Scans & Tests Overview Flashcards
List 3 types of angiography
- MRI angiography
- CT angiography
- Catheter angiography
Describe MRI angiography
What it images?
What it looks for?
Indications for its use?
Injected with dye, get and MRI scan
Looks for:
- stenosis
- occlusions
- aneurysms
- other abnormalities
Indcations:
- Ischaemic heart disease
- Stroke
Describe CT angiography
Injected with dye, get and CT scan
Very good anatomical detail
Less resolution than angiograms
Can cause contrast allergy and nephropathy
Looks for:
- stenosis
- occlusions
- aneurysms
- other abnormalities
Indcations:
- Ischaemic heart disease with non-typical presentation
- Stroke (cerebral and carotid scans)
Describe catheter angiography
Cateter goes to correct area via your arteries, injects dye, xray is taken
Describe Duplex Ultrasound
Ultrasound scan that scan tell movement relative to the scanner
Indcations:
- Peripheral arterial disease
- Peripheral venous disease
Describe ultrasound scanning
Indcations:
- Abdominal aortic aneurysm (but can’t detect rupture)
Describe perfusion scanning
Nuclear medicine test
Shows vessel occlusion
Indicated for non-acute ischaemic heart disease if:
- exercise ECG not possible
- exercise ECG negative despite classic presentation
- exercise ECG is ambiguous
List relevant blood tests
- Glucose
- LDL
- HDL
- Triglyceride
- Thrombophilia screen
- Creatine kinase
- Troponin I and T
List different types of ECG
- Standard 12 lead ECG
- Exercise (stress test) ECG
- 24 hour monitoring ECG
Describe the ABPI and its use in diagnosing peripheral vascular disease
ABPI = Ankle-Brachial Pressure Index
ABPI = (Ankle pressure)/(brachial pressure)
Normal = 0.9 - 1.2 Claudication = 0.4 - 0.85 Severe = 0 – 0.4
What is the required level of troponin I and T to diagnose an MI?
99th percentile
Why are troponin I and T blood tests good for MI diagnosis?
- Specific to heart muscle
- Their amount indicates the extent of damage
- The increase lasts from 4-6 hours after infarct to ~7 days after, thus they can be used to detect a previous MI
Does a troponin T and I increase = an MI
Why?
No, as other things can cause an troponin rise
List things that can lead to an increase of T and I troponins
STEMI
NSTEMI
Chronic heart failure Massive PE Hypertensive crisis Sepsis Stroke/TIA Pericarditis and Myocarditis Post Arrhythmia
What are BNP and NT-pro-BNP?
What are they used to diagnose?
BNP = Brain Natriuretic Peptide
NT-pro-BNP = the precursor to BNP
used to diagnose heart failure
Describe an echocardiogram
Indications?
Looks for?
Ultrasound of the heart
Indcations:
- Cardiac thrombus
- Heart valve deformities
- Heart deformities
- Hemopericardium (or other excess pericardial fluid)
Looks for:
- Chamber size
- ventricle function
- ejection fraction
- valve disease
- pericardial disease
- impaired filling
- wall abnormalities (e.g. post MI)
Describe cardiac MRI
Used in heart failure
To see:
- left ventricle wall thickness
- the amount of scarring (viable myocardium)
What are the 2 types of echocardiogram?
When would you use each type?
Transthoracic echocardiogram (TTE):
- non-invasive
- like a regular ultrasound
- doesn’t work well with some lung diseases (e.g. COPD)
Transoesophageal echocardiogram (TEE):
- via a probe that goes down the oesophagus
- used if TTE won’t give good results
Describe an electrophysiological study
An arrhythmia is deliberately triggered in the heart so that its mechanism and pathway can be studied
Is an invasive procedure
You can treat the arrhythmia, via ablation of accessory pathways, as part of the same procedure
