Pacing manouvers 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<0.001). 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. This article is protected by copyright. All rights reserved.

Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator? Results From the Multicenter Randomized PARTITA Trial

BACKGROUND

Optimal timing for catheter ablation of ventricular tachycardia is an important unresolved issue. There are no randomized trials evaluating the benefit of ablation after the first implantable cardioverter defibrillator (ICD) shock.

METHODS

We conducted a 2-phase, prospective, multicenter, randomized clinical trial. Patients with ischemic or nonischemic dilated cardiomyopathy and primary or secondary prevention indication for ICD were enrolled in an initial observational phase until first appropriate shock (phase A). After reconsenting, patients were randomly assigned 1:1 in phase B to immediate ablation (within 2 months from shock delivery) or continuation of standard therapy. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure. Amiodarone intake was not allowed except for documented atrial tachyarrhythmias. On July 23, 2021, phase B of the trial was interrupted as a result of the first interim analysis on the basis of the Bayesian adaptive design.

RESULTS

Of the 517 patients enrolled in phase A, 154 (30%) had ventricular tachycardia, 56 (11%) received an appropriate shock over a median follow-up of 2.4 years (interquartile range, 1.4-4.4), and 47 of 56 (84%) agreed to participate in phase B. After 24.2 (8.5-24.4) months, the primary end point occurred in 1 of 23 (4%) patients in the ablation group and 10 of 24 (42%) patients in the control group (hazard ratio, 0.11 [95% CI, 0.01-0.85]; P=0.034). The results met the prespecified termination criterion of >99% Bayesian posterior probability of superiority of treatment over standard therapy. No deaths were observed in the ablation group versus 8 deaths (33%) in the control group (P=0.004); there was 1 worsening heart failure hospitalization in the ablation group (4%) versus 4 in the control group (17%; P=0.159). ICD shocks were less frequent in the ablation group (9%) than in the control group (42%; P=0.039).

CONCLUSIONS

Ventricular tachycardia ablation after first appropriate shock was associated with a reduced risk of the combined death or worsening heart failure hospitalization end point, lower mortality, and fewer ICD shocks. These findings provide support for considering ventricular tachycardia ablation after the first ICD shock.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01547208.

Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator? Results From the Multicenter Randomized PARTITA Trial

BACKGROUND

Optimal timing for catheter ablation of ventricular tachycardia is an important unresolved issue. There are no randomized trials evaluating the benefit of ablation after the first implantable cardioverter defibrillator (ICD) shock.

METHODS

We conducted a 2-phase, prospective, multicenter, randomized clinical trial. Patients with ischemic or nonischemic dilated cardiomyopathy and primary or secondary prevention indication for ICD were enrolled in an initial observational phase until first appropriate shock (phase A). After reconsenting, patients were randomly assigned 1:1 in phase B to immediate ablation (within 2 months from shock delivery) or continuation of standard therapy. The primary end point was a composite of death from any cause or hospitalization for worsening heart failure. Amiodarone intake was not allowed except for documented atrial tachyarrhythmias. On July 23, 2021, phase B of the trial was interrupted as a result of the first interim analysis on the basis of the Bayesian adaptive design.

RESULTS

Of the 517 patients enrolled in phase A, 154 (30%) had ventricular tachycardia, 56 (11%) received an appropriate shock over a median follow-up of 2.4 years (interquartile range, 1.4-4.4), and 47 of 56 (84%) agreed to participate in phase B. After 24.2 (8.5-24.4) months, the primary end point occurred in 1 of 23 (4%) patients in the ablation group and 10 of 24 (42%) patients in the control group (hazard ratio, 0.11 [95% CI, 0.01-0.85]; P=0.034). The results met the prespecified termination criterion of >99% Bayesian posterior probability of superiority of treatment over standard therapy. No deaths were observed in the ablation group versus 8 deaths (33%) in the control group (P=0.004); there was 1 worsening heart failure hospitalization in the ablation group (4%) versus 4 in the control group (17%; P=0.159). ICD shocks were less frequent in the ablation group (9%) than in the control group (42%; P=0.039).

CONCLUSIONS

Ventricular tachycardia ablation after first appropriate shock was associated with a reduced risk of the combined death or worsening heart failure hospitalization end point, lower mortality, and fewer ICD shocks. These findings provide support for considering ventricular tachycardia ablation after the first ICD shock.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01547208.

Comparison between oral procainamide and mexiletine for the treatment of recurrent and refractory ventricular tachyarrhythmias

Funding Acknowledgements

Type of funding sources: None.

Background

The antiarrhythmic therapy of recurrent ventricular arrhythmias 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 2 Cardiology Divisions between January 2010 and January 2020 were enrolled. The patients were divided in group A (oral procainamide) and group B (mexiletine) and the 2 groups were compared to each other. The primary endpoint was the efficacy of therapy; the secondary endpoint was the discontinuation of therapy. All the events occurring during procainamide or mexiletine treatment were compared with a matched duration period before the initiation of the therapy. Antiarrhythmic therapy was considered effective when an ≥80% reduction of the sustained ventricular arrhythmias (SVA) 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. In 27 (39.7%) patients catheter ablation of VT was attempted before therapy initiation. A concomitant therapy with amiodarone was present in 25 (36.8%) patients. The mean dose of procainamide was 1207±487 mg/die. The mean dose of mexiletine was 576±66 mg/die. After a median follow-up of 19 months, 38 (56%) patients had a significant reduction in the SVA burden. After multivariable adjustment (Table 1), 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). Similar results (HR 2.89, 95% CI 1.26-6.62, p=0.01) were found after adjustment using inverse probability weighting by a propensity score including age, gender, left ventricular ejection fraction, ischemic heart disease and concomitant amiodarone therapy. Only 3 patients (9%) treated with procainamide presented severe side effects (dyspnea or hypotension) requiring discontinuation of therapy against 6 patients (18%) treated with mexiletine who interrupted therapy because of severe side effects (p=0.47).

Conclusions

Compared to mexiletine, oral procainamide has a higher efficacy for the treatment of recurrent and refractory VAs and shows a good profile of tolerability

Table 1. Multivariable Cox Proportional Hazards Analysis of Baseline Covariates in Relation to effective VAs suppression.

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.

Safety, efficacy, and reproducibility of cavotricuspid isthmus ablation guided by the ablation index: acute results of the FLAI study

AIMS

Ablation index (AI) is a marker of lesion quality during catheter ablation that incorporates contact force, time, and power in a weighted formula. This index was originally developed for pulmonary vein isolation as well as other left atrial procedures. The aim of our study is to evaluate the feasibility and efficacy of the AI for the ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical atrial flutter (AFL).

METHODS AND RESULTS

This prospective multicentre non-randomized study enrolled 412 consecutive patients with typical AFL undergoing AI-guided cavotricuspid isthmus ablation. The procedure was performed targeting an AI of 500 and an inter-lesion distance measurement of ≤6 mm. The primary endpoints were CTI 'first-pass' block and persistent block after a 20-min waiting time. Secondary endpoints included procedural and radiofrequency duration and fluoroscopic time. A total of 412 consecutive patients were enrolled in 31 centres (mean age 64.9 ± 9.8; 72.1% males and 27.7% with structural heart disease). The CTI bidirectional 'first-pass' block was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting time was achieved in 405 patients (98.3%). Mean procedural, radiofrequency, and fluoroscopic time were 56.5 ± 28.1, 7.8 ± 4.8, and 1.9 ± 4.8 min, respectively. There were no major procedural complications. There was no significant inter-operator variability in the ability to achieve any of the primary endpoints.

CONCLUSION

AI-guided ablation with an inter-lesion distance ≤6 mm represents an effective, safe, and highly reproducible strategy to achieve bidirectional block in the treatment of typical AFL.

Prevalence and ablation of different anatomic locations of atrial tachicardias in the electrophysiology lab of a single large center

Funding Acknowledgements

Type of funding sources: None.

Introduction

Focal atrial tachycardias (ATs) can arise from several different anatomic regions both in the right atrium (RA) and left atrium (LA). The prevalence of focal atrial tachycardia is not well known. A European study of young males applying for pilot licenses demonstrated that 0.34% had asymptomatic atrial tachycardia and 0.46% had symptomatic atrial tachycardia1. It is well-recognized that these foci do not occur randomly throughout the atria but tend to cluster at characteristic anatomic locations. However, the distribution of these sites in the total amount of ATs is not well recognized.

Purpose

The objective of this study was to determine the prevalence of different anatomic locations of ATs in the electrophysiology lab of a single large center (300 ablations per year) and to verify the site of ablation.

Methods

We collected 150 consecutive patients submitted to catheter ablation of ATs between January 2010 to December 2020. Anatomic localization of the atrial focus was performed during tachicardia by analysis of endocardial activation sequence.

Results

The distribution of the different anatomic locations is rappresented in the figure. In 134 patients (89%) ATs were localized in the RA. In the RA, these foci mainly occured along the crista terminalis (32%), the perinodal region (22,6%), the anterior right sided septum, near the foramen ovale (9,3%), the posterior right-sided septum (8%), the ostium of the coronary sinus (5,3%), the tricuspid annulus (5,3%), the superior vena cava (4,6%), the infero-lateral wall (2,5%), the right atrial appendage (0,6%) and the cavotricuspid histhmus (0,6%). In the LA (11%), foci occur predominantly at the pulmonary vein ostia (5,2%) and less commonly at the mitral annulus (2,5%), the left sided septum (0,6%), the appendage ridge (0,6%), the roof (0,6%) and the anterior wall (0,6%). For each location of AT, the ablation was performed at the earliest activation site, but about the perinodal ATs, the ablation was performed at the non coronary sinus of Valsalva of the aortic root, regardless the earliest activation site, for avoiding to create damages to the atrio-ventricular (AV) conduction system.

Conclusions

ATs mainly arise from the RA. Crista terminalis is the most common site but the perinodal region is the second more frequent site. The ablation of ATs from the perinodal region is challenging for the risk of damages to the AV conduction system. The relatively low prevalence of ATs arising from the pulmonary veins could be explained for the likely degeneration of these ATs in atrial fibrillation. Abstract Figure.

Oral procainamide as pharmacological treatment of recurrent and refractory ventricular tachyarrhythmias

Funding Acknowledgements

Type of funding sources: None.

Background

The antiarrhythmic therapy of recurrent ventricular arrhythmias 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 evaluate the efficacy and tolerability of oral procainamide 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 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 ICD interventions after the beginning of procainamide therapy. Secondary endpoints were 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 33 consecutive patients (31 males, 93.3%; mean age 73.3 ± 10 years) were included in the retrospective analysis. The mean time of procainamide treatment was 12.5 ± 13.5 months. The mean dose of procainamide was 1194 ± 495 mg/die. Procainamide therapy significantly decreased ICD interventions (DC shock: 102 vs 132; anti-tachycardia pacing: 418 vs 603; 12 patients manifested DC shock after the beginning of treatment vs 25 patients before treatment). Procainamide also decreased the total number of VT/VF episodes (514 vs 1078 episodes) [p &lt; 0,01]. Only 2 patients (6%) presented severe side effects (hypothension) requiring discontinuation of therapy.

Conclusions

Procainamide was associated with a significant decrease of ICD therapies and ventricular arrhythmias showing an optimal profile of tolerability.

Left Atrial Appendage Thrombosis and Persistent Atrial Fibrillation: combined Treatment with a Totally Thoracoscopic Approach

Minimally invasive surgical ablation is generally contraindicated in patients with atrial fibrillation and thrombosis of the left atrial appendage.

We have treated three of these patients using an innovative technique based on a bilateral video-thoracoscopic approach, performing a continuous encircling lesion at the pulmonary veins outflow with radio-frequency ablation, simultaneously excluding the left atrial appendage. The postoperative course was uneventful, without neurologic events and all patients maintained a stable sinus rhythm at 1-year follow-up.

This procedure represents a new mini-invasive method to treat persistent atrial fibrillation when partial thrombosis of the left atrial appendage contraindicates other ablation techniques.

Cryoballoon or radiofrequency ablation? Alternating technique for repeat procedures in patients with atrial fibrillation

BACKGROUND

Which technique is better for repeat ablation in patients with atrial fibrillation (AF) remains unclear. The aim of the study was to compare long-term efficacy of repeat ablation using the alternative technique for the first redo ablation procedure: (a) cryoballoon (CB) re-ablation after a failed index pulmonary vein isolation (PVI) with radiofrequency (RF) ablation, RF-then-CB group or (b) RF repeat ablation following a failed CB ablation, CB-then-RF group.

METHODS

Within the 1STOP Italian Project, consecutive patients undergoing repeat ablation with a different technique from the index procedure were included.

RESULTS

We studied 474 patients, 349 in RF-then-CB and 125 in CB-then-RF group. Less women (21% vs 30%; P = .041), more persistent AF (33% vs 22%; P = .015), longer duration of AF (60 vs 31 months; P < .001), and more hypertension (50% vs 36%; P = .007) were observed in the RF-then-CB cohort as compared with the CB-then-RF group. The number of reconnected PVs was 3.7 ± 0.7 and 1.4 + 1.3 in RF-then-CB and CB-then-RF group, respectively (P < .001). During the follow-up, significantly less AF recurrence occurred in the CB-then-RF group (22% vs 8%, HR = 0.46; 95% CI: 0.24-0.92; P = .025). Cohort designation was the only independent predictor of AF recurrence.

CONCLUSION

Alternation of energy source for repeat ablation was safe and effective, regardless the energy used first. However, patients initially treated with CB PVI undergoing repeat ablation with RF current had less AF recurrence at long-term follow-up as compared with those originally treated by RF ablation receiving a CB repeat ablation.

[The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual report 2018]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2018 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 23 912 PM implantations were collected (20 084 first implants and 3828 replacements). The number of collaborating centers was 180. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 34.5% of first PM implants, sick sinus syndrome in 18.3%, atrial fibrillation plus bradycardia in 13.0%, other in 34.2%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (19.2% of first implants). Use of single-chamber PMs was reported in 24.9% of first implants, of dual-chamber PMs in 67.6%, of PMs with cardiac resynchronization therapy (CRT) in 1.6%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 5.9%. ICD Registry: data about 18 353 ICD implantations were collected (13 944 first implants and 4359 replacements). The number of collaborating centers was 433. Median age of treated patients was 71 years (63 quartile I; 78 quartile III). Primary prevention indication was reported in 84.3% of first implants, secondary prevention in 15.7% (cardiac arrest in 5.3%). A single-chamber ICD was used in 27.9% of first implants, dual-chamber ICD in 31.9% and biventricular ICD in 40.2%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a large use of prophylactic and biventricular ICD, reflecting a favorable adherence to trials and guidelines in clinical practice. In order to increase and optimize the cooperation of Italian implanting centers, online data entry (http://www.aiac.it/riprid) should be adopted at large scale.

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.

[The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual report 2017]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2017 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 23 457 PM implantations were collected (19 378 first implant and 4079 replacements). The number of collaborating centers was 185. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 37.1% of first PM implants, sick sinus syndrome in 19.5%, atrial fibrillation plus bradycardia in 13.2%, other in 30.2%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (21.0% of first implants). Use of single-chamber PMs was reported in 25.6% of first implants, of dual-chamber PMs in 66.7%, of PMs with cardiac resynchronization therapy (CRT) in 1.4%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 6.3%. ICD Registry: data about 19 023 ICD implantations were collected (13 898 first implants and 5125 replacements). The number of collaborating centers was 437. Median age of treated patients was 71 years (63 quartile I; 78 quartile III). Primary prevention indication was reported in 81.8% of first implants, secondary prevention in 18.2% (cardiac arrest in 6.4%). A single-chamber ICD was used in 27.0% of first implants, dual-chamber in 33.6% and biventricular in 39.3%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a large use of prophylactic and biventricular ICD, reflecting a favorable adherence to trials and guidelines in clinical practice. In order to increase and optimize the cooperation of Italian implanting centers, online data entry (http://www.aiac.it/riprid) should be adopted at large scale.

Use of Allogeneic Bone Marrow Labeled with Neomycin Resistance Gene to Examine Bone Marrow-Derived Chimerism in Experimental Organ Transplantation

Posttransplant infusion of viable donor bone marrow cells (DBMC) has been shown in our previous studies to promote acceptance of incompatible kidney allografts in rhesus monkeys after treatment with polyclonal antithymocyte globulin to deplete peripheral T-lymphocytes. In this nonhuman primate model, the infusion of the DBMC is requisite for the induction of functional graft tolerance and specific MLR and CTLp unresponsiveness, although the relevant role and fate of bone marrow-derived chimeric cells is uncertain. Standard immunological and molecular techniques applied to this monkey model are unable to differentiate between chimeric cells derived from the infused DBMC and those derived from allograft-borne passenger leukocyte emigrants. To distinguish chimerism due to infused DBMC, we transduced DBMC with a functional neomycin resistance gene (Neor) using the retroviral vector pHSG-Neo. Neor-Mransduced BMC were infused into recipients approximately 2 wk after kidney transplantation and treatment with rabbit antithymocyte globulin. No maintenance immunosuppressive drugs were given. Genomic DNA isolated from peripheral blood leukocytes was used to monitor the presence of Neor-positive cells. Tissue samples obtained at necropsy also were assessed for Neor-positive chimeric cells. The presence of DBMC-derived chimerism was assessed by polymerase chain reaction using Neor sequence-specific primers (PCR-SSP). Chimerism was detectable in recipient tissues at various times for up to 6 mo after DBMC infusion. These studies using gene transduction methodology indicate that a stable genetic marker can provide capability to examine DBMC-derived chimerism for prolonged periods in a nonhuman primate model. This approach should facilitate future studies in preclinical models to study the role and type of chimeric cell lineages in relation to functional allograft tolerance.

[The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual report 2015]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2015 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 24 285 PM implantations were collected (19 194 first implant and 5091 replacements). The number of collaborating centers was 218. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 42.8% of first PM implants, sick sinus syndrome in 22.9%, atrial fibrillation plus bradycardia in 15.1%, other in 19.2%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (23.8% of first implants). Use of single-chamber PMs was reported in 26.9% of first implants, of dual-chamber PMs in 63.4%, of PMs with cardiac resynchronization therapy (CRT) in 1.8%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 7.9%. ICD Registry: data about 15 363 ICD implantations were collected (11 453 first implants and 3910 replacements). The number of collaborating centers was 434. Median age of treated patients was 71 years (63 quartile I; 78 quartile III]. Primary prevention indication was reported in 77.3% of first implants, secondary prevention in 22.7% (cardiac arrest in 8.0%). A single-chamber ICD was used in 29.3% of first implants, dual-chamber in 34.6% and biventricular in 36.1%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a large use of prophylactic and biventricular ICD, reflecting a favorable adherence to trials and guidelines in clinical practice.

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.

[The Pacemaker and Implantable Cardioverter-Defibrillator Registry of the Italian Association of Arrhythmology and Cardiac Pacing--Annual report 2014]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2014 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 24 680 PM implantations were collected (19 480 first implant and 5200 replacements). The number of collaborating centers was 208. Median age of treated patients was 81 years (75 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 45.3% of first PM implants, sick sinus syndrome in 23.1%, atrial fibrillation plus bradycardia in 11.7%, other in 19.9%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (22.7% of first implants). Use of single-chamber PMs was reported in 26.9% of first implants, of dual-chamber PMs in 63.6%, of PMs with cardiac resynchronization therapy (CRT) in 1.7%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 7.8%. ICD Registry: data about 17 116 ICD implantations were collected (11 274 first implants and 5842 replacements). The number of collaborating centers was 424. Median age of treated patients was 71 years (62 quartile I; 77 quartile III). Primary prevention indication was reported in 72.3% of first implants, secondary prevention in 27.7% (cardiac arrest in 10.1%). A single-chamber ICD was used in 32.2% of first implants, dual-chamber in 37.1% and biventricular in 30.7%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a large use of prophylactic and biventricular ICD, reflecting a favorable adherence to trials and guidelines in clinical practice.

[The pacemaker and implantable cardioverter-defibrillator registry of the Italian Association Arrhythmology Cardiac Pacing and cardiac pacing - annual report 2013]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2013 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 25 419 PM implantations were collected (19 134 first implant and 6285 replacements). The number of collaborating centers was 275. Median age of treated patients was 80 years (74 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 43.6% of first PM implants, sick sinus syndrome in 24.7%, atrial fibrillation plus bradycardia in 12.9%, other in 18.8%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (23.2% of first implants). Use of single-chamber PMs was reported in 27.2% of first implants, of dual-chamber PMs in 62.6%, of PMs with cardiac resynchronization therapy (CRT) in 1.8%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 8.4%. ICD Registry: data about 16 519 ICD implantations were collected (11 474 first implants and 5045 replacements). The number of collaborating centers was 430. Median age of treated patients was 71 years (63 quartile I; 77 quartile III). Primary prevention indication was reported in 76% of first implants, secondary prevention in 24.0% (cardiac arrest in 7.8%). A single-chamber ICD was used in 27.2% of first implants, dual-chamber in 35.9% and biventricular in 36.8%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a constant increase in prophylactic and biventricular ICD use, reflecting a favorable adherence to trials and guidelines in clinical practice.

Prevalence and Prognostic Value of Concealed Structural Abnormalities in Patients With Apparently Idiopathic Ventricular Arrhythmias of Left Versus Right Ventricular Origin

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.

[The pacemaker and implantable cardioverter-defibrillator registry of the Italian Association of Arrhythmology and Cardiac Pacing - Annual Report 2012]

BACKGROUND

The pacemaker (PM) and implantable cardioverter-defibrillator (ICD) Registry of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) monitors the main epidemiological data in real-world practice. The survey for the 2012 activity collects information about demographics, clinical characteristics, main indications for PM/ICD therapy and device types from the Italian collaborating centers.

METHODS

The Registry collects prospectively national PM and ICD implantation activity on the basis of European cards.

RESULTS

PM Registry: data about 25 611 PM implantations were collected (18 870 first implant and 6741 replacements). The number of collaborating centers was 245. Median age of treated patients was 80 years (74 quartile I; 86 quartile III). ECG indications included atrioventricular conduction disorders in 41.9% of first PM implants, sick sinus syndrome in 26.0%, atrial fibrillation plus bradycardia in 13.7%, other in 18.4%. Among atrioventricular conduction defects, third-degree atrioventricular block was the most common type (21.7% of first implants). Use of single-chamber PMs was reported in 29.0% of first implants, of dual-chamber PMs in 61.3%, of PMs with cardiac resynchronization therapy (CRT) in 1.7%, and of single lead atrial-synchronized ventricular stimulation (VDD/R PMs) in 8.0%. ICD REGISTRY: data about 16 606 ICD implantations were collected (11 393 first implants and 5213 replacements). The number of collaborating centers was 427. Median age of treated patients was 71 years (62 quartile I; 77 quartile III). Primary prevention indication was reported in 68.6% of first implants, secondary prevention in 31.4% (cardiac arrest in 9.0%). A single-chamber ICD was used in 29.4% of first implants, dual-chamber in 37.6% and biventricular in 32.9%.

CONCLUSIONS

The PM and ICD Registry appears fundamental for monitoring PM and ICD utilization on a large national scale with rigorous examination of demographics and clinical indications. The PM Registry showed stable electrocardiographic and symptom indications, with an important prevalence of dual-chamber pacing. The use of CRT-PM regards a very limited number of patients. The ICD Registry documented a constant increase in prophylactic and biventricular ICD use, reflecting a favorable adherence to trials and guidelines in clinical practice.

Indication to cardioverter-defibrillator therapy and outcome in real world primary prevention. Data from the IRIDE [Italian registry of prophylactic implantation of defibrillators] study

AIMS

Several trials demonstrated the life saving role of implantable cardioverter-defibrillators (ICD) in primary prevention of sudden cardiac death (SCD). The aim was to evaluate the clinical characteristics and 4-year outcome of consecutive patients treated in clinical practice by prophylactic ICD implantation on the basis of class I recommendations and up-to-date ICD programming.

METHODS AND RESULTS

IRIDE multi-center, prospective and observational study enrolled 604 consecutive patients (mean age: 66 ± 10 years) treated by ICD between 01/01/2006 and 30/06/2010. Main characteristics were similarly distributed among the inclusion criteria of MADIT II (24%), SCD-HeFT (24%), COMPANION (26%) and MADIT-CRT (18%) trials, while a small number of patients met the MUSTT and MADIT (7%) inclusion criteria. Single-chamber ICDs were implanted in 168 (28%) patients, dual-chamber in 167 (28%) and biventricular in 269 (43%) patients. ATP programming was activated in 546 (90%) patients. Overall survival and rate of appropriate ICD intervention by ATP and/or shock at 12-24-36-48 months of follow-up were 94%, 89%, 80%, 75% and 16%, 28%, 37% and 50%, respectively. No difference in mortality rate between the groups who received or did not receive appropriate ICD interventions was demonstrated (p=ns).

CONCLUSIONS

The IRIDE study confirms the effectiveness in real world practice of ICD implantation in patients at risk of SCD. The life saving role of ICD therapy increases as the duration of follow-up is prolonged and the survival benefit is similar in patients who received or did not receive appropriate device treatment, thus suggesting a beneficial effect of up-to-date device programming.

Is there a relationship between atrial septal aneurysm and atrial tachycardia?

We describe the case of a 37-year-old woman with atrial tachycardia associated to atrial septal aneurysm. We consider a localized reentry mechanism as the pathogenetic mechanism of the arrhythmia as demostrated by means of electrophisiological evaluation and electroanatomical mapping. The treatment by radiofrequency appears as an effective and well tolerated treatment of this unusual left atrial tachycardia.

Risk stratification in individuals with the Brugada type 1 ECG pattern without previous cardiac arrest: usefulness of a combined clinical and electrophysiologic approach

AIMS

Risk stratification in individuals with type 1 Brugada electrocardiogram (ECG) pattern (type 1 ECG) for primary prevention of sudden death (SD).

METHODS AND RESULTS

Three hundred and twenty patients (258 males, median age 43 years) with type 1 ECG were enrolled. No patient had previous cardiac arrest. Fifty-four per cent of patients had a spontaneous and 46% a drug-induced type 1 ECG. One-third had syncope, two-thirds were asymptomatic. Two hundred and forty-five patients underwent electrophysiologic study (EPS) and 110 patients received an implantable cardiac defibrillator (ICD). During follow-up [median length 40 months (IQ20-67)], 17 patients had major arrhythmic events (MAE) (14 resuscitated ventricular fibrillation (VF) and three SD). Both a spontaneous type 1 ECG and syncope significantly increased the risk (2.6 and 3.0% event rate per year vs. 0.4 and 0.8%). Major arrhythmic events occurred in 14% of subjects with positive EPS, in no subjects with negative EPS and in 5.3% of subjects without EPS. All MAE occurred in subjects who had at least two potential risk factors (syncope, family history of SD, and positive EPS). Among these patients, those with spontaneous type 1 ECG had a 30% event rate.

CONCLUSION

(1) In subjects with the Brugada type 1 ECG, no single clinical risk factor, nor EPS alone, is able to identify subjects at highest risk; (2) a multiparametric approach (including syncope, family history of SD, and positive EPS) helps to identify populations at highest risk; (3) subjects at highest risk are those with a spontaneous type 1 ECG and at least two risk factors; (4) the remainder are at low risk.

Monomorphic ventricular tachycardia in 'Brugada syndrome': clinical case and literature review

A 20-year-old white judoka was admitted for severe palpitations during exercise followed by syncope. The electrocardiogram on admission revealed a wide-complex monomorphic tachycardia at a rate of 260 beats/min, with right bundle brunch block morphology and right axis deviation. Following electrical cardioversion, the electrocardiogram showed sinus rhythm with type 1 pattern of Brugada syndrome. We describe in detail the clinical course, the results of electrophysiological study, and therapeutic management. We reviewed literature data concerning a few cases of 'atypical Brugada syndrome' characterized by monomorphic ventricular tachycardia as clinical arrhythmia.