410 Exam 2 Material Flashcards
echocardiography
- sound waves emmited from an ultrasound transducer through body tissue
- safe, cheap and non invasive
Doppler
waves reflect off moving objects and undergo a frequency shift according to moving objects velocity, direction; computer generates images based on direction of returned waves
Dobutamine
stimulates beta receptors in myocardium causing increased HR and contractility, thus increasing myocardial oxygen demand (mVo2)
ischemia (Stress echocardiography)
Normal at rest but during exercise, hypokinesis develops
Adenosine/Dipyrimadole
causes coronary vasodilation
- BF to myocardium incr. through healthy coronary vessels
Normal responses for stress echocardiography
LV decr. in size during contraction, EF increase, an increase in wall motion
Diagnosis using bl related signs of heart damage
- if myocardial injury
- cardiac troponin 1
Appears w/in 4-6hr; elevated for 5-10 days
Cardiac Troponin T:
- Also appears w/in hours and is elevated for up to 2 weeks
CK-MB:
- Appears w/in 4-6 hr; normal w/in 72hr
Test Sensitivity (Test Outcome)
ability to accurately diagnose a disease
Test Specificity (Test Outcome)
Ability to accurately rule out a disease
Diagnostic Procedures
-many meds or CV conditions prevent accurate diagnosis (BBB, LVH, DIGITALIS PACEMAKERS)
-• 50% of patients w acute mi don’t display characteristic ECG changes; many issues don’t show up w resting ECG
• Sensitivity and specificity are greatly improved w additional tools
Risks for Cardiac Catheterization
- Dislogement of some plaques
- Ischemic cells rely on glucose
- Myocardial perforation
- if catheter hits heart wall it could create arrhythmia
- Infection
Technitium
Detects myocardial bl flow (hibernating tissue)
Thallium
good at detecting ischemic and scarred myocardium
