occurred during procainamide or mexiletine treatment were compared with a matched duration period before the initiation of the therapy. Antiarrhythmic therapy was considered effective when a ≥80% reduction of the sustained ventricular arrhythmias burden recorded by the ICD was achieved. Results: A total of 68 consecutive patients (61 males, 89.7%; mean age 74 ± 10 years) were included in this retrospective analysis. After a median follow-up of 19 months, 38 (56%) patients had a significant reduction in the VA burden. After multivariable adjustment, therapy with procainamide was independently associated with an almost 3-fold higher efficacy on VA suppression compared to mexiletine (HR 2.54, 95% CI 1.06-6.14, p = 0.03). Only three patients (9%) treated with procainamide presented severe side effects (dyspnea or hypotension) requiring discontinuation of therapy compared with six patients (18%) treated with mexiletine who interrupted therapy because of severe side effects (p = 0.47). Conclusions: Compared to mexiletine, oral procainamide had a higher efficacy for the treatment of recurrent and refractory VAs, and showed a good profile of tolerability.

Oral procainamide as pharmacological treatment of recurrent and refractory ventricular tachyarrhythmias: A single-center experience.

BACKGROUND: Antiarrhythmic therapy for recurrent ventricular arrhythmias in patients who have undergone catheter ablation, and in whom amiodarone and/or beta-blockers were ineffective or contraindicated, is a controversial issue. OBJECTIVE: The present study sought to evaluate the efficacy and tolerability of oral procainamide in patients with recurrent ventricular arrhythmias when the standard therapy strategy had failed. METHODS: All patients treated with procainamide for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in our institution between January 2010 and May 2019 were enrolled. The primary endpoint was the total number of implantable cardioverter-defibrillator (ICD) interventions after the beginning of procainamide therapy. Secondary endpoints were the total number of VTs and VFs recorded on the ICDs' controls and discontinuation of therapy. The events occurring during procainamide treatment were compared with a matched-duration period before the initiation of therapy with procainamide. Patients therefore served as self-controls. RESULTS: A total of 34 consecutive patients (32 male, 94.1%; mean age 74.4 ± 9.7 years) were included in the retrospective analysis. The mean time of procainamide treatment was 12.9 ± 13.7 months (median 9 [2-20] months). The mean dose of procainamide was 1207 ± 487 mg/day. Procainamide therapy significantly decreased ICD interventions (median 5 [0-22.5] vs 15.5 [3-32.25], P < .05). Procainamide also decreased the total number of VT/VF episodes (median 5.5 [0.75-30] vs 19 [7.5-30], P < .05). Only 3 patients (8.8%) presented severe side effects (dyspnea or hypotension), requiring discontinuation of therapy. CONCLUSION: Oral procainamide was associated with a significant decrease in ICD therapies and ventricular arrhythmias, showing an acceptable profile of tolerability.

Prognostic role of non-sustained ventricular tachycardia detected with remote interrogation in a pacemaker population.

BACKGROUND: Non-sustained ventricular tachycardia (NSVT) can occur asymptomatically and can be incidentally detected in the internal records of pacemakers (PM). The clinical value of NSVT in the population of PM patients is still uncertain.Our aim was to assess the prevalence of NSVT detected by remote PM control, to describe the clinical and demographic characteristics of patients with NSVT, and to assess the prognostic significance of NSVT in terms of both overall and cardiovascular mortality. METHODS: Consecutive patients followed with PM remote interrogations from September 2010 to December 2015 were included. The transmissions pertaining to the first 12 months of remote control were analysed and the patients were divided by those presenting NSVT and those without NSVT. The two groups were compared in terms of total mortality and cardiovascular mortality based on the administrative data provided by the regional administration of the Italian National Health System. RESULTS: The prevalence of NSVT in 408 patients (62% males, mean age 75.6; SD 10.6 years old) was 21% in a year. During a mean follow-up duration of 44 months, NSVT did not emerge as independently associated with overall mortality, but was associated with cardiovascular mortality in a competing risk regression model with older age, male gender, diabetes, chronic renal insufficiency, ischemic cardiomyopathy and chronic obstructive pulmonary disease. CONCLUSIONS: We show that NSVT episodes recorded by remote control in a PM population are independently associated with cardiovascular mortality with possible implications for risk stratification and therapeutic options.

Efficacy and Safety of Catheter Ablation of Atrial Tachycardia Through a Direct Approach from Noncoronary Sinus of Valsalva.

Noncoronary aortic cusp (NCAC) in the aorta represents a challenging location for catheter ablation of focal atrial tachycardias (ATs) arising near the His-bundle region. The purpose of this study was to provide an updated report on the methods, efficacy, and safety of catheter ablation of ATs originating from NCAC. The study population includes 23 patients (18 women [78%], mean age 65 ± 12 years) with highly symptomatic AT. The atrial mapping was performed during tachycardia to define the earliest atrial activation site. Electrophysiological mapping of the right atrium was initially performed, followed by aortic root mapping when earliest activation was recorded in the proximal electrode of the His-bundle catheter. A direct ablation approach from NCAC was used in every patient independently by the local activation time. Ablations were performed using a steerable 4-mm tip nonirrigated catheter in all patients. Radiofrequency energy resulted in the disappearance of arrhythmias in 22 of the 23 patients (95%). In all procedures, there were no complications. During a mean follow-up of 41 ± 25 months, no patient presented with a recurrence, except the 1 patient where the ablation was not effective. In conclusion, catheter ablation of para-hisian ATs through a direct approach from NCAC shows to be safe and effective after 1 procedure per patient.

Prevalence and prognostic value of concealed structural abnormalities in patients with apparently idiopathic ventricular arrhythmias of left versus right ventricular origin: a magnetic resonance imaging study.

BACKGROUND: Routine diagnostic work-up occasionally does not identify any abnormality among patients with monomorphic ventricular arrhythmias (VAs) of left ventricular (LV) origin. Aim of this study was to investigate the value of cardiac MRI (cMRI) for the diagnostic work-up and prognostication of these patients. METHODS AND RESULTS: Forty-six consecutive patients (65% males; mean age, 44±15 years) with monomorphic VAs of LV origin and negative routine diagnostic work-up were included. Seventy-four consecutive patients (60% males; mean age, 40±17 years) with apparently idiopathic monomorphic VAs of right ventricular origin served as control group. Both groups underwent comprehensive cMRI study and were followed-up for a median of 14 months (25th-75th percentiles, 7-37 months). The outcome event was an arrhythmic composite end point of sudden cardiac death or nonfatal episode of ventricular fibrillation or sustained ventricular tachycardia requiring external cardioversion or appropriate implantable cardioverter defibrillator therapy. The 2 groups of patients did not differ in age (P=0.14) and sex (P=0.57). No significant difference was observed between patients with VAs of LV origin and VAs of right ventricular origin about biventricular volumes and systolic function. cMRI demonstrated myocardial structural abnormalities in 19 (41%) patients with VAs of LV origin versus 4 (5%) patients with VAs of right ventricular origin (P<0.001). The outcome event occurred in 9 patients; myocardial structural abnormalities on cMRI were significantly related to the outcome event (hazard ratio, 41.6; 95% confidence interval, 5.2-225.0; P<0.001). CONCLUSIONS: Myocardial structural changes are detected by cMRI in a non-negligible proportion of patients with apparently idiopathic monomorphic VAs of LV origin and are associated with worse outcome.

Predictors for restoration of normal left ventricular function in response to cardiac resynchronization therapy measured at time of implantation.

There are no parameters predicting the individual probability of "full response" to cardiac resynchronization therapy (CRT). The aim of this work was to find prognostic factors of full clinical and echocardiographic responses (i.e., ≥50% left ventricular ejection fraction [LVEF] and New York Heart Association class I) after 1 year of CRT. This was a prospective follow-up study that involved 2 hospitals. Patients (n = 75) with advanced heart failure (64 ± 9 years of age, 87% men, LVEF 24 ± 7%) who received CRT were followed for 17 ± 9 months. Univariate and multivariate regression analyses were used to identify predictors of full CRT response. A nomogram predicting the individual probability of full CRT response during follow-up was calculated. There were 13 patients with restoration of normal LVEF versus 62 without (mean LVEF 56% ± 5% vs 31% ± 8%, respectively, p <0.001). Predictors of full response included cause of heart disease, baseline QRS width, and degree of QRS shortening in response to CRT. Patients with nonischemic heart disease, baseline QRS width ≤150 ms, and QRS shortening ≥40 ms in response to CRT had a >75% probability of restoration of normal LVEF. In conclusion, our nomogram using a combination of cause, baseline QRS width, and degree of QRS shortening in response to CRT allows assessment of individual probability of full response. This observation awaits further confirmation from larger series.