EP Learning Library
High-quality, in-depth topic pages covering core electrophysiology — mechanism, ECG clues, EP study findings, ablation targets, and key references.
19 In-Depth Topics
Each topic covers the five pillars: mechanism → ECG clues → EP study findings → ablation targets → key references.
AVNRT
Atrioventricular nodal reentrant tachycardia — the most common paroxysmal SVT. Dual AV nodal physiology, slow-fast and atypical variants, Koch's triangle anatomy, and slow pathway ablation.
AVRT & WPW Syndrome
Accessory pathway-mediated tachycardia. Orthodromic vs. antidromic AVRT, delta wave localization using the Arruda algorithm, SPERRI risk stratification, and AP ablation by location.
Fascicular VT (Belhassen)
Idiopathic left ventricular tachycardia with a verapamil-sensitive Purkinje network circuit. RBBB + left-axis morphology, P1-P2 diastolic potentials, posterior vs. anterior variants, and mapping targets.
Bundle Branch Reentry VT
Macroreentrant VT using the right and left bundle branches as circuit limbs. Associated with dilated CMP and prolonged HV interval. His-precedes-V diagnostic sign and right bundle branch ablation.
VT Mapping Principles
Systematic electroanatomic approach to scar-based ventricular tachycardia. Activation, entrainment, and substrate mapping strategies — voltage criteria, LAVA targets, critical isthmus identification, and PPI-TCL.
Conduction System Pacing
Physiological pacing via His bundle (HBP) or left bundle branch area (LBBAP). Selective vs. non-selective capture, LVAT verification, implant technique, and clinical outcomes compared to conventional RV pacing.
LBBAP vs HBP vs BiV Pacing
Head-to-head comparison of the three resynchronization strategies. QRS morphology differences, threshold stability, COMPANION/CARE-HF evidence base, upgrade strategies, and which patients benefit from each modality.
PVC-Induced Cardiomyopathy
Reversible LV dysfunction from frequent PVCs. Burden thresholds, RVOT/LVOT/aortic cusp ECG localization, risk factors for PVC-CMP, EF recovery after ablation, and distinguishing PVC-CMP from coincidental DCM.
Atrial Flutter
Typical (CTI-dependent) and atypical flutter. Counterclockwise and clockwise variants, sawtooth ECG patterns, entrainment mapping, CTI ablation with bidirectional block confirmation.
Atrial Tachycardia
Focal and macro-reentrant AT. Automaticity, triggered activity, and micro-reentry mechanisms. P-wave morphology localization (Kistler algorithm), post-AF ablation AT, and mapping strategies.
AF Ablation
Pulmonary vein isolation strategy, RF vs cryoballoon vs pulsed field ablation. Lesion sets, CLOSE protocol, landmark trials (CASTLE-AF, EAST-AFNET 4, FIRE AND ICE), redo procedures, and complications.
Outflow Tract VT
RVOT, LVOT, and aortic cusp VT. Triggered activity mechanism, ECG localization algorithms, pace mapping, activation mapping in the aortic root, coronary safety assessment, and GCV/summit approaches.
Sinus Node Dysfunction
SA node physiology, intrinsic vs extrinsic SND, sinus arrest, SA exit block, chronotropic incompetence, tachy-brady syndrome. SNRT, cSNRT, pacing indications, and mode selection.
AV Block
First, second (Mobitz I and II), and third-degree AV block. Nodal vs infra-Hisian localization, HV interval significance, 2:1 block differentiation, pacing indications, and His/LBBAP alternatives.
Brugada Syndrome
SCN5A sodium channel disease with coved ST elevation in V1-V3. Type 1 vs Type 2 patterns, provocation testing, Shanghai Score, epicardial RVOT substrate ablation, ICD indications, and quinidine therapy.
Long QT Syndrome
Genotype-phenotype correlations for LQT1-3. T-wave morphology by subtype, Schwartz score, genotype-specific triggers, beta-blocker therapy, LCSD, mexiletine for LQT3, and ICD indications.
ARVC
Arrhythmogenic right ventricular cardiomyopathy. Desmosomal mutations, fibrofatty replacement, triangle of dysplasia, epsilon waves, Task Force criteria, endo-epicardial VT ablation, and exercise restriction.
Cardiac Channelopathies
CPVT, Short QT Syndrome, and Early Repolarization Syndrome. RyR2 mutations, bidirectional VT, J-wave syndromes, Gollob score, quinidine therapy, LCSD, and molecular autopsy in sudden death.
Lead Extraction
Transvenous lead extraction indications, pre-procedural imaging, locking stylets, powered sheaths (laser, rotational, electrosurgical), femoral snare techniques, SVC tear management, and outcomes.
About This Library
Each topic page is written for cardiology fellows, practicing electrophysiologists, and advanced trainees. Content is based on peer-reviewed literature and reflects current clinical practice. These are educational resources and are not intended as clinical protocols — always apply individual clinical judgment. Full disclaimer →