Feeding behavior modifies the circadian variation in RR and QT intervals by distinct mechanisms in mice.

Rhythmic feeding behavior is critical for regulating phase and amplitude in the ≈24-h variation of heart rate (RR intervals), ventricular repolarization (QT intervals), and core body temperature in mice. We hypothesized changes in cardiac electrophysiology associated with feeding behavior were secondary to changes in core body temperature. Telemetry was used to record electrocardiograms and core body temperature in mice during ad libitum-fed conditions and after inverting normal feeding behavior by restricting food access to the light cycle. Light cycle-restricted feeding modified the phase and amplitude of 24-h rhythms in RR and QT intervals, and core body temperature to realign with the new feeding time. Changes in core body temperature alone could not account for changes in phase and amplitude in the ≈24-h variation of the RR intervals. Heart rate variability analysis and inhibiting ß-adrenergic and muscarinic receptors suggested that changes in the phase and amplitude of 24-h rhythms in RR intervals were secondary to changes in autonomic signaling. In contrast, changes in QT intervals closely mirrored changes in core body temperature. Studies at thermoneutrality confirmed that the daily variation in QT interval, but not RR interval, primarily reflected daily changes in core body temperature (even in ad libitum-fed conditions). Correcting the QT interval for differences in core body temperature helped unmask QT interval prolongation after starting light cycle-restricted feeding and in a mouse model of long QT syndrome. We conclude feeding behavior alters autonomic signaling and core body temperature to regulate phase and amplitude in RR and QT intervals, respectively.NEW & NOTEWORTHY We used time-restricted feeding and thermoneutrality to demonstrate that different mechanisms regulate the 24-h rhythms in heart rate and ventricular repolarization. The daily rhythm in heart rate reflects changes in autonomic input, whereas daily rhythms in ventricular repolarization reflect changes in core body temperature. This novel finding has major implications for understanding 24-h rhythms in mouse cardiac electrophysiology, arrhythmia susceptibility in transgenic mouse models, and interpretability of cardiac electrophysiological data acquired in thermoneutrality.

A stepwise external cardioversion protocol for atrial fibrillation to maximize acute success rate.

AIMS: Cardioversion is a very commonly performed procedure for persistent atrial fibrillation (AF). However, there is no well-defined protocol to address failed external electrical direct current cardioversion. The aim of the study is to test the efficacy of a pre-defined stepwise cardioversion protocol for patients with persistent AF of ≤12 months. Success was the achievement of sinus rhythm. METHODS AND RESULTS: The study population included patients with persistent AF of ≤12 months duration requiring rhythm management. Patients were offered cardioversion using a pre-defined stepwise protocol using different electrode placement locations, applying compression at end of expiration, and higher energy delivered simultaneously through two defibrillators. : A total of 414 patients were included in the study, of which 362 (87.4%) required a single successful cardioversion. The remaining 52 (12.5%) patients required additional cardioversion attempts using the stepwise cardioversion protocol with an overall success rate of 99.3%. Two simultaneous defibrillators were required in 14 patients (3.4%). Patients with multiple cardioversions (13.5%) experienced more local skin irritation and pain compared with patients with single cardioversion (13.5% vs. 3.5%, P = 0.004). The predictor for the need for multiple cardioversion attempts is high body mass index, while high transthoracic impedance is associated with failed cardioversion. No major complications were observed during the study. CONCLUSION: The stepwise cardioversion protocol has a high success rate of >99% and can be safely performed in outpatient or inpatient settings.

COVID-19-associated Brugada pattern electrocardiogram: Systematic review of case reports.

AIMS: To summarize published case reports of patients diagnosed with coronavirus disease 2019 (COVID-19) and Brugada pattern electrocardiogram (ECG). METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist were followed. A literature search was conducted using PubMed, EMBASE, and Scopus up until September 2021. The incidence, clinical characteristics, and management outcomes of COVID-19 patients with a Brugada pattern ECG were identified. RESULTS: A total of 18 cases were collected. The mean age was 47.1 years and 11.1% were women. No patients had prior confirmed diagnosis of Brugada syndrome. The most common presenting clinical symptoms were fever (83.3%), chest pain (38.8%), shortness of breath (38.8%), and syncope (16.6%). All 18 patients presented with type 1 Brugada pattern ECG. Four patients (22.2%) underwent left heart catheterization, and none demonstrated the presence of obstructive coronary disease. The most common reported therapies included antipyretics (55.5%), hydroxychloroquine (27.7%), and antibiotics (16.6%). One patient (5.5%) died during hospitalization. Three patients (16.6%) who presented with syncope received either an implantable cardioverter defibrillator or wearable cardioverter defibrillator at discharge. At follow-up, 13 patients (72.2%) had resolution of type 1 Brugada pattern ECG. CONCLUSION: COVID-19-associated Brugada pattern ECG seems relatively rare. Most patients had resolution of the ECG pattern once their symptoms have improved. Increased awareness and timely use of antipyretics is warranted in this population.

Wearable Cardioverter-Defibrillator after Myocardial Infarction.

BACKGROUND: Despite the high rate of sudden death after myocardial infarction among patients with a low ejection fraction, implantable cardioverter-defibrillators are contraindicated until 40 to 90 days after myocardial infarction. Whether a wearable cardioverter-defibrillator would reduce the incidence of sudden death during this high-risk period is unclear. METHODS: We randomly assigned (in a 2:1 ratio) patients with acute myocardial infarction and an ejection fraction of 35% or less to receive a wearable cardioverter-defibrillator plus guideline-directed therapy (the device group) or to receive only guideline-directed therapy (the control group). The primary outcome was the composite of sudden death or death from ventricular tachyarrhythmia at 90 days (arrhythmic death). Secondary outcomes included death from any cause and nonarrhythmic death. RESULTS: Of 2302 participants, 1524 were randomly assigned to the device group and 778 to the control group. Participants in the device group wore the device for a median of 18.0 hours per day (interquartile range, 3.8 to 22.7). Arrhythmic death occurred in 1.6% of the participants in the device group and in 2.4% of those in the control group (relative risk, 0.67; 95% confidence interval [CI], 0.37 to 1.21; P=0.18). Death from any cause occurred in 3.1% of the participants in the device group and in 4.9% of those in the control group (relative risk, 0.64; 95% CI, 0.43 to 0.98; uncorrected P=0.04), and nonarrhythmic death in 1.4% and 2.2%, respectively (relative risk, 0.63; 95% CI, 0.33 to 1.19; uncorrected P=0.15). Of the 48 participants in the device group who died, 12 were wearing the device at the time of death. A total of 20 participants in the device group (1.3%) received an appropriate shock, and 9 (0.6%) received an inappropriate shock. CONCLUSIONS: Among patients with a recent myocardial infarction and an ejection fraction of 35% or less, the wearable cardioverter-defibrillator did not lead to a significantly lower rate of the primary outcome of arrhythmic death than control. (Funded by the National Institutes of Health and Zoll Medical; VEST ClinicalTrials.gov number, NCT01446965 .).

Gender associated disparities in atrioventricular nodal reentrant tachycardia: A review article.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common sustained supraventricular arrhythmias. An understanding of gender-related differences in AVNRT epidemiology, diagnosis, treatment, outcome, and complications can help guide a more effective diagnosis and treatment of the condition. The study aimed to perform a review of the available literature regarding all aspects of gender-related differences of AVNRT. We focused on all aspects of gender-related differences regarding AVNRT between men and women. A literature search was performed using Google Scholar, PubMed, Springer, Ovid, and Science Direct. Many investigations have demonstrated that the prevalence of AVNRT exhibited a twofold women-to-men predominance. The potential mechanism behind this difference due to sex hormones and autonomic tone. Despite being more common in women, there is a delay in offering and performing the first-line therapy (catheter ablation) compared to men. There were no significant gender-related discrepancies in patients who underwent ablation therapy for AVNRT, regarding the acute success rate of the procedure, long-term success rate, and recurrence of AVNRT. AVNRT is more common in women due to physiological factors such as sex hormones and autonomic tone. Catheter ablation is equally safe and efficacious in men and women; however, the time between the onset of symptoms and ablation is significantly prolonged in women. It is important for the medical community to be aware of this discrepancy and to strive to eliminate such disparities that are not related to patients' choices.

Clinical outcomes of adjunctive posterior wall isolation in persistent atrial fibrillation: A meta-analysis.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation but the recurrence rate remains relatively high in persistent patients with AF. Therefore, posterior wall isolation (PWI) in addition to PVI has been proposed to increase freedom from AF. OBJECTIVE: To evaluate the success of adjunctive PWI in persistent AF. METHODS: We searched electronic database using specific terms. The primary outcomes are recurrence rate of AF and recurrence of atrial arrhythmias. The secondary outcomes were atrial flutter/tachycardia (AFL/AT), procedure time, fluoroscopy time, and procedure related complications. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were evaluated. RESULTS: Six studies were included (1334 patients with persistent AF). Adjunctive PWI resulted in a significant reduction in the recurrence rate of AF compared with patients who had PVI only (19.8% vs 29.1%; RR, 0.64; 95% CI, 0.42-0.97; P < .04; I2 = 76%). There was a significant reduction in the recurrence rate of all atrial arrhythmia (30.8% vs 41.1%; RR, 0.75; 95% CI, 0.60-0.94; P < .01; I2 = 60%). Compared with PVI only, adjunctive PWI did not increase the rate of AFL or AT (11.6% vs 13.9%; RR, 0.85; 95% CI, 0.54-1.32; P < .46; I2 = 47%) or the rate of procedure related complications (4.6% vs 3.6%; RR, 1.25; 95% CI, 0.72-2.17; P < .44; I2 = 0%). CONCLUSION: In patients with persistent AF, adjunctive PWI was associated with decreased recurrence of AF and atrial arrhythmias compared with PVI alone without an increased risk of AFL or AT or procedure related complications.

Preclinical evaluation of efficacy and pharmacokinetics of gentamicin containing extracellular-matrix envelope.

BACKGROUND: Using synthetic antibiotic-eluting envelope (ABE) is an effective intervention for prevention of cardiovascular implantable electronic device (CIED) infection. The biologic extracellular-matrix envelope (ECME), may offer potential advantages over the synthetic ABE. To further minimize the risk of infection, the ECME can be hydrated in gentamicin prior to CIED implantation. We aimed to evaluate the efficacy and pharmacokinetics (PK) of gentamicin containing ECME in an animal model. METHODS: For all experiments, the ECME was hydrated in gentamicin (40 mg/Ml) (treatment) for 2 min. In vitro antimicrobial efficacy against six different bacterial species was assessed. In vivo experiments were conducted using a rabbit model of CIED pocket infection. Serum and ECM gentamicin concentrations were measured. Five different organisms were inoculated into the device pocket of control (ECME hydrated in 0.9% saline) and treatment groups. Macroscopic appearance and colony forming units from CIED, ECME, and tissue were determined. RESULTS: No bacteria were recovered from any culture after 12 h of exposure to the gentamicin containing ECME. Serum gentamicin levels dropped below the limit of quantification at 15 h after implant. Gentamicin concentration in the ECME remained relatively stable for up to 7 days. Signs of clinical infection were observed in the control but not in the treatment group. In the presence of gentamicin, statistically significant reduction was demonstrated across all tested bacterial species. CONCLUSIONS: In this preclinical animal infection model, gentamicin containing ECME was highly effective in reducing bacterial burden in the implant pocket, while systemic exposure after implantation remained low.

Characteristics of and current practice patterns of pacing for high-degree atrioventricular block after transcatheter aortic valve implantation in comparison to surgical aortic valve replacement.

OBJECTIVE: We aimed to investigate the current practice patterns of permanent pacing, especially the timing of implantation, for high-degree AV block (HDAVB) following transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). BACKGROUND: Comparative data regarding current practice patterns of permanent pacing for HDAVB between TAVI and SAVR is limited. METHODS: Using the National Inpatient Sample database, we identified patients who underwent TAVI or SAVR between 2012 and 2014. The incidence of HDAVB, the rate of permanent pacemaker implantation, and the timing of implantations were compared between TAVI and SAVR groups. RESULTS: We identified 33 690 and 202 110 patients who underwent TAVI and SAVR, respectively. HDAVB occurred in 3480 patients (10.3%) in the TAVI group and 11 405 patients (5.6%) in the SAVR group (P < 0.001). Among the patients who developed HDAVB, patients in the TAVI group were more likely to undergo permanent pacemaker implantation than those in the SAVR group (74.1% vs 64.7%; P < 0.001). The median interval from TAVI to pacemaker implantation was 2 days (interquartile range 1-3 days) vs 5 days (interquartile range 3-7 days) from SAVR to pacemaker implantation (P < 0.001). Among the patients who developed HDAVB, TAVI was associated with higher rates of permanent pacemaker implantation after adjusting for other comorbidities (odds ratio 1.41:95% confidence interval 1.13-1.77; P = 0.003). CONCLUSIONS: HDAVB occurred more commonly after TAVI compared to SAVR. HDAVB after TAVI compared to SAVR was associated with a higher rate of permanent pacemaker implantation at an earlier timing from the index procedure.

Outcomes of fibrinolytic therapy for patients with metastatic cancer and acute pulmonary embolism.

INTRODUCTION: Malignancy is a common cause of morbidity and mortality in the United States and around the world and the second leading cause of death in the United States. There is little data on the impact of metastatic cancer on the risk of hemorrhagic stroke or mortality among patients undergoing fibrinolytic therapy (FT) for acute PE. METHODS: Using the National Inpatient Sample (NIS) database, we extracted admissions with a primary diagnosis of acute pulmonary embolism that underwent FT from 2010 to 2014. We performed a case control matched analysis between patients with and without metastatic cancer. Our primary outcome of interest was Mortality and our secondary outcome of interest was hemorrhagic stroke (HS). RESULTS: Of the 883,183 patients with a primary diagnosis of acute PE between 2010 and 12014, 23,690 patients (2.7%) underwent FT. After exclusion, 22,592 patients were included in the analysis. Of these, 941 patients (4.2%) were reported to have metastatic cancer. There was a higher incidence of cerebrovascular accidents and intubation/mechanical ventilation in the metastatic cancer arm. Mortality was significantly higher in the metastatic cancer arm with no difference in the incidence of HS. In multivariate regression analysis, among all patients that underwent FT for acute PE, metastatic cancer was associated with a significant odds for mortality (OR 1.91, 95% CI 1.11-5.82, p < .001). CONCLUSION: The presence of metastatic cancer in patients undergoing fibrinolytic therapy for acute pulmonary embolism is associated with increase mortality.

Gender differences in management of patients undergoing catheter ablation of atrioventricular nodal reentry tachycardia.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia (SVT). Similar to other cardiac tests and interventions, gender bias may influence clinical decision making in providing appropriate care for AVNRT patients. We assessed for gender differences in the diagnosis and management of AVNRT patients who underwent catheter ablation. METHODS: Patients who underwent catheter ablation for AVNRT were included. We explored the gender difference on various clinical parameters such as the time from SVT symptoms, SVT diagnosis, and first electrophysiology consult to time of catheter ablation. RESULTS: Among 140 patients screened, 116 patients met the inclusion criteria, including 67.2% women. Median time from symptoms onset to SVT diagnosis was 18.5 months (interquartile range [IQR] 4.0-58.5) in women versus 4.0 months (0.75-34.7) in men, P = .005. Once SVT was diagnosed, women took a median of 12.5 months (IQR 3.0-57.0) to proceed with ablation versus 3.0 months (1.0-7.0) for men, P ≤ .001. It took a longer time from the first electrophysiology consultation to ablation: 54.5 days (20.75-144.75) for women versus 20.5 days (6.0-46.25) for men, P = .008. Overall, it took 60.0 months (IQR 12.8-132.0) for women to have an ablation from initial symptoms onset versus 15 months (IQR 4.6-48.0) for men, P = .001. Prior to ablation, women had 3.78 ± 3.79 (mean ± SD) emergency department visits for SVT versus men 1.52 ± 1.72 and women tried 1.28 ± 0.82 medications versus men 0.76 ± 0.68, P < .001 and .001, respectively. CONCLUSIONS: This study demonstrates significant and multifactorial gender-related disparities in AVNRT diagnosis and treatment. Larger studies are needed to confirm these results.

Use of digoxin in atrial fibrillation: One step further in the mortality controversy from the AFFIRM study.

BACKGROUND: Whether there is a causal association between digoxin and mortality among patients with atrial fibrillation (AF), with or without congestive heart failure (HF), has been controversial; in particular, two prior analyses of data from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial have yielded conflicting results. We sought to investigate how digoxin impacts mortality, in the full AFFIRM cohort and for various subgroups, by applying marginal structural modeling (MSM) to AFFIRM data. METHODS: MSM is a newer statistical approach, which estimates causal association in the absence of randomization. MSM more effectively accounts for time-varying treatment and mitigates potential biases, in contrast to the two statistical approaches used in prior analyses of the AFFIRM data. RESULTS: Among 4,060 patients in AFFIRM, 660 (16.3%) died during follow-up. Digoxin was associated with significantly higher mortality in the full cohort (estimated hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.11-1.60, P  =  0.002) and in 3,121 patients without HF (HR 1.36, 95% CI 1.07-1.72, P  =  0.011). There was a trend toward higher mortality with digoxin in 939 patients with HF (HR 1.29, 95% CI 0.96-1.72, P  =  0.090). Associations were nonsignificant in 463 patients with HF and left ventricular ejection fraction (EF) ≥40% and in 155 patients with EF ≤30%. CONCLUSIONS: Digoxin is associated with significantly increased mortality among AFFIRM patients collectively, as determined by MSM statistical methodology. However, the impact of digoxin among AFFIRM patients with coexisting HF is inconclusive.

Junctional ectopic rhythm after AVNRT ablation: An underrecognized complication.

BACKGROUND: Ablation is an effective treatment for atrioventricular nodal reentrant tachycardia (AVNRT). The occurrence of junctional ectopic rhythm (JER), including junctional ectopic tachycardia, following AVNRT ablation has been described as an extremely rare phenomenon, but may be underestimated. We aimed to determine the incidence of JER following AVNRT ablation within our institution, as well as that reported in the literature via an extensive review. METHODS: We reviewed our adult ablation institutional experience for the occurrence of JER after AVNRT ablation from 2009 to 2016. Additionally, we conducted an extensive literature search using different databases looking for AVNRT ablation case series. The individually reported complications of these studies were reviewed, with a primary endpoint defined as the occurrence of JER shortly after AVNRT ablation. The study was approved by our institutional review board. RESULTS: Our institutional data revealed 6/126 patients (prevalence 4.8%) developed non-preexisting JER post-AVNRT ablation. Four patients were asymptomatic. Two patients had persistent symptoms lasting over a year, with one patient requiring repeat ablation. The literature review included 149 adult and pediatric studies. There were three cases of reported JER, out of a total of 37,541 patients (31,768 adults and 5,773 pediatric; prevalence 0.008%). The three JER patients were pediatric, and all required further therapeutic intervention. CONCLUSION: JER might be an underreported complication of AVNRT ablation. It seems most often to be transient and self-limited, occurring days to weeks after ablation, but may also be debilitating, requiring more aggressive management.

Use of adenosine to shorten the post ablation waiting period for cavotricuspid isthmus-dependent atrial flutter.

BACKGROUND: Dormant conduction unmasked by adenosine predicts clinical recurrences of cavotricuspid isthmus (CTI) dependent atrial flutter following catheter ablation. Conventional practice involves a waiting period of 20 to 30 minutes after achievement of a bidirectional line of block (BDB) to monitor for recovery of conduction. OBJECTIVE: Assess whether abolition of dormant conduction with adenosine immediately after CTI ablation and BDB can predict the lack of CTI conduction recovery during the following 30 minutes. METHODS: Consecutive patients undergoing catheter ablation for CTI-dependent atrial flutter were studied. Following the completion of CTI ablation and documentation of BDB, adenosine (≥12 mg IV) was administered immediately. In cases of dormant conduction, the CTI was ablated again until its abolition. After the achievement of BDB without dormant conduction, spontaneous CTI reconnection during the following 30 minutes and dormant conduction with adenosine at 30 minutes were evaluated. RESULTS: A CTI block was achieved in 171 patients. Nine patients (5.3%) had dormant conduction across the CTI immediately after ablation and BDB, and required further ablation. Two patients (1.2%) had subsequent spontaneous time-dependent reconnection within 30 minutes. Two other patients (1.2%) developed late dormant conduction with adenosine at 30 minutes. All 4 patients underwent further ablation. CONCLUSION: A negative adenosine challenge immediately after CTI ablation with bidirectional block, or after abolition of dormant conduction with further ablation, strongly predicted the absence of subsequent spontaneous reconnection within 30 minutes. Based on these results, the conventional waiting period is unnecessary in 97.6% patients without dormant conduction after CTI-dependent flutter ablation.

Long-term follow-up of patients with paroxysmal atrial fibrillation and severe left atrial scarring: comparison between pulmonary vein antrum isolation only or pulmonary vein isolation combined with either scar homogenization or trigger ablation.

AIMS: Left atrial (LA) scarring, a consequence of cardiac fibrosis is a powerful predictor of procedure-outcome in atrial fibrillation (AF) patients undergoing catheter ablation. We sought to compare the long-term outcome in patients with paroxysmal AF (PAF) and severe LA scarring identified by 3D mapping, undergoing pulmonary vein isolation (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI+ ablation of the non-PV triggers. METHODS AND RESULTS: Totally, 177 consecutive patients with PAF and severe LA scarring were included. Patients underwent PVAI only (n = 45, Group 1), PVAI+ scar homogenization (n = 66, Group 2) or PVAI+ ablation of non-PV triggers (n = 66, Group 3) based on operator's choice. Baseline characteristics were similar across the groups. After first procedure, all patients were followed-up for a minimum of 2 years. The success rate at the end of the follow-up was 18% (8 pts), 21% (14 pts), and 61% (40 pts) in Groups 1, 2, and 3, respectively. Cumulative probability of AF-free survival was significantly higher in Group 3 (overall log-rank P <0.01, pairwise comparison 1 vs. 3 and 2 vs. 3 P < 0.01). During repeat procedures, non-PV triggers were ablated in all. After average 1.5 procedures, the success rates were 28 (62%), 41 (62%), and 56 (85%) in Groups 1, 2, and 3, respectively (log-rank P< 0.001). CONCLUSIONS: In patients with PAF and severe LA scarring, PVAI+ ablation of non-PV triggers is associated with significantly better long-term outcome than PVAI alone or PVAI+ scar homogenization.

Use of Cardioplegia to Guide Alcohol Ablation for Incessant Ventricular Tachycardia.

Incessant scar-related reentrant ventricular tachycardia is an important cause of morbidity and mortality. In patients not amenable to emergent radiofrequency catheter ablation, selective transcoronary alcohol ablation has been successfully performed. In our case study, we introduce the novel use of cardioplegia as a mapping technique for identification of the critical ventricular tachycardia isthmus to guide efficient transcoronary alcohol ablation and prevent unnecessary myocardial damage.

Acute Effects of Implantable Cardioverter-Defibrillator Shocks on Biomarkers of Myocardial Injury, Apoptosis, Heart Failure, and Systemic Inflammation.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) shocks are potentially associated with myocardial injury, altered hemodynamics, apoptosis, and inflammatory signaling. Their precise cellular impact can be explored after defibrillation testing (DFT) via biomarkers. We evaluated changes in biomarkers after ICD shocks during DFT. METHODS: We prospectively enrolled outpatients presenting for first implantation of a cardiac device. Biomarkers indicative of myocardial injury, inflammation, and apoptosis were measured before and after implantation, and compared between patients receiving DFT (DFT+) to those not (DFT-). RESULTS: Sixty-three patients were enrolled, 40 in the DFT+ group and 23 in the DFT- group. Average levels of troponin I, hsCRP, Calprotectin, N-terminal pro B-type natriuretic peptide (NTproBNP), and sFas increased by >50% after cardiac device implantation compared to baseline. Increase in troponin never exceeded the 50-fold upper limit of normal (2 ng/mL). Troponin trended higher in the DFT+ group at 8 hours (median 0.18 ng/mL, interquartile range [IQR] 0.11-0.48) versus the DFT- group (0.10 ng/mL, IQR 0.06-0.28, P = 0.0501); NTproBNP had a similar trend (P = 0.0581). sFas significantly increased in the DFT+ group from baseline (median 4663 pg/mL, IQR 2908-5679) to 24 hours (5039 pg/mL, IQR 3274-6261; P = 0.0338) but not in the DFT- group (P = 0.4705). CONCLUSION: DFT testing is associated with acutely increased plasma levels of troponin and sFas, a biomarker of apoptosis, along with a trend toward higher NTproBNP.

A New Combined Parameter to Predict Premature Ventricular Complexes Induced Cardiomyopathy: Impact and Recognition of Epicardial Origin.

INTRODUCTION: Reversible premature ventricular complexes-induced cardiomyopathy (PVC-CMP) is a well-described, multi-factorial entity. Single predictors, such as PVC burden or QRS duration, may not apply equally to all patients in contemporary unselected populations including patients with structural heart disease (SHD) or with particular origin such as epicardial (EPI) PVC. We sought to evaluate clinical criteria associated with PVC-CMP notably focusing on the EPI origin impact and ECG recognition and the value of a new composite predictor of PVC-CMP, the PVC-CMP-Index. METHODS AND RESULTS: We studied 107 consecutive patients (69 men; mean age = 56 ± 16 years) with frequent PVC (23.1 ± 11.5%) referred for PVC ablation. Thirty-six patients (33.6%) had an underlying SHD and 25 patients (23.4%) an EPI PVC origin. After a mean follow-up of 22.7 ± 15.3 months, 72.9% achieved a long-term successful ablation and 54.2% had PVC-CMP. PVC-CMP prevalence was significantly higher in patients with an EPI compared to endocardial PVC focus (84.0% vs. 45.1%, respectively, P < 0.001). EPI PVC origin (OR = 68.7 IC95% [3.5-1363], P = 0.005), as well as SHD (OR = 12.3 IC95% [1.6-92.6], P = 0.015), was independent predictor of PVC-CMP. While PVC burden (AUC = 0.78) or PVC-QRS width (AUC = 0.68) independently predicted PVC-CMP, the PVC-CMP-Index (values ≥39) defined as: PVC burden (0-1) × PVC-QRS width (milliseconds) × a constant C (1.28 for SHD or 2 for ECG suggesting EPI origin based on our ECG 3-step algorithm), highly correlated with PVC-CMP (AUC = 0.91, sensitivity = 93%, specificity = 80%). CONCLUSION: We developed a new index, which incorporates PVC burden, QRS width, and presence of SHD or suspected EPI origin that best predicted PVC-CMP.

Predictors, Morbidity, and Costs Associated with Pneumothorax during Electronic Cardiac Device Implantation.

BACKGROUND: Pneumothorax (PTX) is a major cause of morbidity associated with cardiac implantable electronic devices (CIEDs). We sought to evaluate predictors of PTX at our centers during CIED implantations, including the venous access technique utilized, as well as to determine morbidity and costs associated with PTX. METHODS: We reviewed records of all patients undergoing cardiac device implant or revision with new venous access at our institutions between 2008 and 2014. Common demographic and procedure characteristics were collected including age, sex, body mass index (BMI), comorbidities, and method of venous access (axillary vein vs classic proximal subclavian vein technique). RESULTS: We identified 1,264 patients who met criteria for our analysis, with a total of 21 PTX cases during CIED implantation. The strongest predictor for PTX was the venous access strategy: 0 of 385 (0%) patients with axillary vein approach versus 21 of 879 (2.4%) with traditional subclavian vein approach, P = 0.0006. Additional predictors of PTX included advanced age, female sex, low BMI, and a new device implant (vs device upgrade). The occurrence of PTX was associated with increased length of stay: 3.0 days (median; interquartile range [IQR] 3) versus 1.0 day (median; IQR: 1), P = 0.0001, with a cost increase of 361.4%. CONCLUSION: An axillary vein vascular access strategy was associated with greatly reduced risk of iatrogenic PTX versus the traditional subclavian approach for CIED placement. Similarly, device upgrade with patent vascular access carried less risk of PTX compared to new device implantation. PTX occurrence significantly prolonged hospitalization and increased costs.

Periprocedural stroke and bleeding complications in patients undergoing catheter ablation of atrial fibrillation with different anticoagulation management: results from the Role of Coumadin in Preventing Thromboembolism in Atrial Fibrillation (AF) Patients Undergoing Catheter Ablation (COMPARE) randomized trial.

BACKGROUND: Periprocedural thromboembolic and hemorrhagic events are worrisome complications of catheter ablation for atrial fibrillation (AF). The periprocedural anticoagulation management could play a role in the incidence of these complications. Although ablation procedures performed without warfarin discontinuation seem to be associated with lower thromboembolic risk, no randomized study exists. METHODS AND RESULTS: This was a prospective, open-label, randomized, parallel-group, multicenter study assessing the role of continuous warfarin therapy in preventing periprocedural thromboembolic and hemorrhagic events after radiofrequency catheter ablation. Patients with CHADS2 score ≥1 were included. Patients were randomly assigned in a 1:1 ratio to the off-warfarin or on-warfarin arm. The incidence of thromboembolic events in the 48 hours after ablation was the primary end point of the study. The study enrolled 1584 patients: 790 assigned to discontinue warfarin (group 1) and 794 assigned to continuous warfarin (group 2). No statistical difference in baseline characteristics was observed. There were 39 thromboembolic events (3.7% strokes [n=29] and 1.3% transient ischemic attacks [n=10]) in group 1: two events (0.87%) in patients with paroxysmal AF, 4 (2.3%) in patients with persistent AF, and 33 (8.5%) in patients with long-standing persistent AF. Only 2 strokes (0.25%) in patients with long-standing persistent AF were observed in group 2 (P<0.001). Warfarin discontinuation emerged as a strong predictor of periprocedural thromboembolism (odds ratio, 13; 95% confidence interval, 3.1-55.6; P<0.001). CONCLUSION: This is the first randomized study showing that performing catheter ablation of AF without warfarin discontinuation reduces the occurrence of periprocedural stroke and minor bleeding complications compared with bridging with low-molecular-weight heparin. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01006876.

A Practical ECG Criterion to Unmask Left Accessory AV Connections in Patients With Subtle Preexcitation.

BACKGROUND: Accessory AV-connections capable of antegrade conduction need to be recognized because of the potential for life-threatening arrhythmias. However, the preexcited ECG pattern may be subtle, especially among left-sided AV-connections. We explored whether additional ECG criteria might help identify left-sided AV-connections. METHODS: We analyzed 156 patients who underwent an electrophysiology study (EPS) and ablation for paroxysmal supraventricular tachycardias (PSVT). Patients were divided into 2 groups: those with left-sided AV-connections (Group 1) and all other PSVT (Group 2). Various ECG parameters were compared before and after ablation in both groups. RESULTS: The EPS identified left-sided AV-connections among 43 patients (Group 1) and excluded it among 113 (Group 2). Baseline ECG in Group 1 demonstrated obvious preexcitation among 24/43 patients (55.8%), the remaining 19/43 missing obvious preexcitation. R/S ratio > 0.5 in V1 was noted in 38/43 (88.4%) patients in Group 1 before ablation (median 1.00; IQR 0.58-2.20), including 16/19 (84.2%) patients lacking obvious left-sided AVconnections. Conversely, only 10/113 (8.8%) patients in Group 2 had R/S ratios in V1 ≥ 0.5 (0.20; 0.10-0.31), P < 0.0001. After ablation, the R/S ratio decreased significantly in Group 1 (0.29; 0.17-0.45), P < 0.0001. Thus, a combined criterion of classic preexcitation or R/S ratio ≥ 0.5 on ECG identified 40/43 left-sided AV-connections (sensitivity 93.0%). The negative predictive value of this combined criterion was 103/106 (97.2%). CONCLUSIONS: In symptomatic patients, combining the R/S ratio (≥ 0.5) in lead V1 with the classic preexcitation pattern on ECG markedly improved the sensitivity to diagnose left-sided AV-connections. This ratio may be particularly useful among patients lacking obvious preexcitation.