CRT是否还有进步空间？来自Mayo医院的经验（英文）—课件，幻灯.pptVIP

Cumulative Enrollment in CRT Randomized Trials CRT Reverse myocardial remodeling Improve quality of life Improve NYHA class Reduce hospitalizations for heart failure Improve survival Why not every patient response to CRT QRS morphology and duration Upgrade vs de novo implantation Etiology of cardiomyopathy Sinus rhythm vs atrial fibrillation Reversibility of LV myocardium LV lead position Percentage of biventricular pacing Device programming NYHA Class Pre- and Post-CRT LV Systolic Function: Pre- and Post-CRT Survival After CRTDe Novo vs Upgrade groups Comparison of changes after CRT in patients with DCM and ICM Comparison of Changes After CRT Biventricular Pacing Percentage in All Patients Survival Free from Heart Failure Hospitalization and All-Cause Mortality Measuring VTI Obtain Doppler velocities across the aortic valve Use the apical long axis view Find the best programmed V-V Delay that provides the largest VTI (SV) Using the Velocity Time Integral (VTI) to Optimize V-V Timing The volume of blood ejected by the LV each beat = Stroke Volume (SV) SV = LVOT area x Velocity Time Integral (VTI) Since LVOT is constant, the larger the VTI the larger the SV Distribution of Optimized V-V Summary of V-V Timing Results Sequential biventricular pacing produced the greatest stroke volume in 75% of patients. The median improvements in stroke volume when sequential biventricular pacing were 11.4%, and 9.5% at implant and 6 months respectively. Cleland: JACC, 2009 Therapeutic benefit Risk Maximum therapeutic benefit Too well tobenefit Too sick tobenefit Thank you. As shown here, patients were grouped according to QRS morphology on their pre-CRT EKG. Among 505 patients, 50% of patients had an intrinsic LBBB, 25% of patients had a predominantly paced LBBB (usually if they were greater than 40% paced), 7% had right bundle branch block, 11% had intraventricular conduction delay, and an additional 7% had a narrow QRS duration, defined as less than 120 ms. Am