Pericardial Disease & Cardiac Trauma Flashcards
What are the three most common responses to pericardial injury?
- Acute Pericarditis
- Pericardial Effusions
- Constrictive Pericarditis
A stiff, fibrous membrane that attaches to the sternum, mediastinum, and diaphragm.
-Helps maintain hearts position in the thoracic cavity
Parietal Pericardium
What is the Pericardial Sac?
-Space between layers (Visceral and Parietal Pericardium)
-Pericardial fluid lubricates the heart
Which type of Pericarditis occurs after an MI?
Dressler’s Syndrome (!!)
Delayed. Weeks to months after a myocardial event
-Often auto-immune response to damage to pericardium
What causes Acute Pericarditis?
Mostly caused by viral infection.
-Usually transient and uncomplicated
-Sometimes follows an MI
-1-3 days post transmural MI
What is Acute Benign Pericarditis?
-Acute pericarditis in absence of pericardial effusion
-Does NOT alter cardiac function
-Inflammation for unknown reason.
What are the S/Sx of Pericarditis?
Chest pain, friction rub, EKG changes
-Chest pain is acute and worsens with inspiration
-Low grade fever with sinus tachycardia
-Friction rub
How do you diagnose Pericarditis?
-Symptoms
-EKG changes in 90% of people (diffuse ST segment elevation and PR segment depression and t wave inversions)
-Caused by inflammation of superficial myocardium
What is the treatment for Acute Pericarditis?
1) Aspirin or NSAIDs!!!
-Decrease the inflammation
2) Codeine (for pain relief)
3) Colchicine
-Anti-inflammatory used for Gout
4) Steroids frequently cause relapse once discontinued, so used only if other therapy doesn’t work
What is unique about Relapsing Pericarditis?
-Can be relapsing or chronic in nature
-Relapses are rarely life threatening (usually don’t effect cardiac function)
-Two types: Incessant or Intermittent
What is Incessant Pericarditis?
Pericarditis that relapses when anti-inflammatory drugs are withdrawn (<6weeks).
-Colchicine is associated with less relapse
What is Intermittent Pericarditis?
Relapses after prolonged periods without drug treatments (>6weeks)
What is Resistant Pericarditis?
Treated with standard therapies (ASA, Prednisone)
-may respond to Immunosuppressant therapy- azathioprine (Imuran)
What is Pericarditis after Cardiac Surgery?
-Postcardiotomy syndrome presents as acute pericarditis
-The cause is infective or autoimmune
-Can occur in any patient who had pericardectomy (all CABG, valve, epicardial pacer implantation, and most congenital surgery)
-Incidence of 10-40% of cardiac surgery patients
-Less common with OHT due to immunosuppression
-More common in pediatric patients
-Treat like pericarditis (ASA or NSAIDS)
-Tamponade is possible, but rare (0.1-0.6%)
What is an effusion?
An increase in pericardial volume
How much fluid is usually contained in the Pericardial Space?
25-50 ccs
What are causes of Acute Pericarditis & Pericardial Effusion?
1) Infection: Viral, Bacterial, Fungal, TB
2) Myocardial Infarction (Dressler’s)
3) Trauma or Cardiotomy
4) Metastatic Disease
5) Drugs
6) Mediastinal radiation
7) Systemic Disease - Rheumatoid Arthritis, Lupus, Scleroderma
Define Acute Pericardial Effusion
Quick changes as small as 50ml can lead to increased pressure (tamponade).
Define Chronic Pericardial Effusion
-Gradual increases allow for pericardial stretch
-Up to 2 liters can be accumulated
How does Cardiac Tamponade develop from pericardial effusion?
As pericardial pressure increases, RAP increases in parallel.
-Atrial and ventricular filling is restricted
-SV becomes fixed, so CO becomes rate dependent
-Remember: CO=HR x SV
What are the clinical features of cardiac tamponade?
-Acute increases of only 40-50 ml of fluid will cause a rapid rise in pressure and tamponade
-Large effusions compress adjacent structures (esophagus, trachea, lung) leading to anorexia, dyspnea, cough, hoarseness, dysphagia
-Kussmaul’s Sign
-Pulsus Paradoxus
-CVP almost always increased above RVP – this is what maintains forward flow and preserves CO
-Activation of the SNS into overdrive (especially tachycardia) is an attempt to maintain CO and patient survival. CO is HR dependant
-Contractility is great, preload is lacking
-Primary problem is reduced ventricular preload, not failure of myocardial contractility
-Eventual “equilibration of pressures”
What is Kussmaul’s Sign?
JVD during inspiration
What is Pulsus Paradoxus?
-Decrease in SBP > 10mmHG during inspiration
-Selective impairment of diastolic filling of the LV
-Present in 75% of patients with acute tamponade vs 30% of patients with chronic pericardial effusion.
What do Kussmaul’s Sign and Pulsus Paradoxus reflect?
Both Kussmaul’s sign and Pulsus paradoxus reflect dyssynchrony or opposing responses of the RV and LV to filling during the respiratory cycle. Also called Ventricular Discordance
What is Beck’s Triad?
Seen in 1/3 of acute tamponade patients.
-Muffled heart tones
-Distended neck veins
-Hypotension
Describe the pathophysiology of Cardiac Tamponade
Transmural pressure = the pressure necessary to distend a chamber.
-In tamponade, the intrapericardial pressure (IPP) is elevated, so RAP must increase to maintain a constant transmural pressure
-Compression of the LV prevents diastolic expansion
-Plateau of pressures is caused by the rise in filling pressures so that eventually: IPP=RAP=RVEDP=PAEDP=PAOP=LVEDP
What are the causes of Cardiac Tamponade?
-Trauma or iatrogenic (cardiac cath lab, PM insertion….)
-Infection
-Neoplastic disease, uremia, connective tissue disorders
-Acute MI
-Postoperative bleeding
-Aortic dissection
What is the tx for Cardiac Tamponade?
-Pericardiocentesis at the bedside (CVRU)
-Drainage of pericardial fluid through subxiphoid or mini-thorocotomy incision (in the OR)
Describe Anesthetic Mgmt of Cardiac Tamponade
Fast, Tight, Full
-Goals are: Tachycardia, vasoconstriction, volume
-Volume expanders, catecholamines (Epi, dopamine)
-In severely hypotensive patient pericardiocentesis can be done at bedside with local anesthesia
-Avoid drugs that depress myocardium. Beta blockade= death
-Ketamine is the drug of choice (etomidate is acceptable)
-Arterial BP monitoring (prior to induction)
-Correct metabolic acidosis from the low CO state
-If general anesthetic is used, the ideal plan is to allow patient to spontaneously breathe until tamponade is relieved
-In reality, paralyze and provide fast RR and low TV (“panting respirations”) until tamponade is relieved
-Surgeon is standing scrubbed and ready as patient is induced in the OR (very much as you do an emergent C-section in OB)
-Quick case with quick resolution; ICU post-op for observation
-Be prepared for post op HTN after release of the tamponade
-Especially important in cases of aortic dissection or aneurysm!
What is Constrictive Pericarditis?
Characterized by a fibrous scarring and adhesions that obliterate the pericardial space, creating a “rigid shell” around the heart
What are the causes of Constrictive Pericarditis?
Either idiopathic (most common) or the result of previous cardiac surgery, exposure to radiotherapy or TB.
-Most commonly post cardiac surgery
-Sometimes result of infections
What are the S/Sx of Constrictive Pericarditis?
-“Soft signs” of progressive dyspnea and fatigue (dec. CO), increased CVP, JVD, edema, ascites, and 25% have atrial fibrillation
-Signs mimic RV failure
-Difficult to diagnose, requires TEE, CT or MRI
-Like tamponade except the restriction to ventricular filling occurs only during last 2/3 of diastole
-SV is maintained
-Right ventricular pressure tracing shows “square root sign”
-Increased CVP without other signs of heart disease
-Kussmaul sign and pulsus paradoxus are present
What does the “Square Root Sign” indicate?
Rapid early diastolic filling, completed filling in mid-diastole (prolonged diastasis), then leveling off (“dip and plateau morphology”).
-The Ventricle is completely filled by the end of the “rapid filling phase”
Describe Anesthetic Mgmt of Constrictive Pericarditis
-Acute decompensation is not as worrisome as with tamponade
-Still choose agents to maintain HR, volume, contractility (Ketamine, pancuronium)
-Pericardium is adhered to heart: Can be long case with significant blood loss
-Arrhythmias, hypotension and bleeding common
Which part of the heart is most likely to be injured in trauma?
RV is directly under sternum and more likely to be injured
How does Pericardial Trauma occur?
Usually MVA’s but blunt deceleration trauma, shearing, soft tissue crushing, injuries to the aorta, pericardial laceration, valve injury.
-Blunt injuries to the chest can result in CV injury
-Wide range of potential severity (even death within minutes)
-Autopsies reveal that pericardial lacerations are common
-Diaphragmatic rupture and bowel evisceration is possible, Heart can fully or partially herniate into abdomen
-Rib fractures on CXR…. may mean heart injuries
-Unexplained dysrhythmias or HOTN after initial trauma resuscitation could be due to pericardial trauma
What are the S/Sx of Myocardial Contusion?
Chest pain and palpitations
How do you diagnose Myocardial Contusion?
ECG, TTE, or TEE
-Elevated CK enzymes
-Very non specific (CK released from damaged skeletal muscle
Describe treatment and anesthetic mgmt of Myocardial Contusion
-Hemodynamic support
-Avoid depressant drugs and prepare to support circulatory and myocardial function
What is Commotio Cordis?
A syndrome caused by blunt trauma over the heart, and leading to ventricular dysrhythmias (death if untreated).
-A focused mechanical “thud” during the small window of ventricular polarization causes “R on T” phenomenon
What is the Tx of Commotio Cordis?
Rapid defibrillation with AED
