Cardiac Flashcards
What is MC anomalous branching anatomy of aortic arch?
Common origin of the brachiocephalic artery and left common carotid artery?
13%
“Bovine aortic arch” - true bovine arch in cattle features a single great vessel arising from the aortic arch.
What are the anomalous branching patterns of the aortic arch?
Common origin of the brachiocephalic artery and left common carotid artery - 13%
Aberrant right subclavian - 1%
Left vertebral origin off the aorta - 6%
What is an aberrant right subclavian?
1% of patients
Right subclavian artery arises directly from the aortic arch distal to the left subclavian and loops behind the esophagus on its way into the right arm.
Uncommon to cause symptoms, but may cause dysphagia via esophageal compression, called dysphagia lusoria. Posterior indentation of the esophagus on esophagram.
Recurrent laryngeal nerve will not be in the usual location.
Diverticulum of Kommerel = small bulge at the origin of the aberrant subclavian artery.
Posterior indentation of the esophagus on esophagram?
Aberrant right subclavian artery - can cause symptoms - dysphagia lusoria.
What is Dysphagia Lusoria?
Esophageal compression due to an aberrant right subclavian artery.
What is a Diverticulum of Kommerel?
Small bulge at the origin of the aberrant subclavian artery.
What is acute aortic syndrome?
Clinical spectrum of three related diseases - damage to at least one component of the aortic wall - presents as severe chest pain.
Penetrating Atherosclerotic Ulcer - defect in the intima
Intramural Hematoma - Defect in the media only
Aortic Dissection - Defect in the intima extending to the media.
Defect in all 3 layers (aortic transection) is almost always due to trauma.
What can cause disruption of the aortic intima?
Ulcerative plaque, trauma, or aneurysm.
What is the key feature of an aortic dissection?
Disruption of the intima, which allows high-pressure blood to infiltrate and expand the media.
Aortic dissection secondary to atherosclerosis is more common in Type
B
What is an Intramural Hematoma?
Variant of dissection where blood collects w/in the media, without intimal flap to connect the intramural hematoma with the aortic lumen.
Thought to the due to rupture of the vasa vasorum, which are small blood vessels that supply the aortic wall.
HTN or trauma.
Clinically identical to aortic dissection.
Same treatment recommendations
Faint peripheral hyperattenuating (45-50 HU) crescent w/in the aorta - best seen on noncontrast CT - only done if suspicion of IMH.
Cause of an intramural hematoma?
Rupture of vasa vasorum within the media - blood collects w/in the media - without intimal flap to connect the intramural hematoma with the aortic lumen.
What is a Penetrating Atherosclerotic Ulcer?
Focal defect in the intima that occurs at the site of an atherosclerotic plaque - may cause media to enlarge, leading to anerysm formation.
May lead to saccular aneurysm formation.
In contrast to dissection and intramural hematoma, penetrating ulcers tend to be caused by atherosclerosis rather than HTN. Can lead to dissection.
Contrast ulcerating beyond the expected contour of the aortic wall. Different than simple ulcerated atherosclerotic plaque - which would not extend beyond the expected contour of the aortic wall.
Cause of penetrating atherosclerotic ulcers?
Tend to be caused by atherosclerosis rather than HTN, incontrast to dissection and intramural hematoma.
Difference between a penetrating atherosclerotic ulcer and simple ulcerated plaque?
PAU - Contrast ulcerating beyond the expected contour of the aortic wall.
Simple ulcerated atherosclerotic plaque - would not extend beyond the expected contour of the aortic wall
What are the relatively fixed levels of the aorta where traumatic aortic injuries occur secondary to deceleration injury?
Aortic root
Isthmus - 95%
Hiatus
What are the direct CT signs of traumatic aortic injury?
Dissection flap, pseudoaneurysm, and intramural hematoma.
Mediastinal hemorrhage that is separated from an intact aorta by a fat plane can be presumed to be venous - conservative treatment.
Hemorrhage in contact with the aortic wall is suggestive of aortic injury - surgical treatment.
What is a thoracic aortic aneurysm?
Ascending aortic diameter >4 cm or descending thoracic aorta >3 cm. May also be normalized to BSA and compared to reference values.
Most are caused by atherosclerosis - the descending TAA more commonly affected. Almost 1/3 will have associated abdominal aortic aneurysm.
Non-atherosclerotic causes - connective tissue disorders (Marfan and Ehlers-Danlos syndromes), bicuspid aortic valve associated aortopathy, vasculitis (including Takayasu arteritis, giant cell arteritis, ankylosing spondylitis, and relapsing polychrondritis), cystic medial necrosis, and infectious aortitis.
MC cause of thoracic aortic aneurysm?
Atherosclerosis.
Non-atherosclerotic causes - connective tissue disorders (Marfan and Ehlers-Danlos syndromes), bicuspid aortic valve associated aortopathy, vasculitis (including Takayasu arteritis, giant cell arteritis, ankylosing spondylitis, and relapsing polychrondritis), cystic medial necrosis, and infectious aortitis.
Non-atherosclerotic causes of thoracic aortic aneurysm?
Non-atherosclerotic causes - connective tissue disorders (Marfan and Ehlers-Danlos syndromes), bicuspid aortic valve associated aortopathy, vasculitis (including Takayasu arteritis, giant cell arteritis, ankylosing spondylitis, and relapsing polychrondritis), cystic medial necrosis, and infectious aortitis.
MC cause is atherosclerosis.
What is Annuloaortic Ectasia?
Dilated sinuses of Valsalva and ascending aorta with effacement of the sinotubular junction, resulting in a tulip bulb-shaped aorta.
Associated with Marfan and Ehlers-Danlos syndromes.
Dilated sinuses of Valsalva and ascending aorta with effacement of the sinotubular junction?
Annuloaortic Ectasa - results in tulip bulb-shaped aorta.
When is surgical treatment recommended for thoracic aortic aneurysms?
Ascending TAA >5.5 cm
Descending TAA >6 cm
However, patients with connective tissue disorders and bicuspid aortopathy (meeting criteria for valve replacement) have a lower surgical threshold of 4.5 cm.
Annual growth rate >1cm/year (or >5 mm/6months)
What is the draped aorta sign?
Drooping of the posterior aorta against the spine on an axial image - sign of impending rupture.
Complications of thoracic aortic aneurysm?
Rupture, dissection, infection, endoleak, and paraplegia (caused by artery of Adamkiewicz occlusion)
What is an abdominal aortic aneurysm?
Aortic diameter >3 cm.
What is the annual risk of rupture of a AAA based on size?
5.5 - 5.9 cm is 9.4% annual risk
6.0 - 6.5 cm is 10.2%
6.5 - 6.9 cm is 19.2%
>7 cm is 32.5%
Follow-up recommendations for AAA
<4 cm - f/u in 6 months, if no change - annual surveillance
4-4.5 cm - f/u in 6 months, if no change - 6-month suveillance
5-5.5 cm - consider surgery
> 5.5 cm - surgery recommended
When is surgery recommended for a AAA?
> 5.5 cm and expanding at rapid rate (>5.5 mm/year) or symptomatic.
5-5.5 cm - consider surgery
Mortality of elective open repair is >3%
Urgent repair is 19%
Ruptured repair is at least 50%.
What are the complications of AAA endovascular repair?
Rupture, dissection, infection, endoleak, and aorto-enteric fistula
What is an endoleak?
Persistent flow into an excluded aneurysm sac after endovascular treatment with a stent graft.
What is a Type I endoleak?
Inadequate graft seal
IA is proximal
IB is distal
What is a Type II endoleak?
Persistent collateral flow to the excluded aneurysm sac - typically arises from the lumbar arteries or the inferior mesenteric artery.
What is a Type III endoleak?
Device failure causing leakage through graft fabric or segments of a modular graft.
Defect in the graft.
What is a Type IV Endoleak?
Caused by a porous graft and is typically transient and seen intra-procedurally.
Usually resolves w/in 1 month after withdrawl of anticoagulation. Rarely seen in modern grafts.
What is a Type V endoleak?
Also called endotension - continued expansion of the aneurysm w/o any other endoleak present - thought to be due to endoleak below the resolution of imaging.
What is the complication of infectious aortitis?
Development of a mycotic aneurysm.
Causes of inflammatory aortitis?
Takayasu arteritis, giant cell arteritis, ankylosing spondylitis, polyarteritis nodosa, rheumatoid arthritis, and immune complex disease.
MRI findings of active aortitis?
Aortic wall thickness >2 mm and enhancement of the aortic wall.
Circumferential mural thickening and enhancement. In contrast to intramural hematoma, aortitis tends to cause circumferential thickening than the eccentric, crescentic thickening of IMH.
Chronic phase will cause long segment stenosis and/or aneurysms.
What is Takayasu Arteritis?
Idiopathic, inflammatory, large-vessel vasculitis - involves the thoracic and abdominal aorta, subclavian arteries, carotid arteries, pulmonary arteries, and large mesenteric arteries.
Pulseless disease.
Young to midle-aged women.
Long smooth stenoses are classic. Imaging is often indistinguishable from giant cell arteritis - patients age is the main distinguishing factor.
TA is younger patients
Giant cell arteritis is rare in patients under 50
How to tell difference between Takayasu Arteritis and Giant Cell Arteritis?
Often indistinguishable based on imaging. Both cause long smooth stenoses.
Age is main distinguishing factor:
TA is younger patients
Giant Cell Arteritis is rare in patients under 50.
What is the difference between the adult and infant forms of coarctation?
Adult - juxtaductal (at the junction of the ductus arteriosus) - leading to upper extremity hypertension.
Infant - Presenting with CHF due to coarctation is usually due to a preductal variant, which functions as a left ventricular obstructive lesion.
What is pseudocoarctation of the aorta?
Focal narrowing of the aorta, similar in morphology to true coarctation, but no pressure differential and thus no collaterals.
How much stenosis is coronary CT sensitive for?
> 50% luminal narrowing.
Stenosis found on CT may be overcalled, especially if calcified plaque, which can cause a blooming artifact.
How do you estimate radiation dose for coronary CT?
Multiply the dose-length product (DLP) by a conversion factor of 0.017 to arrive at the dose in millisieverts
What is retrospective coronary gating?
Continuous CT scanning is performed throughout the cardiac cycle and images are correlated to the ECG cycle afterwards.
Main advantage - ability to create cine reconstructions to evaluate cardiac and valvular function.
Main disadvantage - significant increase in radiation exposure compared to a prospectively gated study.
What is prospective coronary gating?
ECG is used to time image acquisition at a specific phase of the cardiac cycle - exposing patient to radiation only during this segment of the cardiac cycle.
Main advantage- decreased radiation exposure
No cine reconstructions.
What is the resolution of coronary CT vs coronary artery luminal diameter?
Resolution of 0.35 to 0.5 mm
Coronary arteries have an average luminal diameter of about 3 mm.
Only have resolution to grade a stenosis with accuracy greater than about 20% of the diameter.
What categories can coronary artery stenosis be classified as?
<20%
20-50%
50-70%
>70%
> 50% is considered potentially hemodynamically significant.
<50% is considered not hemodynamically significant.
How can you increase temporal resolution with coronary CT?
Need slightly more than 180 degrees of rotation for image acquisition.
Dual source CT decreases temporal resolution.
What drugs are given for coronary CT?
PO Metoprolol for HR <60.
Sublingual nitroglycerin (0.5 - 0.8 mg) to dilate coronary arteries.
What are the three coronary sinuses?
Right (anterior)
Left (lateral posterior)
Non-coronary (right posterior)
Where does the left main coronary artery course?
Between the pulmonary artery and the left atrial appendage.
Branches to LAD, L circumflex, and sometimes Ramus
What are the branches of the left main coronary artery?
LAD and L circumflex
Ramus branch may be present to form a trifurcation.
What is the course of the LAD?
In the anterior interventricular groove.
Gives off diagonal branches (LAD - Diagonal) and septal branches.
What are the branches of the LAD?
Diagonal (LAD - Diagonal) and septal branches
What is the course of the Left Circumflex coronary artery?
Courses underneath the L atrial appendage (LAA) in the left AV groove (between the left ventricle and left atrium).
Gives off the Obtuse Marginal (OM; circOMflex) branch - which supplies the posterolateral wall of the LV. The angle of the lateral wall of the obtuse marginal artery is obtuse, hence the name
Uncommonly (~7%) supplies the posterior descending artery (PDA) - left-dominant system
What are the branches of the Left Main Coronary Artery distally?
Left main -
LAD, Circumflex, and Ramus
LAD -
Diagonal (LAD - Diagonal) and septal branche
Left Circumflex -
Obtuse Marginal
Posterior Descending Artery (~7%)
What is the course of the right coronary artery?
Within the right atrioventricular groove - mirrors the LCs in course.
Branches of the right coronary artery?
Conal (supplies the RVOFT)
SA nodal branch (supplies the SA node)
Acute Marginal Branch - courses anterior to the RV free wall and muscular branches to supply the RV fee wall
AV nodal branch - branches as the crux (junction of the four chambers)
Posterior descending artery (85%) - to supply the posterior half of the ventricular septum.
Posterolateral artery - supplies the posterior left ventricle
What is the terminal branch of the RCA and what does it do?
Posterolateral artery - supplies the posterior left ventricle.
What does the obtuse marginal branch supply?
Branch of the left circumflex artery - supplies the posterior lateral wall of the LV.
What does the acute marginal branch supply?
Branch of the RCA - supplies the RV free wall
What does the posterior descending artery supply?
Branch of the RCA - supplies the posterior half of the ventricular septum
What does the posterolateral artery supply?
Terminal branch of the RCA - Supplies the posterior left ventricle.
What is a malignant coronary artery anomaly?
Carries increased risk of sudden death (in up to 40%), often associated with exercise.
Can be malignant (if arising from the pulmonary artery) or potentially malignant (depending on course)
What determines if a coronary artery anomaly is malignant or potentially malignant?
Malignant - arising from the pulmonary artery
Potentially Malignant - depending on course
What are the malignant coronary artery anomalies?
CA arising from the pulmonary artery = malignant
ALCAPA - anomalous left coronary artery from the PA
RCAPA - anomalous right coronary artery from the PA
What are the potentially malignant coronary artery anomalies?
RCA arising from left coronary sinus
Left main arising from the right coronary sinus
Left circumflex or LAD arising from right coronary sinus
Any artery arising from the noncoronary sinus.
Interarterial coure (between the aorta and PA) of an anomalous CA is malignant Retroaortic, prepulmonic, and septal coronary artery course are all considered benign.
What is an intramural course of a coronary artery?
When the vessel courses through the wall of the aorta for a short segment. Is associated with sudden death.
Slit-like configuration on CCTA.
Tx is bypass, reimplantation, or unroofing procedure when opens and enlarges the ostium from inside the aorta.
What is Bland-White-Garland Syndrome?
ALCAPA - Anomaous Left Coronary from the Pulmonary Artery
90% mortality
What is myocardial bridging?
Band of myocardium overlying a segment of a coronary artery - MC seen in the mid LAD.
Usually asymptomatic - may cause angina, MI, or even death.
If present and thought to be cause of patients symptoms, further evaluation is recommended with exercise myocardial perfusion
Sequences used in cardiac MRI
Steady-sate free precession (SSFP) and/or gradient echo cine sequences
Tissue characterization is typically performed with double or triple inversion fast spin echo sequences - fat suppression
SSFP = “white blood” - excellent contrast between myocardium and blood pool. High temporal resolution and excellent contrast.
What is the difference between first-pass and delayed contrast-enhanced MRI?
First-pass contrast-ehanced perfusion MRI is performed pre and post vasodilator stress to evaluate myocardial perfusion. Normal myocardium enhances, while areas of decreased perfusion will be relatively hypoenhancing.
Delayed contrast-enhanced MRI is used to image changes in myocyte to interstitial space ratio. This ratio decreases most commonly after myocardial infarction - myocytes replaced with scar tissue. Any delayed enhancement in DE-MR is abnormal and represents an increase in extracellular volume fraction.
What does delayed contrast-enhanced MRI look for?
Used to image changes in myocyte to interstitial space ratio.
Ratio decreases most commonly after myocardial infarction - myocytes replaced with scar tissue. Any delayed enhancement in DE-MR is abnormal and represents an increase in extracellular volume fraction.
What are the nonischemic types of delayed enhancement?
Mid-myocardial delayed enhancement - Dilated cardiomyopathy, sarcoidosis, chagas disease, and hypertrophic cardiomyopathy.
Epicardial/subepicardial delayed enhancement - Myocarditis, Chagas, Sarcoidosis
Circumferential subendocardial delayed enhancement - Amyloidosis and cardiac transplant
What are the causes of mid-myocardial delayed enhancement?
Dilated cardiomyopathy
Sarcoidosis - nodular or patchy pattern
Chagas Disease
Hypertrophic Cardiomyopathy - at junction of IV septum and RV free wall.
What is dilated cardiomyopathy and what type of delayed enhancement does it cause?
Most common nonischemic cardiomyopathy - most commonly idiopathic, but may be caused by alcohol abuse, myocarditis, or drug toxicity.
Mid-myocardial delayed enhancement.
Will see diffuse chamber enlargement and reduced EF.
What is Sarcoidosis and what type of delayed cardiac enhancement does it cause?
Systemic disease of noncaseating granulomas with cardiac manifestations of arrhythmias, LV dysfunction, and restrictive cardiomyopathy. Usually see cardiac findings in conjunction with other manifestations of sarcoid - lung disease and adenopathy.
Mid-myocardial or subepicardial delayed enhancement in a nodular or patchy pattern.
What is Chagas Disease and what type of delayed cardiac enhancement does it cause?
Caused by protozoan Trypanosoma cruzi - can lead to cardiomyopathy.
Epicardial or mid-myocardial delayed enhancement.
What is hypertrophic cardiomyopathy and what type of delayed enhancement does it cause?
Abnormal LV myocardial thickening w/o dilation. Pathologic thickening may be diffuse or focal. Can cause sudden death.
Mid-myocardial delayed enhancement in regions of hypertrophied myocardium and at the junctions of the IV septum and the RV wall - due to myofibril disarray.
Will see reduced diastolic filling of the LV on cine clips.
What are the causes of Epicardial/subepicardial delayed enhancement?
Myocarditis
Chagas Disease
Sarcoidosis
What diseases can cause both epicardial/subepicardial and mid-myocardial delayed enhancement?
Chagas Disease
Sarcoidosis
What is myocarditis and what type of delayed enhancement does it cause?
Inflammation of the myocardium - multiple causes, viral infection is the most common, followed by autoimmune disorders and drug toxicity.
Subepicardial delayed enhancement. Will also see wall motion abnormalities in the affected regions.
What are the causes of circumferential subendocardial delayed enhancement?
Amyloidosis
Cardiac Transplant
What is Amyloidosis and what type of delayed cardiac enhancement does it cause?
Disorder of glycoprotein deposition throughout the extracellular spaces.
Can cause biventricular myocardial thickening, leads to diffuse ventricular subendocardial delayed enhancement.
What type of delayed cardiac enhancement can be seen after cardiac transplant?
Circumferential subendocardial delayed pathological enhancement, thought to correlate with the presence of myocardial fibrosis pathologically.
What are the cardiovascular diseases with an enlarged cardiac silhouette?
Cardiomyopathy 2/2 congestive heart failure, valvular regurgitation (aortic, mitral, tricuspid regurgitation), high output or volume overload states, dilated cardiomyopathy, pericardial effusion, and paracardiac mass.
What are the cardiovascular diseases with a normal-sized cardiac silhouette?
Valvular stenosis (aortic or mitral), pulmonary artery HTN, hypertrophic cardiomyopathy, restrictive physiology, and acute MI.
What are the key structures to look at to distingush between the various causes of enlarged heart cardiac disease?
Left atrium and Aorta.
Enlarged left atrium - suggests mitral regurgitation
Enlarged aorta - suggests aortic regurgitation.
If neither LA or aorta is enlarged - suggests one of the other etiologies.
What are the key structures to look at to distingush between the various causes of normal sized heart cardiac disease?
Left atrium and aorta
Enlarged left atrium and cardiac silhouette is normal - suggests mitral stenosis.
Enlarged aorta and cardiac silhouette is normal - suggests aortic stenosis or aortic aneurysm.
If neither the LA or aorta is enlarged - suggests one of the other etiologies.
What is the most anterior cardiac chamber?
RV
Enlargement causes displacement of the cardiac apex in a leftward direction (in contrast to LV enlargement - causes displacement in a left-inferior direction).
Can cause opacification of the retrosternal clear space on the lateral radiograph.
What chamber forms the right heart border?
RA
RA enlargement causes lateral bulging or elongation of the right heart border.
What chamber forms the left heart border?
LV
LV enlargement causes displacement of the cardiac apex in the left-inferior direction.
Hypertrophic cardiomyopathy does not cause enlargement of the external contour of the ventricle.
What is the most posterior cardiac chamber?
LA
Enlargement may be caused by mitral regurgitation (with an enlarged cardiac silhouette) or mitral stenosis (with a normal cardiac silhouette)
Enlarged LA may splay the carina, seen on the frontal view. On lateral radiograph, an enlarged LA can elevate the left upper lobe bronchus.
Double density - right aspect of the enlarged LA visualized through the RA.
Difference between a true LV aneurysm and a pseudoaneurysm?
True LV aneurysm is focal outpouching of ventricular wall with all layers of the muscular wall affected. True aneurysms are associated with occlusion of the LAD.
False aneurysm (pseudoaneurysm) - contained ventricular rupture with only pericardial adhesions preventing a complete rupture - no myocardium in the wall of a false aneurysm. Associated with LCx and RCA occlusion. Surgical treatment.
Occlusion of which vessels causes LV aneurysm vs pseudoaneurysm?
Aneurysm - LAD
Pseudoaneurysm - LCx and RCA.
What is Dressler Syndrome?
Autoimmune pericarditis - often associated with pericardial and pleural effusions.
What are Mitral Annulus Calcification associated with?
Mitral regurgitation - can be associated with increased risk of stroke, adverse cardiovascular events, and atrial fibrillation. Also considered a risk marker for CV disease.
Unlike mitral valve calcifications, MAC is not associated with mitral stenosis.
What is Takotsuba Cardiomyopathy?
Catecholamine Induced Cardiomyopathy - broken heart syndrome.
Older women in the setting of acute emotional stress- can present as chest pain, abnormal ECG, and elevation of cardiac enzymes. Cardiac cath is normal. Self-limited
Characteristic ballooning of the cardiac apex. No abnormal delayed enhancement on MRI.
What causes ballooning of the cardiac apex?
Takotsuba/Catecholamine cardiomyopathy.
What is Arrhythmogenic Cardiomyopathy?
Previoiusly called arrhythmogenic RV dysplasia
Fibrofatty replacement of the ventricular myocytes, causing focal contraction abnormalities and/or aneurysm formation.
Diagnosis is difficult - imaging plays a supportive role - look for RV enlargement or presence of focal aneurysm. Presence of focal fat is no longer in the criteria as fat can be seen in normal individuals with aging.q
What is Myocardial Noncompaction?
Developmental defect in embryologic formation of the LV - due to failure of part of the LV to form a solid myocardium.
Have increased risk of adverse cardiac events - arrhythmias, thrombus formation, stroke, and cardiomyopathy.
LV appears heavily trabeculated as the RV with relatively thin LV.
What is hypertrophic cardiomyopathy?
AD cardiomyopathy with hypertrophic LV myocardium. MC cardiomyopathy.
The asymmetric septal hypertrophy variant - idiopathic hypertrophic subaortic stenosis - may cause LVOT obstruction.
Wall thickness of >15mm and a ratio of >1.5 compared to the lateral wall. Wall thickness of >30mm is an indication for ICD placement
Systolic anterior motion of the anterior leaflet of the mitral valve can cause mitral regurgitation and resultant LA enlargement.
What is Idiopathic Hypertrophic Subaortic Stenosis?
Asymmetric septal hypertrophy variant - may cause LVOT obstruction.
Wall thickness >15 mm and a ratio of >1.5 compared to the lateral wall. A wall thickness >30 mm is an indication for ICD placement.
What is restrictive cardiomyopathy?
Small, stiff, thickened ventricles that impair diastolic filling. Results in dilated atria and ultimately a dilated IVC.
May be idiopathic or due to sarcoidosis, hemochromatosis, or myocardial deposition diseases (e.g. amyloidosis).
Restrictive cardiomyopathy and constrictive physiology are different entities.
Role of imaging is to exclude constrictive pericarditis (can be treated surgically) as the etiology of the diastolic dysfunction.
What is Dilaated Cardiomyopathy?
Concentric ventricular chamber enlargement with impaired systolic function. Typically both ventricles enlarged.
Can be ischemic or idiopathic in etiology - MRI or CT is useful to determine etiology.
What is Lipomatous Hypertrophy of the interatrial septum?
Proliferation of fatty deposits w/in the interatrial septum - typically along the lateral right heart border.
Incidental finding - no treatment.
Where is lipomatous hypertrophy of the interatrial septum occur?
lateral right heart border
What is abnormal thickness of the pericardium?
<2 mm = normal
>4 mm = abnormal.
What are common causes of pericardial calcification?
Prior pericarditis - MC viral or uremic etiology.
What is congenital absence of the pericardium?
Ranging from focal defect to complete absence of the R and L pericardium. Total absence is rare.
MC involves the L pericardium in the region of the LA appendage and adjacent PA.
Partial absence = at risk for herniation of a portion of the heart through the defect.
Defects in the L pericardium can cause leftward displacement of the heart, which may in some cases be the only imaging finding.
What is the difference between a vascular sling and ring?
Complete encircling of the trachea and esophagus by the aortic arch or great vessels = vascular ring.
A sling refers to an anomalous course of the left pulmonary artery - which arises aberrantly from the right pulmonary artery and traps the trachea in a “sling” on three sides.
What is a vascular ring?
Complete encircling of the trachea and esophagus by the aortic arch or great vessels
What is a vascular sling?
Anomalous course of the left pulmonary artery which arises aberrantly from the right pulmonary artery and traps the trachea in a “sling” on three sides.
What is an important clue to a potential vascular cause of stridor?
Right sided aortic arch.
The PA sling is the only vascular anomaly that causes stridor in a patient with a normal (left) aortic arch.
What is the only vascular anomaly that causes stridor with a normal (left) aortic arch?
PA sling
What are the three most important vascular causes of stridor?
Double aortic arch, right arch with aberrant left subclavian, and pulmonary sling.
Each will show abnormality on the lateral radiograph or esophagram - Double arch and right arch with aberrant left subclavian look the same on radiography/esophagram - each producing a posterior impression on the esophagus.
What is the most common vascular ring?
Double aortic arch.
What is a double aortic arch?
MC vascular ring.
The arches encircle both the trachea and esophagus, and may cause stridor.
Right arch is usually superior and larger in caliber than the left - imaging to determine which is dominant - surgery will ligate the non-dominant arch.
Will see posterior indentation of the esophagus (by the right arch) and anterior indentation of the trachea (by the left arch)
What is a right arch with an aberrant left subclavian?
2nd MC vascular ring.
The right arch indents the anterior trachea while the aberrant left subclavian wraps posteriorly around the esophagus.
The ring is completed by ligamentum arteriosum.
What makes up the vascular ring with a double aortic arch?
Right arch indents the posterior esophagus.
Left arch indents the anterior trachea.
What makes up the vascular ring with a right arch with an aberrant left subclavian?
The right arch indents the anteiror trachea.
Aberrant left subclavian wraps posteriorly around the esophagus.
The ring is completed by the ligamentum arteriosum.
LEFT ARCH WITH ABERRANT RIGHT SUBCLAVIAN IS USUALLY ASYMPTOMATIC AND NOT A VASCULAR RING.
What is a Pulmonary Sling?
Anomalous left pulmonary artery arising from the right pulmonary artery - forms a sling by coursing in between the trachea and esophagus.
Usually only the trachea is trapped in the sling, but occasionally the bronchus intermedius may also be compressed.
Pulmonary artery sling is the only vascular cause of stridor in a patient with a left arch. Aortic branching pattern is normal.
Associated with tracheal anomalies including tracheomalacia and bronchus suis (RUL bronchus originating from the trachea).
What is the only vascular cause of stridor in a patient with a left arch?
Pulmonary artery sling
What is Bronchus Suis?
RUL bronchus originating from the tracha.
Associated with pulmonary artery sling.
What indents the posterior esophagus and anterior trachea with a double aortic arch?
Posterior esophagus - right arch
Anterior trachea - left arch
What indents the posterior esophagus and anterior trachea with a right arch with aberrant left subclavian artery?
Posterior esophagus - aberrant left subclavian
Anterior trachea - right arch
Does a left arch with aberrant right subclavian cause stridor?
No. Passes posterior to the esophagus. Not a ring.
Dysphagia Lusoria - aberrant right subclavian passes posterior to esophagus.
What is Innominate Artery Syndrome?
In infants, the large thymus can occasionally cause the normal innominate artery to press against the anterior trachea.
Not a vascular ring.
Cause of posterior impression on esophagus with anterior tracheal impression?
Double aortic arch and Right arch with aberrant left subclavian - appear identical on lateral radiograph/esophagram.
Cause of posterior impression on esophagus with no anterior tracheal impression? Can be asymptomatic or have dysphagia?
Left arch with aberrant right subclavian.