ICL 5.6: Clinical Pericardial Diseases Flashcards
what are the two layer of the pericardial sac?
rigid, avascular fibrous sac made of 2 layers?
- outermost fibrous pericardium
- inner serous pericardium (parietal and visceral layers)
what is the function of the pericardium?
- a barrier to infection
- limits distention of cardiac chambers
- fluid between the pericardial layers reduces the friction between the myocardium and surrounding structures
how much fluid is in the pericardium?
15-50 mL
what are the causes of acute pericarditis?
- infectious
- radiation
- injury
- drugs/toxins
- metabolic
- malignancy
- collagen vascular disease
- immune mediated
what is the clinical presentation of acute pericarditis?
- “flu like” or GI symptoms early on
- sharp, pleuritic chest pain – worst by laying flat and relieved by leaning forward
- EKG changes
- friction rub at left sternal border
- pericardial effusion
what helps with the pain seen with pericarditis? why?
sharp pain that’s worst by laying flat and relieved by leaning forward
inflammation of the nerves that supply the pericardium and with gravity, the inflammation and gravity is placed on the nerves which are posteriorly located
when the person sits forward, some of the pressure/inflammation is taken off the pericardial space
how do you differentiate between a pleural vs. pericardial friction rub?
ask the patient to hold their breath
pleural friction rub will stop because they’re not breathing and lungs aren’t causing friction
pericardial friction rub will persist
what EKG changes are consistent with acute pericarditis?
ST elevation diffusely in all leads
also PR depression early in the course of pericarditis
but the one exception is aVR has PR elevation and ST depression
in later stages the ST normalizes and there’s T wave inversions
what are the PE findings during routine evaluation of acute pericarditis?
- pericardial rub
- diffuse ST elevation and PR depression
- pericardial effusion with or without tamponade on echo
- CXR is usually normal but you may see cardiomegaly “water bottle” heart shadow indicative of pleural effusions
- inflammatory marker elevation = ESR, CRP, WBC
- markers of myocardial necrosis* = troponin and CKMB
how do you diagnose acute pericarditis?
2+ criteria:
- characteristic chest discomfort = persistent, pleuritic and positional
- suggestive EKG changes
- pericardial friction rub
- new or worsening pericardial effusion
what would indicate that acute pericarditis needs to be treated in hospital?
most cases can be managed in the outpatient setting but sometimes hospitalization is needed if:
- high fever
- subacute onset
- large pericardial effusion
- signs of tamponade
- signs of myocarditis
- immunosuppressed patient because infection can spread
how do you treat acute pericarditis?
symptom relief and decrease inflammation via:
- NSAIDs/salicylates – add aspirin if underlying CAD
- colchicine (3 months) – great anti-inflammatory properties and also big reduction in recurrent pericarditis which is a significant problem with acute pericarditis
AVOID glucocorticoids and pericardioectomy –> avoid steroids early on because they have lower rates of recurrent pericarditis
what are the potential causes of hemorrhagic pericardial effusion?
- malignancy
- surgery/procedure complication
- post-pericardiotomy syndrome
- complications of MI
- idiopathic
- aortic dissection
- infection (TB)
what is the biggest risk factor of an effusion causing cardiac tamponade?
the rate of fluid accumulation
if a small effusion accumulates in minutes that can lead to tamponade very quickly as opposed to a large effusion that has gradually accumulated over weeks or months
this is because when there’s fluid around the chambers, it can cause pressure; the pericardium has a degree of elasticity and it has a limit; once you reach the limit there’s the potential for tamponade and chamber compression –> depending on how fast you ask the pericardium to stretch you may get tamponade immediately or later on if it’s an effusion that happens over time
what are the symptoms of cardiac tamponade?
- dyspnea
- chest discofort or fullness
- peripheral edema
- fatiguability
- sinus tachycardia
- JVD
- pulsus paradoxus
- instant heart sounds
- clear lung fields
- hypotension
what are the EKG changes seen with pericardial effusions?
- tachycardia
- electrical alternans = QRS complexes are small then big and they alternate every beat
the heart is shining back and forth in the large pericardial effusion and that leads to the QRS variation
what is the pathophysiology of pericardial tamponade?
- changes in systemic venous return
venous return is bimodal and peaks during systole and early diastole – compression effects cardiac volume and the venous return is shifted to systole as diastolic return decreases
- respiratory variation in venous return
venous return increases with inspiration due to decline in thoracic pressure – if there’s a pericardial effusion that limits the amount of space the heart has to expand, the right ventricle is limited by the rigid pericardium/effusion which leads to internal building of the interventricular septum into the already underfilled LV which decreases SV and CO and BP –> this causes pulsus paradoxus
what is the mechanism of pulsus paradoxus?
inspiration leads to increased venous return so the RV increases in volume which leads to bulging of the septum into the LV with decreased LV filling, decreased aortic flow, and signs of hypotension
but then during expiration, flow to the LV increases and the septum is free to go back to the middle and pressure increases which leads to a relative increase in BP
this is the mechanism of pulsus paradoxus!
what is the clinical definition of tamponade?
hypotension 10+
mmHg fall between inspiration and expiration
there’s also elevated venous pressure with blunted or absent y descent
what is Beck’s traid?
- hypotension
- muffled heart sounds
- JVD
pathoneumonic for cardiac tamponade
what conditions can cause pulsus parades?
- respiratory
- severe bronchial astham
- tension pneumothorax
- COPD - cardiac
- cardiac tamponade
- constrictive pericarditis
- pericardial effusion
- restrictive cardiomyopathy
- other
- anaphylactic shock
- obesity
how do you treat pericardial effusion with tamponade?
urgent pericardiocenesis
accomplished percutaneously rather than surgically
so use a needle guided by echo to remove fluid
IV fluids help improve CO but it’s just a temporary fix; do NOT give diuretics because it’ll decrease preload
what is constrictive pericarditis?
it’s a thickened, rigid pericardium that restricts cardiac chamber enlargement
what are the causes of constrictive pericarditis?
- idiopathic
- viral
- post-cardiac surgery
- post-radiation therapy
- connective tissue disorder
- post infectious like tuberculosis or purulent pericarditis
- other: malignancy, trauma, drugs, asbestosis, sarcoidosis, uremic pericarditis
