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
what is the most common surgical procedure for aortic stenosis/narrowing of the aortic valve?
aortic valve replacement
what is another common valve problem that may require valve replacement?
aortic regurgitation
- AKA aortic insufficiency
what is aortic regurgitation?
the valve allows blood to return backward throught the valve and into the heart, instead of moving it forward and out to the body
- can eventually lead to heart failure
what is mitral regurgitation?
- the mitral valve allows oxygenated blood to flow backward into the lungs instead of continuing through the heart as it should
- may experience SOB, irregular heartbeats, and chest pain
how do surgeons fix damaged valves?
- can repair/replace it with an artificial valve or biological valve made from pig, cow, or human heart tissue
- one option is to insert a catheter through a large blood vessel, guide it to the heart and inflate & deflate a small balloon at the tip of catheter to widen the narrow valce
what is the success rate after a mitral valve repair?
- 95% of patients are free of reoperation at 10 years
- 90% free of reoperation at 20 years
when would some undergo cardiac ablation?
- unsuccessful with medications to treat arrhythmia
- have had serious side effects from medication to treat arrhythmias
- have a certain type of arrhythmia that respond well to ablation
- have a high risk of complications from their arrhythmias
what is the procedure of a cardiac ablation?
- scarring or destroying tissue in your heart that triggers or sustains an abnormal heart rhythm
- referred to as the MAZE procedure since surgeons create a maze of scar tissue throughout the heart
- sometimes done through open-heart surgery, but often done through catheters
what is the success rate of cardiac ablations?
- 70-95% of people free of AFib long term after procedure
- some may still need medication after
what is a heart transplant and the criteria to get one?
- surgical procedure used to treat the most serious cases of heart disease
- criteria: people who’ve experienced heart disease/failure due to:
- a cogenital defect
- coronary artery disease
- a valve dysfunction or disease
- a weakened heart muscle
- cardiomyopathy
- also criteria considered:
- age (under 65)
- overall health
- attitude (commitment of change from patient)
how is heart failure caused in adults?
- a weakening of the heart muscle
- coronary artery disease
- heart valve disease
- a heart problem you’re born with
- dangerous recurring abnormal heart rhythms not controlled by other treatments
- failure of a previous heart transplant
what are risks of heart transplants?
- rejection of the donor heart
- immunosuppressants helps avoid that
- primary graft failure
what is primary graft failure?
- the most frequent cause of death in the first few months after transplant
- the donor heart doesn’t function
what is a ventricular assist device?
- a mechanical pump implanted in your chest that helps pump blood from the lower chambers of your heart (ventricles) to the rest of your body
- commonly used as temporary treatments for people waiting for heart transplants
