Overview CRT in the non-LBBB patient When to Consider LV lead Placement in the Non-LBBB IVCD Patient ? • What is the real issue here? Jag Singh MD DPhil FHRS • Is the concern secondary to Associate Chief, Cardiology Division » patient substrate? Professor of Medicine, Harvard Medical School Massachusetts General Hospital, Boston » the LV lead strategy in this patient cohort? Deputy Editor, Journal Am Coll Cardiol: Clinical EP • Is there a role for an individualized LV lead Disclosures: Consultant: Biotronik, Boston Scientific, Impulse Dynamics, Liva Nova, Medtronic, Respicardia Inc, St. Jude Medical, theHeart.org, Research Grants : St. Jude Medical, Boston Scientific implantation approach? Conventional LV Placement Approach Levels of Electrical Dyssynchrony Anatomical Suggested optimal • locations • Postero-lateral wall Inter-atrial dyssynchrony • Lateral wall Atrio-ventricular • LV lead Suggested mechanics dyssynchrony • • Resets the electrical Inter-ventricular activation sequence dyssynchrony • Reverses free wall • RV dyssynchrony Intra-ventricular lead dyssynchrony The problem CRT Provides the Electrical Fix: • • • Inter and Intra-individual Pacing wave-fronts from the RV and • LV lead variability Intramural dyssynchrony Adjusting the A-V and V-V timings • • Auricchio et al. Am J Cardiol 1999 Singh JP and Gras D. Eur. Heart Journal 2012 Butter C et al. Circulation 2001 Truong QA, Hoffman U and Singh JP; Critical Pathways in Cardiology 2008 • 29 Singh JP et al JACC 2005 1
QRS: Wider is Better Variability in Electrical Activation Sequence Across all patients Endocardial Maps LBBB RBBB RBBB + LAHB Mechanistic point of view: - - Greater dyssynchrony Considerable variability in electrical activation sequence • - Forgiving response to LV lead position Argues against the one-size fit all ‘ anatomical lead positioning ’ • The ESC guidelines had already endorsed 150 ms in 2010 - strategy Influenced HFSA guideline committee ’ s approach in 2011 - May partially explain the variability in CRT response • Piechl et al, PACE 2004:1105-12; Fantoni et al, JACC 2007, Sipahi I et al, Archives of Internal Medicine, 2011;171:1454-62 Segmental LV Lead Location (Apical vs. Non- QRS Morphology Apical) Determinants of CRT response Longitudinal Axis Overall population • LBBB improved across the board Apical lead locations (via the coronary venous tree) are associated with • • Non-LBBB variability in response worse outcome • Variability in activation sequence • Conventional implant approach may not work Irrespective of QRS morphology and electrical activation sequence • • Does that make it a sub-optimal population ? Singh JP / Klein H et al, Circulation 2011 (MADIT-CRT Study) Sipahi I et al. Am Heart Journal 2012;163: 260-267 2
LV Pacing Location & Response: CRT an Electrical Fix Thinking Beyond Anatomical Targeting Targeting Electrical Delay, Clinical Outcome & Reverse Remodeling • Activation Map Surrounding Tissue Scar • Ant Health Substrate RV-LV fusion • Lat Response • Post-Lat Lead To Depolarization Location wavefront • Voltage Map LV pacing Myofibrillar Proximity to pattern Purkinje Orientation Electro-mech. of electrode coupling Gold MR, Green U, Singh JP et al.; European Heart Journal 2011 Ryu, P / Singh JP et al; JCE 2010 Singh JP et al. Mela T; Heart Rhythm , 2006;3:1285-92 • 30 Quadripolar lead: Electrical Targeting in non-LBBB Electrical Distancing within the Apical segment Clinical & Echocardiographic outcome Distal 1 M2 M3 Proximal 4 32.2 ms 27.6 ms 32.6 ms 46.5 ms Intra-procedural • LVLED in non-LBBB a determinant of outcome Graded remodeling • response Prospectively being • IVCD evaluated in the Quadripolar lead in the Apical region (32) • LBBB ENHANCE-CRT RBBB (71) Variable electrical delay among electrodes (18) • study Increased sensed electrical delay in the apical position=better outcome • Needs to be tested prospectively • Kandala J / Singh JP et al. European Heart Journal 2013 Kandala, J / Singh JP et al J Cardiovasc Electrophysiology 2012 3
Targeting Mechanical Dyssynchrony Non-LBBB and CRT Response STARTER Trial Underlying substrate different • • Different myopathic process • Mechanical dyssynchrony » Varied regions of dyssynchrony » Limited Co-existent co-morbidities • » CAD » COPD, etc. Temporal relationship of conductive disease to • cardiomyopathy? Saba S / Gorcsan J et al Circulation HF 2013 Can Alternative approaches help? Recognizing RV-LV interactions - Shoulder Access to LV via Transseptal route It’s not all about the LV lead….. C 1 B 1 C 2 B 2 A Endocardial approach Animal Study • • Limited understanding provides the needed Complete CRT Implant via Shoulder approach with • RV lead position can impact acute hemodynamic response individualization LV lead implantation individualized to area of most Individual variability for same LV lead position: clinically meaningful ? Best site is variable delayed electrical activation • Septal CRT Study: No difference at the population level • Singh JP and Gras D; EHJ 2011 Singh JP et al, JICE, 2006 :17, 51-58 • Exner D, Auricchio A and Singh JP. Heart Rhythm 2012 LeClercq C et al. Europace 2015 Kumar P / Singh JP et al. JICE 2012 4
ALSYNC: LV Endocardial approach WISE Technology Potential for individualized approach in the non-LBBB patient (Investigational, ? individualized approach) • Synchronized • Targeted LV pacing Phased Array Ultrasound Transmitter • is Implanted in Intercostal Space Receiver Electrode (RE) is Implanted in • LV endocardium • Converts ultrasound energy to electrical pulse. SELECT LV Study* • – Prospective, non randomized study with LV pacing pellet – 35 patients who failed Morgan JM et al. European Heart Journal 2016 , 37: 2118-27 conventional CRT Early data looks good – SOLVE-CRT underway • * Reddy V et al. HRS 2015, * Singh JP, JACC: CEP August 2015 Take Home Points Thank You Levels of Electro-mechanical Dyssynchrony • Anatomical targeting not specific enough • » Considerable inter-individual variability Selecting the non-LBBB patient • » Avoid the pure RBBB » Wider is better Individualizing the approach in non-LBBB • » Targeting electrical & mechanical delay » Ongoing trials (ENHANCE-CRT) Recognizing RV-LV lead interaction • Future strategies may further individualization • » Endocardial approach 5
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