diagnostic procedures Flashcards
what is the EVH (Eucapnic Voluntary Hyperpnea) challenge?
the sensitive and specific diagnostic method that triggers exercise-induced bronchoconstriction (EIBC) by hyperventilation of safe concentrations of dry gases
what is the EVH challenge protocol?
- prior:
- refrain from taking short-acting bronchodilators for 8 hours
- refrain from taking long-acting/sustained release bronchodilators for 48 hours in order to maximize the airway response
- FEV1 is taken before, 3 times.. highest one is the baseline for the test
- a ventilation rate of 21x FEV1 at baseline = a positive response for those with asthma
- a ventilation rate of 30x FEV1 at baseline is recommended for those without a diagnosis of asthma
- FEV1 assessed after 5, 10, 15, and 20 mins post challenge
what do different EVH responses mean?
- the percent decline between the FEV1 obtained pre-challenge and the FEV1 obtained post-challenge is used to determine the airway response
- EVH response >12% is considered a positive response
- FEV1 baseline - lowest FEV1 post-EVH x 100 = % decline
what will the FEV1 range be with someone with COPD?
between 50-79% of the predicted normal values with an FEV1/FVC of less than 70%
what are symptoms of COPD?
- SOB after activity
- cough & sputum production are more noticable
what is pulse oximetry?
measuring oxygen saturation or the percentage of hemoglobin saturated with oxyen in arterial blood
- normal levels = 95-100%
- 88% or below = hypoxemia
what is a holter monitor?
ambulatory or portable electrocardiogram (ECG)
- records the electrical activity of the heart continuously over 24 hours or longer
- a standard or “resting” ECG is one of the simplest and fastest tests used to evaluate the heart
why do people use holter monitors?
for patients suspected of/or with atrial fibrillation, pre ventricular contractions, pre atrial contractions, atrial flutter, and bradycardia
why would someone order a cholesterol test?
to get a better understanding of risk factors of a heart attack or other types of CVD
what does it mean when you have high triglycerides?
- you regularly eat more calories than you burn
- high levels can increase your risk of heart disease
how low should your triglyceride levels be?
less than 150 mg/dL (1.7 mmol/L)
what is non-high density lipoprotein (non-HDL-C)?
the difference between total cholesterol and HDL cholesterol
- includes cholesterol in lipoprotein particles that are involved in hardening of the arteries
what are high sensitivity C-reactive proteins (HS-CRP)?
- a protein made by the liver that plays an integral role in the body’s response to injury and infection
- key in the inflammatory response
- greater inflammation = increased risk of heart attack, stroke, and other CVDs
- buildup of fats, cholesterol and other substances (plaque) can resrtict blood flow, triggering a blood clot
why should HS-CRP tests be done multiple times, and how often?
- CRP levels can temporarily increase by many situations (ex: cold, or going for a long run)
- should be done twice, two weeks apart
what HS-CRP levels indicate higher risk of heart disease and what medications help?
- above 2.0 mg/L
- cholesterol-lowering statin medications
what is the purpose of testing for troponin?
- troponin T is found in heart muscle
- mesuring levels can determine whether or not a heart attack has occured and can help determine risk of CVD
- increased levels of troponin T = greater risks of CVD in those without symptoms
what is an echocardiogram and how is it done?
- a graphic outline of the heart’s movement
- ultrasound from a hand-held wand placed on the patient’s chest (AKA transthoracic echocardiogram)
- often combined with Doppler ultrasound and colour Doppler to evaluate blood flow across the heart’s valves
what is a transesophageal echocardiogram (TEE)?
- echocardiogram that provides clearer. images of the heart that are difficult to view with a standard echo
- always preceded after the standard echocardiogram
- ultrasound probe inserted in the esophagus to rest closer to the heart
what is the purpose/goals of a coronary artery bypass graft (CABG)?
- use for those patients with coronary artery disease to improve blood flow to the heart
- goal:
- improve the patients quality of life
- decrease angina, and other CVD symptoms
- improve the pumping action of the heart
- lower risk of heart attack
- allow patient to resume/begin a more active lifestyle
what is the procedure for CABG?
- take a healthy artery/vein from body and connecting/grafting to the blocked coronary artery
- healthy artery will go around (bypass) blocked artery and blood
- chest bone opened to access the heart
- heart gets stopped by medication & heart-lung bypass machine used to keep body functioning
- after surgery, blood flow to heart is resotred and heart typicall will start beating on its own
what is the success rate for CABG?
- sometimes patients will need a repeat CABG is grafted arteries/veins become blocked or if there are new blockages
- 85% of patients who undergo CABG experience reduced symptoms, less risk of heart attacks, and a 10 year decrease in dying
what is off pump CABG?
- similar to traditional CABG since the chest bone is opened, but the heart isn’t stopped, and heart-bypass machine isn’t used
what is coronary artery bypass grafting and why is it used?
- similar to off-pump CABG but there is no large cut to open chest bone
- uses small incisions on the left side of the chest between the ribs
- used for bypasing the blood vessels in front of the heart
- done less often than other CABG types
- not done on those who need one or two coronary arteries bypassed
what valves are most commonly replaced?
aortic valve
mitral valve