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U.S. Department of Health and Human Services Quantitative Assessment of Congestive Heart Failure with Noninvasive Imaging: Background and Current Approaches Jonathan F. Plehn, M.D. National Institutes of Health National Heart, Lung, and Blood Institute NIH/NHLBI Cardiovascular Branch Congestive Heart Failure (CHF): A Syndrome of Epidemic Proportions • Approximately 4.9 million cases in the United States today • Over 400,000 new cases per year • The most common cause of hospitalization in people over 65 years • Increasing numbers of CHF patients due to the aging population Cardiomyopathy : • disease of cardiac muscle • can be symptomatic or asymptomatic Congestive Heart Failure (CHF): • inability of the heart to meet the body’s metabolic demands • manifest by Forwards failure: weakness, fatigue Backwards failure: dyspnea (shortness of breath), peripheral edema (leg swelling) Systolic Heart Failure: reduced LV contractility (EF <40%) Diastolic Heart Failure: preserved EF (>40%), delayed LV relaxation and increased chamber stiffness Noninvasive Imaging of Cardiac Function • Echocardiography (2D/M-mode, 3D, Doppler) • Radionuclide Cineangiography (MUGA, gated SPECT) • Magnetic Resonance Imaging • Contrast Left Ventriculography (Cath) • CT Angiography Normal Systolic Function Severely Depressed Systolic Function Symptoms • Diuretics • Digoxin • ACE Inhibitors • ARBs • Beta Blockers Survival • ACE Inhibitors • Beta Blockers • Hydralazine/Isordil • Aldactone (Class II-IV) LV Remodeling • ACE Inhibitors • ARBs • Beta Blockers Regional Wall Stress: Finite Element Analysis Left Bundle Branch Block Sinus node His Bundle AV node Left Bundle Branch After Kass D. New dimensions in device-based therapy for heart failure–mechanisms of stimulation for heart failure. Heart Failure Society of America 2000. Normal Left Bundle Branch Block Prevalence of LBBB in Heart Failure Normal LVEF Impaired LVEF 8% 24% NYHA Class III-IV 38% 1. Masoudi, et al. JACC 2003;41:217-23 2. Aaronson, et al. Circ 1997;95:2660-7 Association of QRS Duration on Survival in VEST QRS Duration (msec) Cumulative Survival 100% <90 90% 90-120 80% 120-170 170-220 70% >220 60% 0 60 120 180 240 300 360 Days in Trial MRI Tissue Tagging with SPAMM Yeon et al. JACC 2001;38 Normal LV Phasic Contraction Nelson GS et al. Circulation 2000;101 Abnormal Phasic Contraction: Dilated Cardiomyopathy Nelson GS et al. Circulation 2000:101 Forms of Cardiac Dyssynchrony in Heart Failure • Intra-ventricular: septal/lateral • Inter ventricular: LV/RV • Atrio-ventricular: (atrial booster pump) BIVENTRICULAR PACING THERAPY Sinus node AV node Biventricular Pacing Kass D. New dimensions in device-based therapy for heart failure–mechanisms of stimulation for heart failure. Heart Failure Society of America 2000. Bi-ventricular Pacing 1) 2) 3) Right atrium: AV synchrony Right ventricle: Inter-ventricular synchrony Left ventricle: Intra-ventricular synchrony Right Atrial Lead Left Ventricular Lead Right Ventricular Lead Doug Smith: Benefits of CRT in CHF 1. Improved Exercise Capacity (treadmill, 6 minute walk) 2. Increased Quality of Life (questionaires) 3. Improved Survival 4. LV Reverse Remodeling, Increased LV Ejection Fraction 5. Reduction in Neurohormone Levels 6. Reduction in Mitral Regurgitation 7. Increased Heart Rate Variability 8. Reduction in Myocardial Oxygen Consumption (energetics) 9. Improvement in LV Stroke Work The Next Step Beyond Drug Therapy Downsides of CRT in CHF 1. Device is expensive 2. Implantation is time-consuming and sometimes unsuccessful 3. Occasional complications (e.g. tamponade) Unresolved Issues in CRT • At least 20-30% of patients with wide QRS complexes are non-responders: – No dyssynchrony – Inadequate pacing site – Too much pump damage at baseline • QRS width correlates only roughly with mechanical dyssynchrony • Dyssynchrony in patients with normal QRS widths or right bundle branch block. These may respond to CRT MRI Dysynchrony Index Predicts Improvement with Resynch Pacing Nelson GS et al. Circulation 2000;101 2D-Guided M-mode Echo Segmental Wall Motion Analysis: 2D Echo Before CRT Bi-V Pacer Firing 3D Echo 3D Echo Segmental Wall Motion Analysis Doppler Tissue Imaging: Sampling Velocities of Single Points Doppler Strain Rate Imaging: Sampling Differences Between Two Points D’hooge J et al. Eur J Echo 2000;1 Doppler Tissue Velocity Imaging Doppler Strain Rate Imaging Radionuclide Cineangiography Current Limitations of Noninvasive Dyssynchrony Evaluation • Approach is usually tomographic (1 or 2D) leading to limitation in spatial quantitation • Data is noisy • Quantitative analysis is time-consuming • Inter-observer variability in the community is unknown