Cardiac Flashcards
Right Atrium
Defined by the IVC. The Crista Terminalis is a frequently tested normal
structure (it’s not a clot or a tumor). It is a muscular ridge that runs from the entrance o f the
SVC to that o f the inferior vena cava. Another normal anatomic structure that is frequently
shown (usually on IVC gram) is the IVC valve or Eustachian valve. It looks like a little flap
in the IVC as it hooks up to the atrium. When the tissue o f this valve has a more
trabeculatated appearance it is called a Chiari Network.
Coronary Sinus
The main draining vein o f the myocardium. It runs in the AV groove
on the posterior surface o f the heart and enters the right atrium near the tricuspid valve.
Right Ventricle
Defined by the Moderator Band. Has several characteristics that are
useful for distinguishing it (and make good test questions).
The tricuspid papillary muscles insert on the septum (not the case with the mitral valve). There is no fibrous connection between the AV valve / outflow tract.
The pulmonary valve has three cusps, and is separated from the tricuspid valve by a thick muscle known as the crista supraventricularis . This differs from the left ventricular outflow
tract, where the mitral and aortic valves lie side by side.
Left Atrium
overview
The most posterior chamber. When you think about multiple choice
questions regarding the left atrium, think about the various signs of enlargement.
Left Atrium
double density
(direct sign): Superimposed second contour on the right heart, from
enlargement o f the right side o f the left atrium
Left Atrium
splaying of the carina
(indirect sign): Angle over 90 degrees suggests enlargement
Left Atrium
walking man sign
(indirect sign): Posterior displacement o f the left main stem
bronchus on lateral radiograph. This creates an upside down “V ” shape with the
intersection o f the right bronchus (looks like a man walking).
Left Ventricle
The leaflets o f the mitral valve are connected to the papillary muscles
via cord-like tendons called chordae tendinae. The papillary muscles insert into the lateral
and posterior walls as well as the apex o f the left ventricle (not the septum, as is the case on the right).
Echogenic Focus in Left Ventricle
Relatively common sonographic observation seen on pre-natal ultrasound. It is a calcified papillary muscle that usually goes away by the third trimester. So who gives a shit? Well they are associated with an increased incidence of Downs (13%). Don’t get it twisted, having one means nothing other than you should look for other signs of downs (most of the time it’s normal).
Lipomatous Hypertrophy
of the Interatrial Septum:
This has a very classic look o f a dumbbell (bilobed) appearance of fat density in the atrial septum, sparing the fossa ovalis. This sparing of the fossa ovalis, creates a dumbbell appearance {when it doesn’t spare it think lipoma). It’s associated with being fat and old. As a point of trivia it can cause supraventricular arrhythmia, although usually does nothing. Additional even more high-yield trivia is that it can be hot on PET because it’s often made of brown fat.
Lipomatous
Hypertrophy of the
Interatrial Septum
quick
common
ft in the atrial sptum, thicker than 2cm
spares the fossa ovalis
can be PET hot
RAre assoiated with arhythmias (usually asymptomatic)
Interatrial septum lipoma
rare
encapsulated
does not spare fossa ovalis
if multiopl = tuberous sclerosis
is usually PET HOT, T1 birght, drops out on fat sat
rarely associated with arrhythmias (usually asymptomatic)
Normal coronaries origin
There are three coronary cusps; right, left, and non-coronary (posterior).
The left main comes off the left cusp, the right main comes off the right cusp.
With regard to what perfuses what, the following are high yield factoids:
- RCA perfuses SA node 60%
* RCA perfuses AV node 90%
Posterior Descending Artery
PDA
RCA 65%-80%
-(*the other 20% have the PDA
supplied by the left coronary)
Conus
Off of RCA
*About 1/2 the time this
is the first branch.
-It supplies the
ventricle outflow tract.
Acute marginal
off the RCA, R forms an acute angle
nodal branc
off the RCA
Left main
LAD, circumfles, diagonals, obtuse marginals
obtuse marginals
supply the lateral margin
The 2 Chamber view
This displays the LV and LA (2 chambers). This is
good for a few things (1) Wall motion / Global LV
function , and (2) Mitral valve issues - regurg, etc.
The anatomy trick would be to have you ID the
coronary sinus on this view.
The 3 Chamber view
Some people will call this an “apical long axis
view.” The major plus to this view is that it lets you
see the left ventricular outflow tract (LVOT), - and is
ideal for look at flow through this area (i.e. aortic
regurg). A way a question could be asked is “what
view is best for aortic regurg? / stenosis?” or “which
of the following views” - and make you pick out the
picture of the 3 chamber. Or just straight ask you -
what is this view?
Dominance
Coronary Dominance is determined by what vessel gives rise to the
posterior descending artery and posterior left ventricular branches (most are right-
85%). You can be “co-dominant” if the posterior descending artery arises from the right
coronary artery and the posterior left ventricular branches arise from the left circumflex
coronary artery.
Malignant Origin
Most Common and Most Serious: LCA from the Right Coronary Sinus, coursing between the Aorta and Pulmonary Artery. This guy can get compressed and
cause sudden cardiac death.