Perfusion A Flashcards
Preload
volume of blood entering the ventricles at the end of diastolic
Afterload
resistance left ventricles must overcome to circulate blood (systolic) and eject the contents
Cardiac output
Heart Rate*Stroke Volume
Normal cardiac output
4-8 L/min
Ejection Fraction
if low, heart is failing
amount of blood pumped out of the ventricle/total amount of blood in the ventricle=EF
Normal 55-70%
MAP
Mean Arterial Pressure
SBP+2(DBP)/
3
Normal 60-70
Angina
“heart attack”
pain caused by insufficient coronary blood flow resulting in lack of oxygen
Chronic stable angina
pt needs rest; deep breaths
-deep chest pain pain radiates to neck jaw shoulders back and arms -pain radiates L side normally -n/v; indigestion -dyspnea, diaphoresis, lightheadness
Atypical Angina
Women
indigestion, aching jaw, fatigue, sleep disturbances, shob
may not have “chest pain”
Atypical Angina
Elderly
no chest pain
shob, disorientation/confusion
Unstable Angina
Acute Coronary Syndrome
Pre-infarction pain, WILL FEEL LIKE AN EMERGENCY -Usually lasts longer than 15 minutes -Causes severe activity limitations -Is not relieved by rest and nitroglycerin
people have this before a heart attack
Variant (Prinzmetal’s) angina
Due to coronary artery spasms
Similar to stable angina
Lasts for a longer period of time
Labs for Angina
Lipid profile
(triglyceride 35-160,
<200 cholesterol)
Na 135-145 K 3.5-5.3 Ca 8.5-10.5 Mg 1.5-2.5 BUN 6-20 CRT 0.7-1.7 Glucose 65-99
C-Reactive Protein
- shows inflammation in the body; not specific to the heart
- can have a role in the development and progression of atherosclerosis
Coagulation studies
want this to be high for blood to be thinner
PT 11-`13.5 seconds
PTT 20-35 seconds (Heparin)
INR 0.9-1.9 (Coumadin)
Troponins T and 1
found only in patients with myocardial muscle ischemia or necrosis, so any rise in value indicates possible MI (levels rise within 3-6 hours)
Creatinine Kinase MB(CK-MB)
most specific for MI (rises 2-3 hours after cardiac cells are injured and remains elevated for 12 hours)
Myoglobin
is a small oxygen-binding protein found in heart and skeletal muscled which is released when heart or skeletal muscles are injured
ECG
The electrocardiogram provides a graphic record of the heart’s electrical activity.
- dysrhythmias
- electrolyte imbalances
- conduction abnormalities
- enlarged heart
- effects of drugs
Exercise ECG (Stress Test)
- Non-invasive
- Patient should rest, avoid smoking and use of alcohol
- No food 2 hours before test
Pharmacological ECG (Stress Test)
- Invasive (used when patient cannot tolerate exercise)
- Must have IV access
- -Dobutamine- strengthen heart muscles
- -Dipyridamole- anticoagulant
Contraindications for CST
- Severe HTN
- HF
- Unstable angina
- Acute myocarditis
Goals for Cardiac Stress Test (CST)
- Target heart rate: 80-90% of maximum predicted heart rate
- Discontinue stress test if significant changes noted in the ECG especially changes in ST segment
Trans-Esophageal Echocardiography (TEE)
- Examines cardiac structure and function
- May be done with pharmacologic stress test
- NPO 4 to 6 hours before and 4 hours after procedure (avoid aspiration)
- IV access, moderate sedation
- Monitor for:
- –Bleeding
- –Sore throat
- –Aspiration
- –Vocal cord paralysis
- –Pain (could indicate perforation)
- monitor airway and swallow test