Diagnostic Testing for Cardiovascular Disease [Compatibility Mode]

Diagnostic Testing for Cardiovascular Disease [Compatibility Mode]

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Unformatted text preview: Diagnostic Testing for Cardiovascular Disease Diagnosis of IHD Nuclear Nuclear Exercise Studies (http://brighamrad.harvard.edu/education/online/Cardiac/SS/SS.html) (http://brighamrad.harvard.edu/education/online/Cardiac/SS/SS.html) A radionucleotide is injected intravenously at peak exercise radionucleotide and nuclear imaging is then performed Looking for “cold spots” in images Looking for cold spots in images 90 90 percent sensitive; 80 percent specific Exercise Exercise Echocardiography Pharmacologic Pharmacologic Stress Tests For For patients unable to exercise Nuclear Imaging Labeling Labeling die is injected and resting images are taken at 30 minutes and 60 minutes Stress Stress test is performed and patient receives injection about 1 minute before the test is over Recovery images are taken 30 min, 60 min and 30 60 sometimes sometimes several hours after stress Types Types TcTc-99 sestamibi or thalous (thallium) chloride-201 chlorideMost Most common and more sensitive is Sestamibi with single photon emission computed tomography (SPECT) 1 2 Findings of Previous Imaging Study Extensive rest perfusion defects in the apex, apical-anterior, inferior, inferolateral, and lateral walls -- consistent with mixed transmural (arrows), and nontransmural MI (pink arrows) in all three vascular territories with a small area of questionable stress-induced ischemia (lines) in the apical two thirds of the lateral wall. No fill-in in the delayed images, therefore no evidence of hibernating myocardium. Septum, the apical anterolateral wall, and probably the basal half of the anterior wall are viable and could potentially improve in function if they are dysfunctional at the time of imaging. The remaining myocardium has such low uptake (<< 50% of max) that it is very unlikely that improvement in function could occur if these portions of myocardium were revascularized. Exercise Echocardiography Imaging Imaging modality (ultrasound) that determines structure and function of the heart Performed Performed on cycle ergometer, rest images are compared to exercise images Less costly than nuclear imaging and does not require exposure to ionizing radiation May May detect wall motion abnormalities earlier than ECG or SxS (ischemic cascade) Limitations Limitations – specificity and operator Sensitivity Sensitivity – 86% ; Specificity – 79% 3 Pharmacologic Stress Tests For For patients unable to exercise Dobutamine Dobutamine with stress echocardiography Increases HR to pre-determined end point or Increases reuntil SxS Use Use echocardiography to look at wall motion Adenosine Adenosine with nuclear imaging Vasodilates Vasodilates normal epicardial arteries only Radionuclide Ventriculargraphy (MUGA) Used Used to estimate ejection fraction and ventricular wall motion Patient Patient lies still and technitium tagged solution is injected that tags red blood cells is injected that tags red blood cells Gives Gives a functional picture of the 4 chambers during diastole and systole Poor Poor sensitivity for CAD disease (60%) 4 Dx and Tx of MI (as a consequence of CAD) Dx Dx ECG ECG abnormalities Serum Serum Markers of Infarction Elevated electrolytes in blood several hours after Elevated electrolytes in blood several hours after infarction infarction depending on time course Rx Rx Acute Acute usually involves thrombolytic therapy PTCA PTCA Hospital Hospital Management 5 ...
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This note was uploaded on 01/16/2012 for the course KINE 430 taught by Professor Dr.jenniferblevins-mcnaughton during the Fall '11 term at Tarleton.

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