The impact of race on utilization of durable left ventricular assist device therapy in patients with advanced heart failure.

BACKGROUND: Heart failure affects >6 million people in the United States alone and is most prevalent in Black patients who suffer the highest mortality risk. Yet prior studies have suggested that Black patients are less likely to receive advanced heart failure therapy. We hypothesized that Black patients would have decreased rates of durable left ventricular assist device (LVAD) implantation within our expansive heart failure program. METHODS: A retrospective single-center cohort study was conducted at a single high-volume academic medical center. Patients between 18 and 85 years admitted with a diagnosis of cardiogenic shock or congestive heart failure between 1, 2013 and 12, 2017 with a left ventricular ejection fraction < 30% and inotropic dependence or need for mechanical circulatory support were included. Patients with contraindications to durable LVAD were excluded. An adjusted logistic regression model for durable LVAD implantation within 90 days of the index admission was used to determine the effect of race on durable LVAD implantation. RESULTS: Among the 702 study patients (60.9% White, 34.1% Black), durable LVAD implantation was performed within 90 days of the index admission in 183 (26%) of the cohort. After multivariate analysis, Black patients were not found to have a statistically significant difference in durable LVAD implantation rates compared to White patients in our study (OR: 0.68 [95% confidence interval: 0.45-1.04; p: .074]). CONCLUSIONS: Black patients in our study did not have a statistically significant difference in the rate of durable LVAD implantation compared with White patients after adjustments were made for age, sex, socioeconomic, and clinical covariates. Larger prospective studies are needed to validate these findings.

Outcomes following cardioversion for patients with cardiac amyloidosis and atrial fibrillation or atrial flutter.

Atrial arrhythmias commonly occur in patients with cardiac amyloidosis (CA), but there is limited data on safety or efficacy of cardioversion (DCCV) for management of these rhythms in CA. We identified 25 patients with CA (20 with transthyretin (TTR) and 5 with light-chain (AL) amyloidosis) at Duke University who underwent DCCV for atrial arrhythmias and documented procedural success, complications, and long-term morbidity and mortality. While DCCV successfully restored sinus rhythm in 96% of patients, 36% of patients experienced immediate procedural complications (primarily bradycardia and hypotension), 80% had recurrence of atrial arrhythmias at 1 year, and 52% died at 3 years, highlighting short-term safety concerns, long-term inefficacy, and poor prognosis associated with symptomatic atrial arrhythmias requiring DCCV in CA.

Implantable cardioverter-defibrillator lead revision following left ventricular assist device implantation.

INTRODUCTION: Lead dysfunction can lead to serious consequences including failure to treat ventricular tachycardia or fibrillation (VT/VF). The incidence and mechanisms of lead dysfunction following left ventricular assist device (LVAD) implantation are not well-described. We sought to determine the incidence, mechanisms, timing, and complications of right ventricular lead dysfunction requiring revision following LVAD implantation. METHODS: Retrospective observational chart review of all LVAD recipients with pre-existing implantable cardioverter-defibrillator (ICD) from 2009 to 2018 was performed including device interrogation reports, laboratory and imaging data, procedural reports, and clinical outcomes. RESULTS: Among 583 patients with an ICD in situ undergoing LVAD implant, the median (interquartile range) age was 62.5 (15.7) years, 21% were female, and the types of LVADs included HeartWare HVAD (26%), HeartMate II (52%), and HeartMate III (22%). Right ventricular lead revision was performed in 38 patients (6.5%) at a median (25th, 75th) of 16.4 (3.6, 29.2) months following LVAD. Mechanisms of lead dysfunction included macrodislodgement (n = 4), surgical lead injury (n = 4), recall (n = 3), insulation failure (n = 8) or conductor fracture (n = 7), and alterations in the lead-myocardial interface (n = 12). Undersensing requiring revision occurred in 22 (58%) cases. Clinical sequelae of undersensing included failure to detect VT/VF (n = 4) and pacing-induced torsade de pointes (n = 1). Oversensing occurred in 12 (32%) and sequelae included inappropriate antitachycardia pacing ([ATP], n = 8), inappropriate ICD shock (n = 6), and ATP-induced VT (n = 1). CONCLUSION: The incidence of right ventricular lead dysfunction following LVAD implantation is significant and has important clinical sequelae. Physicians should remain vigilant for lead dysfunction after LVAD surgery and test lead function before discharge.

Catheter ablation of atrial fibrillation in cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis is a progressive infiltrative disease involving deposition of amyloid fibrils in the myocardium and cardiac conduction system that frequently manifests with heart failure (HF) and arrhythmias, most frequently atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT). METHODS: We performed an observational retrospective study of patients with a diagnosis of cardiac amyloid who underwent catheter ablation at our institution between January 1, 2011 and December 1, 2018. Patient demographics, procedural characteristics, and outcomes were determined by manual chart review. RESULTS: A total of 13 catheter ablations were performed over the study period in patients with cardiac amyloidosis, including 10 AT/AF/AFL ablations and three atrioventricular nodal ablations. Left ventricular ejection fraction was lower at the time of AV node ablation than catheter ablation of AT/AF/AFL (23% vs 40%, P = .003). Cardiac amyloid was diagnosed based on the results of preablation cardiac MRI results in the majority of patients (n = 7, 70%). The HV interval was prolonged at 60 ± 15 ms and did not differ significantly between AV nodal ablation patients and AT/AF/AFL ablation patients (69 ± 18 ms vs 57 ± 14 ms, P = .36). The majority of patients undergoing AT/AF/AFL ablation had persistent AF (n = 7, 70%) and NYHA class II (n = 5, 50%) or III (n = 5, 50%) HF symptoms, whereas patients undergoing AV node ablation were more likely to have class IV HF (n = 2, 66%, P = .014). Arrhythmia-free survival in CA patients after catheter ablation of AT/AF/AFL was 40% at 1 year and 20% at 2 years. CONCLUSIONS: Catheter ablation of AT/AF/AFL may be a feasible strategy for appropriately selected patients with early to mid-stage CA, whereas AV node ablation may be more appropriate in patients with advanced-stage CA.

Left atrial appendage closure: A therapy uniquely suited for specific populations of patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common clinically relevant arrhythmia and confers a fivefold increased risk for stroke. Cardioembolic stroke secondary to AF is a devastating event, but is largely preventable with appropriate oral anticoagulation (OAC). The PROTECT and PREVAIL trials demonstrated that the WATCHMAN left atrial appendage closure (LAAC) device in combination with short-term warfarin therapy is noninferior to long-term warfarin with respect to a composite endpoint of stroke, cardiovascular death, and systemic embolism. Importantly, the WATCHMAN confers a significant reduction in life-threatening bleeding compared to OAC. Although direct-acting oral anticoagulant (DOAC) are superior to warfarin in eligible patients, several important AF populations exist in whom left atrial appendage (LAA) closure may be preferable to DOAC. Populations warranting strong consideration of LAAC include patients with contraindications to DOAC, end-stage renal disease, prior intracranial hemorrhage, recurrent gastrointestinal bleeding, and patients undergoing transcatheter aortic valve replacement or left atrial electrical isolation. Device-related thrombosis is an important complication of LAAC, and DOAC may be preferential to warfarin for prevention and treatment of this complication remains unexplored. Prospective clinical trials comparing DOAC to LAAC in these unique populations are either ongoing or needed.

Predicting atrial fibrillation recurrence after ablation in patients with heart failure: Validity of the APPLE and CAAP-AF risk scoring systems.

BACKGROUND: Compared with medical therapy, catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) improves cardiovascular outcomes. Risk scores (CAAP-AF and APPLE) have been developed to predict the likelihood of AF recurrence after ablation, have not been validated specifically in patients with AF and HF. METHODS: We analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in a cohort of 230 consecutive patients with AF and HF undergoing PVI in the Duke Center for Atrial Fibrillation registry from 2009-2013. RESULTS: During a follow-up period of 12 months, 76 of 230 (33%) patients with HF experienced recurrent AF after ablation. The median APPLE and CAAP-AF scores were 1.5 ([Q1, Q3]: [1.0, 2.0]) and 4.0 ([Q1, Q3]: [3.0, 5.0]), respectively and were not different from those patients with and without recurrent AF. Freedom from AF was not different according to APPLE and CAAP-AF scores. Discrimination for recurrent AF with the CAAP-AF score was modest with a C-statistic of 0.60 (95% CI 0.52-0.67). Discrimination with the APPLE score was similarly modest, with a C-statistic of 0.54 (95% CI: 0.47-0.62). CONCLUSIONS: Validated predictive risk scores for recurrent AF after catheter ablation exhibit limited predictive ability in cohorts of AF and HF. Additional tools are needed to facilitate risk stratification and patient selection for AF ablation in patients with concomitant HF.

Ranolazine reduces atrial fibrillatory wave frequency.

AIMS: Antiarrhythmic medications for the treatment of atrial fibrillation (AF) have limited efficacy and rare but potentially life-threatening side effects. Ranolazine is an antianginal agent that may have antiarrhythmic activity in AF. METHODS AND RESULTS: Using the Duke Enterprise Data Unified Content Explorer database, we analysed a cohort of AF patients on ranolazine. Patients served as their own historic control. Electrocardiograms (ECGs) were analysed before and after ranolazine initiation to determine the effect of ranolazine on dominant frequency (DF), f-wave amplitude, and organizational index (OI). We identified 15 patients with ECGs in AF before and after ranolazine. Ranolazine was associated with lower DF by an average of 10% (5.10 ± 0.74 vs. 5.79 ± 0.96 Hz, P = 0.04) but not with changes in OI (0.47 ± 0.11 vs. 0.50 ± 0.12, P = 0.71) or amplitude (0.47 ± 0.43 vs. 0.41 ± 0.40 mV, P = 0.82). Ranolazine was also associated with lower DF in patients (n = 10) not on concomitant antiarrhythmic therapy (5.25 ± 0.78 vs. 6.03 ± 0.79 Hz, P = 0.04). CONCLUSION: Ranolazine is associated with lower AF DF but no change in OI or fibrillatory wave amplitude. Prospective trials are needed to evaluate ranolazine's potential as a novel antiarrhythmic drug for AF.

Protocol modifications reduce risk of delayed pericardial effusions after vein of Marshall ethanol infusion: follow-up from the Maine experience.

BACKGROUND: While ethanol infusion into the vein of Marshall (VOM) as an adjunct to atrial fibrillation ablation has shown promise, adoption has been limited by the technical expertise required, unclear antiarrhythmic mechanism, and complication risk. Delayed pericardial effusions have been associated with ethanol infusion into the VOM in prior studies. Very little is known about how the procedural approach itself can impact the risk of delayed effusions. We sought to understand the incidence and influence of procedural technique on complications including delayed pericardial effusions from VOM ethanol infusion at a large single medical center. METHODS: A total of 275 atrial ablation cases wherein VOM ethanol infusion was attempted were identified from the time of the program's inception in 2019 at Maine Medical Center (Portland, ME) until October of 2023. Cases were classified into phase I cases (early experience) and phase II cases (later experience) based upon temporal programmatic changes in the ethanol dose and infusion rate as well as the use of routine VOM venography. Procedural details and complications were adjudicated from the medical record. RESULTS: The overall VOM ethanol infusion success was 91.4%. Nine complications (3.3%) occurred in eight patients (2.9% of patients). These were more frequent in phase I (5.8%) compared to phase II (1.3%, p = 0.047). This difference was driven by a difference in delayed presentations of tamponade, which occurred in four patients in phase I (3.3%) and in no patients in phase II (0%, p = 0.037). Twelve-month estimated atrial arrhythmia freedom did not differ between groups (73.8% phase I vs 70.4% phase II, p = 0.24). CONCLUSION: In our single-center experience, adjustments to the procedural approach with lower ethanol infusion rate and dosage, combined with utilizing selective VOM venography, associated with a lowering of complication rates and in particular, delayed pericardial tamponade.

Efficacy and Safety of Adjunctive and Primary Use of the TightRail Mechanical Cutting Sheath for Lead Extraction.

BACKGROUND: Rotational cutting tools are increasingly used in transvenous lead extraction. There are limited data on their safety and efficacy, particularly when used adjunctively for stalled progression. The aim of this study was to evaluate the utilization, safety, and effectiveness of mechanical rotational cutting tools for transvenous lead extraction. METHODS: Patients undergoing transvenous lead extraction at a single tertiary center (April 2015 to January 2021, n=586) were included in this retrospective analysis. The study characterized the 251 patients (42.8%) whose cases involved the TightRail mechanical cutting tool. RESULTS: Among 251 patients, 526 leads were extracted and TightRail was used for 70.5%. The TightRail was used adjunctively with the laser for 65.2% of leads, 97.8% of the time as the second tool after stalled progression. Using a multivariable logistic regression model, we found that active-fixation leads (odds ratio, 2.78 [95% CI, 1.62-4.78]; P=0.0002), dual-coil leads (odds ratio, 3.39 [95% CI, 1.87-6.16]; P<0.0001), and lead dwell time (odds ratio, 1.16 [95% CI for 1-year increase, 1.11-1.21]; P<0.0001) were factors independently associated with adjunctive TightRail use. Stalled progression requiring TightRail occurred most often in the innominate vein and superior vena cava (59.3%). The clinical success rate was 96.8%, and the rate of major adverse events was 2.8%. Only 1 major adverse event was observed during TightRail use. CONCLUSIONS: Rotational cutting with TightRail was used in 42.8% of transvenous lead extractions, predominantly in an adjunctive manner after stalled laser progression in the innominate vein and superior vena cava, and more frequently for dual-coil and leads with longer dwell times. Adjunctive TightRail use carries a low risk of major complications.

Lead Extraction and Mortality Among Patients With Cardiac Implanted Electronic Device Infection.

Importance: Complete hardware removal is a class I recommendation for cardiovascular implantable electronic device (CIED) infection, but practice patterns and outcomes remain unknown. Objective: To quantify the number of Medicare patients with CIED infections who underwent implantation from 2006 to 2019 and lead extraction from 2007 to 2019 to analyze the outcomes in these patients in a nationwide clinical practice cohort. Design, Setting, and Participants: This cohort study included fee-for-service Medicare Part D beneficiaries from January 1, 2006, to December 31, 2019, who had a de novo CIED implantation and a CIED infection more than 1 year after implantation. Data were analyzed from January 1, 2005, to December 31, 2019. Exposure: A CIED infection, defined as (1) endocarditis or infection of a device implant and (2) documented antibiotic therapy. Main Outcomes and Measures: The primary outcomes of interest were device infection, device extraction, and all-cause mortality. Time-varying multivariable Cox proportional hazards regression models were used to evaluate the association between extraction and survival. Results: Among 1 065 549 patients (median age, 78.0 years [IQR, 72.0-84.0 years]; 50.9% male), mean (SD) follow-up was 4.6 (2.9) years after implantation. There were 11 304 patients (1.1%) with CIED infection (median age, 75.0 years [IQR, 67.0-82.0 years]); 60.1% were male, and 7724 (68.3%) had diabetes. A total of 2102 patients with CIED infection (18.6%) underwent extraction within 30 days of diagnosis. Infection occurred a mean (SD) of 3.7 (2.4) years after implantation, and 1-year survival was 68.3%. There was evidence of highly selective treatment, as most patients did not have extraction within 30 days of diagnosed infection (9202 [81.4%]), while 1511 (13.4%) had extraction within 6 days of diagnosis and 591 (5.2%) had extraction between days 7 and 30. Any extraction was associated with lower mortality compared with no extraction (adjusted hazard ratio [AHR], 0.82; 95% CI, 0.74-0.90; P < .001). Extraction within 6 days was associated with even lower risk of mortality (AHR, 0.69; 95% CI, 0.61-0.78; P < .001). Conclusions and Relevance: In this study, a minority of patients with CIED infection underwent extraction. Extraction was associated with a lower risk of death compared with no extraction. The findings suggest a need to improve adherence to guideline-directed care among patients with CIED infection.

Colchicine for the Prevention of Recurrent Arrhythmia After Catheter Ablation of Atrial Fibrillation: Results of a Single-Center, Retrospective Study.

BACKGROUND: There is evidence to suggest that colchicine reduces the risk of recurrent atrial fibrillation (AF) after catheter ablation; however, the tolerability and safety of colchicine in routine practice is unknown. METHODS: Patients undergoing catheter ablation for AF who received colchicine after ablation were matched 1:1 to patients who did not by age, sex, and renal function. Recurrent AF was compared between groups categorically at 12 months and via propensity weighted Cox proportional hazards models with and without a 3-month blanking period. RESULTS: Overall, 180 patients (n = 90 colchicine and n = 90 matched controls) were followed for a median (Q1, Q3) of 10.3 (7.0, 12.0) months. Mean age was 65.3 ± 9.1 years, 33.9% were women, mean CHA2DS2-VASc score was 2.9 ± 1.5, and 51.1% had persistent AF. Most patients (70%) received colchicine 0.6 mg daily for a median of 30 days. In the colchicine group, 55 patients (61.1%) were receiving at least one known interacting medication with colchicine. After ablation, one patient required colchicine dose reduction and four patients required discontinuation. After adjusting for covariate imbalance using propensity weighting, no significant association between colchicine use and AF recurrence was identified (adjusted hazard ratio 0.94, 95% confidence interval [CI] 0.48-1.85; p = 0.853). No significant association was found between colchicine use and all-cause hospitalizations (adjusted odds ratio 0.74, 95% CI 0.28-1.96; p = 0.548). CONCLUSION: Despite the frequent presence of drug-drug interactions, a 30-day course of colchicine is well-tolerated after AF ablation; however, we did not observe any association between colchicine and lower rates of AF recurrence or hospitalization.

Cases of Azygous Coil Extraction.

BACKGROUND: Procedural and clinical outcomes of patients undergoing extraction or removal of azygous coils are not well characterized. OBJECTIVE: Evaluate outcomes in patients who undergo device extraction with an azygous coil in situ. METHODS: Patients undergoing extraction with an azygous coil in situ between May 2015 and January 2021 were included in this retrospective single-center analysis. Outcomes included procedural success, use of laser and mechanical cutting tools during the procedure, procedural complications, and mortality. RESULTS: We identified 2 patients undergoing device extraction with an azygous coil in situ with a dwell time greater than 12 months. The patients were male, aged 73 and 83 years. Both had a history of hypertension, atrial fibrillation, heart failure (ejection fractions <15% and 20%), and cardiomyopathy (nonischemic and ischemic), and presented with an infection (case 1 with a single-chamber ICD and Staphylococcus aureus bacteremia, case 2 with a cardiac resynchronization therapy defibrillator pocket infection). The mean dwell time of all 6 leads extracted was 6.43 years (range 1.33-12.63 years), and the 2 azygous coils had dwell times of 1.33 and 6.04 years. In case 1, the azygous coil was inferior to the cardiac silhouette, while in case 2 it was superior. A 14F laser sheath was employed to remove both azygous coils. Both extractions were a complete procedural success in which all leads were removed completely without intraoperative complications. CONCLUSION: These cases demonstrate the variable courses of azygous coils, provide proof of concept that they can be removed safely, and illustrate that azygous coils can be removed with the same techniques that are commonly used to remove other types of leads.

Diagnosis-to-ablation time predicts recurrent atrial fibrillation and rehospitalization following catheter ablation.

BACKGROUND: Wait times for catheter ablation in patients with symptomatic atrial fibrillation (AF) may influence clinical outcomes. OBJECTIVE: This study examined the relationship between the duration from AF diagnosis to ablation, or diagnosis-to-ablation time (DAT), on the clinical response to catheter ablation in a large nationwide cohort of patients. METHODS: We identified patients with new AF who underwent catheter ablation between January 2014 and December 2017 using the IBM MarketScan databases. Cox proportional hazard models were used to estimate the strength of the association between DAT and the outcomes of AF recurrence and hospitalization at 1 year postablation. RESULTS: Among 11,143 AF patients who underwent ablation, the median age was 59 years, 31% were female, and the median CHA2DS2-VASc score was 2. Median DAT was 5.5 (2.6, 13.1) months. At 1 year postablation, 10.0% (n = 1116) developed recurrent AF. For each year increase in DAT, the risk of AF recurrence increased by 20% after adjustment for baseline comorbidities and medications (hazard ratio [HR] 1.20, 95% confidence interval [CI] 1.11-1.30). A longer DAT was associated with an increased risk of hospitalization (HR 1.08 per DAT year, 95% CI 1.02-1.15). DAT was a stronger predictor of AF recurrence postablation than traditional clinical risk factors, including age, prior heart failure, or renal failure. CONCLUSION: Increasing duration between AF diagnosis and catheter ablation is associated with higher AF recurrence rates and all-cause hospitalization. Our findings are consistent with a growing body of evidence supporting the benefits of prioritizing early restoration of sinus rhythm.

Electrical storm in patients with left ventricular assist devices: Risk factors, incidence, and impact on survival.

BACKGROUND: Ventricular arrhythmias (VAs) and electrical storm (ES) are recognized complications following left ventricular assist device (LVAD) implantation; however, their association with long term-outcomes remains poorly understood. OBJECTIVE: The purpose of this study was to describe the clinical impact of ES in a population of patients undergoing LVAD implantation at a quaternary care center in the United States. METHODS: This was an observational retrospective study of patients undergoing LVAD implantation from 2009 to 2020 at Duke University Hospital. The incidence of ES (≥3 sustained VA episodes over a 24-hour period without an identifiable reversible cause) was determined from patient records. Risk factors for ES were identified using multivariable Cox proportional hazards modeling. RESULTS: Among 730 patients undergoing LVAD implant, 78 (10.7%) developed ES at a median of 269 (interquartile range [IQR] 7-766) days following surgery. Twenty-seven patients (34.6%) developed ES within 30 days, while 51 (65.4%) presented with ES at a median 639 (IQR 281-1017) days after implant. Following ES, 41% of patients died within 1 year. Patients who developed ES were more likely to have a history of VAs, ventricular tachycardia ablation, antiarrhythmic drug use, and perioperative mechanical circulatory support around the time of LVAD implant than patients without ES. CONCLUSION: ES occurs in 1 in 10 patients after LVAD and is associated with higher mortality. Risk factors for ES include a history of VAs, VT ablation, antiarrhythmic drug use, and perioperative mechanical circulatory support. Optimal management of ES surrounding LVAD implant, including escalation of medical therapy, catheter ablation, or adjunctive sympatholytic therapies, remains uncertain.

Cardiac Resynchronization Therapy With or Without Defibrillation in Patients With Nonischemic Cardiomyopathy: A Systematic Review and Meta-Analysis.

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Arabidopsis has two functional orthologs of the yeast V-ATPase assembly factor Vma21p.

How individual protein subunits assemble into the higher order structure of a protein complex is not well understood. Four proteins dedicated to the assembly of the V(0) subcomplex of the V-adenosine triphosphatase (V-ATPase) in the endoplasmic reticulum (ER) have been identified in yeast, but their precise mode of molecular action remains to be identified. In contrast to the highly conserved subunits of the V-ATPase, orthologs of the yeast assembly factors are not easily identified based on sequence similarity. We show in this study that two ER-localized Arabidopsis proteins that share only 25% sequence identity with Vma21p can functionally replace this yeast assembly factor. Loss of AtVMA21a function in RNA interference seedlings caused impaired cell expansion and changes in Golgi morphology characteristic for plants with reduced V-ATPase activity, and we therefore conclude that AtVMA21a is the first V-ATPase assembly factor identified in a multicellular eukaryote. Moreover, VMA21p acts as a dedicated ER escort chaperone, a class of substrate-specific accessory proteins so far not identified in higher plants.

Cardiac Implantable Electronic Devices: A Window Into the Evolution of Conduction Disease in Cardiac Amyloidosis.

OBJECTIVES: This study characterized the relationship between conduction disease and cardiac amyloidosis (CA) through longitudinal analysis of cardiac implantable electronic device (CIED) data. BACKGROUND: Bradyarrhythmias and tachyarrhythmias are commonly reported in CA and may precede a CA diagnosis, although the natural history of conduction disease in CA is not well-described. METHODS: Patients with CA (transthyretin amyloidosis cardiomyopathy [ATTR-CM] and light-chain amyloidosis [AL-CA]) and a CIED were identified within the Duke University Health System. Patient characteristics at the time of implantation, including demographics and data relevant to CA diagnosis, cardiac imaging, and CIED were recorded. CIED interrogations were analyzed for pacing and atrial fibrillation (AF) burden, activity level, lead parameters, and ventricular arrhythmia incidence and/or therapy. RESULTS: Thirty-four patients with CA (7 with AL-CA, 27 with ATTR-CM [78% with wild-type]; 82% men) with median age of 75 years and a mean ejection fraction of 42 ± 13% had a CIED implanted for bradycardia (65%) or prevention of sudden cardiac death (35%). CIED implantation preceded CA diagnosis in 14 patients (41%). Over a mean follow-up of 3.1 ± 4.0 years, right ventricular sensing amplitudes decreased but did not result in device malfunction; lead impedances and capture thresholds remained stable. Between post-implantation years 1 and 5, mean ventricular pacing increased from 56 ± 9% to 96 ± 1% (p = 0.003) and AF burden increased from 2 ± 1.3 to 17 ± 3 h/day (p = 0.0002). Ventricular arrhythmias were common (mean episodes per patient per year: 6.7 ± 2.3 [ATTR-CM] and 5.1 ± 3.2 [AL-CA]) but predominately nonsustained; only 1 patient with AL-CA required implantable cardioverter-defibrillator therapy. CONCLUSIONS: Longitudinal analysis of CIED data in patients with CA revealed progressive conduction disease, with high AF burden and eventual dependence on ventricular pacing, although lead parameters remained stable. Ventricular arrhythmias were common but predominantly nonsustained, particularly in ATTR-CM.

Reducing ECG Artifact From Left Ventricular Assist Device Electromagnetic Interference.

Background Left ventricular assist devices (LVADs) generate electromagnetic interference that causes high-frequency noise artifacts on 12-lead ECGs. We describe the causes of this interference and potential solutions to aid ECG interpretation in patients with LVAD. Methods and Results Waveform data from ECGs performed before and after LVAD implantation were passed through a fast Fourier transform to identify LVAD-related changes in the spectral profile. ECGs recorded in 9 patients with HeartMate II, HeartMate 3, and HeartWare LVADs were analyzed to identify the LVAD model-specific spectral patterns. Waveform data were then passed through digital low-pass and bandstop filters and redisplayed to evaluate the effect of filtering on LVAD-related electromagnetic interference. The spectral profile of patients with HeartMate II and HeartMate 3 LVADs demonstrated a prominent signal at the device-specific frequency of impeller rotation. In patients with the HeartMate 3 LVAD, 2 additional peaks were observed at the frequencies equivalent to the LVAD's artificial pulsatility rotational speeds. Patients with HeartWare devices demonstrated a prominent signal peak at a frequency equal to double their LVAD's set rotational speed. Applying a low-pass filter to a value below the observed frequency peak from the LVAD significantly improved the waveform tracing and quality of the ECG. Applying a speed-specific bandstop filter to remove the observed LVAD frequency peak also improved the clarity of the ECG without compromising physiological high-frequency signal components. Conclusions LVADs create impeller rotational speed-specific electromagnetic interference that can be ameliorated by application of low-pass or bandstop filters to improve ECG clarity.

Cardiac Arrest in the Setting of Diffuse Coronary Ectasia: Perspectives on a Unique Ischemic Insult.

A 69-year-old man with a history of coronary artery ectasia, potentially resulting from an underlying heritable connective tissue disorder, presented with ventricular fibrillation. Despite medical management of ischemia, he developed recurrent ventricular tachycardia with poor neurological recovery. We highlight challenges in the management of coronary artery ectasia. (Level of Difficulty: Beginner.).