Racial and ethnic differences in left atrial appendage occlusion wait time, complications, and periprocedural management.

PURPOSE: Non-white patients are underrepresented in left atrial appendage occlusion (LAAO) trials, and racial disparities in LAAO periprocedural management are unknown. METHODS: We assessed sociodemographics and comorbidities of consecutive patients at our institution undergoing LAAO between 2015 and 2020, then in adjusted analyses, compared procedural wait time, procedural complications, and post-procedure oral anticoagulation (OAC) use in whites versus non-whites. RESULTS: Among 109 patients undergoing LAAO (45% white), whites had lower CHA2 DS2 VASc scores, on average, than non-whites (4.0 vs. 4.8, p = .006). There was no difference in median time from index event (IE) or initial outpatient cardiology encounter to LAAO procedure (whites 10.5 vs. non-whites 13.7 months, p = .9; 1.9 vs. 1.8 months, p = .6, respectively), and there was no difference in procedural complications (whites 4% vs. non-whites 5%, p = .33). After adjusting for CHA2 DS2 VASc score, OAC use at discharge tended to be higher in whites (OR 2.4, 95% CI [0.9-6.0], p = .07). When restricting the analysis to those with prior gastrointestinal (GI) bleed, adjusting for CHA2 DS2 VASc score and GI bleed severity, whites had a nearly five-fold odds of being discharged on OAC (OR 4.6, 95% CI [1-21.8], p = 0.05). The association between race and discharge OAC was not mediated through income category (total mediation effect 19% 95% CI [-.04-0.11], p = .38). CONCLUSION: Despite an increased prevalence of comorbidities amongst non-whites, wait time for LAAO and procedural complications were similar in whites versus non-whites. Among those with prior GI bleed, whites were nearly five-fold more likely to be discharged on OAC than non-whites, independent of income.

Long-term arrhythmia follow-up of patients with myotonic dystrophy.

BACKGROUND: Myotonic dystrophy (MD) is the most common muscular dystrophy in adults and is associated with sudden death. Reported predictors of sudden death in this population include atrial tachyarrhythmias, a PR interval greater than 240 milliseconds, aberrant QRS conduction, and any degree of AV block. OBJECTIVE: We sought to report on the arrhythmic outcome of a cohort of patients with a new diagnosis of genetically proven MD. METHODS: We performed a retrospective review of 37 patients with genetically confirmed MD referred to our electrophysiology clinic for primary cardiac screening. RESULTS: There were 25 patients with MD type 1 (MD1) and 12 patients with MD type 2 (MD2). Eight patients with MD1 (32%) had atrial fibrillation, compared to only one patient with MD2 (8.3%). Patients with MD1 were more likely to have evidence of conduction disease abnormalities (40% vs. 8.3%, P = ns) and had a higher all-cause mortality (16% vs. 0%) than those with MD2. Criteria for recommending ICD implantation were based on sudden death risk factors suggested by published literature. Eleven patients were offered an ICD, 2 refused and died within the next year. Of the 9 patients who received an ICD, 8 had MD1. Three patients received appropriate shocks, 2 for monomorphic VT, and one for polymorphic VT. CONCLUSION: The presence of AV conduction disturbance in MD patients is associated with a greater risk for ventricular arrhythmias. MD1 was more likely to be associated with cardiac arrhythmias than MD2. The incidence of ventricular arrhythmias among those who received a primary prevention ICD was 33% over 22 months, with 2 patients experiencing monomorphic VT and one experiencing polymorphic VT.

Glove and gown effects on intraoperative bacterial contamination.

OBJECTIVE: Experiments were performed to determine the risk of bacterial contamination associated with changing outer gloves and using disposable spunlace paper versus reusable cloth gowns. BACKGROUND: Despite decades of research, there remains a lack of consensus regarding certain aspects of optimal aseptic technique including outer glove exchange while double-gloving and surgical gown type selection. METHODS: In an initial glove study, 102 surgical team members were randomized to exchange or retain outer gloves 1 hour into clean orthopedic procedures; cultures were obtained 15 minutes later from the palm of the surgeon's dominant gloved hand and from the surgical gown sleeve. Surgical gown type selection was recorded. A laboratory strike-through study investigating bacterial transmission through cloth and paper gowns was performed with coagulase-negative staphylococci. In a follow-up glove study, 251 surgical team members, all wearing paper gowns, were randomized as in the first glove study. RESULTS: Glove study 1 revealed 4-fold higher levels of baseline bacterial contamination (31% vs 7%) on the sleeve of surgical team members wearing cloth gowns than those using paper gowns [odds ratio (95% confidence interval): 4.64 (1.72-12.53); P = 0.0016]. The bacterial strike-through study revealed that 26 of 27 cloth gowns allowed bacterial transmission through the material compared with 0 of 27 paper gowns (P < 0.001). In glove study 2, surgeons retaining outer gloves 1 hour into the case had a subsequent positive glove contamination rate of 23% compared with 13% among surgeons exchanging their original outer glove [odds ratio (95% confidence interval): 1.97 (1.02-3.80); P = 0.0419]. CONCLUSIONS: Paper gowns demonstrated less bacterial transmission in the laboratory and lower rates of contamination in the operating room. Disposable paper gowns are recommended for all surgical cases, especially those involving implants, because of the heightened risk of infection. Outer glove exchange just before handling implant materials is also recommended to minimize intraoperative contamination.

Risk of stroke or transient ischemic attack after atrial fibrillation ablation with oral anticoagulant use guided by ECG monitoring and pulse assessment.

INTRODUCTION: We sought to gain insight into stroke risk after atrial fibrillation (AF) ablation. METHODS AND RESULTS: We followed 1,990 patients for >1 year (49 ± 29 months) who underwent AF ablation. Prior to stopping oral anticoagulants (OAC), we performed 3-week transtelephonic ECG monitoring (TTM) and taught patients heart rate and pulse assessment. Documented AF or inability to do monitoring or assess pulse precluded stopping OAC in CHADS2 ≥1 patients. OAC was stopped in 546/840 (65%) with CHADS2  = 0; 384/796 (48%) with CHADS2  = 1 and 101/354 (40%) with CHADS2 ≥ 2. Sixteen strokes or TIAs occurred (0.2%/patient-year); 5 in CHADS2  = 0 patients (all off OAC); 5 in CHADS2  = 1 (1 off and 4 on OAC); and 6 in CHADS2 ≥2 (2 off and 4 on OAC). Twelve of 16 patients (75%) with stroke or TIA had documented AF. In patients "off " OAC, stroke rate/year stratified by the CHADS2 score was similar (CHADS2  = 0: 0.28%; CHADS2  = 1: 0.07%; CHADS2 ≥2: 0.50%; P = NS). There was no difference in stroke risk "on" versus "off " OAC in CHADS2  = 1 (0.48% vs. 0.07%) or CHADS2 ≥2 (0.39% vs. 0.50%). Risk of major bleeding per patient year "on" OAC was > "off " OAC (13/1,138 (1.14%) versus 1/832 (0.1%); P<0.016). CONCLUSIONS: Post-AF ablation with OAC guided by TTM and pulse assessment: (1) Overall stroke or TIA rate risk is low and risk is due to recurrent AF and (2) OAC can be stopped in 40% of CHADS2 ≥2 patients with low stroke and hemorrhagic risk.

Unipolar voltage abnormality is associated with greater left ventricular dysfunction in ischemic cardiomyopathy.

INTRODUCTION: Following myocardial infarction (MI), left ventricular function is determined by cardiac remodeling occurring in both infarcted and noninfarcted myocardium (NIM). Unipolar voltage mapping may detect remodeling changes in NIM that are associated with the left ventricular ejection fraction (LVEF). We aimed to identify (1) unipolar voltage characteristics in patients with chronic MI, and (2) association of voltage abnormalities with degree of left ventricular dysfunction (LVD). METHODS AND RESULTS: Two groups of patients with ischemic cardiomyopathy (ICM) who underwent LV endocardial mapping during catheter ablation for ventricular tachycardia (VT) between January 2010 and December 2012 were studied. The first group (19 males) had mild to moderate LVD (M-LVD, LVEF >35%) and was matched for age, sex, infarction size, and infarction location with 10 males who had severe LVD (S-LVD, LVEF <35%). Both bipolar and unipolar endocardial abnormal voltage areas were measured and compared between groups. Abnormal bipolar area was comparable in both groups (30 ± 8% in the S-LVD group vs 28 ± 8% in the M-LVD group; P = 0.5). Total abnormal unipolar voltage area was significantly larger in the S-LVD group (57 ± 14% vs 43 ± 13%; P = 0.02). The abnormal unipolar voltage area within the normal bipolar voltage area was greater in the S-LVD group (26 ± 11% vs 15 ± 16%; P = 0.03). In receiver operating characteristic curve analysis, an 18.0% cut-off value for abnormal unipolar area within NIM identified severe LVD, with 90% sensitivity and 79% specificity (area under the curve 0.821). CONCLUSIONS: Patients with ICM and severe LVD have larger areas of unipolar voltage abnormality in the noninfarcted tissue than patients with M-LVD.

Same-day contralateral implantation of a permanent device after lead extraction for isolated pocket infection.

AIMS: The purpose of this study is to examine the safety and outcomes of same-day reimplantation at the contralateral pectoral site in patients with device extraction for pocket infection but with negative blood cultures and no signs of systemic infection. METHODS AND RESULTS: Clinical and procedure-related data were retrospectively collected on 15 (11 male, mean age 77) device-dependent patients who underwent device and complete lead extraction (mean 2.5 leads per patient, mean implant duration 6.2 years) for local pocket infection, and who had a new contralateral device implanted on the same day. Temporary pacing via the femoral vein was used during extraction. The infected pocket was managed with an elliptical skin incision, debridement, full capsule resection, and primary wound closure with the end of the wound left open for a Penrose drain. Intravenous antibiotics were used prior to and through the procedure, and continued for a mean of 2 days post-procedure, with oral antibiotics used thereafter for a mean course of 2 weeks. No infections of the new device system occurred, with a mean follow-up of 39.6 months (range 12-74 months). CONCLUSION: In the setting of device erosion and isolated pocket infection without systemic or bloodstream involvement, a new contralateral device may be implanted on the same day as pocket debridement and system extraction without developing infection of the new permanent hardware. This strategy can be useful in patients with pacemaker-dependence, as an alternative to using a temporary pacing system.

RV-only pacing can produce a Q wave in lead 1 and an R wave in V1: implications for biventricular pacing.

BACKGROUND: Biventricular (bi-v) pacing improves congestive heart failure and mortality in patients with left ventricular (LV) dysfunction and electrical dyssynchrony. Effective resynchronization must include an LV pacing contribution to the QRS. Leads 1 and V1 are often exclusively used to verify proper biventricular pacing. METHODS: In 40 patients referred to our cardiac resynchronization therapy (CRT) optimization clinic, 12-lead electrocardiograms (ECGs) were obtained during bi-v pacing, right ventricular (RV)-only pacing, LV-only pacing, and a range of atrio-ventricular and ventriculo-ventricular intervals. The presenting bi-v QRS morphology was compared to RV and LV pacing, and RV-only pacing was evaluated for the presence of a Q wave in lead 1 and an R wave in V1. RESULTS: In 22 patients (55%), RV pacing produced an initial Q wave in lead 1 and/or R wave in V1, mimicking bi-v pacing. In three patients, the presenting bi-v paced ECG looked identical to RV-only pacing. In 28 patients (70%), LV pacing was advanced by a mean of 30 ms after CRT optimization. Using all 12 ECG leads, especially the precordial leads, was necessary to appreciate the QRS changes that occurred when LV pacing meaningfully contributed to electrical activation. CONCLUSIONS: Because of LV pacing latency, some patients require an earlier LV offset to achieve proper resynchronization pacing. Commonly used ECG criteria cannot verify meaningful LV pacing contribution during biventricular pacing because RV-only pacing often creates a Q wave in lead 1 and/or R wave in V1. The full 12-lead ECG during biventricular pacing should be compared with isolated RV and LV pacing to verify that LV pacing is properly contributing to the QRS.

Assessing arrhythmia burden after catheter ablation of atrial fibrillation using an implantable loop recorder: the ABACUS study.

INTRODUCTION: Arrhythmia monitoring in patients undergoing atrial fibrillation (AF) ablation is challenging. Transtelephonic monitors (TTMs) are cumbersome to use and provide limited temporal assessment. Implantable loop recorders (ILRs) may overcome these limitations. We sought to evaluate the utility of ILRs versus conventional monitoring (CM) in patients undergoing AF ablation. METHODS AND RESULTS: Forty-four patients undergoing AF ablation received ILRs and CM (30-day TTM at discharge and months 5 and 11 postablation). Over the initial 6 months, clinical decisions were made based on CM. Subjects were then randomized for the remaining 6 months to arrhythmia assessment and management by ILR versus CM. The primary endpoint was arrhythmia recurrence. The secondary endpoint was actionable clinical events (change of antiarrhythmic drugs [AADs], anticoagulation, non-AF arrhythmia events, etc.) due to either monitoring strategy. Over the study period, 6 patients withdrew. In the first 6 months, AF recurred in 18 patients (7 noted by CM, 18 by ILR; P = 0.002). Five patients in the CM (28%) and 5 in the ILR arm (25%; P = NS) had AF recurrence during the latter 6 months. AF was falsely diagnosed frequently by ILR (730 of 1,421 episodes; 51%). In more patients in the ILR compared with the CM arm, rate control agents (60% vs 39%, P = 0.02) and AADs (71% vs 44%, P = 0.04) were discontinued. CONCLUSION: In AF ablation patients, ILR can detect more arrhythmias than CM. However, false detection remains a challenge. With adequate oversight, ILRs may be useful in monitoring these patients after ablation.

Efficacy and safety of implantable cardiac defibrillators for treatment of ventricular arrhythmias in patients with cardiac sarcoidosis.

AIMS: Implantable cardiac defibrillator (ICD) implantation is a class IIA recommendation for patients with cardiac sarcoidosis (CS). However, little is known about the efficacy and safety of ICDs in this population. The goal of this multicentre retrospective data review was to evaluate the efficacy and safety of ICDs in patients with CS. METHODS AND RESULTS: Electrophysiologists at academic medical centres were asked to identify consecutive patients with CS and an ICD. Clinical information, ICD therapy history, and device complications were collected for each patient. Data were collected on 235 patients from 13 institutions, 64.7% male with mean age 55.6 ± 11.1. Over a mean follow-up of 4.2 ± 4.0 years, 85 of 234 (36.2%) patients received an appropriate ICD therapy (shocks and/or anti-tachycardia pacing) and 67 of 226 (29.7%) received an appropriate shock. Fifty-seven of 235 patients (24.3%) received a total of 222 inappropriate shocks. Forty-six adverse events occurred in 41 of 235 patients (17.4%). Patients who received appropriate ICD therapies were more likely to be male (73.8 vs. 59.6%, P = 0.0330), have a history of syncope (40.5 vs. 22.5%, P = 0.0044), lower left ventricular ejection fraction (38.1 ± 15.2 vs. 48.8 ± 14.7%, P ≤ 0.0001), ventricular pacing on baseline electrocardiogram (16.1 vs. 2.1%, P = 0.0002), and a secondary prevention indication (60.7 vs. 24.5%, P < 0.0001) compared with those who did not receive appropriate ICD therapies. CONCLUSION: Patients with CS and ICDs are at high risk for ventricular arrhythmias. This population also has high rates of inappropriate shocks and device complications.

Stemmed knee replacement in a patient with an irremovable tibial nail.

A patient with a cemented centrally located intramedullary tibial nail that occluded the proximal tibial canal underwent knee reconstruction with a total knee design utilizing a custom hollow tibial stem. In this oncology case, a rotating-hinge knee design was used that incorporates an intra-articular inverted post-in-channel central rotational post design. This design allowed for a rather straightforward reconstruction that functioned well for 3 years. Although rarely encountered, utilization of a hollow-stemmed tibial total knee component may allow salvage of an extremity with central occlusion of the proximal tibial canal.

Allergic reaction to suture material after an ICD procedure: device infection mimicry.

When an implanted device is infected, complete explantation of the device system, including lead extraction, is usually required. Superficial problems with wound healing may be managed more conservatively, but distinguishing between a surface process and deeper infection can pose a clinical challenge. We present a case of poor wound healing after an ICD pocket revision procedure, and an allergic reaction to the suture material was found to be the cause. Diagnosis, management, and future implications of suture allergy are discussed.

Multicenter experience with transvenous lead extraction of active fixation coronary sinus leads.

BACKGROUND/OBJECTIVE: Active fixation coronary sinus (CS) leads limit dislodgement and represent an attractive option to the implanter. Although extraction of passive fixation CS leads is a common and frequently uncomplicated procedure, data regarding extraction of chronically implanted active fixation CS leads are limited. METHODS: We performed a retrospective cohort study of patients undergoing active fixation CS lead extraction at six centers. Patient and procedural characteristics, indications for extraction, use of extraction sheath (ES) assistance, and outcomes are reported. RESULTS: Between January 2009 and February 2011, 12 patients underwent transvenous lead extraction (TLE) of Medtronic StarFix® lead (Medtronic Inc., Minneapolis, MN, USA). The cohort was 83% male with mean age 71 ± 14 years. Average implant duration was 14.2 ± 5.7 months (2.3-23.6). All leads but one were removed for infectious indications (67% systemic infection). At the time of explant, the fixation lobes were completely retracted in only one of the 12 cases and ES assistance was required for lead removal in all cases (58% laser, 25% cutting, 25% mechanical, and 25% femoral). The majority of cases required advancement of the sheath into the CS (75.0%) and often into a branch vessel (41.7%). One lead could not be removed transvenously and required surgical lead extraction. There were no major complications. Examination of the leads after extraction frequently revealed significant tissue growth into the fixation lobes. CONCLUSIONS: Although TLE of active fixation CS leads can be a safe procedure in select patients and experienced hands, powered sheaths and aggressive techniques are frequently required for successful removal despite relatively short implant durations. This raises significant concern regarding future TLE of active fixation CS leads with longer implant durations.

Simultaneous Leadless Pacemaker and Subcutaneous ICD Implantation With Intraoperative Screening: Workflow in Two Patients.

A communicating subcutaneous implantable cardioverter-defibrillator (ICD) and leadless pacemaker system is being developed for patients who require both pacing and ICD therapy. It is important to ensure that the paced morphology from the leadless pacemaker will be sensed appropriately by the subcutaneous ICD. We present 2 cases illustrating our approach and workflow. (Level of Difficulty: Intermediate.).

Use of Ambulatory Patch Monitoring Devices to Supplement Inpatient Telemetry-A Descriptive Study of a Single-center Experience During the Coronavirus Disease 2019 Pandemic.

To accommodate the surge in patients with coronavirus disease 2019 during the spring of 2020, outpatient areas in our health system were repurposed as inpatient units. These spaces often lacked the same resources as the standard inpatient unit, including telemetry equipment. We utilized mobile cardiac outpatient telemetry (MCOT) in place of traditional telemetry and suggest that MCOT is an appropriate substitution only for patients at low risk of developing arrhythmia given the prolonged time to notification of the care team regarding events and imprecise measurements of the corrected QT interval when compared to 12-lead electrocardiography.

Tissue-specific variability in human epicardial impedance.

INTRODUCTION: Epicardial ablation can be employed to treat ventricular tachycardia. Voltage attenuation in regions of fat can mimic epicardial scar, limiting its specificity. Ablation over fat may not be as effective. Prior animal data have shown that infarcted myocardium has lower impedance than normal, and human bioimpedance studies suggest peripheral fat displays higher impedance. Therefore, we tested the hypothesis that human epicardial fat has higher impedance than myocardium when measured with standard ablation tools. METHODS: Patients undergoing elective surgery for coronary artery or valve disease were enrolled. A reference patch was placed on the patients' back between the scapulae and connected to a standard RF generator (Stockert, GmBH, Germany). Impedance was measured by passing a 1 µA, 50 kHz current from the catheter tip to the patch. After sternotomy but before initiation of cardiopulmonary bypass, an ablation catheter (Celsius, Biosense Webster, Diamond Bar, CA, USA) was placed onto the epicardial surface in ventricular regions visually identified as fat or myocardium. At each site, impedance was recorded from the generator. RESULTS: A total of 37 (7 patients) points were sampled. Impedance was significantly higher in regions of fat versus normal muscle (697 Ω vs. 301 Ω; P = 0.01). Moreover, normal sites from the LV had higher impedance than from the RV (381 Ω vs. 271 Ω; P = 0.01). CONCLUSIONS: Human epicardial fat has higher tissue impedance than normal muscle. Using epicardial impedance and voltage mapping in conjunction may improve differentiation of arrhythmia substrate from epicardial fat and improve the efficacy of epicardial ablation.

Sinus rhythm ECG criteria associated with basal-lateral ventricular tachycardia substrate in patients with nonischemic cardiomyopathy.

INTRODUCTION: Patients with nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) usually have basal-lateral scar in the left ventricle (LV). We sought to determine electrocardiogram (ECG) characteristics that may help identify NICM patients with basal-lateral scar and VT. METHODS AND RESULTS: Phase I, study patients (n = 25) had NICM, VT, and endocardial/epicardial basal-lateral LV low voltage consistent with scar on detailed mapping. ECGs were compared to controls (n = 18) with NICM, and comparable age and gender without VT/known scar. All patients had either sinus or paced atrial rhythm ECGs without bundle-branch block or ventricular pacing. In phase II, criteria were evaluated prospectively, blinded to clinical data, using ECGs from 15 NICM patients, of which 7 patients had VT and endocardial/epicardial basal-lateral LV scar on detailed mapping. Of ECG characteristics studied, V1 R and R:S ratio, and V6 S and S:R ratio were univariately associated with basal-lateral-scar associated VT. Controlling for LVEF and multicollinearity in multivariate analyses, V1 R ≥ 0.15 mV (P = 0.001) and V6 S ≥ 0.15 mV (P < 0.001), or V6 S:R ≥ 0.2 mV (P < 0.001), best predicted presence of basal-lateral scar. In Phase II, the former criteria best identified those with NICM and VT because of basal-lateral scar, with sensitivity and specificity 0.86 and 0.88, respectively. CONCLUSIONS: Among patients with NICM, VT, and normal QRS duration, V1 R ≥ 0.15 mV and V6 S ≥ 0.15 mV predicted presence of basal-lateral LV areas of bipolar low voltage. This ECG information may have important value in defining presence of LV scar and possible risk for VT in NICM patients.

Racial differences in the incidence of atrial fibrillation after cryptogenic stroke.

BACKGROUND: The incidence of atrial fibrillation (AF) is lower in nonwhites than in whites despite a higher burden of AF risk factors. However, the incidence of new AF after cryptogenic stroke in minorities is unknown. OBJECTIVE: The purpose of this study was to determine the incidence of AF after cryptogenic stroke in different racial/ethnic groups. METHODS: We retrospectively analyzed 416 consecutive patients undergoing insertable cardiac monitor implantation at our hospital from 2014 through 2019. Incidence of AF was identified through the review of device monitoring, including adjudication of AF episodes for accuracy, and compared by race. RESULTS: The mean follow-up time was 1.5 ± 1.1 years. The predominantly nonwhite cohort included 244 (59%) blacks and 109 (26%) Hispanics, and 45% (n=189) were male. The mean age was 62 ± 12 years; Blacks and Hispanics had more hypertension, diabetes, and chronic kidney disease and higher body mass index than did whites. In blacks and Hispanics, the cumulative incidences of AF at 1, 2, and 3 years were 14.1%, 19.9%, and 24% and 12.9%, 18.3%, and 20.9%, respectively. By comparison, the incidence in whites was significantly higher: 20.8%, 34.3%, and 40.3%. In a Cox proportional hazards model adjusting for common AF risk factors, blacks (hazard ratio 0.49; confidence interval 0.26-0.82; P = .03) and Hispanics (hazard ratio 0.39; confidence interval 0.18-0.83; P = .01) were less likely to have incident AF than whites. CONCLUSION: In patients with an insertable cardiac monitor after cryptogenic stroke, the incidence of newly detected AF is approximately double in whites compared with both blacks and Hispanics. This has important implications for the investigation and treatment of nonwhites with cryptogenic stroke.