Investigations/imaging - MRI, CT, stress test Flashcards
What are the complications of coronary angio?
Local vascular complications are the most common complications
(acute thrombosis, distal embolisation, dissection, bleeding/haematoma, pseudoaneurysm, arteriovenous fistula)
Major - death, MI, stroke, serious arrhythmia
Contrast reaction
What is significant stenosis?
> 70% diameter stenosis on angio
What is fractional flow reserve (FFR)?
It is a functional test to determine if the stenosis is flow limiting or haemodynamically significant
Measured by distal coronary pressure / proximal coronary pressure
Use of FFR in multivessel disease resulted in less stent use with improved outcomes
If FFR >0.75 —> can be safely managed conservatively
If FFR <0.75 or 0.8 —> PCI preferred
What are the features of spontaneous coronary artery dissection (SCAD)?
Typically affect young/middle aged women - most present with ACS
Without known CAD or risk factors
Unclear aetiology ?hormonal, ?CTD
Treatment is conservative - avoid PCI esp if non critical obstruction
Associated with fibromuscular dysplasia - screen cerebral and renal arteries
When to revascularise?
In stable angina - mainly symptomatic benefit
ACS (unstable angina/NSTEMI) - early invasive strategy preferred
If LV dysfunction present
In multivessel disease - PCI equivalent to CABG in low Syntax score, CABG preferred in intermediate to high Syntax score
When is CTCA most useful?
It has high sensitivity and is useful in excluding obstructive CAD
Can be used in below contexts:
- Most useful to exclude obstructive CAD
- Equivocal stress test
- Non-acute chest pain with intermediate risk
- Acute chest pain with normal ECG and biomarkers
- Cardiomyopathy – exclude CAD
- Coronary anomalies
- Patency of grafts
- Prior to redo cardiac surgery
Warranty period of normal CTCA >5 years
Functional test is preferred if already known CAD
Cardiac MRI - What is late gadolinium enhancement?
Delayed enhancement/wash out - in regions of fibrosis, necrosis, expanded extracellular space
Correlates with scar on histology
Black area = normal myocardium
How do you differentiate ischemic vs non-ischemic on late gadolinium enhancement on cardiac MRI?
Ischemic condition always involves subendocardium
In non-ischemic subendocardium is spared
What is the best way of assessing for cardiac involvement of systemic sarcoidosis?
Cardiac MRI - subepicardial, dense, often extensive (can have almost any pattern of LGE, mimics many conditions)
When is T2* mapping used on cardiac MRI?
Iron quantification
What are some applications of cardiac MRI?
Congenital heart disease - anatomy, function (EF), flow quantification, shunt fraction
Dilated cardiomyopathy - MRI more reproducible than echo, allows detection of small changes in EF, LV thrombus can be missed on echo. LGE is a prognostic factor as it can predict higher risk of major adverse cardiac event
Hypertrophic cardiomyopathy - LGE represents fibrosis and predicts adverse events
Amyloidosis - mimics HCM, diffuse extending from subendocardium
Anderson Fabry disease - mimics HCM, it is a treatable deficiency in alpha galactosidase A
What is calcium scoring cardiac CT?
Identify calcified atherosclerotic plaques (coronary calcium almost pathognomonic of coronary atherosclerosis). Non-contrast scan, powerful prognostic marker
Use in ASYMPTOMATIC patients
What are different types of stress testing?
- ETT
- Stress echo - exercise vs dobutamine stress
- Stress nuclear myocardial perfusion imaging - exercise vs vasodilator stress (higher sensitivity than echo, used for risk stratification before non-cardiac surgery)
- Stress perfusion MRI - usually vasodilator stress, greater accuracy than nuclear
