Heart Rhythm December 2023/Dr.Chen

Hello, this is Dr. Peng Shen Chen, the Editor-in-Chief of Heart Rhythm. Because I'm completing my 10-year term as the Editor-in-Chief, this will be my final podcast for the journal.

The December 2023 issue is a focus issue on devices. The first article is titled Result of the Physiological Pacing Registry, an International Multicenter Prospective Observational Study. of conduction system pacing. The International Prospective Observational Registry included 44 sites from 16 countries globally between November 2018 and May 2021.

A total of 870 subjects were enrolled. This multi-center study demonstrates that the conduction system pacing is technically feasible in most patients with relatively high implant success and suggests that with current technology the left bundle branch area pacing may have better pacing parameters than the his bundle pacing. The next one is left bundle branch area pacing reduces epicardial dispersion of repolarization compared to biventricular cardiac resynchronization therapy.

The purpose of the study was to compare the effects of temporary biv-epi, biv-indo, and left bundle branch area pacing. on epicardial left ventricular vaporization using electrocardiographic imaging or ECGI. The authors found that a temporary LBBAP reduces epicardial dispersion or repolization compared with conventional 5V epicardial pacing. Up next,

is long-term outcomes of abandoned leads of cardiac implantable electronic devices. This retrospective cohort study revealed a single-center CIED registry. 2,962 procedures performed from 1984 to 2018 and identified 130 patients with abandoned leads. The authors found that patients with a single abandoned lead showed similar risks of CIED-related infections, venous thrombosis stenosis, and all-cause mortality.

as those without abandoned leads. In contrast, those with multiple abandoned leads showed increased risk of infection and all-cause mortality. Coming up is acute human defibrillation performance of a subcutaneous implantable cardioverter defibrillator with an additional coil electrode. The purpose of this study was to accurately assess the defibrillation efficacy of parallel and transverse configurations in patients receiving the subcutaneous ICD. The study enrolled 35 patients.

Compared to the conventional subcutaneous ICD system, mean shock impedance decreased for both parallel and transverse configurations. The authors conclude that adding a second shock coil particularly in the parallel configuration, significantly reduced impedance and had a higher likelihood of defibrillation success at energies less than or equal to 40 joules. This may enable the development of a smaller subcutaneous ICD. The next article is ECG characteristics of true left-bounded branch block.

Insights from Transcaster, Aiotic Valve-related LBBB and His Bundle Conduction System Pacing Correctable LBBB. The purpose of this study was to characterize electrocardiographic morphological features of left-bundle branch block patterns in patients with one left-bundle branch block after transcaster aortic valve replacement of TAVR. And number two, let boundary branch block correctable by conduction system pacing. The Strauss criteria is,

QRS duration greater than equal to 140 milliseconds for men or 130 milliseconds for women. QS or RS complex in these V1 and V2 and the mid-QRS notching or slurring of greater than or equal to 2 of the following leads, V1, V2, V5, V6, lead 1, and AVL. The authors found that Strauss criteria and the QRS notching are highly prevalent in LBBB after TAVR and LBBB correctable by conduction system pacing.

Up next is safety of same-day discharge after lead extraction procedures. In this analysis of 111 patients who underwent elective transvenous lead extraction, 80 patients of 72% were discharged on the same day. This is the same day discharge group. While 31 patients of 28% stayed overnight. And this is the overnight group.

No major complications were reported in either group. Patients who underwent a procedure using advanced extraction techniques were 3.5 times more likely to stay overnight. The authors conclude. that in selected patients. Same day discharge is feasible and safe. Higher body mass index fewer extracted leads shorter lead dwell time less than 10 years and the less frequent use of laser-powered extraction sheath were associated with an increased likelihood of same-day discharge.

Coming up is chlorhexidine gluconate pocket lavage to prevent cardiac implantable electronic device infection in high-risk procedures. Patients from a prospective multi-center registry undergoing high-risk procedures were included. Clohexidine gluconate, or CHG lavage, was performed by irrigating. the generator pocket with 20 cc of 2% CHG without alcohol followed by normal saline irrigation. Only normal setting irrigation was performed in the comparison group.

The authors found that CHG lavage during high-risk procedure was associated with a reduction of CIED-related infections without any adverse events reported. The benefits of CHG lavage was observed even during long-term follow-up and in propensity score analysis. The final article of the focus issue is association between nighttime heart rate and cardiovascular mortality in patients with implantable cardioverter defibrillator, a cohort study.

A total of 534 ICD recipients with sinus rhythm were included in this study. The mean baseline nighttime heart rate was 59 beats a minute. During the follow-up periods of 16 months, 88 patients experienced cardiovascular mortality. Each one beat per minute increase in nighttime heart rate was associated with 7.8%. 10.1%, and 5.7% increase in the risk of cardiovascular mortality in the total population, patients with heart failure and the patients without heart failure, respectively.

The authors conclude that continuous monitoring of nighttime heart rate may identify patients at high risk of cardiovascular mortality. In addition to the device-focused articles,

We also have the following regular articles. The first one is titled Atrial ventricular node ablation is an effective management strategy for atrial fibrillation in patients with hypertrophic cardiomyopathy. The authors performed a multicenter study with retrospective analysis of a prospectively collated HCM registry. 59 patients with head AV node ablation. During post-AVN ablation follow-up of 80 months, left ventricular ejection fraction remained stable.

49 patients, or 83.1%, reported an improvement in symptoms. The authors conclude that AV node ablation improved the symptoms without impacting left ventricular function. in a majority of patients. The data suggests that AV node ablation is an effective and safe management approach for atrial fibrillation. in hypertrophic cardiomyopathy and should be further evaluated in larger prospective studies.

The next one is sinus rhythm QRS morphology reflects right ventricular activation and anatomical ventricular tachycardia isthmus conduction in repaired tetralogy overload. The patient with repaired TOF and complete right bundle branch block referred for transcaster pulmonary valve replacement.

or presenting with sustained VT underwent comprehensive three-dimensional mapping in sinus rhythm. Patients with isthmus block between the pulmonary annulus and the ventricular septal defect patch and between the ventricular septal defect patch and the tricuspid annulus, were more likely to demonstrate lower amplitude R' waves and QRS fragmentation in lead V1. and terminal S waves indeed AVF than those without intact conduction. These findings provide a mechanistic link between RV activation

and common electrocardiographic findings. Up next is the association of epicardial and intramylocardial fat with ventricular arrhythmia. Patients enrolled in the PROS-ICD registry who underwent contrast-enhanced computed tomography were included. The authors found that in ischemic cardiomyopathy patients, Increased fat distribution heterogeneity is associated with ventricular arrhythmia in non-ischemic cardiomyoparcipations and increased volume of intramyocardial fat.

and epicardial adipose tissue is associated with a higher risk for ventricular arrhythmia. These findings suggest that the fat distribution to ventricular arrhythmia depends on underlying substrate. Coming up is cryothermal energy demonstrates shorter ablation time and lower complication rates compared with radiofrequency.

in surgical hybrid ablation for recurrent ventricular tachycardia. Between 2009 and 2022, 43 patients underwent either a cryothermal or radiofrequency hybrid epicardial ablation procedure with direct surgical access. The ablation time was significantly shorter in those undergoing cryothermal ablation versus radiofrequency ablation. There were no complications in the cryothermal ablation group compared with six patients.

with complications in the radio frequency group. Recurrent VT episodes and all-cause mortality were similar in both groups. The authors conclude that hybrid surgical VT ablation with cryothermal or radiofrequency energy demonstrated similar efficacy outcomes. Qualothermal ablation was more efficient and safer than radiofrequency in a surgical setting and should be considered when surgical access is required.

The next one is diagnostic pitfalls in patients referred for arrhythmogenic right ventricular cardiomyopathy. The authors studied 726 patients with previously diagnosed or suspected ARVC. Among them, ARVC was ruled out in 365, or 50.3%. On the basis of outside evaluation, 23.8% of these patients had received ICDs and device extraction was recommended in 9% after re-evaluation.

An additional 5.5% had received ICD recommendations or reversed on re-evaluation. The authors conclude that the false suspicion or misdiagnosis was found in most patients referred for ARVC, resulting in inappropriate ICD implantation or recommendation in 14.5%. Misdiagnosis or false suspicion was most commonly due to misinterpretation of cardiac magnetic resonance imaging.

posterior extension of early repolarization in patients with J-wave syndrome. 40 patients diagnosed with early repolarization syndrome were included. J-waves were observed. in the lateral, inferior, and posterior leads of 26, 31, and 39 patients, respectively. Body surface mapping was evaluated in nine patients, all of whom

exhibited a positive area on the posterior region. The authors conclude that the posterior J-waves are common in early riparization syndrome patients. This abnormality can be detected. using leads V7 to V9 and the body surface mapping system. The next one is pacemaker lead insertion size contribute.

to abnormalities of myocardial function and histopathology. This was a single-center retrospective study including 122 patients who underwent cardiac CT. and three patients with histological specimens available. The authors found that lead insertion site associated with regional wall motion abnormalities are common. and associated with systemic ventricular dysfunction. Histopathological alterations, including myocardial compression, fibrosis, and calcifications beneath active leads

may explain this finding. Next up is a multicenter retrospective evaluation of magnetic resonance imaging in pediatric and congenital heart disease patients. with cardiac implantable electronic devices. Across 14 institutions, 314 patients underwent 389 MRIs. There were 288 pacemakers, so 74%, and 87 ICDs, or 22%. or CIED changes occurred in 4.9% of MRI scans, which is 6.1% of all patients. Of nine occasions, so 2%,

Warmth or pain occurred. Pacing capture threshold or lead impedance changes occurred in 1.4% and 2.0% of CIEDs post-MRI. and add a follow-up. These data provide evidence that MRIs can be performed in pediatric and congenital heart disease patients with CIEDs, including non-MRI conditional CIEDs and apicardial and or abandoned leads with rare minor symptoms or CIED changes but no other complications. Next up is selective blockade.

of interleukin-6 transsignaline depresses atrial fibrillation. Interleukin-6 or IL-6 signaling is predominantly pro-inflammatory. In patients studied, the elevation of IL-6 transsignaling levels was positively associated with AF occurrence. IL-6 transsignaling activation was recapitulated in the mouse model of atrial fibrillation. In transverse aortic constriction-challenged mice, the selective blockade of IL-6 transsignaling

with SGP130FC attenuated AF inducibility. SGP130FC administration also reduced immune cell infiltration and oxidative stress in the mouse atrium. The authors conclude that IL-6 trans-signaling activation contributes to AF development, and its selective blockade may promise a novel therapeutic strategy. The above original article is followed by a contemporary review titled Restoration of Calcium Release Synchrony.

a novel target for heart failure and ventricular arrhythmia. This narrative review evaluates the role of aberrant calcium release synchrony In the pathophysiology of cardiomyopathies and ventricular arrhythmias, the potential therapeutic benefits of restoration of calcium release synchrony in heart failure and ventricular arrhythmias are also discussed.

The following two articles show two different viewpoints about castor ablation of long QT syndrome. The proponent's viewpoint is titled epicardial arrhythmogenic substrate in long QT syndrome. The authors report that RV epicardial ablation resulted in QTC shortening, similar to left cardiac sympathetic denervation procedure, but without surgical complications.

The counterpoint article is titled Epicardial Ablation in Long QT Syndrome. The authors pointed out that most patients with long QT syndrome do not need and should not receive RF ablation. until and unless more substantial and convincing evidence emerges. The issue also publishes two letters. The first one is titled Safety

of direct oral anticoagulant use in patients taking virapamil or diltiazin. The non-dihydropyridine calcium channel blockers, diltiazin and virapamil, can potentially interact with DOACs via cytochrome P450 enzymes and the P-glycoprotein substrate inhibition. These properties may increase bleeding complications in patients taking DOAC. However, the authors found no substantially significant increase in the risk of clinically relevant bleeding.

in patients who received DOAC and varapamil or deltaizan concomitantly. The second letter is feasibility and efficacy of dual cathode modality in left bundle branch pacing. The dual cathode pacing uses the tip and the ring electrode as the cathode simultaneously. The authors found that the dual cathode pacing could be a feasible and effective modality.

in left-bound branch area pacing. I hope you have enjoyed listening to my final podcast. For Heart Rhythm, I'm the Editor-in-Chief, Dr. Peng Shen Qian.