Clinical implications of left ventricular assist device implantation in patients with an implantable cardioverter-defibrillator

Purpose

This study aims to study the clinical implications of the concomitant use of a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD).

Methods

In this retrospective study, all patients who underwent LVAD (Heart Mate II) implantation with concomitant ICD therapy at our institution between June 2007 and August 2012 were included. We sought to investigate (1) the electromagnetic interference between LVAD and ICD telemetry, (2) the effect of LVAD implantation on right ventricular (RV) lead parameters and (3) the ventricular tachyarrhythmias (VAs) that occur post-LVAD implantation.

Results

Of the 23 patients (53?±?9 years, 73 % male, LVEF 19?±?9 %) included, ICD telemetry was lost in four patients post-LVAD implantation (Saint-Jude-Medical Atlas V-193, V-240, V-243, and Sorin CRT-8750), prompting either use of a metal shield (n?=?1), a change in position of the programmer head (n?=?1) or ICD replacement (n?=?2). LVAD implantation was associated with a decrease in both RV signal amplitude (p?=?0.04) and RV impedance (p?<?0.01), and a trend towards an increased RV pacing threshold (p?=?0.08), without affecting clinical outcome. Eleven patients (47.8 %) experienced VAs after LVAD implantation, which on the whole were well tolerated. Their occurrence was strongly linked to a history of VAs before device implantation (p?<?0.01).

Conclusions

Electromagnetic interference between LVADs and ICD telemetry may necessitate ICD replacement. LVAD placement is associated with significant changes in RV lead parameters that have minimal clinical significance. VAs occur in approximately half of LVAD patients seen and their occurrence is strongly related to a history of VAs prior to LVAD implantation.     

Programmed ventricular stimulation in patients with idiopathic dilated cardiomyopathy and syncope receiving implantable cardioverter-defibrillators: a case series and a systematic review of the literature

BACKGROUND: The role of programmed ventricular stimulation (PVS) in patients with idiopathic dilated cardiomyopathy (DCM) and syncope receiving implantable cardioverter-defibrillators (ICD) remains controversial. METHODS AND RESULTS: Between 1994 and July 2002, 20 patients with DCM and syncope underwent PVS and ICD implantation at the Onassis Cardiac Surgery Center or the Alexandra General Hospital. At PVS 10 patients had inducible sustained monomorphic ventricular tachycardia (SMVT), 3 patients had inducible sustained polymorphic ventricular tachycardia or ventricular fibrillation, and 7 patients had no inducible arrhythmia. The latter 7 patients received an ICD because of clinical occurrence of ventricular tachycardia (n=5) or fibrillation (n=2). Mean age was 55+/-14 years; 80% were men. During a mean follow-up of 2.8+/-2.3 years, 12 of the 20 patients received an appropriate shock. The incidence of appropriate shocks at 1 and 3 years was 69% and 84% in the inducible SMVT group, and 56% and 67% in the group without inducible SMVT (p=0.93, log rank test). Overall survival was similar in both groups (p=0.53). In a systematic review of the published literature 18 of 75 (24%) patients with DCM, syncope and a negative PVS had an appropriate ICD shock after a mean follow-up of 27 months. CONCLUSION: PVS has a limited role in risk stratification of patients with DCM and syncope.     

Response to programmed ventricular stimulation and clinical outcome in cardiac arrest survivors receiving randomised assignment to implantable cardioverter defibrillator or antiarrhythmic drug therapy.

BACKGROUND: Using a prospective design which randomly assigned implantable cardioverter defibrillator (ICD) versus antiarrhythmic drugs (AADs), we investigated the usefulness of programmed ventricular stimulation (PVS) for prediction of outcome and therapy effectiveness in cardiac arrest (CA) survivors. METHODS AND RESULTS: We performed baseline PVS in 285 survivors of CA enrolled in the Cardiac Arrest Study Hamburg (CASH) and randomised to ICDs or AADs. Sustained ventricular arrhythmia (VA) was induced in 134 (47.0%) patients. We compared the outcomes of different subgroups based on response to baseline PVS and randomly assigned therapy. Patients were followed for a median of 55 months. The raw death rate was greater among inducible (51.3% [95% CI: 44.9-58.3%]) than non-inducible patients (28.8% [CI: 23.4-36.1%, p = 0.0003]). When challenged in a multivariate model, inducibility still had an independent power for predicting all-cause death (hazard ratio (HR), 1.5 [95% CI, 1.1-2.3], p = 0.041), but not sudden death (SD) (HR, 1.2 [95% CI, 0.7-3.6], p = 0.162). Subgroup analysis showed that, when compared to AADs, assignment to ICDs was associated with a lower risk of all-cause death (HR, 0.4 [95% CI, 0.1-0.9], p = 0.044) in patients with EF < or =0.35 and non-inducible arrhythmias, but not in other patient subgroups. CONCLUSIONS: In CA survivors, inducibility at baseline PVS is independently associated with an increased risk of all-cause death, but not SD. In addition, response to PVS may help to identify subgroups of patients who could most benefit from ICD.     

Role of nonsustained ventricular tachycardia and programmed ventricular stimulation for risk stratification in patients with idiopathic dilated cardiomyopathy

Background: The prognostic role of asymptomatic nonsustained ventricular tachycardia (NSVT) and programmed ventricular stimulation (PVS) in patients with idiopathic dilated cardiomyopathy (IDC) remains controversial. Methods: The prognostic significance of ventricular arrhythmias, ejection fraction, NYHA class, atrial fibrillation and age for overall and sudden death mortality was prospectively studied in 157 patients with IDC (group 1) free of documented sustained ventricular arrhythmia and syncope. In 99 patients with asymptomatic NSVT (group 2), PVS with 2 – 3 extrastimuli was performed. Non-inducible patients were discharged without specific antiarrhythmic therapy, whereas those with inducible monomorphic ventricular tachycardia were implanted with an ICD. Results: In group 1, 48% of patients had NSVT. Overall and sudden death mortality were significantly higher in patients with NSVT (34.2 vs. 9.8%, p = 0.0001 and 15.8 vs. 3.7%, p = 0.0037; follow-up 22 ± 14 months). Multivariate analysis revealed that NSVT independently predicts both overall and sudden death mortality (p = 0.0021 and .0221, respectively; adjusted for EF, NYHA class and age). In group 2, inducibility of sustained ventricular tachyarrhythmia was 7%, but sustained monomorphic VT occurred in 3% only. Two of 7 inducible patients experienced arrhythmic events during a follow-up of 25 ± 21 months (positive predictive value 29%). Overall and sudden death mortality were 29% and 0% in the inducible group vs. 17 and 4% in the non-inducible group. Both overall and sudden death mortality were signi.cantly lower in non-inducible patients from group 2 as compared to patients from group 1 with NSVT (p = 0.0043 and 0.0048), most likely due to a more common use of betablockers and a higher EF in the former group (p < 0.001, respectively). Conclusions: In patients with IDC, NSVT independently predicts both overall and sudden death mortality. Due to a low inducibility rate and a poor positive predictive value, PVS seems inappropriate for further arrhythmia risk assessment. However, in spite of documented NSVT, the incidence of SCD in patients on optimized medical treatment including betablockers seems to be very low, questioning the need for specific arrhythmia risk stratification. Received: 21 August 2002, Returned for revision: 24 September 2002, Revision received: 8 October 2002, Accepted: 7 November 2002, Published online: 12 May 2003 Correspondence to: R. Becker, MD     

First worldwide use of pulsed-field ablation for ventricular tachycardia ablation via a retrograde approach

Introduction

We present the first worldwide use of pulsed-field ablation (PFA) for ventricular tachycardia (VT) ablation via a retrograde approach.

Methods

The patient had previously failed conventional ablation of an intramural circuit underneath the aortic valve. The same VT circuit was inducible during the procedure. The Farawave PFA catheter and Faradrive sheath were used to deliver PFA applications.

Results

Post ablation mapping demonstrated scar homogenization. There was no evidence of coronary spasm during PFA applications and no other complications occurred. VT was non-inducible post ablation and the patient has remained free of arrhythmia at follow-up.

Conclusion

PFA for VT via a retrograde approach is feasible and effective.     

Amiodarone therapy for sustained ventricular tachycardia after myocardial infarction: long-term follow-up, risk assessment and predictive value of programmed ventricular stimulation

We determine the value of the programmed ventricular stimulation (PVS) and of clinical, angiographic and electrophysiologic variables in assessing the long-term risk of arrhythmia recurrence in a group of coronary artery diseased patients presenting with a first episode of monomorphic sustained ventricular tachycardia (VT) treated with amiodarone. Mortality and arrhythmia recurrence rates were retrospectively assessed in 55 consecutive patients with previous myocardial infarction presenting with a first VT episode. Results of left heart catheterization, echocardiography and time-domain signal-averaging were collected. Patients underwent PVS after amiodarone oral loading and were classified according to inducibility before being all discharged on amiodarone (200 mg daily). The mean follow-up was 42+/-31 months. Total and cardiac mortality rates were 29% (16 patients) and 23% (13 patients) respectively. Sudden death (SD) occurred in nine patients (16%). VT recurred in 13 patients (23%). Sustained monomorphic VT was inducible in 40 patients (72%) after amiodarone loading. Neither total mortality (10/40 vs. 6/15) nor cardiac mortality (3/40 vs. 1/15) were significantly different between inducible and non-inducible patients. Recurrent VT rate was 27% (11/40 patients) for the inducible group and 13% (2/15 patients) for the non-inducible group (NS). SD occurred in 6/40 inducible patients (15%) and in 2/15 non-inducible patients (13%) (NS). Arrhythmic events occurred in 42% (17/40) inducible patients vs. 26% (4/15) non-inducible patients (P=0.07). Parameters correlated with outcome were ejection fraction (EF) (5 SD/11 patients with EF <0.3 vs. 4/44 with EF >0.3, P=0.003), mitral insufficiency (MI) (4 SD/10 patients with MI vs. 4/44 patients without MI, P=0.004) and age (65+/-9 years for patients with VT recurrence vs. 58+/-9, P=0.02). Although the risk stratification can be improved, reliable and safe long-term prediction of recurrence of malignant ventricular arrhythmia in individual patients cannot be made. Consequently, the systematic implantation of a cardioverter-defibrillator in case of a first episode of sustained VT occurring in coronary artery disease patients should be further debated.     

Predictive value of programmed ventricular stimulation in patients with ischaemic cardiomyopathy: implications for the selection of candidates for an implantable defibrillator.

AIMS: The present study assessed the role of programmed ventricular stimulation (PVS) in risk stratification of patients with ischaemic cardiomyopathy (ICM), candidates for implantable cardioverter-defibrillator (ICD). METHODS AND RESULTS: Consecutive patients with ICM and LVEF < or = 40% (n = 106, age 61 +/- 7 years, LVEF 27 +/- 7%) underwent PVS. This was considered positive in case of inducibility of monomorphic ventricular tachycardia (VT) with < or =3 extrastimuli; polymorphic VT, ventricular fibrillation (VF), and fast monomorphic VT (CL < or = 230 ms) with < or =2 extrastimuli. Primary end-point was the combination of arrhythmic death and VF requiring ICD shock. Forty-nine patients (46%) were inducible at PVS; 74 (70%) were implanted with ICD. During a 24-month follow-up, the primary end-point occurred more frequently in positive PVS patients among the overall population, among patients with LVEF < or = 30% (n = 80) and among patients with an ICD. The negative predictive value of PVS was 96% in each group. In the overall population, both PVS (HR 7.32, 95% CI 1.6-32) and LVEF (HR 4.59, 95% CI 1.6-13) predicted the primary end-point. CONCLUSION: PVS may still have a role in predicting the arrhythmic risk in patients with ICM. A negative PVS identifies a subgroup with a very low risk of arrhythmic events even in patients with LVEF < or = 30%.     

Differential Effects of Atropine and Isoproterenol on Inducibility of Atrioventricular Nodal Reentrant Tachycardia

Background: Radiofrequency ablation of the slow pathway in atrioventricular nodal reentrant tachycardia (AVNRT) relies on tachycardia non-inducibility after ablation as success criterion. However, AVNRT is frequently non-inducible at baseline. Thus, autonomic enhancement using either atropine or isoproterenol is frequently used for arrhythmia induction before ablation. Methods: 80 patients (57 women, 23 men, age 50±14 years) undergoing slow pathway ablation for recurrent AVNRT were randomized to receive either 0.01mg/kg atropine or 0.5-1.0g/kg/min isoproterenol before ablation after baseline assessment of AV conduction. The effects of either drug on ante- and retrograde conduction was assessed by measuring sinus cycle length, PR and AH interval, antegrade and retrograde Wenckebach cycle length (WBCL), antegrade effective refractory period (ERP) of slow and fast pathway and maximal stimulus-to-H interval during slow and fast pathway conduction. Results: Inducibility of AVNRT at baseline was not different between patients randomized to atropine (73%) and isoproterenol (58%) but was reduced after atropine (45%) compared to isoproterenol (93%, P<0.001). Of the 28 patients non-inducible at baseline isoproterenol rendered AVNRT inducible in 21, atropine in 4 patients. Dual AV nodal pathway physiology was present in 88% before and 50% after atropine compared to 83% before and 73% after isoproterenol. Whereas both drugs exerted similar effects on ante- and retrograde fast pathway conduction maximal SH interval during slow pathway conduction was significantly shorter after isoproterenol (300±48ms vs. 374±113ms, P=0.012). Conclusion: Isoproterenol yields higher AVNRT inducibility than atropine in patients non-inducible at baseline. This may be caused by a more pronounced effect on antegrade slow pathway conduction.     

Acquired Pulmonary Vein Stenosis After Radiofrequency Ablation for Atrial Fibrillation: Single-Center Experience in Catheter Interventional Treatment

Objectives

The aim of the present study was to analyze and report a single-center experience with catheter interventional treatment of radiofrequency-induced pulmonary vein stenosis (PVS) following atrial fibrillation (AF) ablation.

Posttraumatic stress disorder and mortality in VA patients with implantable cardioverter‐defibrillators

Background

The association between posttraumatic stress disorder (PTSD) and mortality in patients undergoing implantable cardioverter‐defibrillator (ICD) placement has not been evaluated in US veterans.

Hypothesis

PTSD in veterans with ICD is associated with increased mortality.

Methods

We studied a retrospective cohort of 25 678 veterans who underwent ICD implantation between September 30, 2002, and December 31, 2011. Of these subjects, 3280 carried the diagnosis of PTSD prior to ICD implantation. Primary outcome was all‐cause mortality between date of ICD implantation and end of follow‐up (September 30, 2013). We used Cox proportional hazard models to compute multivariable adjusted hazard ratios with corresponding 95% confidence intervals for the relation between PTSD diagnosis and death following ICD placement.

Results

During a mean follow‐up of 4.21 ± 2.62 years, 11 015 deaths were reported. The crude incidence rate of death was 87.8 and 103.9/1000 person‐years for people with and without PTSD, respectively. We did not find an association between presence of PTSD before or after ICD implantation and incident death when adjusted for multiple risk factors (hazard ratio: 1.003, 95% confidence interval: 0.948–1.061). In secondary analysis, no statistically significant association was found.

Conclusions

In this retrospective cohort study among more than 25 000 veterans undergoing ICD implantation, almost 13% had a diagnosis of PTSD. Subjects with PTSD were significantly younger, yet they had a higher incidence of coronary heart disease, major cardiac comorbidities, cancer, and mental health conditions. We found no association between presence of PTSD before or after ICD implantation and incident death when adjusting for all covariates.     

Ventricular Arrhythmias after LV Remodelling: Surgical Ventricular Restoration or ICD?

Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular stimulation (PVS) to evaluate surgical ventricular restoration (SVR) that excludes scar and lower ventricular volume alters the early and late arrhythmia process without ICD utilization.Methods: Clinical and hemodynamic results before and after SVR in post-infarction patients, are compared to contrast spontaneous and/or inducible ventricular tachycardia to patients without arrhythmias. Study arrhythmia groups included: Spontaneous in 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia: Inducible in 105 patients without clinical ventricular arrhythmias but PVS inducible ventricular tachycardia; and No arrhythmias in 190 patients without spontaneous or PVS inducible ventricular tachycardia.Results: Preoperative LV end systolic volume index helped define preoperative arrythmia potential: Spontaneous > 120/m², inducible > 100 ml/m², and none < 100ml/m². Overall operative mortality rate was 7.6% (29/382). Sudden cardiac death rate was 2.5% causing 18.7% of all deaths. Surgical management reduced inducible ventricular tachycardia, from 41% preoperatively (144/352) to 8% (26/307) at early study, and 8% (14/177) one year later. Cardiac mortality was low at 5-years and not different between groups, despite use of only one late ICD device.Conclusions: Favorable electrical success rate and low mortality always included volume reduction to interrupt functional re-entry circuits, but also added endocardiectomy, cryoablation, CABG and mitral repair when needed. Overall SVR findings show volume and shape alteration limits ventricular arrhythmias that impair prognosis, and suggests ICD devices are not needed.     

Long-term follow-up in patients treated by stent implantation for post-ablation pulmonary vein stenosis

Purpose

Symptomatic severe pulmonary vein stenosis (PVS) after catheter ablation of atrial fibrillation (AF) is a rare but well-recognized complication. Treatment options include pulmonary vein angioplasty with or without drug eluting balloons or angioplasty with stent implantation. The treatment of choice is unclear. In our center, pulmonary vein stenting is the treatment of choice for significantly stenotic veins. We present the long-term clinical outcome of 9 patients treated with stent implantation.

Methods

Between 2001 and 2015, 3048 patients with AF were treated with catheter ablation at our institution, of which 9 developed symptomatic PVS. A total of 11 PVS were treated. Pre-procedural imaging (CT, MR, transesophageal echocardiography, angiography) was performed in all patients.

Results

Mean time from ablation to stenting was 18 months. Three patients had recurrent pneumonia and the remaining reduced functional capacity (NYHA 2). All patients were in functional capacity NYHA 1 (p?<?0.05) after a mean follow-up of 64 (18–132) months. Three patients still had paroxysmal AF, of which two have undergone repeated ablation.

Conclusions

Symptomatic PVS after AF ablation can be successfully treated by stent implantation with durable results and good clinical outcome. AF ablation is still a feasible option after stent deployment.

     

Subcutaneous implantable cardioverter defibrillator eligibility according to a novel automated screening tool and agreement with the standard manual electrocardiographic morphology tool

Background

Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) can have multiple exits exhibiting divergent ECG features.

Methods

In a series of 131 patients with VAs with LVOT origin, 10 patients presented with divergent QRS morphologies. Multisite endo- and epicardial mapping of different exit sites was performed.

Results

The earliest ventricular activity of 23 LVOT VAs in 10 patients was detected in the endocardium of the LV in 7 patients, the aortic sinuses of Valsalva (SoV) in 3 patients, the distal coronary sinus in 6 patients, the anterior interventricular vein in 3 patients, and the posterior right ventricular outflow tract (RVOT) in 4 patients. Simultaneous elimination of two divergent QRS morphologies of LVOT VAs by ablation from a single site was achieved in 5 patients (aorto-mitral continuity in 3 patients, SoV and RVOT in each 1 patient) using a mean maximum ablation energy of 46?±?5 W. Sequential ablation from two or three different sites, including trans-pericardial and distal coronary sinus ablation in each 2 patients, led to elimination of the divergent VA QRS morphologies in the other 5 patients. During the follow-up of 28?±?29 months, 4 of the 10 patients had recurrence of at least one LVOT VA. A 43-year-old patient with muscular dystrophy Curschmann-Steinert had recurrence of sustained LVOT VTs and died of sudden cardiac death.

Conclusions

Multisite mapping of different exit sites of LVOT VAs can guide ablation of intramural foci but the recurrence rate after initially successful ablation was high.

     

Design and characteristics of the prophylactic intra-operative ventricular arrhythmia ablation in high-risk LVAD candidates (PIVATAL) trial

Background

The use of a Left Ventricular Assist Device (LVAD) in patients with advanced heart failure refractory to optimal medical management has progressed steadily over the past two decades. Data have demonstrated reduced LVAD efficacy, worse clinical outcome, and higher mortality for patients who experience significant ventricular tachyarrhythmia (VTA). We hypothesize that a novel prophylactic intra-operative VTA ablation protocol at the time of LVAD implantation may reduce the recurrent VTA and adverse events postimplant.

Methods

We designed a prospective, multicenter, open-label, randomized-controlled clinical trial enrolling 100 patients who are LVAD candidates with a history of VTA in the previous 5 years. Enrolled patients will be randomized in a 1:1 fashion to intra-operative VTA ablation (n = 50) versus conventional medical management (n = 50) with LVAD implant. Arrhythmia outcomes data will be captured by an implantable cardioverter defibrillator (ICD) to monitor VTA events, with a uniform ICD programming protocol. Patients will be followed prospectively over a mean of 18 months (with a minimum of 9 months) after LVAD implantation to evaluate recurrent VTA, adverse events, and procedural outcomes. Secondary endpoints include right heart function/hemodynamics, healthcare utilization, and quality of life.

Conclusion

The primary aim of this first-ever randomized trial is to assess the efficacy of intra-operative ablation during LVAD surgery in reducing VTA recurrence and improving clinical outcomes for patients with a history of VTA.     

Hemodynamic comparison of different multisites and multipoint pacing strategies in cardiac resynchronization therapies

Purpose

Late cure after a previously failed ablation of ventricular arrhythmias (VAs) is a relatively common phenomenon. The present study sought to delineate the incidence and electrophysiological characteristics of late cure in idiopathic VA patients.

Methods

Totally, 45 idiopathic VA cases (mean age 44?±?18 years, 27 males) either failed acutely or recurred within 12 h were enrolled in this study. Based on intensive clinical observations in the acute period, 19 (42%) patients demonstrated late cure in the first week after the procedure.

Results

The late cure patients had significantly better acute and cumulative ablation effects during the procedure than did those without a late cure. Additionally, they had a prediction that originated from the right ventricular outflow tract, aortic-mitral continuum, and left summit area relative to other sites (13/18 vs 6/27, p?<?0.01). In a median follow-up of 24 [14, 46] months, 7/19 (37%) patients had their VAs recurred. The late cure group had significantly more patients cured at long-term follow-up than those without (12/19 vs 0/26, p?<?0.01). A cutoff value of the “time to eliminate VAs” >?7.0 s was able to predict a long-term recurrence of the VAs with 62.5% sensitivity and 85.7% specificity.

Conclusions

The late cure of VAs occurs in more than one third of patients who have a seemingly unsuccessful ablation session, which is clustered in the first week after the procedure. However, long-term recurrence of VAs occurred in 37% of the late cure patients, emphasizing the importance of long-term follow-up.

     

Electrocardiographic features of failed and recurrent right ventricular outflow tract catheter ablation of idiopathic ventricular arrhythmias

1 Introduction

Various ECG algorithms have been proposed to identify the origin of idiopathic outflow tract (OT)‐ventricular arrhythmia (VA). However, electrocardiographic features of failed and recurrent right ventricular outflow tract (RVOT) ablation of idiopathic OT‐VAs have not been clearly elucidated.

2 Methods and results

A total of 264 consecutive patients (mean age: 44.0 ± 13.0 years, 96 male) undergoing RVOT ablation for OT‐VAs with a transition ≥V₃, including 241 patients (91.6%) with initially successful procedures and 23 patients (8.4%) with failed ablation. Detailed clinical characteristics and ECG features were analyzed and compared between the two groups. VAs with failed RVOT ablation had larger peak deflection index (PDI), longer V₂ R wave duration (V₂Rd), smaller V₂ S wave amplitude, higher R/S ratio in V₂, higher V₃ R wave amplitude, and larger V₂ transition ratio than those with successful ablation. Multivariate analysis demonstrated that PDI, V₂Rd, V₂ transition ratio, and pacemapping score acquired during mapping independently predicted failed ablation (P  =  0.01, P  =  0.01, P  =  0.01, and P < 0.001, respectively). In 31 recurrent cases (12.8%) after initially successful ablation, multivariate Cox regression analysis showed that only the earliest activation time acquired during mapping predicted the recurrences after successful ablation (P  =  0.001). The recurrent cases displayed different ECG features comparing with those with failed ablation.

3 Conclusion

The electrocardiographic features of failed RVOT ablation of idiopathic OT‐VAs with a transition ≥V₃ were characterized by PDI, V₂Rd, V₂ transition ratio, and pacemapping score acquired during mapping, unlike the recurrent RVOT ablation.     

Evaluation by MRA of aortic dilation late after repair of tetralogy of Fallot

Objectives

This study evaluated predictors for aortic dilation (AD) in patients with repaired tetralogy of Fallot (rTOF) using magnetic resonance angiography (MRA).

Background

AD is common in patients with rTOF and may result in increased morbidity and mortality. There are no guidelines for evaluation of AD for rTOF patients.

Methods

All adults with rTOF who previously underwent MRA had retrospective aortic measurements at the sinuses of Valsalva (SoV) and ascending aorta (AsAo). Rate of change in diameter was determined in patients with multiple MRAs. Chart review identified risk factors for AD. Univariate and multivariate analyses tested predictors of AD.

Results

Of the 87 patients who met the inclusion criteria, 12 (14%) had AD. At baseline, mean diameter was 3.6 ± 0.6 cm and 3.1 ± 0.6 cm at the SoV and AsAo, respectively. The AsAo was larger than the SoV in 17%. Predictors of AD included male gender, age, right aortic arch, pregnancy, older age at complete repair, smoking, and systemic hypertension. Serial studies were available in 55 patients; the rate of growth was slow: 0.4 ± 0.9 mm/year (SoV) and 0.1 ± 0.8 mm/year (AsAo).

Conclusions

AD is common in rTOF at the SoV and AsAo. Transthoracic echocardiography, which does not always image the AsAo as well as MRA, may not image AD in rTOF in cases in which the AsAo is dilated. Although several risk factors correlate with AD in rTOF, the rate of aortic growth is slow, suggesting that rTOF patients may not require frequent aortic imaging.     

Overweight and obesity as protective factors against mortality in nonischemic cardiomyopathy patients with an implantable cardioverter defibrillator

BackgroundPrevious studies have reported inconsistent results on the relationship between body mass index (BMI) and clinical outcomes in implantable cardioverter defibrillator (ICD) patients. Additionally, research on ICD patients with nonischemic cardiomyopathy (NICM) is lacking.HypothesisThis study aimed to investigate the impact of BMI on mortality and ventricular arrhythmias (VAs) in NICM patients with an ICD.MethodsThis study retrospectively analyzed the data from the Study of Home Monitoring System Safety and Efficacy in Cardiac Implantable Electronic Device‐implanted patients (SUMMIT) in China. Four hundred and eighty NICM patients with an ICD having BMI data were enrolled. Patients were divided into two groups: underweight and normal range group (BMI < 24 kg/m²), overweight and obese group (BMI≥24 kg/m²). The primary endpoint was all‐cause mortality. The secondary endpoint was the first occurrence of VAs requiring appropriate ICD therapy or shock.ResultsDuring a median follow‐up of 61 (1‐95) months, 70 patients (14.6%) died, 173 patients (36%) experienced VAs requiring appropriate ICD therapy, and 112 patients (23.3%) were treated with ICD shock. Multivariate Cox regression modeling indicated a decreased mortality risk in the overweight and obese group compared with the underweight and normal range group (hazard ratio = 0.44, 95% confidence interval 0.26‐0.77, P = .003). However, the risk of VAs was similar in both groups in univariate and multivariate Cox models.ConclusionsCompared with underweight and normal weight, overweight and obesity are protective against mortality but have only a neutral impact on VAs risk in NICM patients with an ICD.     

Ventricular arrhythmias after LV remodelling: surgical ventricular restoration or ICD?

Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular stimulation (PVS) to evaluate surgical ventricular restoration (SVR) that excludes scar and lower ventricular volume alters the early and late arrhythmia process without ICD utilization. METHODS: Clinical and hemodynamic results before and after SVR in post-infarction patients, are compared to contrast spontaneous and/or inducible ventricular tachycardia to patients without arrhythmias. Study arrhythmia groups included: Spontaneous in 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia: Inducible in 105 patients without clinical ventricular arrhythmias but PVS inducible ventricular tachycardia; and No arrhythmias in 190 patients without spontaneous or PVS inducible ventricular tachycardia. RESULTS: Preoperative LV end systolic volume index helped define preoperative arrythmia potential: Spontaneous > 120/m(2), inducible > 100 ml/m(2), and none < 100ml/m(2). Overall operative mortality rate was 7.6% (29/382). Sudden cardiac death rate was 2.5% causing 18.7% of all deaths. Surgical management reduced inducible ventricular tachycardia, from 41% preoperatively (144/352) to 8% (26/307) at early study, and 8% (14/177) one year later. Cardiac mortality was low at 5-years and not different between groups, despite use of only one late ICD device. CONCLUSIONS: Favorable electrical success rate and low mortality always included volume reduction to interrupt functional re-entry circuits, but also added endocardiectomy, cryoablation, CABG and mitral repair when needed. Overall SVR findings show volume and shape alteration limits ventricular arrhythmias that impair prognosis, and suggests ICD devices are not needed.     

Ablation of atrial fibrillation in Brugada syndrome patients with an implantable cardioverter defibrillator to prevent inappropriate shocks resulting from rapid atrial fibrillation

Background

Inappropriate shocks resulting from atrial tachyarrhythmias are highly problematic for patients with an implantable cardioverter defibrillator (ICD). We aimed to determine the effectiveness of catheter ablation of atrial fibrillation (AF) in preventing inappropriate shocks due to rapid AF in patients diagnosed with Brugada syndrome (BS) who were implanted with an ICD.

Methods

We performed AF ablation in 5 BS patients with ICDs who experienced inappropriate shocks caused by rapid paroxysmal AF and in a BS patient scheduled to determine an indication of an ICD implantation who frequently experienced rapid AF.

Results

Although 2 patients underwent a 2nd ablation procedure because of AF recurrences, 5 of the 6 patients were finally free from AF after their last procedure during a median follow-up period of 43.2 months. No further inappropriate shocks caused by rapid AF occurred after the 1st ablation session in any of the patients. A patient developed a ventricular fibrillation storm during his electrophysiological study following the ablation procedure, and then was implanted with an ICD.

Conclusions

AF ablation in BS patients may be reasonable to prevent inappropriate ICD shocks resulting from rapid AF. However, ventricular extrastimuli just after the ablation had better be avoided in them.