Quantitative Assessment of Congestive Heart Failure with Noninvasive Imaging: Background and Current Approaches

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Quantitative Assessment of Congestive Heart
Failure with Noninvasive ImagingBackground and
Current Approaches
Jonathan F. Plehn, M.D. NIH/NHLBI Cardiovascular
Branch
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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

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• Cardiomyopathy
• disease of cardiac muscle
• can be symptomatic or asymptomatic
• Congestive Heart Failure (CHF)
• inability of the heart to meet the bodys
  metabolic demands
• manifest by
• Forwards failure weakness, fatigue
• Backwards failure dyspnea (shortness of
  breath), peripheral edema (leg swelling)

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Systolic Heart Failure reduced LV contractility
(EF lt40)
Diastolic Heart Failure preserved EF (gt40),
delayed LV relaxation and increased chamber
stiffness
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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

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Normal Systolic Function
Severely Depressed Systolic Function
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• 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

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Regional Wall Stress Finite Element Analysis
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Left Bundle Branch Block
Sinus node
His Bundle
AV node
Left Bundle Branch
After Kass D. New dimensions in device-based
therapy for heart failuremechanisms of
stimulation for heart failure. Heart Failure
Society of America 2000.
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Normal
Left Bundle Branch Block
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Prevalence of LBBB in Heart Failure
Normal LVEF 8 Impaired LVEF 24 NYHA Class
III-IV 38
1. Masoudi, et al. JACC 200341217-23 2.
Aaronson, et al. Circ 1997952660-7
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Association of QRS Duration on Survival in VEST
QRS Duration (msec)
lt90
90-120
120-170
170-220
gt220
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MRI Tissue Tagging with SPAMM
Yeon et al. JACC 200138
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Normal LV Phasic Contraction
Nelson GS et al. Circulation 2000101
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Abnormal Phasic Contraction Dilated
Cardiomyopathy
Nelson GS et al. Circulation 2000101
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Forms of Cardiac Dyssynchrony in Heart Failure

• Intra-ventricular septal/lateral
• Inter ventricular LV/RV
• Atrio-ventricular (atrial booster pump)

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BIVENTRICULAR PACING THERAPY
Sinus node
AV node
Kass D. New dimensions in device-based therapy
for heart failuremechanisms of stimulation for
heart failure. Heart Failure Society of America
2000.
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Bi-ventricular Pacing

1. Right atrium AV synchrony
2. Right ventricle Inter-ventricular synchrony
3. Left ventricle Intra-ventricular synchrony

Doug Smith
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Benefits of CRT in CHF

• Improved Exercise Capacity (treadmill, 6 minute
  walk)
• Increased Quality of Life (questionaires)
• Improved Survival
• LV Reverse Remodeling, Increased LV Ejection
  Fraction
• Reduction in Neurohormone Levels
• Reduction in Mitral Regurgitation
• Increased Heart Rate Variability
• Reduction in Myocardial Oxygen Consumption
  (energetics)
• Improvement in LV Stroke Work

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The Next Step Beyond Drug Therapy
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Downsides of CRT in CHF

1. Device is expensive
2. Implantation is time-consuming and sometimes
   unsuccessful
3. Occasional complications (e.g. tamponade)

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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

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MRI Dysynchrony Index Predicts Improvement with
Resynch Pacing
Nelson GS et al. Circulation 2000101
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2D-Guided M-mode Echo
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Segmental Wall Motion Analysis 2D Echo
Bi-V Pacer Firing
Before CRT
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3D Echo
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3D Echo Segmental Wall Motion Analysis
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Doppler Tissue Imaging Sampling Velocities
of Single Points
Doppler Strain Rate Imaging Sampling
Differences Between Two Points
Dhooge J et al. Eur J Echo 20001
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Doppler Tissue Velocity Imaging
Doppler Strain Rate Imaging
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Radionuclide Cineangiography
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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