Radiology - CVS Flashcards
What are the 3 things we look for in PE?
Is the heart big?
Is there pleural effusions?
Is there interstitial edema?
Clinical tip for CHF
- progression of CHF may be one of the only signs that a patient’s CAD is progressing
- things as insignificant as viral infections can lead to CHF
Cardiac output
Measure of the volume of blood that your heart pumps per unit of time.
Stroke volume x heart rate = cardiac output
Why is cardiac output important?
it is crucial to adequate pulmonary or peripheral perfusion
Why is ejection fraction important?
we really want to know is how well the heart is working or how much blood is being pumped?
Ejection fraction formula
(end diastolic volume - end systolic volume) / end diastolic volume = ejection fraction
Mitral stenosis
- Back pressure from an incompetent mitral valve increases the pressure in the left atrium (LAA) and that “can” be seen in a CXR
- With continued backup, the pulmonary artery would be under increased pressure (pulmonary hypertension)
Double density sign
Means you have left atrial enlargement.
–When you look at the lateral xray you’ll see posterior enlargement of the heart.
Mitral stenosis vs. regurgitation on film
- Splaying of the carina by massively enlarged atrium
- Enlarged heart favors mitral regurgitation over mitral stenosis
Why is cardiac blood supply important?
- Coronary arteries are end arteries – they have little or no anastomosis
- Cardiac tissue has a high metabolic need
- Cardiac tissue extracts nearly all oxygen available on its pass through the heart (the blood leaving the heart is completely cyanotic)
Thus, any impediment to flow, decrease in rate or suboptimal conditions leads to immediate tissue ischemia
Do cardiac arteries fill on systole or diastole?
-They are the only arteries to fill on diastole
Coronary Angiography
- Imaging of coronary arteries with fluoroscopy and contrast dyes injected directly into arteries
- Definitive test for evaluation of CAD
Indications for Coronary Angiography
Patients who have reversible ischemia and patients with unstable angina.
Important Findings on Coronary Angiography
- Narrowing of 50% is considered Hemodynamically significant
- Narrowing >70% are usually needed to produce significant ischemia/symptoms
Relative Contraindications for Angiography:
- Creatinine greater than 1.5
- Anytime measurement of Creatinine of greater than 2.0
Prevention of kidney toxicity by high molecular weight contrast dyes
- pretreat with bolus IV hydration, 2hrs before and 2 hrs after
- acetylcysteine (Mucomyst) for two days and proceed to contrast study
Coronary angiography requires
multiple separate views
Indications for Noninvasive Cardiac Testing
Confirm diagnosis of angina – stable
*requires a patient that is generally healthy because they have to be able to reach specific heart rates.
Contraindications for Exercise Stress Testing
- Patients where there is ongoing unstable angina or a suspicion of myocardial infarction!!!!!
- Treadmill tests in women are misleading (50%) and seldom done
Other Considerations for Stress Testing
-To evaluate success of non-invasive therapies (conservative treatments)
-Equivocal in asymptomatic patients
–false positive may exceed true positives
–this leads to “disability” and anxiety
used if there is a strong family history of early cardiac death or hypercholesterolemia
–used in occupations where there is high risk if undetected – airline pilot