bluuebunny/crossref_metadata_2025 huggingface dataset:
Pacemaker implantation after cardiac surgery: a contemporary analysis
Authors: Taha A , David A , Ragnarsson S , Szamlewski P , Jamaly S , Jeppsson A , Martinsson A
Published: November 2023

Background

Cardiac surgery entails an increased risk for bradyarrhythmias. Currently known rates for permanent pacemaker (PPM) implantation after cardiac surgery are derived from non-contemporary studies.

Purpose

We sought to explore the one-year incidence and indications for PPM implantation after different cardiac surgical procedures in the modern era.

Methods

All patients in Sweden from 2006 to 2020 who underwent first-time cardiac surgery without previous PPM or implantable cardioverter-defibrillator (ICD) were included in this nationwide population-based study using data from three national registries (SWEDEHEART, National Patient Registry and Swedish ICD & Pacemaker Registry). Patients who received an ICD (n=1,714) and patients undergoing heart transplantation (n=376) were excluded. Sex- and age-matched controls from the general population were used for comparison.

Results

A total number of 83,484 patients and 82,921 controls were included. Median follow-up was 6.3 years (range 0-15 years). A PPM was implanted in 8.0% (n= 6,707) of the patients, out of these 46.2% (n= 3,101) had pacemaker implanted during the first postoperative year. Atrioventricular block was the main indication in 1,988 (64.1%) of the patients and 1,113 (35.9%) received a PPM due to sinoatrial disease. The incidence rate per 100 patient-years for PPM implantation during the first postoperative year was 1.4 (95% confidence interval 1.3-1.5) for those who underwent coronary artery bypass grafting (CABG), 15.8 (14.6-18.4) following mitral valve surgery, 7.0 (6.6-7.5) after aortic valve surgery and 9.6 (8.6-10.3) for those with combined CABG and valve surgery. The median time from surgery to PPM implantation was 10 days (IQR 7 – 28, Figure 1A and Figure 1B). Compared to the control population, the risk for PPM implantation after cardiac surgery was higher even beyond the first post-operative year.

Conclusions

The need for PPM after cardiac surgery is highest during the first 30 postoperative days and mostly due to atrioventricular block. The incidence rate for PPM implantation after mitral valve surgery was higher than that following CABG, aortic valve, or combined CABG and/or valvular surgery.Figure 1AFigure 1B
The impact of sick sinus syndrome on flow velocity of the left atrial appendage in patients with atrial fibrillation
Authors: Takahashi S , Mine T , Fukuda Y , Yoshikawa F , Takai K , Iio C , Takada M , Fujita K , Nishibori Y , Maruyama T
Published: November 2023

Background

Sick sinus syndrome (SSS) itself has been suspected as one of potential embolic stroke sources, however, the mechanism remains unclear. Reduced flow velocity of left atrial appendage (LAAFV) plays a major role in thrombus formation in patients with atrial fibrillation (AF). We evaluated the contribution of SSS to LAAFV in patients with AF.

Methods

We studied 153 consecutive patients (age 69±10, 100 males, 79 paroxysmal AF, CHADS2 score 1.6±1.2) who underwent catheter ablation (CA) for AF at our hospital and our college of medicine. All patients enrolled in this study underwent transesophageal echocardiography (TEE) and transthoracic echocardiography prior to CA. LA global mean voltage and LA activation time were also measured using High-density LA mapping during CA. Clinical characteristics and laboratory data was obtained before CA for AF. SSS was defined as sinus arrest with 3 seconds or more by Holter ECG, or pacemaker implantation due to SSS.

Results

Reduced LAAFV was associated with old age (R²=0.0783, P=0.0005), female (R²=0.0260, P=0.0285), non-paroxysmal AF (R²=0.1403, P<0.0001), hypertension (R²=0.0226, P=0.0338), history of congestive heart failure (R²=0.0890, P=0.0007), high CHADS2 score (R²=0.1248, P<0.0001), high level of BNP (R²=0.2054, P<0.0001), AF rhythm during TEE (R²=0.1577, P<0.0001), low LV ejection fraction (R²=0.0255, P=0.0488), large LA diameter (R²=0.1544, P<0.0001), high E wave (R²=0.1168, P<0.0001), low LA global mean voltage (R²=0.1775, P<0.0001), long LA activation time (R²=0.1383, P<0.0001) and SSS (n=29, R²=0.0957, P=0.0002). On multiple linear regression analysis, SSS, AF rhythm during TEE, BNP, female was independently related to reduced LAAFV (Table).

Conclusion

SSS itself might be related to reduced LAAFV in patients with AF.Table
Eight year follow-up data on a leadless pacing system real life experience in comparison to data of the prospective trial
Authors: Winter S , Tuscher T , Nguyen D Q , Sinning J M
Published: November 2023

Introduction

The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine in 2015, with its next generation MICRA AV ™ in 2020. Feasibility, implantation safety, and acute success have been proven in the setting of controlled studies. Even apart from controlled studies, this new technology was beneficial for the individual patient. We aimed to report our single center follow-up (FU) data with a follow-up of up to six years.

Methods

In 272 patients (136 men; age: 81±5,7 y), Micra™ implantation was performed.

Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, then every 6 month) up to 84 months. Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial.

Results

The implantation was successful in all 272 attempts with only one pericardial effusion as major complication. During follow up there were two patients developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system.

The average acute thresholds, sensing and impedance after system release were: 0.57±0.34V@0.24ms; 10,02±3,96mV and 752±1201Ohm. During follow up of up to 7 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.75 ± 0.38V @ 0.24 ms; 18,38 ±2,75 mV and 525 ± 102 Ohm. During seven years, no significant changes from acute to long-term measurements were detectable. In comparison to the controlled trial, our measurements of this real-life cohort were very similar.

Conclusion

In a real-life setting, the implantation of the leadless Micra™ system demonstrates a high rate of implantation success without major complications. We were also able to show stable long-term system parameters in the clinical setting of up to seven years of follow up with a very good battery longevity of about 12,3 years.
Aveir Leadless Pacemaker implantation in pediatric population: a case series
Authors: Masilamani M S J , Cortez D
Published: November 2023

Background

While the Medtronic Micra pacemaker provided a small device for leadless pacemaker implantation, the Aveir device allows chronic retrievability and mapping prior to fixation. We present the first Aveir leadless pacemaker implantations in a pediatric population.

Purpose

To describe the first retrievable leadless pacemaker implants in children.

Methods

Retrospective review of pediatric Aveir implants occurred between November 2022 and December 2022. All patients were implanted via internal jugular vein insertion utilizing the Aveir sheath and catheter deployment system with mid-atrial approach taken prior to insertion of the catheter across the tricuspid valve. All patients had initial mapping of capture threshold, impedance and R-wave noted prior to deployment. Indications for pacing included sinus pauses and intermittent atrioventricular block.

Results

Three patients underwent Aveir leadless pacemaker implantation with weights of 32.3kg, 44kg, and 51kg. Capture thresholds were all 0.75Volts@0.2 milliseconds with impedance range of 370-1110 ohms, and R-waves of 8-14 millivolts (mV). Follow-up at 3 months ranged from 0.5V@0.2ms to 1V@0.2ms with impedances ranging 400-700 ohms, and R-wave 7-14 mV. At VVI 50-55bpm, with pacing ranged from 5% to 14%, predicted longevities ranged from 20 to 24.5 years at 3 months follow-up.

Conclusion(s)

Retrievable leadless pacemaker implantation is feasible in children and may offer good longevities for intermittent pacing need.Aveir Leadless Pacemaker in RVAveir Leadless Pacemaker in RV
Impact of leadless pacemaker therapy on tricuspid regurgitation
Authors: Mendoza I M , Ukani Z , Rodriguez E R , Rangel A R
Published: November 2023

Background

The association between conventional transvenous pacemaker leads and tricuspid regurgitation (TR) has been well described. Leadless pacemakers (LP) have risen as an alternative to conventional transvenous pacemakers in order to avoid lead associated complications. Prior studies have included a mix of leadless pacemaker types including: Nanostim, Micra, etc. This is the first study exploring only one model of LP.

Purpose

The purpose of the study was to investigate the impact of leadless pacemaker therapy on tricuspid regurgitation.

Methods

Adult patients who underwent Micra leadless pacemaker implantation at a single center from 2016 to 2022 were identified retrospectively. Patients who had an echocardiogram prior to the procedure and within 24 months after the procedure were included. Echocardiograms were reviewed to assess for change in presence or in severity of tricuspid regurgitation.

Results

There were 310 patients in total who received LP at our hospital. Of these, 104 met inclusion criteria. 189 patients were excluded because they did not have an echocardiogram before or after the procedure. 17 more were excluded because their post procedure echo was done more than 2 years later. The average age of our patient population was 78. Of the 104 total patients, 97 had some TR before LP implantation (Trace 41%, Trace-Mild 4%, Mild 31%, Mild-Moderate 7%, Moderate 13%, Moderate-Severe 1%, Severe 2%). After implantation, 34 patients had worsening TR (33%), 23 patients had improved TR (22%), and 47 patients had no change in TR severity (45%) p=0.053.

Conclusion

Overall, the results did not show a statistically significant improvement or worsening in TR severity after LP implantation. Further studies should be done to validate these findings, to evaluate the effect of a larger sample size, and to examine whether controlling for additional confounders maintains or contradicts this finding.
Cardioneuroablation for symptomatic bradyarrhythmia: for whom it fails?
Authors: Wichterle D , Stiavnicky P , Jansova H , Peichl P , Stojadinovic P , Haskova J , Borisincova E , Cihak R , Kautzner J
Published: November 2023

Background

Cardioneuroablation (CNA) has been proposed as a new therapeutic approach in selected patients with symptomatic functional bradyarrhythmia including recurrent neurally-mediated syncope.

Purpose

In patients after CNA, we investigated the potential predictors of the recurrence of clinically significant bradyarrhythmia.

Methods

A retrospective study included 187 consecutive patients (age: 40±12 years; 57 % of males; predominant AV nodal phenotype of the disorder in 37 % of patients; post-atropine sinus rate acceleration by 72±31 %) who underwent their first CNA at our centre from 2014 to 2022 and were followed for the minimum of 3 months. Biatrial radiofrequency ablation was performed under general anaesthesia by irrigated-tip catheter at empirical sites of ganglionated plexi (GP) with the navigation by 3D electroanatomic mapping system and intracardiac echocardiography. Anterior right GP and posteromedial left GP were always targeted to modulate the innervation of both sinoatrial and atrioventricular nodes, irrespective of the clinical manifestation of the disease. The loss of responsiveness of both nodes to extracardiac vagus nerve stimulation (frequently bilateral) was the procedural endpoint. The association of baseline, procedural, and early follow-up characteristics with the recurrence of clinically significant bradyarrhythmia was analyzed.

Results

CNA with the procedural duration of 154±32 min and radiofrequency time of 14±7 min resulted acutely in sinus rate acceleration by 27±13 bpm, shortening of AH interval by 16±28 ms, an increase of Wenckebach point by 26±28 bpm, shortening of AV node effective refractory period by 114±128 ms, and sinus node recovery time by 462±867 ms. At the 3-month visit, the sinus rate was still significantly higher (83±14 bpm) than at baseline (61±13 bpm); with acceleration by 23±14 bpm. During a median follow up of 33 months (IQR: 18-48 months), recurrence of clinically significant bradyarrhythmia was documented in 18 (10 %) patients. Re-CNA was performed in 11 patients and was scheduled in 3 patients. In 6 (3 %) patients, a pacemaker was finally implanted. Compared to the rest of the population, patients with bradyarrhythmia recurrence were non-significantly younger (36±12 vs. 40±12 years, P=0.16) and had non-significantly less acceleration of sinus rate at the 3-month post-CNA visit (by 18±11 vs. 23±13 bpm, P=0.10) suggesting a trend to more pronounced reinnervation of the sinus node.

Conclusion

Long-term clinical efficacy of CNA is reasonably high. We did not identify practically useful predictors of CNA failure. This investigation was significantly limited by the low rate of clinical events.
Regional differences in extracellular volume increase arrhythmia vulnerability in aortic stenosis patients with and without diffuse fibrosis: a computational study
Authors: Sobota V , Augustin C M , Nordmeyer S , Vigmond E J , Bayer J D
Published: November 2023

Background

Extracellular volume (ECV) determined by magnetic resonance imaging (MRI) is considered a marker of myocardial fibrosis and a predictor of mortality. In addition to diffuse fibrosis, aortic stenosis (AS) patients present increased ECV. However, the impact of regional ECV differences on arrhythmia vulnerability in AS patients has not been assessed.

Purpose

To investigate regional ECV differences in AS patients and to determine their impact on ventricular arrhythmia vulnerability.

Methods

MRI was performed in 51 AS patients (32 males, 19 females) before and 3 months after aortic valve replacement (AVR). Regional differences in ECV were measured between mid-ventricular and basal planes. To investigate their impact on arrhythmia vulnerability, a computational biventricular model was developed from MRI data of the patient who presented the highest ECV difference between the planes in absence of a scar determined by late gadolinium enhancement (male 75y, post-AVR, ECV mid 25.5%, ECV base 31.3%, Figure A). The model was divided in two regions and extracellular conductivities (GE) were adjusted in each region as described previously (1), with additional GE reduction in the high ECV region representing increased interstitial fibrosis. This approach resulted in GE being 26.4% lower for ECV of 31.3% when compared to ECV of 25.5%. A model with uniform ECV of 25.5% was used as a control. Myocardial tissue was modelled with a cell radius of 16 micrometers, as reported in AS patients (2). The right ventricular apex was paced with S1=750 ms for 10 beats, followed by rapid pacing with different cycle lengths spanning the 20 ms window before the loss of stimulus capture to test arrhythmia inducibility. The simulations were repeated with an additional GE reduction by 30% and 60% in both regions to mimic conduction delays from diffuse fibrosis.

Results

Cardiac MRI showed significantly higher ECV in the basal plane of AS patients when compared to the mid-ventricular plane, both before and after AVR (Figure B), with the largest ECV found after AVR (mid-ventricular: p<0.0001; basal: p=0.0011). No sex-specific differences were found. Simulations in the model with patient-derived ECV showed slightly longer QRS and lower CV than the model with uniform ECV (Table). By contrast, myocardial fibrosis had a larger impact on CV slowing. Arrhythmia was inducible when either diffuse fibrosis was present or ECV at the ventricular base was increased (Table).

Conclusion

Regional differences in ECV were found in the ventricles of AS patients. Computer simulations suggest that these differences have a minimal effect on ventricular conduction when compared to diffuse fibrosis. However, they might increase arrhythmia vulnerability even in the absence of diffuse fibrosis. Additional studies are necessary to investigate the effects of each on arrhythmia maintenance and cardiac mechanics.
LDL electronegativity and male predominance in early ventricular tachyarrhythmias following ST-elevation myocardial infarction: evidence of sexual dimorphism associated reduction of sodium currents
Authors: Chang K C , Wu M Y , Lin Y N , Lee A S , Chen C H
Published: November 2023

Background

Early ventricular tachycardia/fibrillation (VT/VF) in patients with ST-elevation myocardial infarction (STEMI) was associated with a higher morbidity and mortality rate. We sought to investigate the gender-specific risk and explore the underlying mechanisms of early VT/VF in STEMI patients.

Methods

We analyzed the clinical and laboratory data among 2965 consecutive STEMI patients between Jan 1, 2008 and Dec 31, 2021. Early VT/VF was defined as occurrence of spontaneous VT/VF of ≥30 seconds or requirement of immediate cardioversion/defibrillation due to hemodynamic compromise within the first 48 hours after onset of symptoms. To explore the mechanisms underlying early VT/VF, ex vivo ischemic-reperfusion experiments were conducted in 8-week-old ApoE-/- mice fed a high-fat diet for 8 weeks to promote atherogenesis.

Results

Of the 2965 STEMI patients studied, 256 (8.6%) experienced early VT/VF. Patients who developed early VT/VF were younger (58±13 vs. 61±13 years old, P=0.012) and had a higher proportion of males (87% vs. 83%, P=0.043). Notably, some patients with early VT/VF had significantly higher plasma levels of L5, the most electronegative subclass of low-density lipoprotein (LDL), compared to those without early VT/VF (n=19, L5: 10.14±3.09% vs. n=43, L5: 2.11±0.23%, P=0.006). In animal study, we have previously showed that male mice have higher plasma L5 concentrations than female mice. In this study, all male mice (n=4) developed VT/VF following the sham operation, whereas none of the female mice (n=3) did. Moreover, male mice had significantly slower heart conduction velocity than female mice in whole heart preparations (13.37±3.81 cm/s vs. 40.70±4.97 cm/s, P<0.001), despite having similar action potential duration (61.00±7.07 vs. 50.33±4.16 ms, P=0.999). In addition, isolated ventricular myocytes from male mice exhibited markedly lower sodium current density (-29.20±3.04 pA/pF, n=6) compared to those from female mice (-114.05±6.41 pA/pF, n=6, P<0.001). The reduced sodium current density was accompanied by lower membranous Nav1.5 protein expression (0.38±0.06 vs. 0.89±0.09 A.U., P<0.001) and higher cytosolic Nav1.5 levels (0.59±0.06 vs. 0.29±0.04 A.U., P<0.01) in male mice.

Conclusions

Our study demonstrates that male STEMI patients with early VT/VF have higher levels of L5, the most electronegative LDL subclass. This gender disparity in the susceptibility of early VT/VF may be caused by compromised sodium channel trafficking, likely linked to increased LDL electronegativity.
Long-term follow-up in patients with hypertrophic cardiomyopathy after defibrillator implantation: analysis of appropriate and inappropriate therapy
Authors: Basse Christensen E , Vissing C R , Silajdzija E , Mills H L , Thune J J , Bosselmann H , Larroude C E , Philbert B T , Raja A A , Christensen A H , Bundgaard H
Published: November 2023

Background

Treatment with implantable cardioverter-defibrillators (ICD) is effective for prevention of sudden cardiac death (SCD) in patients with hypertrophic cardiomyopathy (HCM). Assessment of SCD risk and identification of patients most likely to benefit from primary prevention ICD is challenging.

Purpose

To investigate the long-term incidence of appropriate and inappropriate ICD therapy in patients with HCM.

Methods

This was a retrospective cohort study including all patients with HCM and ICDs implanted between 1995 to 2022 in our region (population 2.6 million). Both patients treated with primary and secondary prevention ICD were included. Data was retrieved from medical records. Patients with an ICD implanted for primary prevention were stratified into risk groups according to European Society of Cardiology HCM Risk-SCD score.

Results

We included 187 patients (65% male) with HCM and ICDs implanted for primary (80%) or secondary (20%) prevention. The median age at ICD implantation was 50 years (IQR: 40 to 61 years). During a mean follow-up of 9 years (IQR: 4 to 12 years), 53 patients (28%) experienced appropriate ICD therapy (antitachycardia pacing and/or shock), while 17 (9%) patients received inappropriate therapy. Patients with an ICD as secondary prevention were almost twice as likely to receive appropriate ICD therapy compared to patients with a primary prevention ICD (42% vs. 25%, p=0.04). The proportion of patients receiving appropriate shocks was 7 times higher in patients with an HCM Risk-SCD score ≥6% compared to patients with a risk score <4% (29% vs. 4%, p<0.001). There was no significant difference in the proportion of appropriate shocks between patients with a HCM Risk-SCD score ≥6% and patients with a risk score of 4%-6% (29% vs. 21%, p=0.49). (Figure 1).

Conclusion

One in four patients with HCM treated with an ICD experienced appropriate device intervention during 9 years of follow up. Patients with an HCM Risk-SCD score ≥6% had a 7-fold higher risk of appropriate ICD therapy compared to patients with an HCM Risk-SCD score <4%. There was no significant difference in the risk of appropriate shock therapy between patients with a risk score ≥6% and patients with a risk score of 4%-6%. The findings indicate the need for improved selection of patient with HCM for implantation of ICD’s.
Ventricular arrhythmia outcomes in hypertrophic cardiomyopathy from a high level myectomy centre
Authors: Gupta M , Naser A , Doyle M , Williams R B , Okasha O , Biederman R W W
Published: November 2023

Background

The presence of ≥15% late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (MRI) is used as a prognostic indicator for sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). [1] According to the European Society of Cardiology clinical practice guidelines (2014), septal myectomy is only indicated for symptomatic relief from left ventricular outflow tract obstruction (LVOTO) that is refractory to medical therapy, provided LVOTO gradient ≥ 50 mmHg. [2] At present, there is scarce data correlating the burden of ventricular arrhythmia and sudden cardiac death with LGE percentage or showing benefit of myectomy in reducing the burden of the same.

Purpose

We aimed to compare the burden of ventricular arrhythmia burden in patients with HCM who underwent septal myectomy compared with those who did not.

Methods

Adult patients with HCM followed in the advanced heart failure outpatient clinic at Allegheny General Hospital were included in this study. All included patients had cardiac MRI with LGE quantification and data related to cardiac events through devices placed for various indications (such as evaluation of reported palpitations, established supraventricular tachycardia, implantable cardioverter-defibrillator for primary or secondary prevention). Patients were divided into 2 groups: those undergoing myectomy (post myectomy group) and those that did not undergo myectomy (non-myectomy group). Chi square test was used to calculate incidence of premature ventricular contractions (PVCs), non-sustained ventricular tachycardia (NSVT) and sustained ventricular tachycardia (SVT) in the non-myectomy and post myectomy group.

Results

76 patients with HCM (interventricular septal thickness ≥1.5 cm and LGE positive) longitudinally followed in the Allegheny General Hospital advanced heart failure outpatient clinic from 2016 to 2022 were included. 37 patients underwent septal myectomy. Baseline characteristics of post myectomy and non-myectomy group were matched and are listed in table 1. Left ventricular mass index was expectedly higher in patients undergoing myectomy. LGE was quantified on cardiac MRI prior to myectomy (mean 16.4% in myectomy group, 14.6% in non-myectomy group). Burden of ventricular arrhythmia (PVCs, NSVT and SVT) was found to be significantly lower in the post myectomy group (n=13, 44.83%) compared to the non-myectomy group (n=36, 92.31%). None of the patients included were noted to have ventricular fibrillation or sudden cardiac death.

Conclusion

Septal myectomy may reduce the incidence of ventricular arrhythmia and thus impact outcomes related to sudden cardiac death. This is likely a consequence of removal of arrhythmogenic scar tissue. Larger studies are required to further evaluate the burden and correlation of ventricular arrhythmia with scar tissue volume measured on cardiac MRI.
X-linked Emery-Dreifuss muscular dystrophy is associated with a high risk of malignant ventricular arrhythmia
Authors: Cannie D , Syrris P , Rodriguez-Palomares J F , Marini-Bettolo C , Mestroni L , Parikh V N , Barriales-Villa R , Jiminez-Jaimez J , Garcia-Pavia P , Charron P , Biagini E , Garcia-Pinilla J M , Savvatis K , Wahbi K , Elliott P M
Published: November 2023

Background

Emery-Dreifuss muscular dystrophy (EDMD) is caused by variants in EMD (X-linked) and LMNA (autosomal dominant). LMNA variants are known to cause end-stage heart failure (ESHF) and malignant ventricular arrhythmia (MVA) [1], but the risk of cardiac complications in EMD variant-carriers is unknown.

Purpose

To determine the incidence of MVA and ESHF in EMD variant-carriers.

Methods

Consecutively referred individuals carrying EMD variants were recruited from 12 cardiomyopathy units in Europe and the USA. The incidence of MVA and ESHF in male and female EMD variant-carriers was determined. Male EMD variant-carriers with a cardiac phenotype at baseline (EMDcardiac) were compared to consecutively recruited male LMNA variant-carriers with a cardiac phenotype (LMNAcardiac).

Results

Longitudinal follow-up data were available for 38 male and 21 female EMD variant-carriers (mean (SD) ages 33.4 (13.3) and 43.3 (16.8) years, respectively; Table 1). Nine (23.6%) males developed MVA and five (13.2%) developed ESHF during a median follow-up time of 65.0 [24.3, 109.5] months. No female EMD variant-carrier had MVA or ESHF, but nine (42.8%) developed a mild cardiac phenotype at a median [IQR] age of 58.6 [53.2, 60.4] years.

Incidence rates for MVA were similar for EMDcardiac and LMNAcardiac (4.8 versus 6.6 per hundred person-years, respectively; log-rank test p = 0.49; Figure 1). Incidence rates for ESHF were 2.4 per hundred person-years for EMDcardiac and 5.9 per hundred person-years for LMNAcardiac (log-rank test p = 0.09; Figure 1).

Conclusions

Male EMD variant-carriers have a high risk of progressive heart failure and ventricular arrhythmias similar to that of male LMNA variant-carriers. These data suggest that early ICD implantation and heart failure drug therapy should be considered in male EMD variant-carriers with cardiac disease.Table 1Figure 1
Monitoring the electrophysiological effects of hydroquinidine non-invasively in patients with Brugada syndrome
Authors: Isbister J C , Strocchi M , Chiswell K , Yeates L , Cham J , Gray B , Ingles J , Semsarian C , Raju H , Neiderer S , Sy R
Published: November 2023

Background

Quinidine and it’s derivative hydroquinidine are the only drugs shown to reduce arrhythmic events in patients with Brugada syndrome (BrS). There is currently no standardised approach to monitoring the effect of pharmacotherapy in BrS to guide dosing and evaluate an individual’s response to therapy.

Purpose

To investigate if the electrophysiological effects of Hydroquinidine can be detected on non-invasive testing and identify parameters that may be used to study a non-invasive strategy for monitoring pharmacotherapy in BrS.

Methods

Patients with a diagnosis of BrS underwent multimodality non-invasive assessment with electrocardiogram (ECG), signal averaged ECG, 24 hour 12-lead Holter monitor and electrocardiographic imaging (ECGi – a method of non-invasive electroanatomical mapping), at baseline and "on treatment" with hydroquinidine (300mg BD) therapy. A medication survey was used to recorded adverse drug reactions and serum hydroquinidine levels were determined using liquid chromatography mass spectrometry.

Results

Twelve patients with BrS (11 male, mean age 47.6±10.9 years) with spontaneous type 1 BrS pattern or drug inducible type 1 BrS pattern and resuscitated cardiac arrest participated in the study. The mean Shanghai score was 4.6±1.4 and two patients had disease-causing SCN5A variants. During hydroquinidine therapy, there was a significant increase in QRS duration (110.7msec vs 117.8msec, p=0.004) and in mean activation time in the area of late activation in the right ventricular outflow tract (RVOT, 90.9ms to 97.7ms, p=0.020). In nine (75%) patients, the area of late activation (defined as >80ms after initial activation) in the RVOT also increased with hydroquinidine. Repolarisation parameters were also affected by hydroquinidine with an increase in QT interval corrected for heart rate (369.5msec vs 434.8msec, p<0.0001) and T-wave width (232.8msec to 271.2msec p=0.003) and a significant reduction in T-wave amplitude (0.4mV to 0.2mV p=0.001) on treatment. The reduction in T-wave amplitude precluded computation of repolarisation time in the RVOT by ECGi on treatment. No difference in the burden of type 1 BrS ECG pattern over 24 hours was seen on 12-lead Holter monitor between baseline and on treatment assessment. No significant difference in serum hydroquinidine level was detected between those who experienced side effects and those who did not (2.9µmol vs 3.1µmol, p=0.790).

Conclusion

Hydroquinidine affects both ventricular activation and repolarisation in patients with BrS and these effects can be detected non-invasively. Further work is required to determine clinical significance of these observed effects and investigate the feasibility of non-invasive monitoring strategy of pharmacotherapy in BrS.ECGi activation maps
New risk predictor of arrhythmias in patients with congenital Long-QT Syndrome
Authors: Juarez Krijger C , Proost V , Tanck M W T , Dittmann S , Schulze-Bahr E , Schwartz P J , Bezzina C R , Wilde A A M
Published: November 2023

Congenital long-QT syndrome (LQTS), is an inherited cardiac channelopathy characterized by delayed ventricular repolarization, which may lead to Torsade de pointes (TdP), that may degenerate into ventricular fibrillation. Determination of risk remains unrefined. It is well established that the repolarizing current Iks is increased during adrenergic stimulation, as occurs during exercise, thereby playing an important role in shortening the QT interval as an adaptation to increased heart rate. Accordingly, patients with LQTS, in particular those with LQT1 are at high arrhythmic risk during exercise. We hypothesized that changes in QTc during exercise stress test (EST) may be useful for risk stratification in LQTS. Furthermore, we hypothesized that as changes in IKs impact on repolarization reserve, the predictive capacity of the EST may extend to other LQTS genetic subtypes.

Aim

assessing the potential value of QT dynamics during EST to identify high risk patients in patients with LQT1 and LQTS2.

Methods

This study included genotype-positive LQT1 and LQT2 patients from the Netherlands, Italy and Germany. Symptomatic patients; patients whom experienced an arrhythmic syncope, sustained ventricular arrhythmia or (aborted) sudden cardiac death. Twelve-lead ECGs were digitally acquired during exercise testing. QT measurements were determined at specific time points. Statistical analyses were performed using R software. Logistic regression and cox proportional hazards models were used to calculate the predictive value and hazard ratio per ms increase in ΔQTc. Covariates included age, QTc, sex, beta-blocker use, center and genetic variant location.

Results

A total of 222 patients with LQT1 and 164 patients with LQT2 (Table 1), with a pathogenic or likely pathogenic variant in KCNQ1 or KCNH2, were included. In both LQTS1 and LQTS2 patients, the ΔQTc between rest and at 3-4 minutes recovery was the most relevant and significant EST predictor.

For LQT1, the ΔQTc was significantly increased in symptomatic patients versus non-symptomatic ones (46 ms ± 35 vs 18 ms ± 36, p = < 0.001)(figure 1 panel A). Logistic regression model shows a predictive value (AUC) of 89.2% for ΔQTc. Survival analysis showed a hazard ratio of 1.02 with 95% CI of 1.01 – 1.03 for each ms ΔQTc increase.

For LQTS 2 patients, the ΔQTc between rest and 3-4 minutes recovery was also increased in symptomatic patients versus non-symptomatoc ones (27 ms ± 40 vs 12 ms ± 40, p = 0.03). Logistic regression analysis; OR per ms: 1.02 (1.01 – 1.04 95%CI) AUC 78.3%. Survival analysis showed a hazard ratio of 1.02 (1.01 - 1.03 CI) for each ms ΔQTc increase.

Conclusion

The ΔQTc between rest and at 3-4 minutes recovery was significantly increased in symptomatic LQT1 and LQT2 patients compared to non-symptomatic patients, and is a promising risk marker to identify high risk patients, in both LQT1 and LQT2.Table 1
Insights regarding in-hospital outcomes of COVID-19 hospitalisations and co-existing premature ventricular contractions : from national inpatient sample 2020
Authors: Gajjar R , Teaima T , Battikh N , Aziz I , Shoura S , Sad Aldeen Z
Published: November 2023

Introduction

Since the emergence of the COVID-19 pandemic, several reports have highlighted COVID-19 infection's arrhythmogenic consequences on the cardiac conduction system (1). SARS-CoV-2 has a well-established predilection to cardiomyocytes and is associated with myocardial injury with worse predicted outcomes. A wide range of electrocardiographic findings was significantly associated with COVID-19 infection (2). However, literature is scarce on the outcomes of such ECG findings, and its implications are yet to be understood.

Purpose

We sought to illustrate the significant outcomes of patients hospitalised for COVID-19 infection and premature ventricular contractions.

Methods

The National Inpatient Sample database (NIS) - 2020 was analysed to identify adult hospitalisations with a primary diagnosis of COVID-19 with or without co-existing premature ventricular contractions (PVC) using International Classification of Diseases – 10 Clinical Modification (ICD-10-CM) codes. The primary outcome was inpatient mortality, while secondary outcomes included inpatient morbidity, mean length of stay (LOS), and mean total hospital charge (THC). Multivariate logistic regression and linear regression analyses were used to adjust for possible confounders.

Results

Out of 1,050,045 COVID-19 hospitalisations, 7,729 (0.73%) had PVCs. Encounters with COVID-19 and co-existing PVCS had higher adjusted odds of inpatient mortality (Adjusted odds ratio [aOR]: 1.18, 95% confidence interval [CI]: 1.014-1.38, p=0.033), longer mean LOS of 1.8 days (95% CI: 1.4-2.3, p <0.001), and higher mean THC of $21,869 (95% CI: $13,902-$29,835, p <0.001) than those without co-existing PVCs. Figure 1 shows a forest plot illustrating the multivariate analysis of in-hospital morbidities when adjusted for patient demographics, comorbidities, and hospital characteristics.

Conclusion

Among patients hospitalised with COVID-19 infection, those with premature ventricular contractions had worse outcomes regarding in-hospital mortality, sepsis, need for endotracheal intubation, mechanical ventilation, and vasopressors use, in addition to the longer length of hospital stay, and higher total hospital charges. Although PVCs are commonly encountered in hospitalised patients and often require no medical interventions in most cases, they are associated with poor prognosis in patients with COVID-19 infection.Forest plot for adjusted outcomes
Predictors of and outcomes in arrhythmic mitral valve prolapse
Authors: L'hoyes W , Robyns T , Moura-Ferreira S , De Meester P , Dresselaers T , Herregods M C , Rega F , Masci P G , Willems R , Bogaert J , Vandenberk B
Published: November 2023

Background

Recently, the European Heart Rhythm Association (EHRA) defined the phenotype of the arrhythmic mitral valve prolapse (AMVP) complex and proposed management approaches. Assessing the incidence of SCD in this small subset of patients is challenging due to the low event-rate and longitudinal real-world data remain scarce.

Purpose

To determine the predictors of AMVP and study the clinical outcome of patients stratified by ICD indication as proposed by the EHRA consensus statement.

Methods

All consecutive patients with MVP who underwent cardiac magnetic resonance imaging (CMR) were enrolled in a single-center retrospective registry. AMVP was defined as the presence of frequent or complex ventricular arrhythmias (>5% total PVC burden, non-sustained ventricular tachycardia (VT), VT or ventricular fibrillation) in a patient with MVP without alternative arrhythmic substrates. The medical records of these patients included a comprehensive clinical, rhythmic and echocardiographic characterization allowing to collect the key date of transition to AMVP. A forward conditional multivariable logistic regression was performed to identify clinical risk factors for AMVP reporting the odds ratio (OR) and corresponding 95% confidence interval (95% CI). Incidence rates were calculated for the composite endpoint of SCD, sustained VT, ICD shocks, and all-cause mortality.

Results

A total of 169 patients (52.1% male, median age 51.4 years) were included, of which 99 (58.6%) were classified as AMVP. Clinical characteristics are presented in Image 1. Patients with non-arrhythmic MVP and AMVP had comparable left ventricular function, mitral valve regurgitation grade and extent of MVP. Multivariable logistic regression identified the presence of late gadolinium enhancement (LGE, OR 2.82, 95%CI 1.45–5.50, p=0.002) and mitral annular disjunction (MAD, OR 1.98, 95%CI 1.02–3.86, p=0.045) on CMR as only predictors of AMVP. Cardiac CMR results are presented in Image 2. The median overall follow-up since first cardiac contact was 8.0 years (IQR 5.0–15.6), while this was 5.0 years (IQR 2.1–7.4 years) after transition to AMVP. The incidence for the composite endpoint in the overall population was 0.4%/year (95%CI 0.2 – 0.9). The 5-year cumulative event rate was 1.8%. According to the EHRA risk stratification the implantation of an ICD would have been reasonable in 69 patients (69.7%). In total, 5 patients were implanted with an ICD for secondary prevention, but all those patients did not classify as AMVP prior to the life threathening arrhythmic event.

Conclusion

CMR is an important tool in the challenging risk stratification of AMVP given that the presence of MAD and LGE enhancement are predictors of AMVP. There is a lack of longitudinal data to determine when patients transition from MVP to AMVP and how this modifies their outcome.Clinical characteristics and ECG resultsOverview of CMR measurements
Catheter ablation of ventricular arrhythmias in arrhythmogenic cardiomyopathy - comparison of different approaches and results of genetic testing
Authors: Rafaj A , Peichl P , Wichterle D , Stojadinovic P , Cihak R , Krebsova A , Kautzner J
Published: November 2023

Introduction

Arrhythmogenic cardiomyopathy (ACM) is a disease characterized by fatty-fibrous remodeling of the myocardium and a high risk of ventricular tachycardia (VT). Catheter ablation is an effective method that prevents VT recurrences. Although the arrhythmogenic substrate in ACM is located dominantly in the epicardium, in some patients VT can be effectively suppressed only by endocardial ablation.

Purpose

Retrospective analysis of catheter ablation results of VT in patients with ACM and right ventricular involvement.

Methods

Between 2001-2021, catheter ablation of VT was performed in 51 patients (mean age 43±18 years, 9 women) with a clinical diagnosis of ACM and right ventricular involvement. Pathogenic/likely pathogenic mutation was detected during the genetic testing in 80% of patients. Repeated ablation procedures were necessary to suppress VT (a total of 1.9±1.3 procedures/patient). According to the approach, patients were divided into three groups: A - endocardial ablation only (n=20); B - endocardial ablation first, followed by epicardial approach (n=15); C- primary epicardial approach (n=16).

Results

The primary epicardial approach (group C) compared to the endocardial approach (group A+B) was associated with better VT free survival (Figure 1, p<0.02) and significantly fewer procedures needed to suppress arrhythmia recurrences (1.1±0.2 vs 2.3±1.5 procedures/patient; p<0.005). Patients in whom an endocardial approach (group A) was sufficient to control arrhythmias were significantly older than patients in whom an epicardial approach (group B) had to be used (52.9±15.1 vs 36.0±16.0 years; p<0.001). The frequency of pathogenic mutations did not differ among groups (A - 83% vs B - 71% vs C - 86%; p=n.s.). The most commonly found mutation was in the gene for plakophilin 2 (51% of all patients).

Conclusion

Epicardial VT ablation in ACM patients with right ventricular involvement leads to the most effective control of arrhythmias. Endocardial ablation alone may be sufficient to control VT in older patients. The identification of a pathogenic/likely pathogenic mutation does not seem to be relevant for choice of ablation approach.Figure 1
The benefit of a double ventricular extra stimuli protocol to improve functional substrate mapping during ablation of ventricular tachycardia. - The S3-VT-FREE project
Authors: Regany M , Guichard J B , Vazquez S , Pellicer B , Serrano J , Roca I
Published: November 2023

Introduction

Ablation of ventricular tachycardia (VT) based on substrate-based mapping has been proposed to itemize areas of interest identifying areas of low-voltage, late potentials (LPs), and deceleration zones (DZs). However, partial delineation of targets for ablation is likely responsible for a suboptimal long-term success rate.

The abnormal electrograms (EGMs), featuring low-voltage near-field components may be hidden within the high-amplitude far-field signal. We hypothesized that the acquisition of functional mapping after double ventricular extrastimuli (S3 protocol) would uncover relevant areas of functional substrate that could be missed during sinus or S1 map.

We aim to evaluate the potential benefit and the feasibility of functional substrate mapping using an S3 protocol for VT ablation and to assess its colocalization with detected corridors using late gadolinium enhancement magnetic resonance imaging (LGE-MRI).

Methods

We included consecutively 29 patients with structural cardiomypathy who underwent a VT ablation. The S3 protocol included: (1) assessment of the ventricular effective refractory period (ERP), (2) pacing protocol from the apex of the right ventricle with S1 x 6 (cycle length: 600ms) followed by S2 (ERP+30ms) and S3 (ERP+50ms). Electroanatomical mapping was acquired with the EnsiteX system (Abbott, IL) using HD Grid catheter and omnipolar signals. ILAMs were used to identify deceleration zones and areas of late potentials were identified for all maps. A non-invasive substrate assessment was done with LGE-MRI and post-processing with a commercially available system (ADAS3D, Spain) with automated identification of corridors.

Results

The S3 protocol was completed in 25 of the 29 procedures (86.2%). The repeated induction of ventricular arrhythmias did not allow for full protocol of the S3 protocol in 4 patients (13.8%).

The functional substrate identified during the S3 activation mapping was significantly more extensive than the one identified using S1 and S2 activation mappings (p<0.05) (Table). The S3 protocol unmasked a higher number of DZs (p<0.01), a wider area of LPs (p<0.01), and a longer duration of the DZs (p=0.01).

All DZ maps were compared with preprocedural cardiac magnetic resonance. The number of DZs matching with conduction corridors identified by LGE-MRI was higher in the activation mapping of S3 compared with the S1 and S2 ones (p=0.02).

After VT ablation based on an S3 protocol, 88% of patients have been VT free during a median follow-up of 9 months.

Conclusions

This novel substrate-based protocol to assess the ventricular functional substrate is feasible in the majority of patients (86.2%) and allows for a better identification of targets for ablation and could facilitate VT ablation, and improve the prognosis of the patients after ablation.
Effect of ICD on patients with improved EF in idiopathic dilated cardiomyopathy
Authors: Dhaliwal S , Al-Sadawi M , Aslam F , Kim P , Gier C , Henriques M , Tao M
Published: November 2023

Background

The efficacy of implantable cardioverter defibrillator (ICD) therapy in patients who had heart failure with improved ejection fraction (HFimpEF) above guidelines indication for ICD (>35%) during generator change is still controversial. This meta-analysis assesses the impact of ICD therapy in patients with HFimpEF with EF >35% and patient with NICM.

Methods

Databases were searched for studies reporting the association between ICD in patients with NICM and HFimpEF and ventricular arrhythmias (VA) and sudden cardiac death (SCD); including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year.

Results

A total of 38 studies and 13,538 patients (5,829 with improved EF vs 7,709 with EF <35% during follow up) were included; mean follow up was 43 months (ranging between 12 to 74 months). Mean age was 63.5 and 75% were males. Patients with HFimpEF with ICD, wither alone or as part of CRT therapy, was associated with lower risk of VA and SCD (OR 0.39, 95% CI 0.32-0.47; P<0.01; annual rate 4.1 vs. 8%). Sub-analysis for patients with ICD for patient with NICM was associated with lower risk of VA and SCD (OR 0.25, 95% CI 0.1-0.62; P<0.01; annual rate 2.9 vs. 10.2%). (Figure)

Conclusion

Improved EF is associated with reduced VA but with still elevated risk in HFimpEF especially in NICM.