Dual-chamber Implantable Cardioverter-defibrillator Research Articles

Abstract 14766: Pulmonary Vein Isolation Alone is Not Superior to Amiodarone for the Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device: Results From the AATAC Randomized Trial

Introduction: The best treatment option for the management of patients (pts) with heart failure (HF) and persistent AF is unknown. The AATAC trial showed that catheter ablation (CA) is superior to Amiodarone in achieving freedom from AF at follow up. In this analysis we present the outcome sorted by type of AF procedure. Methods: AATAC was a randomized multicenter study. Pts with persistent AF, dual chamber ICD or CRTD, NYHA II-III and LV EF <40% within the last 6 months were randomly assigned (1:1 ratio) to undergo CA for AF (group 1=102 pts) or receive AMIO, (group 2=101 pts). Recurrence of AF was the primary end point. Based on operator’s choice patients could undergo pulmonary vein isolation alone (PVI) or PVI plus posterior wall plus non PV trigger ablation (PVI+PW+NPV) as detected by high dosage of isoproterenol. Results: PVI was performed in 22 patients undergoing ablation, while PVI+PW+NPV ablation was performed in 80 patients. Baseline characteristics were not different between the groups. At 26±8 months follow-up, the success rates in PVI, PVI+PW+NPV, and AMIO groups were 8 [36.4%] and 63 [78.8%] and 34 (34.0%) respectively, p<0.001 (figure). Patients receiving PVI+PW+NPV ablation, showed significantly higher success than those with PVI alone or amiodarone (p <0.001). The outcome in the PVI alone group was not different from AMIO group (p= 0.67). No patient was lost to follow-up during the study period. At the time of analysis, all recurrence-free patients had completed ≥6 month follow-up. Conclusion: This randomized study shows that PVI alone has a low success rate similar to Amiodarone when compared to PVI plus posterior wall plus non pv trigger in patients with heart failure and persistent AF.

Abstract 17295: Effect of Atrial Rate-responsive Pacing in the Incidence of Sustained Atrial Arrhythmias in Patients With Implantable Cardioverter-defibrillators

Introduction: Atrial rate-responsive pacing (RRP) has proved to be safe in pacemaker recipients with chronotropic incompetence, but there is little data regarding its use in implantable cardioverter-defibrillator (ICD) patients. Hypothesis: Atrial RRP may increase the occurrence of sustained atrial arrhythmias when programmed in ICD recipients. Methods: Dual-chamber and triple-chamber ICD patients were included in this multicenter cohort study. Patients with permanent atrial fibrillation (AF) or VVI pacing mode were excluded. The number and duration of atrial tachycardia (AT)/AF episodes were assessed by remote monitoring. Results: Data from 415 patients was collected after a 21.3±14.1 months follow-up. Atrial RRP was programmed in 90 (21.7%) patients and was associated to a higher atrial pacing percentage in the overall study population (51.2±33.8% versus 18.4±25.7%, P<0.001) and to a higher ventricular pacing percentage among dual-chamber devices (22.3±37.6% versus 9.3±25%, P 23 hours) were history of AF (odds ratio: 7.98; 95% confidence interval: 4.11-15.47; p<0,001) and atrial RRP (odds ratio: 3,58; 95% confidence interval: 1.82-7.03; p<0,001). RRP was related to a lower sustained AT/AF episodes-free survival both in patients with and without a history of AF (Figure). Within patients with a history of AF, atrial RRP was also associated with a higher median of AT/AF episodes/patient (18.5 [interquartile range: 339] versus 8 [69], P=0.016) and a higher percentage of time recording AT/AF (9.21% [36.32] versus 1.18% [16.31], P=0.024). Cumulative incidence of sustained AT/AF episodes > 23 hours was proportional to the atrial pacing percentages. Conclusions: Atrial RRP in ICD patients was related to a higher cumulative incidence of sustained atrial arrhythmias >23 hours. This pacing mode seems to have an atrial proarrhythmic effect not described up to now in ICD patients, especially among those with a history of AF.

Defibrillator lead endocarditis:

A 47-year-old female with a history of left pectoral dual-chamber implantable cardioverter-defibrillator (ICD) insertion in her early 30s for syncopal ventricular tachycardia presented with several weeks of shortness of breath and general malaise. Salient history included ICD and lead removal 5 years ago in the setting of near cutaneous extrusion with insertion of a new ventricular lead …

Cost analysis of telemedicine monitoring of patients with implantable cardioverter-defibrillators in the Czech Republic

IntroductionTelemonitoring of patients with implantable cardioverter-defibrillators (ICD) is, in general, considered safer, more efficious, and increasingly cost-effective. The aim of our work was to assess the long-term economic benefit associated with telemetric monitoring of patients with newly implanted ICD using the Home Monitoring™ (HM) system compared to standard outpatient care in the Czech Republic. MethodsPatients were randomized to telemetric monitoring using the HM system with daily automated data transfer and outpatient follow-up at 12-month intervals (HM+) or standard outpatient follow-up (HM−). Average total costs per patient and months of follow-up were estimated based on invoices from health insurance companies, direct costs to patients, and the operating costs of the HM system. ResultsIn total, 198 patients were followed for 37.4±15.2 months. The number of planned outpatient visits was reduced by 48% during the follow-up period in the HM+ group (p<0.001). Significantly shorter hospital stays were also observed in the HM+ group. Data concerning costs were obtained in 75% of patients. Higher costs for outpatient care (223±99CZK vs. 189±93CZK, p=0.039) and medical transport services (640±314CZK vs. 367±187CZK, p=0.003) were found in the HM− group. When taking into account the operating costs of the HM system in addition to the costs for outpatient care and transport, the difference between groups was not significant; however, when the reimbursement of telemetric monitoring and costs for the patient unit were also reflected in the calculations, the average cost in the HM+ group was higher (541±188CZK vs. 401±332CZK, p=0.002). Cost-neutrality could be obtained if all patients were transported free of charge to their outpatient visits. ConclusionIn the Czech Republic, the HM system has been cost-effective for health insurance companies in patients with single- or dual-chamber ICDs. When calculating using the reimbursement from payers of the healthcare, the HM system would remain cost-neutral only if most patients had reimbursed transportation costs. The clinical effect of telemetric monitoring is directly related to the continuity of follow-up and the possibility to detect events very early and to intervene accordingly; we thus believe that the HM system should be automatically paid for in all patients with an implantable ICD. The related increase in costs would be insignificant in the context of the entire healthcare budget.

Efficiencies and Complications of Dual Chamber versus Single Chamber Implantable Cardioverter Defibrillators in Secondary Sudden Cardiac Death Prevention: A Meta-analysis

Dual chamber implantable cardioverter defibrillators (ICDs) are considered to have better clinical outcomes than single chamber ICDs, however, an individual trial may not have sufficient power to prove it. This meta-analysis aimed to compare clinical outcomes of dual chamber ICDs (DC-ICDs) with single chamber ICDs (SC-ICDs) in secondary sudden cardiac death (SCD) prevention. We searched Medline, the Cochrane Library, and other internet sources, without language or date restrictions for articles comparing clinical outcomes between DC-ICDs and SC-ICDs. Studies were selected for inclusion based on the following criteria: Randomised controlled trial.; Controlled design was used to compare SC-ICDs and DC-ICDs; Retrospective study if the survival analysis was performed. Efficacy endpoints were mortality, appropriate therapy, inappropriate detection of SVT, inappropriate therapy. Safety endpoints were lead-related complication and all complications. Relative risk (RR) or odds ratios (ORs) with 95% confidence intervals (CI) were calculated, and a χ2-based test of homogeneity was performed. We identified nine trials (n=2594) with a weighted mean follow-up of 18.9 months. Compared with DC-ICDs, SC-ICDs were associated with a significant reduction in lead complications (RR:3.30; 95% CI: 1.17-9.30; p=0.02). However, both groups had similar rates of mortality (OR: 0.91; 95%CI: 0.91-1.51; p=0.73), appropriate therapy (RR: 0.90; 95%CI: 0.73-1.11; p=0.32), inappropriate detection of SVT (RR: 1.82; 95%CI: 0.71-4.62; p=0.21), inappropriate therapy (RR: 2.08; 95%CI: -0.22-0.19; p=0.86) and all complications (OR: 1.27; 95%CI: 0.19-8.67; p=0.81). Besides more lead-related complications, DC-ICDs had similar efficacy and all complications as SC-ICDs in secondary sudden cardiac death prevention.

High atrioventricular phase index on near-field intracardiac electrogram is associated with risk of ventricular arrhythmia

The purposes of this study were to characterize and quantify concordance between consecutive atrial and ventricular activation time points through analysis of phases and to explore its association with outcomes in patients with implantable cardioverter-defibrillator (ICD). Patients with structural heart disease and dual-chamber ICDs underwent 5min baseline right ventricular (V) near-field and atrial (A) electrogram (EGM) recording. The cross-dependencies of phase dynamics of the changes in consecutive A (AA′) and V (VV′) were quantified and the AV phase dependency index was determined. In Cox regression analysis, a high AV phase index (in the highest quartile, >0.259) was significantly associated with higher risk of ventricular tachyarrhythmias (HR 2.84; 95% CI 1.05–7.67; P=0.04). In conclusion, in ICD patients with structural heart disease, high sinus AV phase dependency index on EGM is associated with the risk of ventricular arrhythmia.

Longevity Performance of St. Jude Medical ICDs at a Single Center

Battery longevity of single (VR) and dual chamber (DR) ICDs depends on many variables, and may be difficult to predict. We sought to assess the longevity of St Jude Medical (SJM) ICDs at our institution and compare them to the product performance reports (PPR) provided by the manufacturer.

Successful implantable cardioverter-defibrillator implantation through a communicating branch of the persistent left superior vena cava

A left pectoral dual chamber implantable cardioverter-defibrillator (ICD) was successfully implanted through a small branch communicating between a persistent left superior vena cava (PLSVC) and right-sided venous drainage with long sheaths. Postprocedural computed tomography identified the communicating branch. ICD lead implantation through a PLSVC is challenging and sometimes unsuccessful. This case illustrates an alternative approach for ICD lead implantation in patients with a PLSVC. A PLSVC system should be carefully inspected for any communicating branches that can be utilized for lead implantation in order to increase the chance of success and minimize the risk of complications.

The experiences of adults living with an implantable cardioverter defibrillator for cardiovascular disease: a systematic review of qualitative evidence protocol.

REVIEW QUESTION / OBJECTIVE The objective of the review is to explore the everyday life experiences of adult individuals living with an implantable cardioverter defibrillator for cardiovascular disease. INCLUSION CRITERIA Types of participants This review will focus on adults who are 18 years or older and have had an implantable cardioverter defibrillator, including single and dual chamber implantable cardioverter defibrillators, for any duration of time for the management of cardiovascular disease. Participants with other co-morbidities or receiving other interventions in addition to the implantable cardioverter defibrillator will be included, regardless of the severity of cardiovascular disease. Types of intervention(s)/phenomena of interest This review will consider the phenomenon of interest of the everyday life experience of adults living with an implantable cardioverter defibrillator. This may include how individuals living with an implantable cardioverter defibrillator conceptualize their sense of wellbeing, how they cope with having an implantable cardioverter defibrillator, and how they manage their daily lives within the context of family relationships, the workplace, everyday roles, personal obligations, medical appointments, interactions with health care providers, disease progression and their spirituality. Context The context of the review includes the experiences of participants from all cultures, socioeconomic backgrounds and countries.

The experiences of adults living with an implantable cardioverter defibrillator for cardiovascular disease: a systematic review of qualitative evidence protocol

The experiences of adults living with an implantable cardioverter defibrillator for cardiovascular disease: a systematic review of qualitative evidence protocol

Full-Body MRI in Patients With an Implantable Cardioverter-Defibrillator: Primary Results of a Randomized Study

BackgroundMagnetic resonance imaging (MRI) of patients with conventional implantable cardioverter-defibrillators (ICD) is contraindicated. ObjectivesThis multicenter, randomized trial evaluated safety and efficacy of a novel ICD system specially designed for full-body MRI without restrictions on heart rate or pacing dependency. The primary safety objective was >90% freedom from MRI-related events composite endpoint within 30 days post-MRI. The primary efficacy endpoints were ventricular pacing capture threshold and ventricular sensing amplitude. MethodsSubjects received either a single- or dual-chamber ICD. In a 2:1 randomization, subjects either underwent MRI at 1.5-T of the chest, cervical, and head regions to maximize radiofrequency exposure up to 2 W/kg specific absorption rate and gradient field exposure to 200 T/m/s per axis (MRI group, n = 175), or they underwent a 1-h waiting period without MRI (control group, n = 88). A subset of MRI patients underwent ventricular fibrillation induction testing post-MRI to characterize defibrillation function. ResultsIn 42 centers, 275 patients were enrolled (76% male, age 60.4 ± 13.8 years). The safety endpoint was met with 100% freedom from the composite endpoint (p < 0.0001). Both efficacy endpoints were met with minimal differences in the proportion of MRI and control patients who demonstrated a ≤0.5 V increase in ventricular pacing capture threshold (100% MRI vs. 98.8% control, noninferiority p < 0.0001) or a ≤50% decrease in R-wave amplitude (99.3% MRI vs. 98.8% control, noninferiority p = 0.0001). A total of 34 ventricular tachyarrhythmia/ventricular fibrillation episodes (20 induced; 14 spontaneous) occurred in 24 subjects post-MRI, with no observed effect on sensing, detection, or treatment. ConclusionsThis is the first randomized clinical study of an ICD system designed for full-body MRI at 1.5-T. These data support that the system is safe and the MRI scan does not adversely affect electrical performance or efficacy. (Confirmatory Clinical Trial of the Evera MRI System for Conditionally-Safe MRI Access; NCT02117414)

Abstract 224: No Difference in Complications or Mortality by Implanted Cardioverter Defibrillator Type in Veterans Enrolled in The Outcomes Among Veterans with Implantable Devices (OVID) Registry

Introduction: Dual chamber ICD implantation has been associated with higher complication rates than single chamber ICD implantation without associated decrease in morbidity or mortality in prior reports. If this association is present using validated long term outcomes or whether the same is true for cardiac resynchronization therapy defibrillator (CRT-D) devices is not well described. Methods: The OVID registry enrolled 3,918 veterans between 2003 and 2009. Retrospective chart abstraction from enrollment to implant date captured pre- and peri-procedural data. Patients were then followed prospectively until death or study conclusion. Abstraction was done by trained abstractors. Clinical outcomes and mortality were abstracted and validated. Mortality was cross referenced with the social security death index. Association of ICD type (single chamber, dual chamber, CRT-D) with mortality, non-fatal major events (major adverse cardiac events, TIA, stroke, cardiogenic syncope, cardiac hospitalization, device complication or infection, procedural complications), and the composite of mortality and non-fatal events was examined using Cox proportional hazards regression, adjusting for baseline clinical characteristics and comorbidities. Results: There were 786 deaths and 1143 non-fatal major events over 11,290 person years of follow up. In unadjusted analyses, CRT-D was associated with non-fatal major events (HR 1.26, 95% CI 1.09-1.45; p&lt;0.05) and the composite outcome (HR 1.12, 95% CI 1.06-1.35; p&lt;0.05) as was Dual chamber ICD (non-fatal major-HR 1.19, 95% CI 1.03-1.37; p&lt;0.05, composite-HR 1.17, 95% CI 1.04-1.31; p&lt;0.05). No significant difference existed in risk between ICD types in the unadjusted analysis of mortality or for any outcome when adjusted for clinical covariates. Conclusions: Unadjusted analyses showed an association between dual chamber ICD and CRT-D devices and risk of non-fatal major events and the composite outcome versus single chamber ICD implantation. This did not persist when adjusted for clinical characteristics and comorbidities, though we are underpowered for small differences. Further study is needed as prior reports may not have adjusted adequately for clinical covariates and lacked validated outcomes.

Clinical Case Session I: Sunday 3 May 2015, 10:00-11:00 * Room: Venecia

Clinical Case Session I: Sunday 3 May 2015, 10:00-11:00 * Room: Venecia

Drier air, lower temperatures, and triggering of paroxysmal atrial fibrillation.

The few previous studies on the onset of paroxysmal atrial fibrillation and meteorologic conditions have focused on outdoor temperature and hospital admissions, but hospital admissions are a crude indicator of atrial fibrillation incidence, and studies have found other weather measures in addition to temperature to be associated with cardiovascular outcomes. Two hundred patients with dual chamber implantable cardioverter-defibrillators were enrolled and followed prospectively from 2006 to 2010 for new onset episodes of atrial fibrillation. The date and time of arrhythmia episodes documented by the implanted cardioverter-defibrillators were linked to meteorologic data and examined using a case-crossover analysis. We evaluated associations with outdoor temperature, apparent temperature, air pressure, and three measures of humidity (relative humidity, dew point, and absolute humidity). Of the 200 enrolled patients, 49 patients experienced 328 atrial fibrillation episodes lasting ≥30 seconds. Lower temperatures in the prior 48 hours were positively associated with atrial fibrillation. Lower absolute humidity (ie, drier air) had the strongest and most consistent association: each 0.5 g/m decrease in the prior 24 hours increased the odds of atrial fibrillation by 4% (95% confidence interval [CI]: 0%, 7%) and by 5% (95% CI: 2%, 8%) for exposure in the prior 2 hours. Results were similar for dew point but slightly weaker. Recent exposure to drier air and lower temperatures were associated with the onset of atrial fibrillation among patients with known cardiac disease, supporting the hypothesis that meteorologic conditions trigger acute cardiovascular episodes.

Gender and outcomes after primary prevention implantable cardioverter-defibrillator implantation: Findings from the National Cardiovascular Data Registry (NCDR)

Clinical trials have demonstrated the benefit of implantable cardioverter-defibrillators (ICDs) for the primary prevention of sudden cardiac death in selected high-risk individuals. Because of small numbers of women enrolled in these trials, outcomes for women after hospital discharge have not been well described. We compared procedure-related complications and outcomes after hospital discharge between men and women undergoing single- or dual-chamber ICD implantation for primary prevention. In patients 65 years or older with Medicare fee-for-service coverage, we identified 38,912 initial implants (25% women) who received single- or dual-chamber ICDs for primary prevention between January 2006 and December 2009 in the NCDR and evaluated gender differences in outcomes. Women had greater comorbidity and more advanced heart failure (HF) at the time of ICD implantation than did men. Device-related complications, death at 6 months, all-cause readmissions, and HF readmissions at 6 months were significantly more common in women (7.2% vs 4.8%, 6.5% vs 5.6%, 37.2% vs 31.7%, and 14.0% vs 10.0% respectively; P < .001 for all). Women continued to have higher odds of procedural complications (odds ratio [OR] 1.39, 95% CI 1.26-1.53, P < .001), 6-month all-cause readmission (OR 1.22, 95% CI 1.16-1.28, P < .001), and 6-month HF readmission (OR 1.32, 95% CI 1.23-1.42, P < .001), with a trend toward higher 6-month mortality (OR 1.08, 95% CI 0.98-1.20, P = .123), compared with men, after adjusting for differences in baseline characteristics and device type (single vs dual chamber). Among older patients receiving ICDs for primary prevention in clinical practice, women experience worse outcomes than do men. Reasons for gender differences in outcomes are poorly understood and require further investigation.

Inappropriate ICD therapies: All problems solved with MADIT-RIT?

The MADIT-RIT study represents a major trial in implantable cardioverter-defibrillator (ICD) therapy that was recently published. It highlights that different programming strategies (high rate cut-off or delayed therapy versus conventional) reduce inappropriate ICD therapies, leave syncope rates unaltered and can improve patient's survival. The study should motivate cardiologist and electrophysiologists to reconsider their individual programming strategies. However, as the study represents largely patients with ischemic or dilated cardiomyopathy for primary prevention of sudden cardiac death supplied with a dual chamber or cardiac resynchronisation therapy ICD, the results may not easily be transferable to other entities or other device types. Despite the success of the MADIT-RIT study efforts still need to be taken to further optimise device algorithms to avert inappropriate therapies. Optimised ICD therapy also includes the avoidance of unnecessary ICD shocks as well as the treatment of all aspects of the underlying cardiac disease.

Time-dependent risk reduction of ventricular tachyarrhythmias in cardiac resynchronization therapy patients: a MADIT-RIT sub-study.

Data on the time-dependent benefit of cardiac resynchronization therapy with defibrillator (CRT-D) compared with a dual-chamber implantable cardioverter-defibrillator (ICD) to reduce death or ventricular tachycardia (VT) or ventricular fibrillation (VF) are limited. We aimed to evaluate the time-related risk of death or sustained VT or VF in patients receiving CRT-D vs. ICD in the MADIT-RIT trial. Kaplan-Meier survival analyses and multivariate Cox regression models were utilized to compare the incidence and the risk of death or sustained VT/VF in the CRT-D and ICD subgroups by the elapsed time after device implantation (6 months). Of the ICD (n = 742) and CRT-D (n = 757) patients enrolled, the risk of death was lower in CRT-D vs. in ICD early after device implantation [hazard ratio (HR) = 0.42, 95% confidence interval (CI): 0.17-1.03, P = 0.058] and beyond 6 months of follow-up (HR = 0.39, 95% CI: 0.21-0.73, P = 0.004), with the 6-month interaction P = 0.899. The overall risk of sustained VT/VF was reduced in CRT-D vs. ICD patients (HR = 0.73, 95% CI: 0.52-1.03, P = 0.07). However, the risk was similar in the first 6 months (HR = 1.00, 95% CI: 0.62-1.62, P = 0.988), and a lower risk emerged 6 months after CRT-D implantation (HR = 0.58, 95% CI: 0.38-0.88, P = 0.011), with the 6-month interaction P = 0.059. The reduced mortality risk of CRT-D compared with an ICD alone began early after device implantation and was sustained during long-term follow-up; the reduced risk for ventricular tachyarrhythmias did not emerge until 6 months after device implantation. http://clinicaltrials.gov/ct2/show/NCT00947310.

Troubleshooting implantable cardioverter-defibrillator sensing problems II.

Accurate atrial sensing during tachycardia is essential for reliable determination of atrial rate, which is a critical component of interval-based dual-chamber supraventricular tachycardia (SVT)–VT discrimination algorithms.1 Thus, atrial sensing in dual-chamber implantable cardioverter-defibrillators (ICDs) must be reliable at fast ventricular rates, a technically challenging requirement. Determining the atrial rate during rapidly conducted atrial flutter (AF) requires accurate sensing of low-amplitude signals (Figure I in the Data Supplement). The required high atrial sensitivity increases the risk of atrial oversensing, especially of far-field R waves. Pacemakers rely on a long postventricular atrial blanking period (PVAB) to prevent oversensing of far-field R waves, but ICDs cannot: for a fixed PVAB, the blanked fraction of the cardiac cycle increases with the ventricular rate. For example, a 100-ms PVAB blanks 10% of the cycle at a bradycardia pacing cycle length of 1000 ms, but 33% during rapidly conducted AF with ventricular cycle length of 300 ms. PVABs longer than ≈80 ms produce clinically significant, functional atrial undersensing in rapidly conducted AF,2 and any PVAB may cause undersensing of alternate atrial electrograms in AF with 2:1 atrioventricular conduction. The inherent trade-off between atrial oversensing and undersensing is problematic. Both cause errors in dual-chamber SVT–VT discrimination algorithms.2–6 In contemporary ICDs, ventricular electrogram morphology algorithms mitigate this problem but do not eliminate it. ### Determinants of Far-Field R Waves #### General Considerations In the absence of atrial lead dislodgement, the amplitude of far-field R wave depends on 4 variables. The first is the amplitude of the ventricular electrogram in ventricular myocardium. Thus, there is a correlation between far-field R–wave oversensing and left ventricular hypertrophy.7 The second is interelectrode spacing.8 Closely spaced electrodes (1.1 mm) minimize far-field R waves in comparison with conventional 10-mm spacing, but they also reduce the amplitude of atrial electrograms during short-term follow-up9,10 and …

Incessant “ventricular tachycardia” in a patient with non-ischemic cardiomyopathy. What is the tachycardia mechanism?

We present an uncommon and unique arrhythmia in a patient with non-ischemic cardiomyopathy and dual chamber implantable cardioverter defibrillator presenting with palpitations and dyspnea. While surface electrocardiogram suggested irregular narrow complex tachycardia, evaluation of stored electrograms from implantable cardioverter defibrillator revealed incessant episodes of non-sustained ventricular tachycardia. The patient underwent electrophysiological study and successful ablation of the arrhythmia with complete resolution of symptoms. We discuss the underlying tachycardia mechanism and challenges in the diagnosing and management of this unusual rhythm disorder.

Dramatic improvement of refractory anemia caused by mechanical hemolysis in a patient with hypertrophic obstructive cardiomyopathy using dual-chamber pacing

A 59-year-old woman with hypertrophic obstructive cardiomyopathy was admitted to our institution with worsening heart failure. She developed mechanical intracardiac hemolysis due to left ventricular outflow tract (LVOT) obstruction. Despite surgical myectomy, the LVOT pressure gradient (PG) remained high and hemolytic anemia recurred. A dual-chamber implantable cardioverter defibrillator was then implanted, which decreased the LVOT-PG and improved hemolysis.