Implantable Cardiac Defibrillator Shock Research Articles

Modified sympathicotomy in patients with refractory ventricular tachycardia and structural heart disease: a single-center experience.

Modified cardiac sympathetic denervation (CSD) with stellate ganglion (SG) sparing is a novel technique for cardiac neuromodulation in patients with refractory ventricular tachycardia (VT). Our aim is to describe the mid- to long-term clinical outcome of the modified CSD with SG sparing in a series of patients with structural heart disease (SHD) and refractory VT. All consecutive patients with SHD and refractory VT undergoing modified CSD were enrolled. Baseline clinical characteristics and periprocedural data were collected for all patients. The primary outcome was any recurrence of sustained VT. We enrolled 15 patients (age: 69.2 ± 7.9years; male 100%) undergoing modified CSD. Left ventricular ejection fraction was 37 ± 11% and all patients had an implantable cardiac defibrillator (ICD); the underlying cardiomyopathy was non-ischemic in 73.3% of them. At least one previous ablation had been attempted in 66.6% of cases. The 73.3% of patients underwent bilateral CSD and the mean effective surgical time was 10.8 ± 2.4min per side; no major periprocedural complication occurred. After a median follow-up time of 15months (IQR: 8.5-24.5months), the primary outcome occurred in 47.6% of cases. All patients experienced a reduction of ICD shocks after CSD (3.1 ICD shocks/patient before vs. 0.3 ICD shocks/patient after CSD; p-value: 0.001). Bilateral CSD and a VT cycle length < 340ms were associated with better outcomes. A modified CSD approach with stellate ganglion sparing appears to be safe, fast, and effective in the treatment of patients with SHD and refractory VTs.

CI-452769-3 INAPPROPRIATE ICD SHOCKS IN PATIENTS WITH LVADS: PREVALENCE, ASSOCIATED FACTORS, AND ETIOLOGIES

Left Ventricular Assist Devices (LVADs) are increasingly used to treat advanced heart failure. While most patients with an LVAD have an implantable cardiac defibrillator (ICD) in situ, there are limited data on the frequency and causes of ICD therapies in patients with LVADs. To define the incidence, programming and patient characteristics associated with appropriate and inappropriate shocks in persons with ICDs and LVADs. We performed a retrospective review at Duke University Hospital of all LVAD recipients implanted with a HeartWare, HeartMate II, and HeartMate III (January 1, 2013 to June 30, 2019) and an ICD in situ. ICD shocks were adjudicated by the treating physician and a 2nd review for the purpose of this study. Among 437 patients with an ICD in situ undergoing LVAD implant, 147 (33.6%) patients had at least one shock episode following LVAD implantation. 12 patients were excluded due to incomplete device history. Among 135 patients, there were a total of 332 shock episodes: 257 (77.4%) appropriate and n=75 (22.6%) inappropriate. Etiologies for inappropriate shocks included SVT (n=66, 19.9%), physiologic oversensing (n=1, 0.3%), and non-physiologic oversensing (n=8, 2.4%). Overall, 92 (68.1%) patients had no inappropriate shock episodes, 43 (31.8%) patients had ≥ 1 inappropriate shock episodes, and 14 (10.4%) patients had ≥ 2 inappropriate shock episodes. Moreover, 26 (19.3%) patients had only inappropriate shock episodes. Among persons with inappropriate shocks, 0 of 47 patients had device programming consistent with consensus AHA recommendations (published after end of follow-up). The rate of inappropriate shocks in LVAD recipients is very high and is most often due to supraventricular arrhythmias. Implementation of current consensus AHA recommendations for LVAD programming may help avoid inappropriate shocks.

How arrhythmic risk changes over time in patients with low risk Brugada syndrome

Abstract Background Brugada Syndrome (BrS) is an inherited disorder associated with an increased risk of sudden cardiac death (SCD) and is diagnosed by the presence of a Brugada type I ECG pattern, either spontaneous or drug-induced. A spontaneous ECG pattern is one of the two main risk factors for SCD, along with syncope. However, there is still no clear evidence on how and how often to screen patients with drug-induced BrS to detect a spontaneous ECG pattern, therefore allowing to reassess their arrhythmic risk. Purpose To determine how many subjects develop a spontaneous ECG pattern among a pool of patients with low risk BrS (drug-induced pattern without history of syncope at the time of diagnosis) observed through systematic ECG Holter monitoring. Methods We retrospectively collected data for all patients with low risk BrS treated at our center for at least 12 months between 2016 and 2021. Each patient was tested yearly with at least one 12-lead 24-hour ECG Holter monitoring with high precordial leads (V1-V2, V3-V4, V5-V6 respectively in 2nd, 3rd and 4th intercostal space parasternal left and right). In case of spontaneous pattern detection at two recordings, patients underwent electrophysiological study (EPS) and in case of inducible ventricular arrhythmias, implantable cardiac defibrillator (ICD) placement. Results We included 63 patients with low risk BrS. During a median follow-up of 48 months: 1 patient died for SCD (1.6%), 1 experienced syncope (1.6%) and 19 exhibited a spontaneous ECG pattern (30.2%). Of these 19 patients: 18 were males and 5 had a mutation of SCN5A; the average age at the time of spontaneous pattern detection was 48.1±11.5 years. The average number of ECG holters/per patient/per year was 1.1±0.6, the average number of ECG Holters until the detection of a spontaneous pattern was 3.3±1.8, whilst the average number of months in between the diagnosis and the detection of a spontaneous pattern was 43.2±41.1. After the observation of a spontaneous pattern: 6 patients were excluded from further investigation (as they had already undergone EPS or refused), 1 was directly treated with ICD and 12 underwent EPS, 4 of whom consequently underwent ICD placement. Among these 5 patients who underwent ICD placement – 7.9% of the original 63 patients – we observed 1 appropriate ICD intervention (antitachycardia pacing), 1 inappropriate ICD shock and 1 ICD related complication. Conclusions In our population of patients with low risk BrS the detection of a spontaneous ECG pattern is the most common determinant of risk reclassification. Systematic ECG Holter monitoring disclosed the presence of a spontaneous ECG pattern in a relevant number of subjects, allowing to reassess their arrhythmic risk and indication for ICD placement. Our study stresses the importance of periodic evaluation of low risk BrS patients with ECG Holter monitoring and the need for further investigation to define the optimal monitoring strategy. Funding Acknowledgement Type of funding sources: None.

Mid-basal left ventricular longitudinal dysfunction as a prognostic marker in mutated transthyretin-related cardiac amyloidosis

Aim: Mutated transthyretin (TTRv) cardiac amyloidosis (CA) represents an uncommon form of CA. Our study aimed to assess the best echocardiographic prognostic parameter in the early stage of TTRv amyloidosis with cardiomyopathy. Methods: In total, 99 patients with TTRv in New York Heart Association class I or II and with no clinical history of previous cardiac disease were studied. Assessment with 99mTc-DPD whole-body scan showed CA in 46 patients. At the first medical contact, an echocardiographic examination was performed. In addition to conventional left ventricular (LV), echocardiographic measurements [ejection fraction (EF), dimensions and diastolic function, global longitudinal strain (GLS), longitudinal strain of the 4 apical segments, longitudinal strain of the 12 mid-basal segments (MBLS)] and their ratio [relative regional strain ratio (RRSR)] were obtained. Patient outcome was evaluated during a follow-up with an average duration of six years. Cardiac death and appropriate implantable cardiac defibrillator (ICD) shock were considered major events. Results: A higher value of LV thickness, E/E’, and RRSR and lower LV volumes, EF, GLS, MBLS were observed in patients with CA than the ones with only TTRv. During follow-up (median of 7.7 years), 25 major events (23 cardiac death and 2 appropriate ICD shocks) occurred. The logistic univariate analyses showed that LV EF, LV septal thickness, E/E’, GLS, and MBLS were all predictors of cardiovascular death. In multivariate analysis, MBLS was the only independent predictor of major events. A cut off of -14 of MBLS was selected as the best value to discriminate a worse prognosis on Kaplan-Meyer analysis. Conclusion: Longitudinal dysfunction is observed in the early stages of ATTRv amyloidosis with cardiomyopathy. Medio-basal LV longitudinal dysfunction is a strong independent echocardiographic predictor of cardiac death.

Cardiovascular implantable electronic device therapy in patients with left ventricular assist devices: insights from TRAViATA

BackgroundThere is conflicting observational data on the survival benefit cardiac implantable electronic devices (CIED) in patients with LVADs. MethodsPatients in whom an LVAD was implanted between January 2008 and April 2017 in the multinational Trans-Atlantic Registry on VAD and Transplant (TRAViATA) registry were separated into four groups based on the presence of CIED prior to LVAD implantation: none (n = 146), implantable cardiac defibrillator (ICD) (n = 239), cardiac resynchronization without defibrillator (CRT-P) (n = 28), and CRT with defibrillator (CRT-D) (n = 111). ResultsA total of 524 patients (age 52 years ±12, 84.4% male) were followed for 354 (interquartile range: 166–701) days. After multivariable adjustment, there were no differences in survival across the groups. In comparison to no device, only CRT-D was associated with late right ventricular failure (RVF) (hazard ratio 2.85, 95% confidence interval [CI] 1.42–5.72, p = 0.003). There was no difference in risk of early RVF across the groups or risk of ICD shocks between those with ICD and CRT-D. ConclusionIn a multinational registry of patients with LVADs, there were no differences in survival with respect to CIED subtype. However, patients with a pre-existing CRT-D had a higher likelihood of late RVF suggesting significant long-term morbidity in those with devices capable of LV‑lead pacing post LVAD implantation.

Selvester score predicts implantable cardioverter defibrillator shocks in patients with non-ischemic cardiomyopathy.

BackgroundThe implantable cardiac defibrillator is the cornerstone of prevention of sudden cardiac death in non‐ischemic cardiomyopathy. The Selvester score, which is frequently investigated in ischemic cardiomyopathy, has not been investigated in the field of non‐ischemic cardiomyopathy.AimThe aim of this study was to evaluate the Selvester score for determining appropriate implantable cardiac defibrillator shocks in non‐ischemic cardiomyopathy patients.Materials and methodsIn all, 131 non‐ischemic cardiomyopathy patients were included in the study. A simplified Selvester score was calculated from ECG data. Patients were divided into two groups according to whether they received ICD shock.ResultsOf the patients, 28.2% received appropriate implantable cardiac defibrillator shock. The Selvester score was significantly higher in patients receiving appropriate shock when compared to patients with no implantable cardiac defibrillator shocks (8.8 ± 4.6 vs 7.2 ± 3.3, P = .040). The median QRS duration was significantly longer in patients receiving appropriate shock than in patients with no shocks (130.14 ± 35.08 ms vs 120.12 ± 20.57 ms, P = .045). We determined that the cutoff value for the Selvester score to predict ICD shocks was 6.5 with a sensitivity of 72.0% and a specificity of 83% (AUC = 0.717; %95 GA: 0.627‐0.807, P < .001).ConclusionSelvester score was higher in patients receiving appropriate shock than in patients who did not receive any implantable cardiac defibrillator shock. From this study, the Selvester score is associated with the risk of ventricular tachycardia/ventricular fibrillation in non‐ischemic cardiomyopathy so that careful attention is necessary to manage the patients with high Selvester score.

Heterogeneity of right ventricular refractory period: a novel prognostic predictor in type-1 Brugada

Abstract Funding Acknowledgements Type of funding sources: None. Risk stratification in Brugada syndrome (BrS) is needed especially for the choice of an Implantable Cardiac Defibrillator (ICD). To date the predictive value of either clinical or conventional electrophysiological indexes in type 1 electrocardiographic pattern BrS is rather low. We aimed to evaluate the eventual prognostic significance of refractoriness heterogeneity of right ventricular outflow tract, an emergent relevant pathophysiological substrate, at electrophysiological study (EPS) in patients with BrS. From 5 centers 348 patients were retrospectively selected (age 44 ± 15 years, males 68%). Eighty-five (24%) patients had an ICD. EPS was proposed in patients with spontaneous type-1 ECG pattern regardless of symptoms, or in patients with drug-induced type-1 ECG pattern with symptoms (n = 174). The difference in the refractory period between the right ventricular outflow tract and the apex (ΔRPRVOT-apex) at EPS was evaluated as a prognostic factor. The optimal ΔRPRVOT-apex cutpoint for prognosis prediction was calculated through a P-spline hazard ratio analysis. Thus, ΔRPRVOT-apex was compared through different statistical analyses to other other clinical or conventional electrophysiological prognostic indexes previosly described in literature. During a 36-month median follow-up (range 6-228) 3 SCD and 10 appropriate ICD shocks (aborted SCD, aSCD) occurred. Fifty patients (29%) had a positive EPS (induction of sustained ventricular tachycardia, VT, or ventricular fibrillation, VF, during the procedure). At multivariable logistic analysis, only ΔRPRVOT-apex and late potentials remained independent predictors of a positive EPS. At Cox Proportional Hazard analysis, family history of SCD, history of syncope, VT/VF inducibility and a ΔRPRVOT-apex &amp;gt;60 ms were all univariate predictors of SCD/aSCD. At bivariate analysis, a ΔRPRVOT-apex &amp;gt;60 ms remained an independent predictor of SCD/aSCD even when adjusted the other univariate predictors. At C-Statistic analysis, the strongest predictive model was the one using ΔRPRVOT-apex &amp;gt;60 ms as covariate with a C-statistics (95% CI) of 0.72 (0.51-0.93). At Kaplan-Meyer curves, ΔRPRVOT-apex &amp;gt;60 ms was confirmed a strong predictor of SCD/aSCD and another very interesting observation was possible: patients with positive EPS, but a ΔRPRVOT-apex &amp;lt; 60 ms, had a similar risk to SCD/aSCD compared to patients with a negative EPS, while those with a positive EPS and a ΔRPRVOT-apex &amp;gt; 60 ms were found to be at a higher risk of events. Refractory period heterogeneity of the right ventricle defined as ΔRPRVOT-apex &amp;gt; 60 ms at EPS is a strong and independent predictor of SCD/aSCD in patients with BrS, beyond VT/VF inducibility at EPS and common clinical predictors. Abstract Figure.

Coronary Angiography After Cardiac Arrest Without ST Segment Elevation

Ischemic heart disease is a common cause of cardiac arrest. However, randomized data on long-term clinical outcomes of immediate coronary angiography and percutaneous coronary intervention (PCI) in patients successfully resuscitated from cardiac arrest in the absence of ST segment elevation myocardial infarction (STEMI) are lacking. To determine whether immediate coronary angiography improves clinical outcomes at 1 year in patients after cardiac arrest without signs of STEMI, compared with a delayed coronary angiography strategy. A prespecified analysis of a multicenter, open-label, randomized clinical trial evaluated 552 patients who were enrolled in 19 Dutch centers between January 8, 2015, and July 17, 2018. The study included patients who experienced out-of-hospital cardiac arrest with a shockable rhythm who were successfully resuscitated without signs of STEMI. Follow-up was performed at 1 year. Data were analyzed, using the intention-to-treat principle, between August 29 and October 10, 2019. Immediate coronary angiography and PCI if indicated or coronary angiography and PCI if indicated, delayed until after neurologic recovery. Survival, myocardial infarction, revascularization, implantable cardiac defibrillator shock, quality of life, hospitalization for heart failure, and the composite of death or myocardial infarction or revascularization after 1 year. At 1 year, data on 522 of 552 patients (94.6%) were available for analysis. Of these patients, 413 were men (79.1%); mean (SD) age was 65.4 (12.3) years. A total of 162 of 264 patients (61.4%) in the immediate angiography group and 165 of 258 patients (64.0%) in the delayed angiography group were alive (odds ratio, 0.90; 95% CI, 0.63-1.28). The composite end point of death, myocardial infarction, or repeated revascularization since the index hospitalization was met in 112 patients (42.9%) in the immediate group and 104 patients (40.6%) in the delayed group (odds ratio, 1.10; 95% CI, 0.77-1.56). No significant differences between the groups were observed for the other outcomes at 1-year follow-up. For example, the rate of ICD shocks was 20.4% in the immediate group and 16.2% in the delayed group (odds ratio, 1.32; 95% CI, 0.66-2.64). In this trial of patients successfully resuscitated after out-of-hospital cardiac arrest and without signs of STEMI, a strategy of immediate angiography was not found to be superior to a strategy of delayed angiography with respect to clinical outcomes at 1 year. Coronary angiography in this patient group can therefore be delayed until after neurologic recovery without affecting outcomes. trialregister.nl Identifier: NTR4973.

Clinical importance of late gadolinium enhancement at right ventricular insertion points in otherwise normal hearts.

Late gadolinium enhancement (LGE) has an established prognostic value in otherwise normal hearts, when detected with a subepicardial or intramyocardial pattern; nevertheless, the clinical relevance of isolated right ventricular insertion point (RVIP) LGE is yet to be defined. From a retrospectively identified cohort of 2000 consecutive patients undergoing CMR, we selected 420 patients according to study's inclusion and exclusion criteria (270 males, mean age 38 ± 17years) with apparently normal hearts: besides 36 patients with non-ischemic pattern LGE (other-LGE group), we found isolated RVIP-LGE in 44 patients and absence of LGE (no-LGE group) in 340 patients. Clinical follow-up was performed for a median of approximately 6years. Primary composite endpoint included cardiac death, resuscitated cardiac arrest, and appropriate implantable cardiac defibrillator shock. Prevalence of cardiac events was significantly lower in RVIP-LGE than in the other-LGE group (p = 0.006). Kaplan Meier curve analysis demonstrated no significant differences between patients with RVIP-LGE and no-LGE for the primary endpoint. On contrast, patients with other-LGE had worse prognosis than those with RVIP-LGE or no-LGE (p < 0.0001). RVIP-LGE in subjects without additional evidence of cardiac damage does not convey worse prognosis when compared to subjects without LGE and it should not be considered a marker of disease. Its diagnostic and prognostic significance is to be considered irrelevant.

Number of electrocardiogram leads in the diagnosis of spontaneous Brugada syndrome

The recently recommended single lead-based criterion for the diagnosis of Brugada syndrome may lead to overdiagnosis of this disorder and overestimation of the risk of sudden cardiac death. To investigate the value of a single-lead diagnosis in patients with Brugada syndrome and a spontaneous type1 electrocardiogram. Consecutive patients with Brugada syndrome were included in a multicentre prospective registry; only those with a spontaneous type1 electrocardiogram were enrolled. Clinical and electrocardiogram data were reviewed by two physicians blinded to the patients' clinical and genetic status. Among 1613patients, 505 (31%) were enrolled (79% male; mean age 46±15 years). A spontaneous type1 electrocardiogram pattern was found in one lead in 250patients (group1), in two leads in 227patients (group2) and in three leads in 27patients (group3). Groups were similar except for individuals in group 3, who presented more frequently a fragmented QRS complex, an early repolarization pattern and a prolonged Tpeak-Tend interval. After a mean follow-up of 6.4±4.7 years, ventricular arrhythmia, sudden cardiac death or implantable cardiac defibrillator shock occurred in 46 (9%) patients, without differences between groups. The prognosis of Brugada syndrome with a spontaneous type 1 electrocardiogram pattern does not appear to be affected by the number of leads required for the diagnosis.

To Exchange or Not: Defibrillators, Ventricular Assist Devices and Hematomas

Purpose To assess peri-procedural complications in left ventricular assist device (LVAD) patients undergoing implantable cardiac defibrillator (ICD) generator exchange for primary prevention of sudden cardiac death. Methods In this single-center study, we retrospectively analyzed all current patients with a durable LVAD (n=39) who underwent ICD generator exchange between January 2014 and August 2018. Data was collected from electronic medical records and clinical outcomes analyzed included death, stroke, infection, any hematoma formation, need for blood products transfusion and hospital admission for above reasons within 30 days of ICD generator exchange. Results Of 39 current LVAD patients 15 (38%) underwent an ICD generator exchange. 14/15 (93%) patients were male and mean age was 73 ± 8.2 years. 11/15 patients (73.3%) had the ICD implanted for primary prevention vs. 4/15 (26.7%) had the ICD for secondary prevention. In the primary prevention ICD cohort, none of the patients received a defibrillator shock during the time course of having the device. Mean follow-up from the date of ICD generator exchange was 2.2 patient years. Pocket hematoma was noted in 3/11 (27.2%) primary prevention patients who underwent ICD generator exchange, of which 1 patient was hospitalized for observation of the hematoma. No patients required blood products. All 3 patients who developed pocket hematoma were on antiplatelet therapy with aspirin as well as warfarin with INRs ranging from 2.2-3.5. There were no infections as a result of ICD generator exchange. Conclusion In this single center study, pocket hematoma formation was noted in 27% of the primary prevention cohort who underwent ICD generator exchange. No patients required a blood product transfusion or developed an infection. Of note, no patients received an ICD shock during the course of follow-up. This raises a clinically relevant central question on indication of ICDs and generator exchange in patients with LVADs and no prior history of arrhythmia.

Effect of coronary revascularization on long-term clinical outcomes in patients with ischemic cardiomyopathy and recurrent ventricular arrhythmia.

Patients with ventricular tachycardia (VT) postmyocardial infarction (MI) are a higher risk group with significant morbidity and mortality. We examined the impact of prior coronary revascularization on clinical outcomes in patients with ischemic cardiomyopathy and VT. The VANISH trial randomized 259 patients with prior MI and antiarrhythmic drug-refractory VT to receive escalated medical therapy or catheter ablation. Clinical outcomes were compared according to whether patients have undergone prior revascularization procedures. The primary outcome was a composite of death, appropriate implantable cardiac defibrillator (ICD) shock, or VT storm. The secondary outcomes included elements of the primary outcome, hospitalization, and any ventricular arrhythmia. 190 patients (73%) had prior coronary revascularization. Revascularization group had more men (97%vs 83%; P=0.0003) and patients in that group were older (mean age 69.3 ± 7.6vs 66.7 ± 9.2; P=0.04), had more renal insufficiency (22.6%vs 8.7%; P=0.01), and were more likely to have an implanted cardiac resynchronization device (23%vs 10%, P=0.03) as compared with the nonrevascularized patients. There were no significant differences in baseline medication use. There was a trend toward fewer hospitalizations in the revascularization group (64%vs 77%; P=0.07); there were no differences in the individual outcomes of mortality, VT storm, ICD shocks, recurrent MI, or cardiac failure. In this cohort of patients with an ischemic cause for VT, a history of prior coronary revascularization was not associated with a reduction in ventricular arrhythmia or mortality.

Electrical Substrate Elimination in 135 Consecutive Patients With Brugada Syndrome.

There is emerging evidence that localization and elimination of abnormal electric activity in the epicardial right ventricular outflow tract may be beneficial in patients with Brugada syndrome. A total of 135 symptomatic Brugada syndrome patients having implantable cardiac defibrillator were enrolled: 63 (group 1) having documented ventricular tachycardia (VT)/ventricular fibrillation (VF) and Brugada syndrome-related symptoms, and 72 (group 2) having inducible VT/VF without ECG documentation at the time of symptoms. About 27 patients of group 1 experienced multiple implantable cardiac defibrillator shocks for recurrent VT/VF episodes. Three-dimensional maps before and after ajmaline determined the arrhythmogenic electrophysiological substrate (AES) as characterized by prolonged fragmented ventricular potentials. Primary end point was identification and elimination of AES leading to ECG pattern normalization and VT/VF noninducibility. Extensive areas of AES were found in the right ventricle epicardium, which were wider in group 1 (P=0.007). AES increased after ajmaline in both groups (P<0.001) and was larger in men (P=0.008). The increase of type-1 ST-segment elevation correlated with AES expansion (r=0.682, P<0.001). Radiofrequency ablation eliminated AES leading to ECG normalization and VT/VF noninducibility in all patients. During a median follow-up of 10 months, the ECG remained normal even after ajmaline in all except 2 patients who underwent a repeated effective procedure for recurrent VF. In Brugada syndrome, AES is commonly located in the right ventricle epicardium and ajmaline exposes its extent and distribution, which is correlated with the degree of coved ST-elevation. AES elimination by radiofrequency ablation results in ECG normalization and VT/VF noninducibility. Substrate-based ablation is effective in potentially eliminating the arrhythmic consequences of this genetic disease. URL: https://clinicaltrials.gov. Unique identifier: NCT02641431.

Outcomes of Brugada Syndrome Patients with Coronary Artery Vasospasm.

Objective To evaluate the outcomes of patients with concomitant Brugada syndrome and coronary artery vasospasm. Methods Patients diagnosed with Brugada syndrome with an implantable cardiac defibrillator were retrospectively investigated, and the coexistence of vasospasm was evaluated. The clinical features and outcomes were evaluated, especially in patients with coexistent vasospasm. A provocation test using acetylcholine was performed in patients confirmed to have no organic stenosis on percutaneous coronary angiography to confirm the presence of vasospasm. Implantable cardiac defibrillator shock status was checked every three months. Statistical comparisons of the groups with and without vasospasm were performed. A univariate analysis was also performed, and the odds ratio for the risk of implantable cardiac defibrillator shock was calculated. Patients Thirty-five patients with Brugada syndrome, of whom six had coexistent vasospasm. Results There were no significant differences in the laboratory data, echocardiogram findings, disease, or the history of taking any drugs between patients with and without vasospasm. There were significant differences in the clinical features of Brugada syndrome, i.e. cardiac events such as resuscitation from ventricular fibrillation or appropriate implantable cardiac defibrillator shock. Four patients with vasospasm had cardiac events such as resuscitation from ventricular fibrillation and/or appropriate defibrillator shock; three of them had no cardiac events with calcium channel blocker therapy to prevent vasospasm. The coexistence of vasospasm was a potential risk factor for an appropriate implantable cardiac defibrillator shock (odds ratio: 13.5, confidence interval: 1.572-115.940, p value: 0.035) on a univariate analysis. Conclusion Coronary artery vasospasm could be a risk factor for cardiac events in patients with Brugada syndrome.

Nonischemic Left Ventricular Scar as a Substrate of Life-Threatening Ventricular Arrhythmias and Sudden Cardiac Death in Competitive Athletes.

Background—The clinical profile and arrhythmic outcome of competitive athletes with isolated nonischemic left ventricular (LV) scar as evidenced by contrast-enhanced cardiac magnetic resonance remain to be elucidated.Methods and Results—We compared 35 athletes (80% men, age: 14–48 years) with ventricular arrhythmias and isolated LV subepicardial/midmyocardial late gadolinium enhancement (LGE) on contrast-enhanced cardiac magnetic resonance (group A) with 38 athletes with ventricular arrhythmias and no LGE (group B) and 40 healthy control athletes (group C). A stria LGE pattern with subepicardial/midmyocardial distribution, mostly involving the lateral LV wall, was found in 27 (77%) of group A versus 0 controls (group C; P<0.001), whereas a spotty pattern of LGE localized at the junction of the right ventricle to the septum was respectively observed in 11 (31%) versus 10 (25%; P=0.52). All athletes with stria pattern showed ventricular arrhythmias with a predominant right bundle branch block morphology, 13 of 27 (48%) showed ECG repolarization abnormalities, and 5 of 27 (19%) showed echocardiographic hypokinesis of the lateral LV wall. The majority of athletes with no or spotty LGE pattern had ventricular arrhythmias with a predominant left bundle branch block morphology and no ECG or echocardiographic abnormalities. During a follow-up of 38±25 months, 6 of 27 (22%) athletes with stria pattern experienced malignant arrhythmic events such as appropriate implantable cardiac defibrillator shock (n=4), sustained ventricular tachycardia (n=1), or sudden death (n=1), compared with none of athletes with no or LGE spotty pattern and controls.Conclusions—Isolated nonischemic LV LGE with a stria pattern may be associated with life-threatening arrhythmias and sudden death in the athlete. Because of its subepicardial/midmyocardial location, LV scar is often not detected by echocardiography.

Increased defibrillator therapies during influenza season in patients without influenza vaccines

BackgroundThe association between influenza vaccination and implantable cardiac defibrillator (ICD) therapies during influenza season is not known and is described in this study. Understanding this association is important since reduction in ICD therapies during influenza season via use of influenza vaccination would benefit patients physically and psychologically. MethodsPatients presenting to the Sunnybrook Health Sciences Center ICD clinic between September 1st, 2011 and November 31st, 2011 were asked to complete a survey evaluating their use of the influenza vaccine. The number of patients with any ICD therapy and the total number of ICD therapies in the six months before and the three months during the 2010–2011 influenza season were determined. Poisson regression analysis was employed to assess differences in the average number of ICD therapies received during the influenza season based on vaccine status (vaccinated vs. unvaccinated). The analysis was repeated after limiting the cohort to patients with a left ventricular ejection fraction ≤35%. ResultsA total of 229 patients completed the survey, 78% of whom received the influenza vaccine. Four patients had more than one ICD shock during the study period. Electrical storm was rare (n=2). A trend toward more ICD therapies (unadjusted incident rate ratio (IRR)=3.2; P=0.07) and appropriate ICD shocks (unadjusted IRR=9.0; P=0.17) was noted for unvaccinated compared to vaccinated patients. This association persisted when analysis was limited to patients with a left ventricular ejection fraction ≤35% (all ICD therapies: unadjusted IRR=5.8; P=0.045; adjusted IRR=2.6; P=0.33). No patient who received the influenza vaccine, and had a reduced ejection fraction, received an approprite ICD shock during influenza season (unadjusted P<0.002). ConclusionA trend toward more ICD therapies during influenza season was observed in patients who did not receive the influenza vaccine compared to those who did. The association was stronger in patients who received appropriate ICD shocks and in patients with left ventricular systolic dysfunction. Further work to confirm these findings is recommended.

Effect of Angiotensin-Converting Enzyme Inhibitors and Receptor Blockers on Appropriate Implantable Cardiac Defibrillator Shock in Patients With Severe Systolic Heart Failure (from the GRADE Multicenter Study)

Sudden cardiac death (SCD) is a leading cause of mortality in patients with cardiomyopathy. Although angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs) decrease cardiac mortality in these cohorts, their role in preventing SCD has not been well established. We sought to determine whether the use of ACEi or ARB in patients with cardiomyopathy is associated with a lower incidence of appropriate implantable cardiac defibrillator (ICD) shocks in the Genetic Risk Assessment of Defibrillator Events study that included subjects with an ejection fraction of ≤30% and ICDs. Treatment with ACEi/ARB versus no-ACEi/ARB was physician dependent. There were 1,509 patients (mean age [SD] 63 [12] years, 80% men, mean [SD] EF 21% [6%]) with 1,213 (80%) on ACEi/ARB and 296 (20%) not on ACEi/ARB. We identified 574 propensity-matched patients (287 in each group). After a mean (SD) of 2.5 (1.9) years, there were 334 (22%) appropriate shocks in the entire cohort. The use of ACEi/ARB was associated with lower incidence of shocks at 1, 3, and 5years in the matched cohort (7.7%, 16.7%, and 18.5% vs 13.2%, 27.5%, and 32.0%; RR= 0.61 [0.43 to 0.86]; p= 0.005). Among patients with glomerular filtration rate (GFR) >60 and 30 to 60ml/min/1.73m(2), those on no-ACEi/ARB were at 45% and 77% increased risk of ICD shock compared with those on ACEi/ARB, respectively. ACEi/ARB were associated with significant lower incidence of appropriate ICD shock in patients with cardiomyopathy and GFR ≥30ml/min/1.73m(2) and with neutral effect in those with GFR <30ml/min/1.73m(2).

0198: Brugada syndrome in women

Brugada syndrome (BrS) is an inherited arrhythmia syndrome with increased risk of syncope and sudden death. Disease manifestation is clearly predominant in males and the studied population mainly consisted in men. The aim of this study is to describe the clinical characteristics of BrS in women. BrS women were recruited from 12 french tertiary centers. Clinical data, investigation of family history, 12-lead ECG and results for pharmacological challenge were collected. Average follow-up was 79±52 months. 202 women were recruited (mean age 46±16 years). Circumstances of diagnoses were: familial screening (n=94, 47%), systematic ECG (n= 61, 30%) and symptoms (n=47, 23%). 69 patients (34%) were symptomatic: resuscitated sudden cardiac death (SCD) in 11 women (5%), 42 syncope (21%), 8 supraventricular tachycardia (4%), 21 palpitations (10%), 24 lipothymia (12%) and 7 pain (3%). 20 women (10%) have a history of familial SCD. Implantable cardiac defibrillator (ICD) was implanted in 44/202 patients (22%). At baseline, mean HR was 71±12 bpm, PR 174±32 mm, QRS 99±17 mm and QTc 419±29 mm. 59 women (29%) have a spontaneous type- 1 ECG. Mean ST elevation were 3.3±1.1 mm. During follow-up, 7/202 patients (3.5%) have an arrhythmic event: resuscitated SCD (n=1), syncope (n=3), ventricular arrhythmia (n=1) and appropriate ICD shock (n=2). Among them, 5 women were symptomatic (syncope) and 2 were asymptomatic. Asymptomatic women don’t have a spontaneous type-1 ECG at baseline whereas 3/5 symptomatic women have a type-1 ECG at baseline. We compared our results to the men of the FINGER BrS Registry (n=745). The number of ICD implanted patients was higher in FINGER cohort (22 vs 47%). Men of the FINGER cohort presented more arrhythmic events than women of this study (5.7 vs 3.5%). Women seem to represent a lower-risk group than men. A spontaneous type-1 ECG at baseline doesn’t seem to be a risk factor for arrhythmic event in women.

Cardiac sympathectomy in humans: Rationale, results & mechanistic insights

The autonomic nervous system plays a critical role in the genesis and maintenance of ventricular arrhythmias. Pharmacological anti-adrenergic interventions, such as beta-blockers are a cornerstone of therapeutic management of ventricular arrhythmias. However, ventricular arrhythmias that remain refractory to standard medical management are associated with a high mortality. Neuraxial modulation using thoracic epidural anesthesia (TEA) and surgical removal of the stellate ganglia and thoracic sympathetic ganglia (cardiac sympathetic denervation, CSD) are therapeutic options for such cases. The protective effects of CSD have been demonstrated in long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia. CSD has also been shown to lengthen ventricular refractoriness and raise the ventricular fibrillation threshold without impairing cardiac contractility. Analysis of data from patients with VT refractory to medical therapy and catheter ablation referred for CSD between 4/2009 and 8/2012 was performed. Thirty eight patients (32 males, 6 females, age 60 ± 12 years, EF 30 ± 15%) with recurrent VT or VT underwent CSD. One patient was referred for idiopathic VF. Patients had experienced a median of 2 catheter ablation procedures and 13 (range 7-55) implantable cardiac defibrillator (ICD) shocks in the 6 months prior to the procedure. At a mean follow up of 356 ± 300 days (median = 160 days), 4 patients (12.5%) underwent heart transplantation and 15 (39%) patients died, two after heart transplantation, one after lead extraction, one from renal failure, and 11 from worsening heart failure or multi-organ failure. Incidence of recurrent arrhythmias from ICD logs was available in 31 patients (82%), 10 with left CSD and 21 with bilateral CSD. Three (30%) of the left CSD patients and 11 (52%) of bilateral CSD patients were completely free of ICD shocks (P < 0.05 for bilateral vs. left). Bilateral CSD demonstrates long-term benefit in reducing ICD shocks in patients with recurrent VT and cardiomyopathy refractory to medical therapy.

Abstract 18950: Invasive Electrophysiology Study has Higher Sensitivity and Specificity for Sudden Cardiac Death in Patients with Congenital Heart Disease than those with Structurally Normal Hearts

Introduction: The use of electrophysiology study (EPS) in pediatric and congenital heart disease (CHD) patients to identify at risk subjects for sudden cardiac death (SCD) and implantable cardiac defibrillator (ICD) is often debated. Objectives: We assessed the hypothesis that EPS was more predictive for SCD or appropriate ICD discharge in patients with CHD compared to those with structurally normal hearts. Methods: A 15 year retrospective database review was performed for subjects undergoing EPS risk stratification for SCD. Positive EPS was defined as inducible sustained ventricular tachycardia or fibrillation by programmed stimulation. Data included demographics, EPS indications, outcome of EPS, ICD complications, and follow up SCD or ICD discharge. The primary endpoint was SCD or appropriate ICD discharge. Results: The study included169 subjects with mean age of 19.1 ± 7.8 years, mean follow up after EPS of 5.8 ± 4.3 years. Of these, 50 subjects (30%) had positive EPS, with ICDs subsequently placed in 28 (56%). There were 119 subjects (70%) with negative EPS, and ICDs were placed in 9 (7%). There were 85 subjects (50%) with CHD. There were no SCDs in either group. During follow-up, 10 of 37 subjects (24%) with ICDs had appropriate discharges (6 with CHD and 4 without CHD). Device related complications including recalls were seen in 21 of 37 patients (57%). The ICD shock rate, sensitivity and specificity of EPS are shown in the Table. Sub group analysis of right heart obstruction CHD lesions (n=44) showed similar results between these patients and all CHD patients (Table). Conclusions: The use of diagnostic EPS has a higher sensitivity and specificity for appropriate ICD discharge in pediatric patients with CHD compared to those with structurally normal hearts.