Day Readmissions: Evidence From the Adaptive CRT Trial. JACC Heart Fail 2015; 3:565. 63. Zanon F, Marcantoni L, Baracca E, et al. Optimization of left ventricular pacing site plus multipoint pacing improves remodeling and clinical response to cardiac resynchronization therapy at 1 year. Heart Rhythm 2016; 13:1644. https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 24/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate 64. Hu F, Zheng L, Ding L, et al. Clinical outcome of left ventricular multipoint pacing versus conventional biventricular pacing in cardiac resynchronization therapy: a systematic review and meta-analysis. Heart Fail Rev 2018; 23:927. 65. Auricchio A, Stellbrink C, Sack S, et al. Long-term clinical effect of hemodynamically optimized cardiac resynchronization therapy in patients with heart failure and ventricular conduction delay. J Am Coll Cardiol 2002; 39:2026. 66. Rao RK, Kumar UN, Schafer J, et al. Reduced ventricular volumes and improved systolic function with cardiac resynchronization therapy: a randomized trial comparing simultaneous biventricular pacing, sequential biventricular pacing, and left ventricular pacing. Circulation 2007; 115:2136. 67. Boriani G, Kranig W, Donal E, et al. A randomized double-blind comparison of biventricular versus left ventricular stimulation for cardiac resynchronization therapy: the Biventricular versus Left Univentricular Pacing with ICD Back-up in Heart Failure Patients (B-LEFT HF) trial. Am Heart J 2010; 159:1052. 68. Thibault B, Ducharme A, Harel F, et al. Left ventricular versus simultaneous biventricular pacing in patients with heart failure and a QRS complex 120 milliseconds. Circulation 2011; 124:2874. 69. Meluz n J, Nov k M, M llerov J, et al. A fast and simple echocardiographic method of determination of the optimal atrioventricular delay in patients after biventricular stimulation. Pacing Clin Electrophysiol 2004; 27:58. 70. Ellenbogen KA, Gold MR, Meyer TE, et al. Primary results from the SmartDelay determined AV optimization: a comparison to other AV delay methods used in cardiac resynchronization therapy (SMART-AV) trial: a randomized trial comparing empirical, echocardiography- guided, and algorithmic atrioventricular delay programming in cardiac resynchronization therapy. Circulation 2010; 122:2660. 71. Brenyo A, Kutyifa V, Moss AJ, et al. Atrioventricular delay programming and the benefit of cardiac resynchronization therapy in MADIT-CRT. Heart Rhythm 2013; 10:1136. 72. Bristow MR, Saxon LA, Boehmer J, et al. Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure. N Engl J Med 2004; 350:2140. 73. Cleland JG, Daubert JC, Erdmann E, et al. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005; 352:1539. 74. McAlister FA, Ezekowitz J, Hooton N, et al. Cardiac resynchronization therapy for patients with left ventricular systolic dysfunction: a systematic review. JAMA 2007; 297:2502. 75. Le n AR, Abraham WT, Curtis AB, et al. Safety of transvenous cardiac resynchronization system implantation in patients with chronic heart failure: combined results of over 2,000 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 25/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate patients from a multicenter study program. J Am Coll Cardiol 2005; 46:2348. 76. Perisinakis K, Theocharopoulos N, Damilakis J, et al. Fluoroscopically guided implantation of modern cardiac resynchronization devices: radiation burden to the patient and associated risks. J Am Coll Cardiol 2005; 46:2335. 77. Fox M, Mealing S, Anderson R, et al. The clinical effectiveness and cost-effectiveness of cardiac resynchronisation (biventricular pacing) for heart failure: systematic review and economic model. Health Technol Assess 2007; 11:iii. 78. Duray GZ, Israel CW, Pajitnev D, Hohnloser SH. Upgrading to biventricular pacing/defibrillation systems in right ventricular paced congestive heart failure patients: prospective assessment of procedural parameters and response rate. Europace 2008; 10:48. 79. Swindle JP, Rich MW, McCann P, et al. Implantable cardiac device procedures in older patients: use and in-hospital outcomes. Arch Intern Med 2010; 170:631. 80. Fish JM, Brugada J, Antzelevitch C. Potential proarrhythmic effects of biventricular pacing. J Am Coll Cardiol 2005; 46:2340. 81. Navia JL, Atik FA. Minimally invasive surgical alternatives for left ventricle epicardial lead implantation in heart failure patients. Ann Thorac Surg 2005; 80:751. 82. Ezelsoy M, Bayram M, Yazici S, et al. Surgical placement of left ventricular lead for cardiac resynchronisation therapy after failure of percutaneous attempt. Cardiovasc J Afr 2017; 28:19. 83. McALOON CJ, Anderson BM, Dimitri W, et al. Long-Term Follow-Up of Isolated Epicardial Left Ventricular Lead Implant Using a Minithoracotomy Approach for Cardiac Resynchronization Therapy. Pacing Clin Electrophysiol 2016; 39:1052. 84. Rickard J, Johnston DR, Price J, et al. Reverse ventricular remodeling and long-term survival in patients undergoing cardiac resynchronization with surgically versus percutaneously placed left ventricular pacing leads. Heart Rhythm 2015; 12:517. 85. Vijayaraman P, Dandamudi G, Zanon F, et al. Permanent His bundle pacing: Recommendations from a Multicenter His Bundle Pacing Collaborative Working Group for standardization of definitions, implant measurements, and follow-up. Heart Rhythm 2018; 15:460. 86. Hua W, Zhang S, Huang D. The implantation technique in His-bundle pacing: evolution and perspectives. Europace 2020; 22:ii3. 87. Upadhyay GA, Vijayaraman P, Nayak HM, et al. On-treatment comparison between corrective His bundle pacing and biventricular pacing for cardiac resynchronization: A secondary analysis of the His-SYNC Pilot Trial. Heart Rhythm 2019; 16:1797. https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 26/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate 88. Beer D, Sharma PS, Subzposh FA, et al. Clinical Outcomes of Selective Versus Nonselective His Bundle Pacing. JACC Clin Electrophysiol 2019; 5:766. 89. Zhang S, Zhou X, Gold MR. Left Bundle Branch Pacing: JACC Review Topic of the Week. J Am Coll Cardiol 2019; 74:3039. 90. Su L, Wang S, Wu S, et al. Long-Term Safety and Feasibility of Left Bundle Branch Pacing in a Large Single-Center Study. Circ Arrhythm Electrophysiol 2021; 14:e009261. 91. Huang W, Chen X, Su L, et al. A beginner's guide to permanent left bundle branch pacing. Heart Rhythm 2019; 16:1791. 92. Wu S, Chen X, Wang S, et al. Evaluation of the Criteria to Distinguish Left Bundle Branch Pacing From Left Ventricular Septal Pacing. JACC Clin Electrophysiol 2021; 7:1166. 93. Ponnusamy SS, Basil W, Vijayaraman P. Electrophysiological characteristics of septal perforation during left bundle branch pacing. Heart Rhythm 2022; 19:728. Topic 3500 Version 31.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 27/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate GRAPHICS Chest radiographs of CRT-P and CRT-D Representative chest radiographs of (A) CRT-P and (B) CRT-D systems. The arrows in (B) denote the presence of a larger pulse generator and associated shocking coil on the right ventricular pacing lead required for https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 28/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate the system to provide defibrillation capability. These elements are not present on the CRT-P system shown in (A). CRT-P: cardiac resynchronization therapy pacemaker; CRT-D: cardiac resynchronization therapy defibrillator. Graphic 116571 Version 1.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 29/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate Contrast venography in the LAO and RAO Contrast venography in the LAO (A) and RAO (B) projections depicting expected venous branches of the coronary sinus. These images were obtained from a patient with a mechanical MV prosthesis in order to provide anatomic orientation. These images also demonstrate both pacing and ICD leads fixed in the right ventricular apex. The RAO image (B) also includes the presence of a pacing lead fixed in the right atrial appendage. The AIV courses in the interventricular groove between the https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 30/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate right and left ventricles. The MCV courses posteriorly over the left ventricle. Venous branches commonly selected for left ventricular lead placement include (1) the anterolateral branch, (2) the midlateral branch, and (3) the posterolateral branch. LAO: left anterior oblique view; RAO: right anterior oblique view; AIV: anterior interventricular vein; MV: mitral valve; MCV: middle cardiac vein; ICD: implantable cardioverter-defibrillator. Graphic 116573 Version 2.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 31/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate Strategies for optimizing cardiac resynchronization therapy Optimization of CRT can be achieved by avoiding scar (B), targeting a Q-LV interval 95 ms (C), employing algorithms to maximize fusion of LV pacing with native conduction (D), and pacing at multiple LV sites (E). LV: left ventricular; CRT: cardiac resynchronization therapy. Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography 2018-2019. All Rights Reserved. Graphic 120743 Version 1.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 32/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate Conceptual overview of electrical activation of the cardiac His-Purkinje fibers Conceptual overview of electrical activation of the cardiac His-Purkinje fibers for (A) normal conduction, (B) with left bundle branch block, (C) with biventricular pacing, and (D) with fusion pacing. In all 4 panels, the length of the x-axis is the biventricular activation time reflected by the width of the QRS complex recorded on a surface electrocardiogram. (A) With normal conduction, biventricular activation is rapid (ie, 90 ms) when impulses propagate antegrade over intact right and left bundles. (B) In a patient with complete left bundle branch block, electrical activation is blocked antegrade due to the underlying disease state and proceeds more slowly following transseptal activation via the right bundle occurring via cell-to-cell connections. The total biventricular activation time of 170 ms is a typical intrinsic QRS duration for a patient with complete left bundle branch block. (C) The grey thunderbolts depict left and right ventricular pacing stimulation resulting in electrical activation largely along myocardial cell-to-cell connections that are typically slower than intact His- Purkinje fibers. The total activation time of 140 ms is a typical paced QRS duration for a patient with biventricular pacing. (D) The concept of fusion pacing is that intrinsic electrical activation proceeds antegrade over an intact right bundle and collides with electrical activation resultant from the left ventricular pacing stimulus https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 33/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate depicted by the grey thunderbolt. The total activation time of 110 ms is afforded by rapid physiologic conduction over the native right bundle. The white thunderbolt depicts the optional delivery of right ventricular pacing stimulation that is delayed and offset from the left ventricular stimulus according to vendor-specific algorithms. As an example, such pacing stimulation could be applied in scenarios when the native His-Purkinje disease is more complicated than an isolated left bundle branch block. RV: right ventricular. Graphic 116574 Version 2.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 34/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate Fluoroscopic view of left bundle branch area pacing lead placement Fluoroscopic view of the heart during implantation of a left bundle branch area pacing lead. A delivery sheath was extended from the left subclavian vein access site to the RV septum. Then, an active fixation pacing lead with a fixed helix at the tip was advanced and fixed deep in the RV septum. The position of the lead was confirmed with iodinated contrast injection, which is seen here at the right of the edge of the spine. The proximal pacing electrode is still within the sheath near the tip. Pacing from the distal electrode resulted in capture of the left bundle branch that travels along the left side of the ventricular septum. Also seen is a J-tip guidewire that was used subsequently to place the atrial lead. https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 35/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate RV: right ventricular. Graphic 141249 Version 2.0 https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 36/37 7/6/23, 10:50 AM Cardiac resynchronization therapy in heart failure: System implantation and programming - UpToDate Contributor Disclosures Bradley P Knight, MD, FACC Grant/Research/Clinical Trial Support: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; MDT [Electrophysiology]; Philips [Electrophysiology]. Consultant/Advisory Boards: Abbott [Electrophysiology]; Atricure [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Electrophysiology]; BSCI [Electrophysiology]; CVRx [Heart failure]; MDT [Electrophysiology]; Philips [Electrophysiology]; Sanofi [Arrhythmias]. Speaker's Bureau: Abbott [Electrophysiology]; Biosense Webster [Electrophysiology]; Biotronik [Electrophysiology]; Boston Scientific [Transeptal catheterization]; BSCI [Electrophysiology]; MDT [Electrophysiology]. All of the relevant financial relationships listed have been mitigated. Jonathan Piccini, MD, MHS, FACC, FAHA, FHRS Grant/Research/Clinical Trial Support: Abbott [Atrial fibrillation, catheter ablation]; AHA [Atrial fibrillation, cardiovascular disease]; Bayer [Atrial fibrillation]; Boston Scientific [Cardiac mapping, pacemaker/ICD, atrial fibrillation care]; iRhythm [Atrial fibrillation]; NIA [Atrial fibrillation]; Philips [Lead management]. Consultant/Advisory Boards: Abbott [Atrial fibrillation, catheter ablation]; Abbvie [Atrial fibrillation]; Bayer [Atrial fibrillation]; Boston Scientific [Cardiac mapping, atrial fibrillation, pacemaker/ICD]; ElectroPhysiology Frontiers [Atrial fibrillation, catheter ablation]; Element Science [DSMB]; Medtronic [Atrial fibrillation, pacemaker/ICDs]; Milestone [Supraventricular tachycardia]; Pacira [Atrial fibrillation]; Philips [Lead extraction]; ReCor [Cardiac arrhythmias]; Sanofi [Atrial fibrillation]. All of the relevant financial relationships listed have been mitigated. Todd F Dardas, MD, MS No relevant financial relationship(s) with ineligible companies to disclose. Contributor disclosures are reviewed for conflicts of interest by the editorial group. When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content. Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence. Conflict of interest policy https://www.uptodate.com/contents/cardiac-resynchronization-therapy-in-heart-failure-system-implantation-and-programming/print 37/37