Chapter 5 m terminology procedures rg
- 1. Procedures related to the Heart
- 2. Stress Test Used to aid in the diagnosis and risk stratification of CAD in both symptomatic and asymptomatic patients Monitors a patients symptoms, blood pressure, and EKG tracing as the treadmill increases speed and slope These increases are repeated usually in 3 min. intervals until the patient experiences symptoms such as shortness of breath, severe fatigue, dizziness, or chest discomfort.
- 3. Stress Test (cont). If patients do not develop signs or symptoms of ischemia, stress testing continues until the heart rate reaches 85% of the max heart rate expected for the patient’s age and gender. Measurements of the activity include: Total duration of exercise Time to onset of ischemic EKG changes or chest discomfort External work performed internal cardiac work (ex: blood pressure) EKG changes including presence of ST-segment depression or elevation and recover time. A positive test result of CHD will include the EKG reading and characteristics of the individual tested. A false negative occurs in approximately 1/3 of cases. This test cannot be performed in patients who have had an MI within the last 48 hours OR who have high-risk unstable angina.
- 4. Cardiac Enzymes 3 main enzymes that provide an indication of heart damage include: Creatine Phosphokinase (CPK) Lactate Dehydrogenase (LDH) Glutamic Oxaloacetic Transaminase (GOT) These enzymes are specific to the heart muscle and can be measured through blood tests via a blood sample taken from a patient’s arm.
- 5. Cardiac Enzymes (cont.) The purpose of using them enzymes can assess: If you are having a heart attack or are at risk for having one in the near future Normal blood flow post surgery of an occluded coronary artery Heart injury after an MI and bypass surgery as dead/damaged tissue is present The blood samples are often taken every 8-12 hours to compare the rise or fall in levels. Results take about one hour. If a heart attack was suspected these tests will continue for 1-2 days. Risks for this assessment are minimal unless a patient has an ongoing bleeding disorder such as a hemophiliac. If a person is prone to bruising after needle contact, there is a high probability of this side effect. Tests results are effected by a variety of reasons including statin use for cholesterol, heavy alcohol use, recent heavy exercise or surgery etc. Essentially other factors that are putting extra work on the heart can vary the initial results.
- 6. Doppler Ultrasound The machine pictured to the right can produce an image based on the movement of sound-echo waves bouncing off tissues and organs This is a non-invasive way to measure the velocity of blood as it moves through the vessels and helps to diagnose blood clots or deep vein thromboses A highly utilized test point is a patient’s neck that contains the carotid artery. Clogging of this artery, as it supplies the oxygenated blood to the brain, can result in a stroke if clogged
- 7. Doppler Ultrasound (cont.) Risk factors that help physicians assess when to perform this type of scan: Strong family history of CHD. According the the NCEP (National Cholesterol Education Treatment Panel) an immediate family member who’s had an event prior to the age of 55 (if male) and 65 (if female). Advanced age, typically men past age 40 and women who have undergone menopause Elevated blood cholesterol. NCEP defines high cholesterol for a high risk patient as total levels >200mg/dL, Triglycerides >150, LDL >100 and HDL <40. Diabetes (Type I or II) This non-invasive procedure is an FDA approved surrogate marker to assess the carotid artery as a predictor of what is likely occurring in the coronary arteries. The image is immediately produced on a video display screen that looks like a television screen or monitor. It’s created based on the type of body structure that the sound travels through, amplitude, frequency, and time it takes for the signal to return from the tissue to the transducer.