Cardiac Tamponade
Description of Medical Condition
Compression of cardiac chambers by acute pressure on the heart from increased volume and pressure of the pericardial fluid
• As fluid accumulates, pressure primarily affects the compliant cardiac wall and transmits the pressure trans-murally, resulting in increased ventricular pressure. This decreases ventricular filling and reduces cardiac output by reducing stroke volume.
• The compensatory mechanisms for tamponade are: ncreased peripheral resistance, increased CVP and increased heart rate. All three increase myocardial oxygen denied the heart at a time when perfusion is limited.
• In some patients, pulsus paradoxus and equalization of pressures may not occur
• in patients with elevated left ventricular diastolic pressures (as with chronic hypertension), resistance to left ventricle (LV) filling is constant. Throughout the cardiac cycle, equalization of pressures in these patients may only be noted in the right heart chambers with LV pressures being higher than right ventricle (RV) pressures.
• The absence of pulsus paradoxus and classic hemody-namic finding does not rule out tamponade
System(s) affected: Cardiovascular
Genetics: N/A
Incidence/Prevalence in USA: N/A
Predominant age: N/A
Predominant sex: N/A
Medical Symptoms and Signs of Disease
• Beck’s triad — distant heart sounds, hypotension, distended neck veins
• Most common complaints are of intolerance to minimal activity and dyspnea. Later may develop agitation, CNS depression, coma and cardiac arrest.
• Decreased systolic blood pressure
• Narrow pulse pressure
• Pulsus paradoxus — greater than 15 mm Hg drop in systolic blood pressure between inspiration and expiration
• Neck veins may be distended and reveal a rapid systolic (X) descent and attenuated or absent diastolic (Y) descent
• Tachycardia — a compensatory mechanism to maintain output
• Right upper quadrant tenderness due to hepatic engorgement
• Increased area of cardiac dullness outside the apical point of maximum impulse
What Causes Disease?
• Physiology of tamponade depends on size and rapidity of development
• Uremia
• Neoplasm — breast, lung, lymphoma, leukemia
• Postmyocardial infarction (Dressler’s)
• Postoperative — as high as 30% post pericardiotomy
• HIV-particularly symptomatic
• Other viruses — Coxsackie group B, influenza, echo herpes
• Bacterial infection — S. aureus, M. tuberculosis, S. pneumoniae (rare)
• Fungal infection — M. capsulatum
• Lupus and rheumatologic disease
• Trauma
• Placement of central venous catheter, pacer wires
• Hypothyroidism
• Drug induced
Risk Factors
• Cardiac tamponade should be suspected in the hemo-dynamically unstable patient:
– With known pericarditis
– Following blunt or penetrating chest trauma
– Following open heart surgery or cardiac catheterization
– With known or suspected intrathoracic neoplasm
– With suspected dissecting aortic aneurysm
– Renal failure on dialysis
Diagnosis of Disease
Differential Diagnosis
• Tension pneumothorax
• Acute RV failure
• Chronic obstructive pulmonary disease
• Constrictive pericarditis
• Acute acceleration of chronic bronchitis
• Acute pulmonary emboli
• Fat emboli
• Excessive or rapid administration of fluids
• Abdominal distention from asdtes or ileus
• Increased intrathoracic pressure from pneumothorax. hemothorax, airway obstruction, or mechanical ventilation
• Administration of vasopressors
Laboratory
• CBC
• Sed rate
• Cardiac enzymes to rule out acute myocardial infarction
• Antinuclear antibodies (ANA)
• Rheumatoid factor
• BUN/creatinine
• Pericardial fluid for — culture of bacteria, fungus, myco-bacteria, Gram stain, hematocrit, cell count, cytology, glucose, protein, rheumatoid factors, complement levels
Drugs that may alter lab results: N/A
Disorders that may alter lab results: N/A
Pathological Findings
Pericardial blood usually does not clot, but occasionally will
Special Tests
• ECG
– May show sinus tachycardia, low voltage QRS
complexes, diffuse ST segment elevation and PR segment depression of pericarditis
– Electrical alternans (R wave variation from beat to beat)
– Electrical alternans is seen in 10-20% of cases of tamponade and 50-60% of these are neoplastic in origin
• Right heart catheterization
– Equalization (within 2-3 mm) of right atrial, pulmonary artery diastolic pressure, pulmonary capillary wedge pressure, left atrial and left ventricular diastolic pressure
– The intracardiac diastolic pressure will approximate the intrapericardial pressure
– The dip and plateau pattern of constriction or restriction pericardial disease is absent
– Loss of Y descent on atrial wave form
Imaging
• Chest x-ray:
– May or may not show enlargement of cardiac shadow (if > 250 cc fluid present)
• Echocardiography:
– Diagnostic cardiac compression
– Doppler — right sided transvalvular flow greatly exaggerated; left sided flows greatly reduced with inspiration
Diagnostic Procedures
N/A
Treatment (Medical Therapy)
Appropriate Health Care
Inpatient
General Measures
• Maintain hemodynamic stability until definitive correction of the pericardial tamponade
• All patients should have q 15 minute blood pressures, heart rate and at a minimum CVP measurement. Strong consideration should be given to placement of a Swan-Ganz catheter if time allows.
• Fluids may be of temporary benefit, but rising filling pressures may further compromise coronary perfusion
Surgical Measures
• Pericardiocentesis surgical treatment:
– Indications — when there is rapid deterioration of hemodynamic function, when there is delay in operation for traumatic effusion and for diagnostic reasons
– If rapid re-accumulation is anticipated (as in malignancy) it may be helpful to insert a long term drainage catheter. Also consider instillation of sclerosing agents.
– Surgery should be performed under the most optimal circumstances available to the operation as the patient’s condition allows
– Blind pericardiocentesis should be performed only in life threatening emergencies
– Ideally echocardiography can be brought to the bedside to assist in needle placement and progress of fluid removal
– Invasive monitoring is also helpful to follow decrease in pericardial pressures
– Fluoroscopy can also be used
– EKG guidance using the “V” lead to avoid contact with the epicardium may be useful
– 20% of patients with tamponade will have a negative tap because the pericardial sac contains coagulated material. Hemorrhagic pericardial effusions usually do not clot.
Activity
Bedrest
Diet
As tolerated
Patient Education
N/A
Medications (Drugs, Medicines)
Drug(s) of Choice
Isoproterenol may temporarily increase cardiac output
Contraindications: Refer to manufacturer’s
literature
Precautions: Refer to manufacturer’s literature
Significant possible interactions: Refer to manufacturer’s literature
Alternative Drugs
N/A
Patient Monitoring
Close monitoring until stable
Prevention / Avoidance
None
Possible Complications
• Cardiac perforation and/or laceration at time of pericardiocentesis
• Pneumothorax at time of pericardiocentesis
• Constriction of pericardium
Expected Course / Prognosis
Good results expected with appropriate treatment
Miscellaneous
Associated Conditions
• Myocardial infarction
• Aortic aneurysm
Age-Related Factors
Pediatric: N/A
Geriatric: N/A
Pregnancy
N/A
International Classification of Diseases
423.9 Unspecified disease of pericardium
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