Fima Macheret, MD, MS

📣Quantitative CT Lead Localization Reveals Proximal Left Bundle Targeting Facilitates Superior Physiologic Pacing — @shunmug_his_mdu @pvijayaraman1 @KennethEllenbog1 #HRX2026 LBCT | Simultaneously published in @hrs_journal ⭐️The Lead to His (LH) and Lead to Endocardium (LE) distances have previosuly been shown to be predictive of ideal CSP. ⭐️ In this single-center study of 186 consecutive CSP patients, 145 had interpretable post-implant CT. A quantitative CT workflow (CARA) classified leads using lead-to-His distance (LH) and lead-to-endocardium distance (LE). ➡️CT classified 68 leads as proximal (LH ≤25 mm), 70 distal (LH >25 mm), and 7 LVSP ➡️In the primary analysis, near-native paced activation was significantly more frequent with proximal vs distal pacing: 62% vs 27% (OR 4.14, P=0.021; adjusted OR 5.35, P=0.013) ➡️The ROC-derived optimal LH cutoff was 24.9 mm, close to the prespecified 25-mm anatomic threshold ➡️Importantly, he procedural LBBP label did not predict proximal vs distal lead position, and neither did the surface ECG (AUC 0.48). 🤔Not all confirmed LBB capture may be physiologically equivalent—the site of capture along the conduction axis matters, and our usual electrical criteria cannot tell us where the lead actually sits. 🎯Proximal LBB targeting (≤25 mm from the His) was associated with substantially greater odds of near-native ventricular activation. Quantitative anatomic localization may add an important new dimension to how we think about—and ultimately target—CSP. heartrhythmjournal.com/artic…

In this systematic review in @hrs_journal , Parlavecchio et al. screened 2,177 articles and identified 67 reports encompassing 77 individual cases of rare LBBAP complications, organizing them into 5 clinically relevant phenotypes. #EPeeps ➡️Septal injury • Interventricular septal hematoma • Partial lead protrusion/ delayed septal perforation • LV thrombus/systemic embolism • Tamponade/hemothorax • Iatrogenic VSD ➡️ Vascular injury • Septal venous channel perforation/dissection • Coronary venous/ arterial fistula • Septal arterial injury • Extrinsic coronary compression • Intraluminal LAD lead placement ➡️Valvular/subvalvular injury • Tricuspid chordal entanglement • Papillary muscle perforation • Mitral chordal injury/rupture and MR ➡️Mechanical/lead-related complications • Lead-to-lead interaction/abrasion • Mechanical oversensing • Helix entrapment, deformation or fracture • Retained helix fragments • Lead/catheter entrapment ➡️Electrophysiological complications • Purkinje-related PVCs, VT/VF & bundle branch re-entry • T-wave and far-field P-wave oversensing • Pacing-induced cardiomyopathy • Loss of capture • Takotsubo syndrome *⃣Practical Takeaways: ➡️ Watch for new chest pain, ST-T changes, arrhythmias, unexpected contrast runoff, changes in QRS morphology or pacing parameters. ➡️ Normal device parameters do not exclude structural injury. ➡️ When suspicion exists, multimodality imaging matters—echocardiography, fluoroscopy, coronary angiography, cardiac CT. ➡️ Management should be phenotype-driven, ranging from observation and serial imaging to lead repositioning/extraction, anticoagulation, coronary intervention, catheter ablation or surgery. tinyurl.com/5d2t62w8