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Stress Myocardial Perfusion Imaging
Aka: Stress Myocardial Perfusion Imaging, Radionuclude Perfusion Imaging, Cardiac Radionuclide Imaging, SPECT Myocardial Perfusion Imaging, Myocardial Single-Photon Emission Computed Tomography, Stress Thallium, Stress Cardiolite
- See Also
- Exercise Stress Test
- Stress Imaging
- Pharmacologic Stress Test
- Stress Echocardiogram
- Preparations
- Thallium T1 201 chloride
- Originally used for imaging
- Technetium agents replaced Thallium for higher efficacy
- Technetium 99mTc-Sestamibi (Cardiolite)
- Technetium Tc-99m-tetrofosmin (Myoview)
- Indications
- Nondiagnostic Stress EKG, Intermediate CAD likelihood
- Resting ST-T Wave abnormalities
- Left Bundle Branch Block
- Ventricular paced rhythm
- Left Ventricular Hypertrophy
- Digoxin treatment
- Suspected Acute Coronary Syndrome, nondiagnostic tests
- CAD Diagnosis, risk stratification, and therapy
- Assess ventricular function
- Identify lesions in planning for PTCA intervention
- Risk stratification prior to noncardiac surgery
- Specific conditions
- Cocaine-associated Chest Pain
- Well-controlled Diabetes Mellitus
- Advantages
- High sensitivity for ischemia (>90%)
- Distinguishes baseline wall motion abnormality from CAD
- Severe valvular disease
- Severe Hypertension
- Idiopathic Hypertrophic Subaortic Stenosis (IHSS)
- Left Bundle Branch Block
- Severe Left Ventricular Hypertrophy
- Atrial Fibrillation
- In above cases angiography may be needed
- Disadvantages
- Test Sensitivity decreases significantly when patient is not actively experiencing Chest Pain
- Efficacy
- Overall SPECT
- Test Sensitivity: 85-90%
- Test Specificity: 80-90%
- Pharmacologic
- Test Sensitivity: 89%
- Test Specificity: 75%
- Symptomatic
- Test Sensitivity: >85%
- Test Specificity >80%
- References
- Metz (2007) J Am Coll Cardiol 49(2): 227-37 [PubMed]
- Prognosis
- Normal perfusion scan: Cardiac event rate <1% per year
- Factors suggestive of worse prognosis
- Increased numbers of involved vascular territories
- Increased severity and extent of defect size
- Decreased reversibility
- Post-stress ejection fraction <45%
- End-systolic volume >70 ml
- Transient ischemic dilation