Card Cath Flashcards
Indications for cardiac catheterization
Suspected CAD, MI, sudden cardiac death, valvular heart disease, congenital heart disease (before surgery), aortic dissection, pericardial constriction/tamponade, cardiomyopathy, heart transplant
What is the Right Anterior Oblique (RAO) view?
RAO is shooting from bottom left to the right shoulder; good for crossing the aortic valve (TAVR)
What is the Left Anterior Oblique (LAO) view?
LAO is shooting from the bottom right to the left shoulder; good view for entering the coronary artery ostia in the aortic root
What view can you see the left main in its entirety?
LAO caudal (spider view)
What is the caudal view best for? Cranial views?
Caudal: LCX
Cranial: LAD
What is the RAO cranial view best for? LAO cranial?
RAO Cranial: LAD with septal perforators going to the left
LAO Cranial: origins of diagonals along the LAD to the right
If you see the diaphragm, what view is it most likely?
Some cranial view (but not always)
What can you see in the LAO cranial view (left)?
LAD courses straight down + septal perforators to the left, diagonal to the right; can see PDA if left-dominant circulation
What can you see in the LAO caudal view (left)?
- The proximal and mid LCX
- Origins of obtuse marginal (OM) branches off LCX
- Left main with ostiums of the LAD and LCX
What can you see in the RAO caudal view (left)?
- LCX
- Obtuse marginals
- Proximal LAD
What can you see in the RAO cranial view (left)?
- LAD
- Septal perforators of LAD
- Diagonal branches of LAD
- Distal LCX and left-sided posterolateral branches
What can you see in the lateral view (left)?
Best view of mid and distal LAD + ramus intermedius branch is well visualized + best view to demonstrate insertions of LIMA to LAD
What views show you the RCA?
LAO cranial and RAO cranial
What can you see in LAO cranial view (right coronary)?
- Origins of RCA and entire length of RCA
- PDA bifurcation (but RAO is better)
What can you see in RAO cranial view (right coronary)?
- RCA (LAO is better for RCA course)
- Bifurcation of the PDA and posterolateral branches
What can you see in the PA cranial view (right)?
Best view for PDA and posterolateral branches (if right-dominant)
What can you see in the lateral view (right)?
Shows RCA origin and mid-RCA
What are the best views for the LIMA?
RAO cranial, LAO cranial, and lateral
How are coronary artery stenoses assessed?
Minimal/mild CAD <40%, Moderate 40-70%, Severe 70-95%, Total occlusion 100%
What are TIMI flow grades?
Qualitative assessments of flow by observing distal runoff; developed from the Thrombolysis In Myocardial Infarction Studies (1980s)
What is TIMI 0 flow?
TIMI 0 = No flow beyond total occlusion
What is TIMI 1 flow?
TIMI 1 = Some contrast filling beyond culprit lesion but no significant antegrade flow
What is TIMI 2 flow?
TIMI 2 = Distal flow in artery less than in non-infarcted arteries
What is TIMI 3 flow?
TIMI 3 = Distal flow rate in artery is equal to non-infarcted arteries
What is fractional flow reserve?
Used to determine ischemic potential of a questionable (40-70%) lesion; ratio of aortic pressure to post-stenotic pressure in coronary artery during hyperemia (adenosine IV infusion or intracoronary bolus)
What is the formula for fractional flow reserve?
Mean pressure of distal artery / mean pressure of aorta
What is a normal fractional flow reserve? What if it is 0.75?
Normal is close to 1; if FFR < 0.75, it is associated with inducible ischemia
What are indications for percutaneous coronary intervention?
Angina pectoris despite optimal medical therapy, mild angina with evidence of ischemia and high-grade lesion, unstable angina or NSTEMI, STEMI, angina after CABG, restenosis after PCI, LV dysfunction, arrhythmia 2/2 ischemia
What are contraindications for PCI or stent?
Inability to tolerate DAPT, need for surgery within 2 weeks, inability to dilate lesion, hypersensitivity to stent material, inability to tolerate anticoagulation during PCI (ACT goal > 250)
What is the rate of restenosis after DES placement?
<10%
Why and when does restenosis occur?
Intimal hyperplasia usually within the first 6 months
What is the rate of in-stent thrombosis?
1-2%
What is the most common case of in-stent thrombosis?
Most commonly due to cessation of antiplatelet therapy or if stent is suboptimally expanded
What are the anticoagulation guidelines for a PCI?
Loading dose of ASA (162-325mg) > 2 hours prior to the procedure; then 325mg daily for one month followed by 81mg daily
What are the anticoagulation guidelines for stents?
Loading dose of P2Y12 inhibitor; DAPT for 12 months (DES) or 4 weeks (bare metal stent)
Normal right heart cath pressure and O2 sats
RA 0-4 (75%), RV 25/5 (75%), PA 25/10 (75%), PCWP 7-12
When are right heart caths necessary?
Valvular heart disease + CHF + RV dysfunction + pericardial disease + cardiomyopathy + intracardiac shunts + congenital abnormalities
How is the mean pressure gradient calculated for AS?
The area under the curve between the LV pressure and the aortic pressure through the systolic ejection period
Difference in LV pressure rise for a fixed obstruction versus a dynamic obstruction
Fixed = steady upstroke of the aortic pressure while the AV is open; Dynamic = aortic pressure rises rapidly at the onset of AV opening and then develops a spike and dome as the obstruction occurs in late systole
When should PCWP be measured?
End-diastole and end-expiration
How can you calculate mitral valve area using pressure measurements?
Mean gradient between LA and LV in diastole (LV pressures + PCWP) which is then used to calculate the MVA
Indications for left ventriculography
Determining LV function in CAD, myopathy, or valvular heart disease + VSD identification + MR severity + quantification of myocardial mass
What is the gold standard to assess cardiac structure and function?
Cardiac MRI
What are contraindications for cardiac MRI?
Cerebral aneurysm clips + PPM/ICD + PA catheter + cochlear implant + metallic foreign bodies + severe CKD
What is the only valve that is NOT cardiac MRI safe?
Starr Edwards valve (1968)
Difference between Spin Echo and Gradient Echo for cardiac MRI?
Spin echo = blood is black + good for assessing anatomy + good for cardiomyopathy/tumors/myocarditis; Gradient echo = blood is bright + good for assessing function/flow/angiography + detects edema/inflammation
What kind of signal is seen with gadolinium injection?
T1-weighted images are bright (tissue takes up gad)
What is late gadolinium enhancement?
5-20 minutes after gadolinium, it washed out of normal tissue and is retained in pathologic tissue only (i.e. in MI, myocarditis, cardiomyopathy, cardiac neoplasms, genetic diseases)
Advantages of MRI perfusion studies
Higher spatial resolution + no radiation exposure + no attenuations + provides perfusion imaging based on changes in signal intensity during the first pass of IV contrast
How does stress myocardial perfusion imaging work?
Stress is applied (dipyridamole or adenosine) and contrast is given; myocardium that is stenotic does not take up more contrast so it is darker (lower intensity)
What is a myocardial perfusion reserve index?
The relative difference of perfusion before and after vasodilation
