Post on 03-Jun-2015
Value of the ECG Value of the ECG before and after before and after
cardiac cardiac resynchronization resynchronization
therapy therapy Sergio L. Pinski
Cleveland Clinic FloridaWeston, FL USA
Value of QRS in CRTValue of QRS in CRT
Before implant– Patient selection– Stimulation site selection ?
After implant– Confirm biventricular capture– Predict response – Optimize programming
Mechanisms of CRTMechanisms of CRT
Reduction in mechanical dyssynchrony of the LV
Reverse remodeling of the LV Optimization of left heart AV interval Reduction of mitral regurgitation Improvement in LV diastolic function
Identifying Responders Identifying Responders In most studies, 20-30% of patients are
non responders
Poor patient selection: there is not enough ventricular dyssynchrony – A wide QRS (ie > 120 ms) is necessary but
not sufficient to predict a positive response– Nonviable myocardium
Failure to resynchronize – Electrode in non optimal position – Inadequate A-V (o V-V) delay. – Arrhythmias (rapid AF, frequent ventricular
ectopy)
Relation between intrinsic QRS with and improvement with stimulation
Kass DA, et al. Circulation 1999;99:1567
Forest plot of parallel-arm randomized clinical trials comparing outcomes by strata of
baseline QRS duration
Bryant et al. J Electrocardiol 2013
Sipahi et al. Arch Intern Med 2011; 171:1454
Impact of QRS Duration on Clinical Event Reduction With Cardiac Resynchronization Therapy: Meta-analysis of Randomized Controlled Trials
Random-effects meta-analyses of the weighted mean difference in baseline QRS duration between responders and
non-responders to CRT, usingremodeling definition of response
Bryant et al. J Electrocardiol 2013
Dupont et al. JACC 2012; 60:592
QRS duration and morphology in consecutive pts undergoing CRT at Cleveland Clinic Ohio
Significance of QRS morphology in determining the prevalence of mechanical dyssynchrony in heartfailure patients eligible for CRT
Haghjoo M et al. Europace 2008;10:566-571
Cumulative probability of heart failure (HF) event or death according to treatment (cardiac resynchronization therapy with defibrillator [CRT-D] versus implantable cardioverter
defibrillator [ICD] only) in patients with left bundle-branch block (LBBB), non-...
Zareba W et al. Circulation 2011;123:1061-1072
Relative risk of primary end point (heart failure event or death) by treatment (CRT-D versus ICD only) according to selected clinical characteristics in patients with or without LBBB
Zareba et al. Circulation 2011;123:1061
QRS Axis and the Benefit of CRT in Patients with Mildly Symptomatic Heart Failure in
MADIT‐CRT
Brenyo et al. J Cardiovasc Electrophysiol 2012
Figure 2
Sipahi et al. Amer Heart J 2012; 163:260 I:10.1016/j.ahj.2011.11.014 )
Bundle-Branch Block Morphology as a Predictor of Outcome After CRTD in 15,000 Medicare Patients
Bilchick et al. Circulation 2010;122:2022
Gold standard for LBBBGold standard for LBBB
No pathology correlate
Endocardial catheter mapping
Echo doppler studies showing delay in contraction of LV free wall vs. septum
Conventional definition of Conventional definition of LBBBLBBB1. QRS duration ≥ 120 ms in adults
2. Broad notched or slurred R wave in leads I, aVL, V5, and V6 and an occasional RS pattern in V5 and V6 attributed to displaced transition of QRS complex.
3. Absent q waves in leads I, V5, and V6, but in aVL, a narrow q wave may be present in the absence of myocardial pathology.
4. R peak time greater than 60 ms in leads V5 and V6 but normal in leads V1, V2, and V3, when small initial r waves can be discerned in the above leads.
5. ST and T waves usually opposite in direction to QRS.
6. Positive T wave in leads with upright QRS may be normal (positive concordance).
7. Depressed ST segment and/or negative T wave in leads with negative QRS (negative concordance) are abnormal
8. The appearance of LBBB may change the mean QRS axis in the frontal plane to the right, to the left, or to a superior, in some cases in a rate-dependent manner
Auricchio et al. Circulation 2004;109:1133
Timing of electrical activation (depolarization) wavefronts in normal conduction (A) and LBBB (B), shown in sagittal view.
Strauss D G et al. Circ Arrhythm Electrophysiol 2008;1:327-336
Strauss et al. Am J Cardiol 2011;107:927
Strauss et al. Am J Cardiol 2011;107:927
Strauss et al. Am J Cardiol 2011;107:927
“True” LBBBnegative terminal deflection in V1 (QS or rS)> 140 ms in men, >130 ms in womenMid QRS notching
Combined effects of conduction defects and hypertrophy on QRS duration.
Strauss DG. J Electrocardiol 2012;45:635
New “gold standard” for New “gold standard” for the definition of LBBBthe definition of LBBB High probability of improvement
with CRT
2004
QRS 100 ms
Aug 5, 2012
QRS 121 ms
Sep 28, 2012
QRS 150 ms
Oct 9, 2012
QRS 172 ms
Oct 16, 2012
BiV
QRS 114 ms
Mascioli et al. PACE 2012; 35:927
ECG Criteria of True Left Bundle Branch Block: A Simple Sign to Predict a Better Clinical
Response to CRT
Patients with longer LV activation have better outcome with CRT
Eitel et al. Europace 2012; 14:358
QRS morphology with QRS morphology with biventricular stimulationbiventricular stimulation
Location of RV electrode Location of wire in coronary wire Presence of fusion with intrinsic
conduction V-V timing (simultaneous versus
sequential). Latency, exit block with epicardial
pacing from coronary vein
Barold & Herweg. Cardiol J 2011; 18: 476
9-17-2001
9-19-2001
Barold & Herweg. Cardiol J 2011; 18: 476
LV
LVRVOT
RVOT
LV
Apex
LV
Mid Septum
ECG Diagnosis of Biventricular Pacing in Patients with Nonapical Right
Ventricular Leads
Jastrzebski et al. PACE 2012; 35:1199
LVLV
Apex Apex
LV
Apex
RVOT
Barold & Herweg. Cardiol J 2011; 18: 610
Latency with LV pacing
Barold & Herweg. Cardiol J 2011; 18: 610
Latency and slow conduction with LV pacing
Barold & Herweg. Cardiol J 2011; 18: 610
Programming V-V timing to circumvent LV latency
Herweg & Barold. PACE 2012;35:249
Lecoq et al. EHJ 2005;26:1094
Baseline and paced QRS duration in responders and nonresponders
The QRS Narrowing Index Predicts Reverse LV Remodelling Following CRT
Rickard et al. PACE 2011;34:604
QRS prolongation induced by CRT correlates with deterioration in LV
function
Rickard et al. Heart Rhythm 2012;9:1674
Jastrzebskiet al. Europace 2013; 15:258
Sweeney et al. Circulation. 121:626, 2010.
Analysis of Ventricular Activation Using Surface ECG to Predict LV Reverse Volumetric Remodeling During Cardiac Resynchronization Therapy.
Strauss et al. Circ Arrhythm Electrophysiol 2008;1:327
Sweeney et al. Circulation. 121:626, 2010.
Analysis of Ventricular Activation Using Surface ECG to Predict LV Reverse Volumetric Remodeling During Cardiac Resynchronization Therapy.
Predictors for Restoration of Normal LV Function in Response to CRT Measured at Time of Implant
Serdoz et al. Am J Cardiol 2011;108:75
Vaillant at al. JACC 2013
Resolution of Left Bundle Branch Block?Induced Cardiomyopathy by Cardiac Resynchronization Therapy
Optimization of the Interventricular Delay in CRT Using the QRS Width
Tamborero et al. Am J Cardiol 2009; 2009;104:1407