non invasive and invasive cardiac monitoring.pptx

non invasive proce

1. Non invasive cardiac procedures

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3. A chest x-ray is obtained to determine the size, contour, and position of the heart. It reveals cardiac and pericardial calcifications and demonstrates physiologic alterations in the pulmonary circulation. Although it does not help diagnose acute MI, it can help diagnose some complications ( eg , HF). Correct placement of pacemakers and pulmonary artery catheters is also confirmed by chest x-ray.

4. Fluoroscopy is an x-ray imaging technique that allows visualization of the heart on a screen. It shows cardiac and vascular pulsations and unusual cardiac contours. During a fluoroscopy procedure, an X-ray beam is passed through the body. The image is transmitted to a monitor so the movement of a body part or of an instrument or contrast agent ("X-ray dye") through the body can be seen in detail.

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6. The stress test helps determine the following: (1) presence of CAD, (2) cause of chest pain (3) functional capacity of the heart after an MI or heart surgery, (4) effectiveness of antianginal or antiarrhythmic medications, (5) dysrhythmias that occur during physical exercise, and (6) specific goals for a physical fitness program. Contraindications severe aortic stenosis, acute myocarditis or pericarditis, severe hypertension, suspected left main CAD, HF, and unstable angina

7. Procedure During an exercise stress test, the patient walks on a tread- mill pedals a stationary bicycle, or uses an arm crank. Exercise intensity progresses according to established protocols. The goal is to increase the heart rate to the “target heart rate,” which is 80% to 90% of the maximum predicted heart rate based on the patient’s age and gender. During the test, the following are monitored: two or more ECG leads for heart rate, rhythm, and ischemic changes; BP; skin temperature; physical appearance; perceived exertion; and symptoms, including chest pain, dyspnea , dizziness, leg cramping, and fatigue.

8. The test is terminated when the target heart rate is achieved or when the patient experiences chest pain, extreme fatigue, a decrease in BP or pulse rate, serious dysrhythmias or ST-segment changes on the ECG, or other complications. When significant ECG abnormalities occur during the stress test (ST-segment depressions or elevations), the test result is reported as positive and further diagnostic testing such as a cardiac catheterization is required.

9. Pharmacologic Stress Testing Procedure Two vasodilating agents, dipyridamole ( Persantine ) and adenosine ( Adenocard ) dobutamine administered IV, are used to mimic the effects of exercise by maximally dilating the coronary arteries. Nursing Interventions In preparation for the pharmacologic stress test, the patient is instructed not to eat or drink anything for at least 4 hours before the test.(caffeine)

10. Patients taking aminophylline, theophylline, or dipyridamole are instructed to stop taking these medications for 24 to 48 hours before the test (if tolerated). The patient is informed about the transient sensations that may occur during infusion of the vasodilating agent, such as flushing or nausea.

11. Echo cardiography

12. Traditional Echocardiography Echocardiography is a non invasive ultrasound test that is used to measure the ejection fraction and examine the size, shape, and motion of cardiac structures. It is particularly useful for diagnosing pericardial effusions; determining chamber size and the etiology of heart murmurs; evaluating the function of heart valves, including prosthetic heart valves; and evaluating ventricular wall motion.

13. Echocardiography involves transmission of high-frequency sound waves into the heart through the chest wall and recording of the return signals. The ultrasound is generated by a handheld transducer applied to the front of the chest. The transducer picks up the echoes, converts them to electrical impulses, and transmits them for display on an oscilloscope and recording on a videotape. An ECG is recorded simultaneously to assist with interpreting the echocardiogram. Myocardial ischemia from decreased perfusion during stress causes abnormalities in ventricular wall motion and is easily detected by echocardiography.

14. Before echocardiography, the nurse informs the patient about the test, explaining that it is painless. Echocardiographic monitoring is performed while a transducer that emits sound waves is moved over the surface of the chest wall. Gel applied to the skin helps transmit the sound waves. Periodically, the patient is asked to turn onto the left side or hold a breath. The test takes about 30 to 45 minutes

15. TRANS ESOPHAGEAL ECHO

16. A probe with an ultrasound transducer at the tip is swallowed while the physician controls angle and depth. As it passes down the esophagus , it sends back clear images of heart size, wall motion, valvular abnormalities, endocarditis vegetation, and possible source of thrombi without interference from lungs or chest ribs. A contrast medium may be injected IV for evaluating direction of blood flow if an atrial or ventricular septal defect is suspected. Doppler ultrasound and colorflow imaging can also be used concurrently.

17. Instruct patient to be NPO for at least 6 hr before test. Remove dentures. IV sedation is administered and throat locally anesthetized. A bite block is placed in the mouth. Monitor vital signs and oxygen saturation levels and perform suctioning as needed during procedure. Patient may not eat or drink until gag reflex returns. Sore throat is temporary.

18. Radionuclide Imaging Radionuclide imaging studies involve the use of radioisotopes to noninvasively evaluate coronary artery perfusion, to detect myocardial ischemia and infarction, and to assess left ventricular function. Thallium 201 (Tl201) and technetium 99m (Tc99m) are two radioisotopes used in cardiac nuclear medicine When these radioisotopes are injected into the bloodstream, the energy emitted can be detected by a gamma scintillation camera positioned over the body. Planar imaging, used with thallium, provides a one-dimensional view of the heart from three locations. Single photon emission computed tomography (SPECT) provides three- dimensional images. With SPECT, the patient is positioned supine with arms raised above the head, while the camera moves around the patient’s chest in a 180- to 360-degree arc to more precisely identify the areas of decreased myocardial perfusion.

19. MYOCARDIAL PERFUSION IMAGING Test of Ventricular Function and Wall Motion Equilibrium radionuclide angiocardiography (ERNA) multiple-gated acquisition (MUGA) scanning Non invasive technique that uses a conventional scintillation camera interfaced with a computer to record images of the heart during several hundred heartbeats. The computer processes the data and allows for sequential viewing of the functioning heart. The sequential images are analyzed to evaluate left ventricular function, wall motion, and ejection fraction. MUGA scanning can also be used to assess the differences in left ventricular function during rest and exercise.