2B: Cardiac Testing Flashcards
What is the typical hematocrit value for women?
37-47%
What is the typical hematocrit value for men?
40-54%
What is normal hemoglobin for women?
12-16 g/dL
What is normal hemoglobin for men?
14-18 g/dL
What is normal WBC count?
4,500 - 11,000 uL
What electrolytes are most important for cardiac function?
Potassium, sodium, calcium, CO2
What value is considered hyperkalemia?
Potassium > 5.9 mmol/L
What value is considered hypokalemia?
Potassium < 3.5 mmol/L
What happens with hyperkalemia?
Na cannot come in, bradycardia, decreased ability for myocardial contractility
What happens with hypokalemia?
K influx, life threatening arrhythmias with tachycardia
What is the normal range for Na2+?
136-143 mmol/L
What is the normal range for Ca+?
4.5-5.3 gm/dL
What value is considered high CO2, and what is the effect?
> 30 mmHg, can result in alkalytic state of muscle weakness
What is an EKG used to diagnosis?
Specific arrhythmias that can be causing symptoms, measure disease progression, and effectiveness of treatment
When is a holter monitor used?
After syncope or repeated arrhythmias - 24 hrs of up to 2 weeks long
Describe a graded exercise stress test?
Testing with either a treadmill or bike to assess exercise tolerance and ischemia
What is the most common graded exercise stress test?
Bruce protocol
When is a stress test indicated?
Chest pain with activity, severe dyspnea, suspicion of CAD and ischemia, risk assessment
What will the results of a stress test be used for?
Determine the need for further testing, location of ischemia, exercise prescription
What are the three reasons why a stress test will be stopped?
- EKG changes
- Angina symptoms
- Extreme dyspnea
What three EKG changes indicate terminating a stress test?
- > 2mm ST segment depression
- Inverted T wave
- Significant Q wave
Describe dyspnea that would cause a stress test to be terminated?
3-4 on dyspnea scale with LE fatigue
What is echocardiography?
Ultrasound of the heart, measure of wall motion
What information does an echo provide?
Valve function, size of ventricle, thickness, integrity of interatrrial and interventricular septums. Also gives value of EF
What are the limitations of an echo?
Posterior wall structure and motion due to interference from spinal bone
When is an echo indicated?
After MI, CHF, unstable angina, syncope episode, cardiomyopathy
What is a Thallium stress test?
Uses a radioactive nuclear marker to detect myocardial perfusion
What does a Thallium stress test look at?
Ischemia by assessing Thallium in blood flow trough the myocardial tissue
What is the risk associated with coronary angiography?
2% risk of stroke
Coronary angiography is a definitive diagnosis for what?
CAD, valvular disease, congenital defects
Describe how a cardio cath is placed
Threaded through femoral or radial artery into coronary artery and injects dye
When is a cardiac catheter used?
Unstable angina, acute MI, positive stress test, positive echo
CAD blockages up to what % are considered mild?
70%
What is indicated with blockages of > 90%?
Conservative management unless risk of MI is imminent, surgical
What are the precautions for cardiac cath with femoral artery entry?
6-12 hours of bedrest with sandbag or compression to prevent bleeding
What are the precautions for cardiac cath with radial artery entry?
Nothing major, can ask MD about use of AT
What does TEE stand for?
Trans Esophageal Echocardiogram
What is a TEE?
Ultrasound head is fiber optic and threaded down the esophagus to give improved visualization of heart structures and function
When is a TEE indicated?
Posterior views
Describe PET
Nuclear technique, provides visualization
What information will PET provide?
Metabolic functions: glucose and fatty acid metabolism, blood flow to the heart
Dynamic functioning of myocardium without exercise
What are draw backs of a PET?
Very expensive, not readily available
What goes MUGA stand for?
Multigated Acquisition Imaging or Gated Pool Imaging
What is a MUGA?
Non-invasive technique to calculate left ventricular ejection fraction - uses multiple EKG views
What is the advantage of a MUGA?
Less expensive than PET
What information does a CT provide?
Cardiac structures and ventricular function
When is a CT indicated?
Pts with probable coronary stenosis