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Bipolar voltage is widely used to characterize the atrial substrate but has been poorly validated, particularly during clinical tachycardias.The purpose of this study was to evaluate the diagnostic performance of voltage thresholds for identifying regions of slow conduction during reentrant atrial tachycardias (ATs).Thirty bipolar voltage and activation maps created during reentrant ATs were analyzed to (1) examine the relationship between voltage amplitude and conduction velocity (CV), (2) measure the diagnostic ability of voltage thresholds to predict CV, and (3) identify determinants of AT circuit dimensions. Voltage amplitude was categorized as "normal" (0.50 mV), "abnormal" (0.05-0.50 mV), or "scar" (0.05 mV); slow conduction was defined as30 cm/s.A total of 266,457 corresponding voltage and CV data points were included for analysis. Voltage and CV were moderately correlated (r = 0.407; P.001). Bipolar voltage predicted regions of slow conduction with an area under the receiver operating characteristic curve of 0.733 (95% confidence interval 0.731-0.735). A threshold of 0.50 mV had 91% sensitivity and 35% specificity for identifying slow conduction, whereas 0.05 mV had 36% sensitivity and 87% specificity, with an optimal voltage threshold of 0.15 mV. Analyses restricted to the AT circuits identified weaker associations between voltage and CV and an optimal voltage threshold of 0.25 mV.Widely used bipolar voltage amplitude thresholds to define "abnormal" and "scar" tissue in the atria are, respectively, sensitive and specific for identifying regions of slow conduction during reentrant ATs. However, overall, the association of voltage with CV is modest. No clinical predictors of AT circuit dimensions were identified.

Cardiogenic shock (CS) is associated with significant morbidity and mortality; however, there are limited randomized data evaluating the association between sex and clinical outcomes in patients with CS. Patients with CS enrolled in the DObutamine compaREd with MIlrinone (DOREMI) trial were evaluated in this post-hoc analysis.The primary outcome was a composite of all-cause mortality, resuscitated cardiac arrest, cardiac transplant or mechanical circulatory support, non-fatal myocardial infarction, transient ischemic attack or stroke, or initiation of renal replacement therapy. Secondary outcomes included the individual components of the primary outcome. We analyzed the primary and secondary outcomes using unadjusted relative risks and performed adjusted analysis for the primary outcome and all-cause mortality using the covariates mean arterial pressure70 mmHg at inotrope initiation, age, and acute myocardial infarction CS.Among 192 participants in the DOREMI study, 70 patients (36 %) were female. The primary outcome occurred in 38 female patients (54 %) compared to 61 male patients (50 %) [adjusted relative risk (aRR) 1.23; 95 % CI 0.78-1.95, p = 0.97]. When stratified by inotrope, there was no difference in the primary outcome comparing females to males receiving dobutamine (RR 1.14; 95 % CI 0.79-1.65, p = 0.50) nor milrinone (RR 1.03; 95 % CI 0.68-1.57, p = 0.87). There was no difference in all-cause mortality comparing females to males (aRR 1.51; 95 % CI 0.78-2.94, p = 0.88). Additionally, there were no differences in any secondary outcomes between males and females (p 0.05 for all endpoints).In patients presenting with CS treated with milrinone or dobutamine, no differences in clinical outcomes were observed between males and females.

An understanding of normal atrial activation during sinus rhythm can inform catheter ablation strategies to avoid deleterious impacts of ablation lesions on atrial conduction and mechanics.The purpose of this study was to describe how the sinus node impulse originates, propagates, and collides in right and left atria with normal voltage.Fifty consecutive patients undergoing catheter ablation of atrial fibrillation with endocardial atrial voltage0.5 mV during high-density 3-dimensional mapping were studied.Sinus node exits varied among patients along a lateral oblique arc extending from the anterior aspect of the superior vena cava (SVC) to the mid-posterior wall of the right atrium (RA). Conduction slowing or block at one of the smooth components that faces the crista terminalis was observed in 54% of cases, including complete block at the SVC musculature and systemic venous sinus in 6% of cases. Depending on these 2 key features of RA activation, interatrial conduction was mediated by the Bachmann bundle (64%) and posterior bundles (54%), with an overlap of the resulting left atrial breakthrough location. Wavefront collision was consistently observed at 3 sites: the septal aspect of the cavotricuspid isthmus, and the lower aspects of the dome and of the mitral isthmus.During sinus rhythm, atrial activation occurs via distinct sequences mediated by a complex interaction of anatomic factors.

Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86%8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.

Ipsilateral approach in patients requiring cardiac implantable electronic device (CIED) revision or upgrade may not be feasible, primarily due to vascular occlusion. If a new CIED is implanted on the contralateral side, a common practice is to explant the old CIED to avoid device interaction.The purpose of this study was to assess a conservative approach of abandoning the old CIED after implanting a new contralateral device.We used an artificial intelligence algorithm to analyze postimplant chest radiographs to identify those with multiple CIEDs. Outcomes of interest included device interaction, abandoned CIED elective replacement indicator (ERI) behavior, subsequent programming changes, and explant of abandoned CIED. Theoretical risk of infection with removal of abandoned CIED was estimated using a validated scoring system.Among 12,045 patients, we identified 40 patients with multiple CIEDs. Occluded veins were the most common indication for contralateral implantation (n = 27 [67.5%]). Fifteen abandoned CIEDs reached ERI, with 4 reverting to VVI 65. One patient underwent explant due to device interaction, and 2 required device reprogramming. Of 32 patients with an implantable cardioverter-defibrillator, 8 (25%) had treated ventricular arrhythmia. There were no failed or inappropriate therapies due to interaction. Eighteen patients (45%) had hypothetical1% annual risk of hospitalization for device infection if the abandoned CIED had been explanted.In patients requiring new CIED implant on the contralateral side, abandoning the old device is feasible. This approach may reduce the risk of infection and concerns regarding abandoned leads and magnetic resonance imaging scans. Knowledge of ERI behavior is essential to avoid device interactions.

When worn on the wrist, smartwatch electrocardiograms may provide important but incomplete information.We sought to evaluate the added benefit of placing the smartwatch on the ankle and on the chest to diagnose various electrocardiographic abnormalities compared with 12-lead electrocardiograms.Two hundred and sixty patients with (n=189) or without (n=71) known cardiac disorders underwent 12-lead electrocardiogram and smartwatch electrocardiogram recordings of lead I (AW-I) and of leads I and II and pseudo chest leads V1 and V6 (AW-4). AW-I and AW-4 diagnoses (three-cardiologist consensus) were compared with 12-lead electrocardiogram diagnoses (three-cardiologist consensus) to calculate sensitivity and specificity.AW-I showed high accuracy for the diagnoses of atrial fibrillation (96% sensitivity, 91% specificity) and complete bundle branch block (85% sensitivity, 98% specificity). Compared with AW-I, AW-4 improved detection of an abnormal 12-lead electrocardiogram (91% vs. 80% sensitivity; P0.01), atrial flutter/tachycardia (69% vs. 25% sensitivity; P=0.04), T-wave abnormalities (77% vs. 34% sensitivity; P0.01), pathological Q-waves (41% vs. 7% sensitivity; P0.01) and left anterior hemiblock (70% vs. 0% sensitivity; P=0.02). AW-4 also enabled better differentiation between atrioventricular block and sinus bradycardia (from 81% to 95% correct; P=0.03) and between atrial fibrillation and atrial flutter/tachycardia (from 71% to 89% correct; P=0.02), but not between bundle branch blocks (from 82% to 87% correct; P=0.57).A smartwatch electrocardiogram on the wrist accurately diagnoses atrial fibrillation and bundle branch block. Recording additional leads significantly improves the accuracy of detecting an abnormal electrocardiogram and repolarization changes, and also allows for better differentiation of brady- and tachyarrhythmias.

The adoption of wearables in medicine has expanded worldwide with a rapidly growing number of consumers and new features capable of real-time monitoring of health parameters such as the ability to record and transmit a single-lead electrocardiogram (ECG). Smartwatch ECGs are increasingly used but current smartwatches only screen for atrial fibrillation (AF). Most of the literature has focused on analyzing the smartwatch ECG accuracy for the detection of AF or other tachycardias. As with the conventional ECG, this tool may be used for many more purposes than only detection of AF. The objectives of this review are to describe the published literature regarding the accuracy and clinical value of recording a smartwatch ECG in other situations than diagnosis of tachycardia and discuss possible techniques to optimize the diagnostic yield.

Objective: To ensure compliance with optimal secondary prevention strategies and document the residual risk of patients following revascularization, we established a postrevascularization clinic for risk-factor optimization at 1 year, with outcomes recorded in a web-based registry. Although coronary revascularization can reduce ischemia, medical treatment of coronary artery disease (CAD) remains the cornerstone of ongoing risk reduction. While standardized referral pathways and protocols for revascularization are prevalent and well studied, post-revascularization care is often less formalized. Patients and Methods: The University of Ottawa Heart Institute is a tertiary-care center providing coronary revascularization services. From 2015 to 2019, data were prospectively recorded in the CAPITAL revascularization registry, and patient-level procedural, clinical, and outcome data are collected in the year following revascularization. Major adverse cardiovascular event (MACE) was defined as death, myocardial infarction, unplanned revascularization, or cerebrovascular accident. Kaplan-Meier curves were generated to evaluate time-to-event data for clinical outcomes by risk-factor management, and comparisons were performed using log-rank tests and reported by hazard ratio (HR) and 95% confidence intervals (CIs). Results: A cohort of 4147 patients completed 1-year follow-up after revascularization procedure that included 3462 undergoing percutaneous coronary intervention (PCI), 589 undergoing coronary artery bypass graft (CABG), and 96 undergoing both PCI and CABG. In the year following revascularization (median follow-up 13.3 months—interquartile range [IQR]: 11.9-16.5) 11% of patients experienced MACE, with female patients being disproportionately at risk. Moreover, 47.7% of patients had ≥2 risk factors (diabetes, dyslipidemia, overweight, active smoker) at the time of follow-up, with 45.0% of patients with diabetes failing to achieve target hemoglobin (Hb) A1c, 54.8% of smokers continuing to smoke, and 27.1% of patients failing to achieve guideline-directed lipid targets. Conclusion: Patients who have undergone revascularization procedures remain at elevated risk for MACE, and inadequately controlled risk factors are prevalent in follow-up. This highlights the need for aggressive secondary prevention strategies and implementation of programs to optimize postrevascularization care.

Background Purkinje ectopics (PurkEs) are major triggers of idiopathic ventricular fibrillation (VF). Identifying clinical factors associated with specific PurkE characteristics could yield insights into the mechanisms of Purkinje-mediated arrhythmogenicity. Objective The purpose of this study was to examine the associations of clinical, environmental, and genetic factors with PurkE origin in patients with PurkE-initiated idiopathic VF. Methods Consecutive patients with PurkE-initiated idiopathic VF from 4 arrhythmia referral centers were included. We evaluated demographic characteristics, medical history, clinical circumstances associated with index VF events, and electrophysiological characteristics of PurkEs. An electrophysiology study was performed in most patients to confirm the Purkinje origin. Results Eighty-three patients were included (mean age 38 ± 14 years; 44 [53%] women), of whom 32 had a history of syncope. Forty-four patients had VF at rest. PurkEs originated from the right ventricle (RV) in 41 patients (49%), from the left ventricle (LV) in 36 (44%), and from both ventricles in 6 (7%). Seasonal and circadian distributions of VF episodes were similar according to PurkE origin. The clinical characteristics of patients with RV vs LV PurkE origins were similar, except for sex. RV PurkEs were more frequent in men than in women (76% vs 24%), whereas LV and biventricular PurkEs were more frequent in women (81% vs 19% and 83% vs 17%, respectively) (P Conclusion PurkEs triggering idiopathic VF originate dominantly from the RV in men and from the LV or both ventricles in women, adding to other sex-related arrhythmias such as Brugada syndrome or long QT syndrome. Sex-based factors influencing Purkinje arrhythmogenicity warrant investigation.

Possible mechanisms of left-axis deviation (LAD) in the setting of left bundle branch block (LBBB) include differences in cardiac electrophysiology, structure, or anatomic axis.The purpose of this study was to clarify the mechanism(s) responsible for LAD in patients with LBBB.Twenty-nine patients with nonischemic cardiomyopathies and LBBB underwent noninvasive electrocardiographic imaging (ECGi), cardiac computed tomography, and magnetic resonance imaging in order to define ventricular electrical activation, characterize cardiac structure, and determine the cardiac anatomic axis.Sixteen patients had a normal QRS axis (NA) (mean axis 8° ± 23°), whereas 13 patients had LAD (mean axis -48° ± 13°; P.001). Total activation times were longer in the LAD group (112 ± 25 ms vs 91 ± 14 ms; P = .01) due to delayed activation of the basal anterolateral region (107 ± 10 ms vs 81 ± 17 ms; P .001). Left ventricular (LV) activation in patients with LAD was from apex to base, in contrast to a circumferential pattern of activation in patients with NA. Apex-to-base delay was longer in the LA group (95 ± 13 ms vs 64 ± 21 ms; P.001) and correlated with QRS frontal axis (RLAD in LBBB appears to be due to electrophysiological abnormalities rather than structural factors or cardiac anatomic axis.

Background Localized staining due to venule injury is attributable to ethanol infusion into the vein of Marshall (Et-VOM). Objective The purpose of this study was to investigate adverse outcomes of localized staining during Et-VOM in patients undergoing ablation for atrial fibrillation. Methods Two hundred four patients (age 64 ± 10 years; 153 male) were sorted based on the aspect of localized staining. Staining of atrial myocardium that spread uniformly along the VOM vascular tree following selective VOM venography was considered normal, in contrast to predominantly localized staining that spread concentrically from a focal point due to vascular injury. Outcomes between the 2 groups were compared. Results Localized staining was observed in 27% of patients. No patients developed clinically significant pericardial effusions during Et-VOM; however, 7 patients developed pericardial effusions on the first postprocedural day (3.6% in patients with vs 3.4% in patients without localized staining). No significant difference was found in achievement of acute mitral isthmus (MI) block (96% vs 98%) and size of the endocardial low-voltage area (8.5 ± 4.1 cm2 vs 9.3 ± 5.3 cm2) in patients with and without localized staining, respectively. Long-term follow-up was not impacted by localized staining. Freedom from recurrent atrial tachyarrhythmias (66% vs 76%) and durability of MI block (57% vs 54%) were not significantly different with and without localized staining. There were no cases of rehospitalization for pericarditis, chronic pericardial effusion, or heart failure. Conclusion In our study, localized staining was frequent but was not associated with clinically relevant impact or disadvantages.

The accuracy of smartwatch ECG recordings in adults has been demonstrated primarily in the automated diagnosis of atrial fibrillation. While the detection of atrial fibrillation is a priority among adults given the arrhythmia's prevalence and actionable ramifications, the potential value of smartwatch ECG recordings in children differs considerably. In this case series, we will describe some examples of smartwatch ECGs recorded in children, highlighting the feasibility and potential indications of this technology in the pediatric population.

Background Beyond pulmonary vein isolation (PVI), the optimal ablation strategy for persistent atrial fibrillation (AF) remains poorly defined. Objective The purpose of this study was to examine a novel comprehensive ablation strategy (Marshall bundle elimination, Pulmonary vein isolation, and Line completion for ANatomical ablation of persistent atrial fibrillation [Marshall-PLAN]) strictly based on anatomical considerations. Methods Left atrial (LA) sites were sequentially targeted as follows: (1) coronary sinus and vein of Marshall (CS-VOM) musculature; (2) PVI; and (3) anatomical isthmuses (mitral, roof, and cavotricuspid isthmus [CTI]). The primary endpoint was 12-month freedom from AF/atrial tachycardia (AT). Results Seventy-five consecutive patients were included (age 61 ± 9 years; 10 women; AF duration 9 ± 11 months; mean LA volume 197 ± 43 mL). VOM ethanol infusion was completed in 69 patients (92%). The full Marshall-PLAN lesion set (VOM, PVI, mitral, roof, and CTI with block) was successfully completed in 68 patients (91%). At 12 months, 54 of 75 patients (72%) were free from AF/AT after a single procedure (no antiarrhythmic drugs) in the overall cohort. In the subset of patients with a complete Marshall-PLAN lesion set (n = 68), the single procedure success rate was 79%. After 1 or 2 procedures, 67 of 75 patients (89%) remained free from AF/AT (no antiarrhythmic drugs). After 1 or 2 procedures, VOM ethanol infusion was complete in 72 of 75 patients (96%). Conclusion A novel ablation strategy that systematically targets anatomical atrial structures (VOM ethanol infusion, PVI, and prespecified linear lesions) is feasible, safe, and associated with a high rate of freedom from arrhythmia recurrence at 12 months in patients with persistent AF.

Background The stented coronary artery remains at high-risk of complications, particularly in the form of stent thrombosis and in-stent restenosis. Improving our ability to identify patients at high-risk for these complications may provide opportunities for intervention. PAI-1 has been implicated in the pathophysiology of stent complications in preclinical studies, suggesting it may be a clinically valuable biomarker to predict adverse events following percutaneous coronary intervention. Methods Plasma PAI-1 levels were measured in 910 subjects immediately after coronary angiography between 2015 and 2019. The primary outcome was the incidence of unplanned revascularization (UR) at 12 months. The secondary outcome was the incidence of major adverse cardiac events (MACE). Results UR and MACE occurred in 49 and 103 patients in 12 months. Reduced plasma PAI-1 levels were associated with UR (4386.1 pg/mL [IQR, 2778.7–6664.6], n = 49, vs. 5247.6 pg/mL [IQR, 3414.1–7836.1], n = 861; p = 0.04). Tertile PAI-1 levels were predictive of UR after adjustment for known clinical risk factors associated with adverse outcomes. In post-hoc landmark analysis, UR was enhanced with low plasma PAI-1 levels for late complications (beyond 30 days). Finally, an updated systematic review and meta-analysis did not reveal an association between plasma PAI-1 and MACE. Conclusion PAI-1 levels are not independently associated with UR nor MACE in patients undergoing angiography but associated with UR following adjustment with known clinical factors. In our landmark analysis, low PAI-1 levels were associated with UR for late stent complications. As such, future studies should focus on the mediatory role of PAI-1 in the pathogenesis of stent complications.

We describe varying physiologic ventricular resynchronization owing to differences in atrial rhythm in a patient with the right-sided accessory pathway and pre-existing right bundle branch block.

Recurrent patellar instability is a common problem and often leads to a tear of the medial patellofemoral ligament. Multiple reconstruction techniques for the medial patellofemoral ligament (MPFL) exist. This Technical Note presents a technique for performing MPFL reconstruction using Achilles tendon allograft with a bone block. The advantages of this technique include (1) bone-to-bone healing in femoral tunnel; (2) docking the bone block in the femoral tunnel obviates the knee for calculating graft and tunnel length; (3) fixing the femoral side before the patellar side allows graft tensioning under direct visualization and avoids over-constraint; (4) the fanned portion of the Achilles tendon allows broad-based MPFL footprint coverage on the medial patellar ridge; and (5) it avoids the need for bone tunnel drilling in the patella, reducing the risk to penetration of the drill holes into the articular cartilage surface as well as the risk for patellar fracture.

Objectives This study sought to examine outcomes of our approach to managing a large cohort of patients with Sprint Fidelis (Medtronic, Minneapolis, Minnesota) leads. Background The optimal management approach for patients with leads under advisory is unknown. Concerns regarding the risk of device infection and complications associated with delaying lead extraction have recently been suggested to argue against abandoning leads under advisory. Methods All patients with a Sprint Fidelis lead implanted at our institute were included. Lead management options were discussed with patients who presented for device surgery at the time of device upgrade, lead fracture, or elective replacement indicator. Implantation of a new lead with abandonment of the Sprint Fidelis lead was the recommended strategy. Patients were subsequently followed at the device clinic at 6-month intervals and were enrolled prospectively in a longitudinal registry. Results A total of 520 patients had Sprint Fidelis leads implanted between December 2003 and October 2007 at the study center; 217 patients underwent lead replacement (213 underwent a lead abandonment strategy and 4 underwent a lead extraction strategy). Mean follow-up after lead replacement was 55 ± 33 months. In patients undergoing lead abandonment, 10 of 213 (4.7%) had a procedural complication and 3 of 213 (1.4%) developed subsequent device infection requiring system extraction. Conclusions In patients with a Sprint Fidelis lead, implanting a new lead without prophylactic extraction may be a feasible and safe strategy but requires longer follow-up.

Visual Abstract, Highlights • In this analysis of 3,396 preclinical studies published in 5 leading cardiovascular journals over a 10-year period, women accounted for 24 ± 17% of authors per manuscript. • Female authorship is increasing in preclinical cardiovascular science, but the proportions of articles with first and senior authors of different sex have remained unchanged, which suggests that segregation by sex in mentorship relationships exists and persists. • In preclinical studies that reported the sex of the animals used, female authorship was positively associated with studying female animals, using animals of both sexes, and reporting sex-specific results, which are findings that persisted in adjusted and sensitivity analyses. • Author sex was not associated with other measures of methodological rigor or with 60-month citation counts., Summary In this analysis of 3,396 preclinical cardiovascular studies, women were first, senior, and both first and senior authors in 41.3%, 20.7%, and 11.0% of the studies, respectively. Female authorship increased over a 10-year period. However, the proportion of studies with first and senior authors of differing sex was low and stable, suggesting that segregation by sex in mentorship relationships exists and persists. Female authors were more likely to consider sex as a biological variable, but author sex was not associated with other measures of experimental rigor or research impact, indicating that women’s underrepresentation was not due to differences in research capacity or impact.