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Welcome to EP Edge Journal Watch, where cardiac electrophysiology meets evidence, precision, and perspective.
Hosted by Dr. Niraj Sharma, this weekly podcast distills high-impact cardiovascular and Cardiac Electrophysiology and arrhythmia research into clear, clinically meaningful insights. Each episode goes beyond headlines and abstracts to uncover what new studies actually mean for patient care, decision-making, and the future of electrophysiology.
What EP Edge Journal Watch stands for:
Evidence-based practice
Precision electrophysiology, arrhythmias analysis
A forward-thinking, edge-driven approach to how we interpret and apply data in real-world clinical settings.
Whether you’re an electrophysiologist, cardiologist, researcher, trainee, or allied health professional, EP Edge Journal Watch brings you the signal not the noise. Expect sharp summaries, thoughtful commentary, and practical takeaways designed for the busy clinician who wants to stay ahead of the curve
This program is for educational purposes only and reflects independent editorial commentary. It is not medical advice and should not replace clinical judgment or review of primary sources and guidelines. The views expressed are those of the host and contributors.
Niraj Sharma:Hello and welcome to epedge Journal Watch. This is Doctor. Sharma. Thank you for joining us for Issue 43, November 2026. Ventricular arrhythmia care often starts with an urgent electrical problem, but the important decisions continue long after the procedure.
Niraj Sharma:Substrate may remain, the diagnosis may evolve, and the implanted system may impose a burden of its own. Infection can then change the meaning of successful long term device therapy. That is the thread connecting our four featured papers: Clear VT, with its companion device analysis Long term idiopathic ventricular fibrillation His Alternative Pacing, and the American Heart Association Endocarditis Statement. We'll examine the evidence that determines durability, then briefly cover the remaining six articles. The objective is to identify what should influence current electrophysiology practice and what still requires prospective confirmation.
Niraj Sharma:Dasa et al. Report Early U. S. Experience with catheter ablation of ventricular arrhythmias with a dual energy lattice tip catheter: Insights from the Clear VT Registry. In JACC, Clinical Electrophysiology, August 2026.
Niraj Sharma:Fifty nine of three twenty seven consecutive ventricular ablation patients at one center received the dual energy catheter, fifty for scar related ventricular tachycardia and nine for premature ventricular complexes. Among the tachycardia patients, forty percent presented with electrical storm, thirty percent had previous failed ablation and mean ejection fraction was thirty five point seven percent. This was selected experience in difficult substrate, not an all comer comparative trial. Radiofrequency was generally delivered first, with pulsed field energy concentrated in dense scar. Forty one of 50 tachycardia procedures used both.
Niraj Sharma:Any efficacy claim therefore concerns a combined strategy and catheter platform. It cannot isolate the incremental contribution of pulsed field energy. Complete non inducibility was achieved in thirty nine of fifty patients. The acute definition excluded specified very fast non clinical tachycardias. All nine targeted premature ventricular complexes were suppressed acutely, but median total ectopic burden later fell from twenty point four to three point five percent, rather than to zero.
Niraj Sharma:Elimination of the targeted morphology and elimination of all ectopy are different endpoints. Nine tachycardia patients recurred over median follow-up of one hundred days. Six month estimated freedom from tachycardia was sixty nine point eight percent, with a confidence interval from fifty four to ninety point three percent. Competing risk cumulative recurrence was twenty eight point four percent, with an interval from eleven to forty five point eight percent. Four patients died, one underwent transplantation and one received a ventricular assist device.
Niraj Sharma:These competing events and unequal follow-up explain why a crude recurrence proportion shouldn't substitute for the longitudinal analysis. The clear VT safety observations deserve equal attention. Three major complications included two bleeding events and irreversible generator failure after pulsed field delivery approximately 7.5 millimeters from a left ventricular lead electrode. Radiofrequency steam pops occurred in eight cases without reported clinical sequelae. In eight non ischemic septal cases, abnormal signals persisted on the opposite septal surface and required additional ablation.
Niraj Sharma:Valve entrapment was another reported procedural hazard. Nakamura and Tandri's editorial emphasizes that acute electrogram silence doesn't establish a durable transmural lesion that caution matters in intramural ventricular tachycardia, where local electrical suppression can precede adequate treatment of the full substrate. Antiarrhythmics were stopped after complete noninducibility, but could continue temporarily with residual inducibility, further complicating attribution of follow-up outcomes. Mahmoudi et al. Extend the hardware question in effects of dual energy lattice tip catheter ablation of ventricular arrhythmias on cardiac implantable electronic device performance.
Niraj Sharma:This 2026 online clinical electrophysiology report was accepted in August. Sixty five patients underwent interrogation before treatment, within seven days afterward and around three months. Forty four overlapped with the preceding fifty nine patient report. Fifty three received both energies, six radiofrequency alone and six pulsed field alone. At three months, right ventricular sensing decreased from 11.7 to 10 millivolts, pacing impedance from four forty one to four twenty two ohms, and capture threshold increased from 0.9 to one volt.
Niraj Sharma:Left ventricular threshold rose from one to 1.4 volts, with a p value of 0.08. Four leads had persistent increases greater than one volt and one patient required reprogramming. No lead revision was needed because of longitudinal parameter changes. However, the acute generator failure was the same event reported in clear VT, with generator replacement and left ventricular lead revision. It must remain visible without being counted as a second independent failure.
Niraj Sharma:Available pair analysis produced different denominators. Home correction covered two time comparisons within each parameter Three months cannot establish battery longevity or late lead durability. The epedge take: These reports support feasibility while identifying hazards that must shape implementation. Mixed energy, selected patients, and short surveillance prevent claims superiority or established hardware safety. The 7.5 millimeters event isn't a safe distance boundary.
Niraj Sharma:Baseline and post procedure interrogation, longitudinal reassessment, and contingency plans for pacing and defibrillation belong in the workflow. Comparative studies need durable arrhythmia outcomes alongside systematic device, coronary and procedural safety assessment. Our next paper by Heisegair et al. Reports Long term outcome following idiopathic ventricular fibrillation and potential emerging etiologies. Paper currently online, only in JACC, clinical electrophysiology report is a 2026 pre proof accepted in September.
Niraj Sharma:46 tertiary centers contributed eight twenty five patients aged fifteen-sixty at the index event, all with defibrillators and at least five years of follow-up. Median follow-up was ten years. The purpose was to describe recurrence, emerging etiologies, and treatment experience experience after an initially idiopathic arrest. Arrhythmia recurrence occurred in fifty two point seven percent. Estimated event free proportions were eighty one, seventy one, sixty five, and fifty seven percent at one, three, five, and ten years.
Niraj Sharma:A substantial interval without recurrence therefore didn't close the arrhythmic story. Twenty seven patients died, ten from cardiac causes. These mortality observations are conditioned on selection of patients who survived and remained observable for at least five years. They cannot be presented as mortality beginning at the original arrest in an unselected idiopathic ventricular fibrillation population. That distinction materially changes how reassuring the mortality results should sound.
Niraj Sharma:A proposed etiology emerged in five sixty eight patients (68.8 percent ). Seventy three had recognized inherited conditions, two seventy two focal sources, and two twenty three definite or probable microstructural abnormalities. Thirty seven developed overt cardiomyopathy. The categories don't all have the same evidentiary status. Definite microstructural diagnoses used mapping, later cardiomyopathy or pathogenic variants.
Niraj Sharma:One hundred and seven of the microstructural cases were classified as probable using device based arrhythmia criteria that require external validation. The reported diagnostic yield therefore includes candidate mechanisms, not exclusively established diseases. Diagnostic workup also varied by center and era. Only seventy five percent underwent magnetic resonance imaging and sixty three point one percent sodium channel blocker testing. Later reclassification can reflect new disease expression, more informative recordings, or a more complete evaluation.
Niraj Sharma:The study cannot assign every diagnostic change to a single biological process. The idiopathic ventricular fibrillation cohort also illustrates a form of ascertainment bias. Recurrence often supplied the recordings or mapping findings needed to assign a mechanism. A subgroup defined using that subsequent information can't then be interpreted as an unbiased baseline predictor of recurrence. Treatment findings were informative but non randomized.
Niraj Sharma:Among selected focal fibrillation patients receiving quinidine, sixty eight point three percent had no recurrence under the study definition. Beta blocker treatment was associated with no recurrence in forty nine point three percent of selected microstructural cases. Ablation was performed in one hundred and eighty one patients, with no reported recurrence in seventy five point seven percent. These percentages aren't competing treatment effects. The patients' indications, mechanisms, and accompanying interventions differed.
Niraj Sharma:Drug dose and adherence, exercise restrictions, and ablation co interventions weren't standardized. Mapping was concentrated in those with recurrent events and genetic variants weren't uniformly reinterpreted. Even a large multicenter cohort cannot recover the causal protection that randomized assignment would provide. The epedge take retain a longitudinal diagnostic approach. Recurrent device recording should trigger a review of the initiating beat and the broader phenotype, alongside reassessment of imaging, family history, and genetic interpretation where appropriate.
Niraj Sharma:The focal versus microstructural framework is useful for organizing questions, particularly when the initial workup leaves no established substrate. Its probable branch still needs independent validation before it becomes a routine classification system. Likewise, the apparent differences with quinidine, beta blockers, and ablation should inform specialist reasoning and prospective trials, not a treatment algorithm inferred from unlike groups. The ablation experience doesn't establish that defibrillator protection can be withdrawn. The important continuity with CLEAR VT is that a favorable interval or acute endpoint doesn't exhaust the clinical question.
Niraj Sharma:Here, follow-up can change the explanation for the arrhythmia itself. A prospective strategy study would need uniform baseline testing, reproducible mechanistic classification, and treatment comparisons defined before outcomes occur, with recurrent burden and patient important endpoints assessed over time. Left bundle area pacing is progressing at a rapid pace. Our next trial comes at this important juncture. Fransen and colleagues report his pacing versus biventricular pacing for cardiac resynchronization therapy, long term follow-up from the His Alternative I trial in JAK clinical electrophysiology August 2026.
Niraj Sharma:Fifty patients with symptomatic heart failure, ejection fraction no greater than 35%, sinus rhythm and strict left bundle branch block were randomized equally. Seven crossed from His to biventricular pacing at implantation and one crossed in the opposite direction. The principal long term analyses were therefore as treated with 19 His and 31 biventricular recipients. Reinterventions were also assessed by intention to treat. Median follow-up was five point three years.
Niraj Sharma:Lead revision affected seven of nineteen. His patients versus one of thirty one biventricular patients, thirty seven versus three percent with a p value of point zero zero three. Generator replacement affected nine versus three, forty seven versus ten percent with a p value of 0.005. Any reintervention occurred in fifty eight versus ten percent as treated. The intention to treat comparison was forty eight versus eight percent with a p value of 0.004.
Niraj Sharma:The persistence of this signal under randomized assignment makes it harder to dismiss as merely a consequence of the implantation crossovers. Thresholds appeared important. A post hoc split at the median implantation threshold separated nine, his patients at or below 2.5 volts at one ms from 10 with higher thresholds. Two of nine in the lower threshold group required reintervention compared with nine of 10 in the higher threshold group. The threshold distinction is clinically plausible, but it wasn't a randomized implantation strategy or a pre specified validated cutoff.
Niraj Sharma:Death or heart failure hospitalization occurred in two versus nine patients. The hazard ratio was 0.32 with a confidence interval from 0.07 to 1.49 and a p value of 0.147. That interval permits substantial benefit and meaningful harm. It doesn't establish clinical superiority, equivalence, or non inferiority. Blinded follow-up echocardiography in his alternative one was available in thirty eight patients.
Niraj Sharma:Volumetric response was eighty nine versus ninety percent, but that is a comparison among those with follow-up imaging. Survivor selection and later treatment changes limit what it says about the originally assigned strategies. Several patients initially receiving his pacing subsequently underwent biventricular or left bundle branch area pacing. Background heart failure therapy also differed. Beta blocker use was seventy four versus ninety four percent, and mineralocorticoid receptor antagonist use forty seven versus eighty one percent.
Niraj Sharma:With such small as treated groups, adjustment cannot fully repair treatment imbalance or recover the original randomized comparison for clinical outcomes. Older implantation practice accepted thresholds up to five volts at one millisecond. That limits direct transfer to contemporary practice, but it doesn't make the high threshold experience irrelevant. Battery demand and capture stability are part of the intervention's long term performance, and the favorable nine patient subgroup is too small to establish equal durability with biventricular pacing. Kano's editorial stresses implantation quality and maintaining expertise across resynchronization approaches.
Niraj Sharma:It describes the 19 versus 31 analysis as per protocol, whereas the primary report identifies it as as treated. Those aren't interchangeable labels when interpreting the protection afforded by randomization. The epedge take: successful correction of activation must be assessed alongside reliable capture and the likelihood of another hardware procedure. A low stable correction threshold is desirable, but this study doesn't validate a universal threshold rule or prove his pacing superior. When capture requirements are unfavorable, alternative strategies deserve consideration rather than acceptance of an electrical endpoint at any cost.
Niraj Sharma:The separate question of contemporary left bundle branch area pacing versus biventricular resynchronization wasn't tested here. Future trials should preserve randomized comparisons and report lead procedures, generator longevity, heart failure outcomes, and longitudinal capture together. Repeated hardware procedures also make infection part of the durability discussion. Our final featured paper is Desimone et al. Infective Endocarditis: Diagnosis, Antibiotic Therapy, and Management, a scientific statement from the American Heart Association published in Circulation in October 2026.
Niraj Sharma:A 12 member multidisciplinary group reviewed literature through a June 2025 search with relevant subsequent evidence. This is an expert scientific statement, not a new trial or a uniformly graded guideline. The authors sought consensus but identified areas where agreement wasn't reached. That transparency matters when turning a broad document into an electrophysiology pathway. The diagnostic framework incorporates the 2023 Duke criteria from the International Society for Cardiovascular Infectious Diseases.
Niraj Sharma:Transthoracic echocardiography remains first line, but transesophageal imaging is particularly important with prosthetic valves, implanted devices, or persistent clinical suspicion. A negative or inconclusive initial examination may require repeat imaging within a week. Computed tomography adds information about perivascular extension. Fluorodeoxyglucose, positron emission tomography with computed tomography is particularly useful in suspected prosthetic valve infection and extracardiac source. Its sensitivity is lower for lead infection than for pocket infection, so a negative examination cannot be used indiscriminately to exclude device involvement.
Niraj Sharma:For the electrophysiologist, the consequential issue is source control. The statement favors complete system extraction for established device endocarditis and prefers extraction in valvular endocarditis even without visible lead vegetation or pocket findings. Absence of a demonstrable mass isn't equivalent to demonstrating that retained hardware is uninvolved. These decisions require early coordination with infectious diseases, imaging, extraction specialists, and cardiac surgery. Surgery remains important when indicated for heart failure, uncontrolled infection or embolic risk.
Niraj Sharma:Neurological complications alter timing and require individualized, multidisciplinary assessment. The statement's value is a coherent diagnostic and treatment process, while the strength of evidence varies across its specific suggestions. Antimicrobial treatment begins with intravenous antibiotics directed at the identified organism. The question is whether selected patients can safely complete treatment orally once the infection has stabilized. The POET trial, partial oral treatment of endocarditis, randomized four hundred stable adults with left sided endocarditis, two zero one switched to oral antibiotics, and one hundred and ninety nine continued intravenous treatment.
Niraj Sharma:Eligible infections were caused by Streptococcus, Enterococcus faecalis, or susceptible Staphylococcus. Methicillin resistant Staphylococcus aureus was excluded. The oral strategy used two active antibiotics selected according to organism susceptibility. The statement's POET based criteria include at least ten days of appropriate intravenous treatment and at least seven days after valve surgery, where applicable. Patients needed clinical improvement, resolution of fever, improving inflammatory markers, and transesophageal imaging without infection progression, abscess, or a new surgical indication.
Niraj Sharma:The primary endpoint combined death, unplanned cardiac surgery, embolic events and relapse of bacteremia through six months after antibiotic treatment ended. It occurred in eighteen oral treatment patients (nine percent ) versus twenty four intravenous treatment patients (12.1 percent ). The absolute difference was 3.1 percentage points favoring oral treatment, with a 95% confidence interval from -3.4 to 9.6 percentage points. The trial met its pre specified non inferiority criterion. That means the data excluded an unacceptable loss of effectiveness according to the trial's predefined margin.
Niraj Sharma:It doesn't establish that oral treatment was superior. Selection matters. The statement notes that approximately eighty percent of screened patients didn't meet enrollment criteria. The evidence supports oral continuation after stabilization, with susceptible organisms, reliable absorption and adherence, and organized follow-up. It doesn't address starting treatment orally during uncontrolled infection.
Niraj Sharma:Cleared blood cultures, drug interactions, and recent transesophageal imaging remain central to the transition. The statement's discussion of the European pathway uses a different postoperative interval from its POET based table, so those criteria shouldn't be blended. The writing group also didn't reach consensus on oral monotherapy versus two active agents. POET tested combination therapy. For staphylococcal prosthetic valve endocarditis, the group agreed that gentamicin's risks outweigh potential benefits.
Niraj Sharma:It didn't reach consensus on adjunctive rifampin. The cited small meta analysis had wide confidence intervals for clinical failure, which don't establish equivalent outcomes with and without these drugs. Toxicity and interactions also inform the judgment. Mechanical aspiration and long acting antibiotics have potential roles in selected cases, but their evidence is less mature. Suppressive antimicrobial therapy isn't a substitute for feasible, definitive source control.
Niraj Sharma:Observational associations between extraction, surgery, multidisciplinary care, and survival remain vulnerable to differences in which patients receive those interventions. The epedge take: Establish the source control plan early and don't let a negative lead image settle a question that still depends on microbiology and clinical probability. Oral continuation can be appropriate when the patient meets a defined stabilization pathway, and the regimen and follow-up are reliable. The statement's practical contribution is coordination across infectious diseases, imaging, electrophysiology and surgery, while preserving uncertainty where evidence or consensus remains incomplete. The remaining studies add useful context without supporting the same breadth of inference.
Niraj Sharma:Reyes reported focal pulse field ablation in 10 men with refractory ventricular tachycardia. All nine formally tested patients were non inducible, but four experienced sustained recurrence during unequal follow-up, including one late event. Zero reported procedural complications in 10 patients cannot establish uncommon event safety, and one patient also underwent alcohol septal ablation. The epedge take is feasibility with an important durability question requiring platform specific prospective assessment. Martini studied ring like enhancement in one hundred and forty nine patients with left dominant or biventricular arrhythmogenic cardiomyopathy.
Niraj Sharma:24 arrhythmic endpoints supported an adjusted hazard ratio of 2.47 for the ring pattern, with an interval from 1.10 to 6.02. Better model fit didn't establish dependable individual prediction or a treatment threshold. The epedge take is to integrate scar distribution with genotype, non sustained tachycardia and clinical history rather than implant solely because of one imaging feature. Millman's START Brugada registry analyzed two thirty four spontaneous arrhythmia episodes in one hundred and fifty one patients with usable onset recordings. Monomorphic episodes differed in several initiation characteristics, but raw coupling intervals weren't significantly different, and the cohort was selected for documented events.
Niraj Sharma:Repeated episodes were handled with clustered analysis, while multiple exploratory comparisons and uncertain quinidine adherence remain limitations. The epedge take is to preserve onset recordings for mechanistic assessment without turning retrospective patterns into prophylactic ablation selection rules. Volio's retrospective pacing cohort found later ventricular dysfunction in forty six of one hundred and eleven patients under a broad definition. Larger baseline left atrial size was associated with lower follow-up ejection fraction and FF admission. Selection for repeat imaging, confounding, and models incorporating follow-up information limit pre implant prediction.
Niraj Sharma:The epedge take is to assess vulnerability beyond ejection fraction, without adopting an unvalidated atrial size cutoff for resynchronization or conduction system pacing. Alhacock's Danish registry included eighty four thousand one hundred and seventy one device recipients. Ten year endocarditis incidents ranged from one percent with conventional pacemakers to two point two percent with resynchronization defibrillators, with substantial competing mortality. Registry coding and residual confounding prevent attribution to device complexity alone, and no preventive intervention was tested. The epedge take is vigilance and prompt investigation of suspicious bacteremia.
Niraj Sharma:Hughes' American College of Cardiology nutrition favors sustainable dietary patterns, appropriate sodium reduction, and attention to food access. It distinguishes feasible substitutions and risk factor effects from proof of reduced arrhythmia events. A food access trial's modest blood pressure improvement isn't an atrial fibrillation outcome kidney function, potassium retaining therapies, and preservation of nutrition and muscle during weight loss require individualization. The epedge take is practical cardiovascular prevention within electrophysiology care, without substituting supplements or dietary claims for established treatment. The featured papers leave us with four connected priorities.
Niraj Sharma:Clear VT and its companion analysis require us to assess the ventricular substrate and implanted system together, without double counting overlapping patients. Hisagare supports continued diagnostic reassessment after apparently idiopathic ventricular fibrillation while keeping probable mechanisms separate from established disease. His alternative one makes reintervention burden part of the resynchronization outcome. The endocarditis statement makes early source control and coordinated follow-up part of preserving a durable clinical result. Across these studies, follow-up is more than confirmation that the initial procedure worked.
Niraj Sharma:It can expose residual substrate, revise a diagnosis, reveal a hardware problem, or change whether an implanted system should remain. Comparative evidence should measure those consequences alongside acute electrical success. Before we close, an announcement for our Spanish speaking colleagues, epedge, Journal Watch and Espanol will be launching this month, November 2026. We look forward to welcoming you and extending these conversations about electrophysiology research and clinical practice to our Spanish speaking audience. The full newsletter, integrated editorials and references are available on LinkedIn and at epedge.substack.com.
Niraj Sharma:Questions, suggestions or concerns can be emailed to epedgeCast@gmail.com. Thank you for listening and for sharing EP EDGE with colleagues. This is Doctor. Sharma.
Niraj Sharma:Until next time, take care and bye for now.