B4.070 Prework 2: Pericardial Effusion/Tamponade Flashcards
normal intra pericardial pressure (IPP)
below intra cardiac pressure
with respiration, has the same changes as intra thoracic and intra cardiac pressures
does IPP influence cardiac filling?
not in normal circumstances
when could IPP affect cardiac filling?
with pericardial fluid buildup
IPP may increase
what determines the hemodynamic effect of a pericardial effusion, and why does this matter?
the IPP, not volume
- if effusion builds slowly, the pericardium may gradually stretch and accumulate a lot of fluid while not causing compression of the cardiac chambers
- if effusion accumulates quickly, pericardium doesn’t have time to stretch and thus the cardiac chambers could be compressed with much less fluid
- *amt of fluid doesn’t determine severity
result of cardiac tamponade
abnormal accumulation of fluid in pericardial sac increased intra pericardial pressure compresses cardiac chambers decreased cardiac filling reduced SV reduced CO
which chamber is the first to be compressed and why
RA
thin, lowest intra cardiac pressure
what is the effect of early tamponade?
increase in pressure in RA can reduce the drainage of blood into the cardiac chambers from the IVC and SVC
effect of IPP > RA diastolic pressure
late diastolic RA inversion
effect of IPP > RV diastolic pressure
early diastolic RV collapse
describe the effect of increased inter-ventricular dependence
during inspiration, more blood empties into the right heart
IV septum compresses LV to accommodate widened RV
LV stroke volume decreases
CO decreases
MAP decreases
symptoms of cardiac tamponade
with reduced SV and CO, HR is increased to try to maintain CO
increased adrenergic tone : sweating, tachy
low BP: dizziness, fatigue, dyspnea, syncope
salt and water retention: edema, wt gain
signs of cardiac tamponade
raised JVP
low BP, fast HR
muffled heart sounds
(Becks triad)
what is pulsus paradoxus?
greater than normal decline in systolic arterial pressure during inspiration (greater than 10 mmHg)
how can you detect pulsus paradoxus with a stethoscope?
use manual sphygmomanometer
listen for first Kortokoff sound
stop decreasing pressure and have patient breathe slowly
will only hear sounds on expiration until a lower BP is reached
how does pericardial tamponade manifest on an ECG?
cardiac muscle further from skin
water/fluid is decreasing transmission of electrical signal
CXR findings with cardiac effusions
large cardiac silhouette
gold standard imaging technique for effusion
echocardiography
what is an echo finding in the case of a large pericardial effusion
heart swings during beats toward chest wall within the fluid sac
what is electrical alternans?
electrical manifestation of heart swinging toward anterior chest wall
alternating high and low voltage beats
how might pericardial effusion by diagnosed incidentally?
CT or MRI done for another reason and finding one
common causes of pericardial effusions
malignancy infection trauma post surgery inflammation (RA) uremia thyroid problems idiopathic
when should you drain a pericardial effusion?
cardiac tamponade
suspicion of infection
large and present for a long time
what is the most common type of pericardial effusion fluid?
serous
yellowish
what do you do if a pericardial effusion is loculated?
leave a drain in place until drainage stops
may need to open a pericardial window if effusions recur or do not stop draining
