Cardiac Flashcards
how can ‘stress’ be initiated in a myocardial perfusion study
physical - treadmill
pharmacologic-adrenergic (dobutamine)
pharmacologic - vasodilatory (adenosine, dipyridamole, regadenoson)
what is the gold standard for evaluating cardiac viability ?
F-18 FDG PET
how does thallium perfusion study work to investigate myocardial perfusion
thallium is only taken up in viable myocardial tissue, therefore during stress - if the tissue is ischaemic it won’t be taken up, but during rest it will revascularise and be taken up again .
when would you use a pharmacological stress ?
patients who can’t exercise, left bundle branch block
how does dipridamole work ?
caused endogenous adenosine to acculumate - this cause vasodilation of the coronary arteries - therefore if a coronary artery has critical stenosis, it won’t be able to relax and therefore have relative perfusion
what must be held before dipyridamole is given ?
caffeine and theophylline
what is the reversal agent to dipyridamole and adenosine ?
aminophylline
when is a vasodilator contraindicated ?
COPD, severe asthma, recent caffeine ?
what would you give if a vasodilator is contraindicated ?
dobutamine ( B-agonist that increases myocardial oxygen demand)
what does myocardial stunning indicate and what is it ?
significant obstructive coronary artery disease
Myocardial stunning is when an acute transient myocardial ischaemic event results in a prolonged wall motion abnormality which eventually resolves.
how can you assess motion artefact on a cardiac study ?
sinogram - will show horizontal lines at the areas of movement
what is hibernating myocardium :
viable but hypo perfused myocardium due to severe chronic schema, which may benefit from revascularization
what is stunned myocardium
delayed recovery of contractile function despite reperfusion after a transient ischaemic insult
what is the gold standard for evaluating myocardial viability and hibernation /
FDG - PET
what is the FDG Pet uptake known as in a hibernating myocardium ?
Increased - mismatch
Low perfusion and normal/increased metabolism
what is amyloidosis ?
extracellular deposition of insoluble proteins
what does left atrial enlargement and cardiomegaly indicate with regards to cardiac valve disease
mitral regurgitation
what does left atrial enlargement and a normal sized heart indicate ?
mitral stenosis
what does enlarged aorta and cardiomegaly indicate ?
aortic regurgitation
what does an enlarged aorta and normal sized heart indicate ?
aortic stenosis
what does the double density sign represent ? q
enlarged left atrium
what is a coronary artery CT angiogram the first line test for ?
patients with acute chest pain, in low to intermediate risk pateitns without known CAD - with normal cardiac enzymes and non-ischemic egg
what is the luminal diameter of a coronary artery ?
3mm
if a coronary artery arises from the pulmonary artery is it benign or malignant ?
malignant
which coronary artery courses are malignant ?
inter arterial course - between the aorta and pulmonary artery
intramural course - within the aortic wall
what is myocardial bridging ?
band of myocardium overlying a segment of a coronary artery most commonly seen in the mid or distal LAD
what is the agatston score ?
the total calcium In the coronary tree
what reporting classification is used to standardised cardiac reports ?
CAD-RADS
If there is a coronary artery stenosis of 25-49% what is recommended ?
preventative therapy
if there is a cadres 70-100% what is recommended ?
function tests, invasive coronary angiography and consider revascularisation
what sings indicate a high risk plaque (increased risk of ACS)
low attenuation (<30)
Spotty calcification
Napkin ring (Low attenuation core and higher outer ring)
Postive remodeeling
what are the main complication following coronary artery stenting ?
stent thrombosis and in-stent restenosis
what is the preferred diagnostic modality to assess coronary bypass grafts ?
cardiac catherterisation
what are the two most common causes of coronary artery dilatation ?
atherscerlosis and Kawasaki disease
In cardiac MRI what is the spin echo sequence used for?
high spatial resolution but slow to obtain - good for anatomy
in cardiac MRI what is the spoiled gradient recalled echo used for ?
faster but more suseptible to metal artefacts - used for quantitive measurements, perfusion and angiography
what is the balanced stead-state free precession gradient echos used for ?
very fast - high temporal resolution with good contrast between myocardium and blood pool. therefore looks at wall motion, valve function and volume quantification
what is the gold standard for evaluating LV volume, EF and mass ?
MRI Cardiac
what does a double IR technique used for ?
make blood black
what is a triple IR technique used for ?
make blood and fat black
what is first pass contrast enhanced perfusion MRI used for ?
evaluate myocardial perfusion. - normal myocardium enhances normally, decreased perfusion will be hypo enhancing.
do malignant masses have a more avid or less avid first pass perfusion?
more avid
what does myocardial tagging involve, and what is It used for ?
grid is placed over the myocardial tissue or mass. looks for movement by assessing how the grid lines change their shape
what does a subendocaridal late gadolinium enhancement mean ?
infarction
- as the subendocardium is most susceptible to iscahemia, and is always in a vascular teritory
what group of patients is circumfrential subendocarial late gadolinium enhancement seen ?
chronic cocain users
what does transmural LGE represent ?
nonviable scar
what are the classical findings of chugs myocarditis ?
Chagas - protozoan disease caused by trypanosome Cruzi .
Causes epicardial or mesocardial LGE specifically involving the apex
what might sarcoidosis of the heart look like on cardiac MRI ?
present with arrhtymias, restrictive cardiomyopathy.
Mesocardial or subepicardial LGE in a nodular or patchy pattern.
what would dilated cardiomyopathy look like on cardiac MRI
Dffused mesocardial LGE
what are non-iscahemic causes of subendocardial delayed enhancement ?
Amyloidosis - extracellular deposition of glycoprotein, causing biventricular myocardial thickening
Cardiac transplant
hypereosinophillic syndrome: eosinophilic infiltration of multiple organs
on a stress cardiac MRI, what does and oedematous region without LGE represent ?
myocardium at risk for ischaemia
what is the classic radiological finding of an acute papillary rupture post cardiac MI ?
acute pulmonary oedema in the right upper lobe due to acute mitral regurgitation
what are true LV aneurysms associated with.
occlusion of the LAD
what is a true LV aneurysm ?
focal out pouching affecting all layers of the muscular wall. usually wall thinning. No risk of rupture. Get medial management
how are cardiac pseudoaenurysms managed ?
surgical closure due to high risk of impending rupture
what is dressers syndrome ?
subacute immune-mediated pericarditis which occurs 2-6 weeks post MI. pericardial and pleural effusions
what is takotsubo ?
broken heart syndrome
High levels of stress causes reversible cardiomyopathy - ballooning of the cardiac apex, that looks like the Japanese lobster pot)
no coronary stenosis
what is arrhytogenic cardiomyopathy and what do patients require ?
fibrofatty replacement of the ventricular heart muscle - usually affecting the right ventricle. Patients at high risk of arrhtymias - therefore need an ICD
what is the most common cardiomyopathy ?
HCM - hypertrophic cardiomyopathy
what is hypertrophic cardiomyopathy :
AD - left ventricular myocardial thickening (diffuse or focal )
what does idiopathic hypertrophic sub aortic stenosis cause ? how big does it have to be to require an ICD ?
septal hypertrophy - resulting in left ventricular outflow tract obstruction. > 30mm needs an ICD.
more than 15mm indicate disease
what is restrictive cardiomyopathy ?
small, stiff thickening ventricles that impair diastolic (relaxing) filling.
what are the causes of restrictive cardiomyopathy ?
idiopathic, sarcoidosis, haemochromatosis, hyperoesinophillic syndrome and amyloidodid
what is dilated cardiomyopathy characterised by ?
diffuse cardiac chamber enlargement with impaired systolic function - so can’t pump the blood out properly
what further investigation is recommended in someone with a new diagnosis of dilated cardiomyopathy ?
catheter angiography
what might cause acquired bicuspid aortic valve
rheumatic fever
what are the causes of valvular aortic stenosis ?
congenital bicuspid aortic valve, age, rheumatic heart disease
what causes supra-valvular aortic stenosis ?
congenital abnormality or Williams syndrome
what causes subvalvular aortic stenosis
fibrous membrane beneath the aortic cusps, hypertrophic cardiomyopathy, narrowing of the LV outlet
does aortic stenosis cause heart enlargement ?
no, causes left ventricular hypertrophy but not and enlarged heart
what defines s a severe aortic stenosis ?
valvular area <1cm and a pressure gradient >40mmhg
does aortic regugitation cause an enlarged heart ?
yes
what is the most common cause of mitral stenosis ?
rheumatic heart disease
which part of the heart does mitral stenosis affect ?
causes left atrial enlargement, but no cardiomegaly
what is an abnormal thickness for the pericardium ?
> 4mm
where do most pericardial metastasis come from
Breast and lung
what is the most common primary pericardial tumour ?
mesothelioma
where do most pericardial cysts occur ?
right cardiophrenic angle
what is the most common benign primary cardiac tumour in adults ?
myxoma
where do most myxomas arise ?
left atirum - usually attached to the inter-atrial septum
what do myxomas look like ?
T1 looks similar to cardiac mucscl
t2 is hyperintense
calcification and blood products from bleeds are common
where do cardiac lipomas most commonly occur ?
in the right atrium - they follow fat signal on all MRI sequences
what does lipomatous hypertrophy of the interatrial septum look like ?
proliferation of fatty deposits within the inter-atrial septum but sparing the fossa ovals so looks like a dumbbell.
where do papillary fibroelastomas occur ?
cardiac valves - usually on the aortic valve.
what is the most common malignant primary cardiac tumours ?
sarcomas
where do angiosarcomas usually affect ?
the right atrium
where do cardiac myxomas tend to occur ?
attached to the septum. by a stlak
What is Carney syndrome
atrial myxoma, facial/buccal pigmentation, sertoli tumours of the testis
