Cardiovascular · Year 1 · from Cardiovascular
Case 2: Cardiac Tamponade - Hemodynamic Emergency
Clinical Image
Source: Wikimedia Commons - Pericardial effusion - CC BY-SA 3.0
Patient Presentation
A 58-year-old woman with metastatic breast cancer presents with progressive shortness of breath and lightheadedness over the past week. She notes that her symptoms are worse when lying flat and she has had to sleep propped up on pillows. Today she nearly fainted when standing up from bed. She completed chemotherapy 2 months ago.
Demographics
- Age: 58 years
- Sex: Female
- Past Medical History: Metastatic breast cancer to bone and liver, treated with chemotherapy
- Medications: Tamoxifen, analgesics for bone pain
- Family History: Mother with breast cancer
Chief Complaint
Progressive dyspnea, orthopnea, and near-syncope
Physical Examination
- Blood pressure: 88/72 mmHg (narrowed pulse pressure)
- Heart rate: 112 bpm
- Respiratory rate: 24/min
- Oxygen saturation: 94% on room air
- Pulsus paradoxus: 18 mmHg (>10 mmHg is abnormal)
- General: Appears ill, anxious, sitting upright
- Neck: JVP elevated to angle of jaw, does not fall with inspiration (Kussmaul sign absent - more typical of constriction)
- Cardiovascular: Distant, muffled heart sounds; tachycardic, regular rhythm
- Extremities: Cool, clammy
Workup
- ECG: Sinus tachycardia, low voltage QRS, electrical alternans (beat-to-beat variation in QRS amplitude)
- Chest X-ray: Enlarged cardiac silhouette ("water bottle" shape), clear lung fields
- Echocardiography:
- Large circumferential pericardial effusion
- Right atrial collapse during late diastole
- Right ventricular diastolic collapse
- Dilated IVC without respiratory variation (plethora)
- Respiratory variation in mitral and tricuspid inflow velocities >25%
- BNP: Mildly elevated (250 pg/mL)
Diagnosis
Cardiac Tamponade due to Malignant Pericardial Effusion
Treatment
- Urgent pericardiocentesis under echocardiographic guidance
- Removed 650 mL of bloody pericardial fluid
- Immediate hemodynamic improvement
- Fluid cytology sent: Positive for malignant cells (adenocarcinoma consistent with breast primary)
- Consider pericardial drain catheter placement to prevent reaccumulation
- Options for recurrence prevention:
- Pericardial window (surgical)
- Intrapericardial sclerotherapy
- Systemic cancer treatment
- Oncology consultation for goals of care
- Avoid diuretics and vasodilators (reduce preload, worsen tamponade)
Physiological Principles Demonstrated
- Beck's triad: Hypotension, elevated JVP, and muffled heart sounds (present in this case) - indicates acute tamponade with hemodynamic compromise.
- Pulsus paradoxus mechanism: In tamponade, ventricular interdependence is exaggerated. Inspiration increases RV filling at the expense of LV filling (septum shifts left), causing >10 mmHg drop in systolic BP.
- Chamber collapse sequence: Right-sided chambers collapse first because pressures are lower. RA collapse occurs in late diastole/early systole; RV collapse occurs in early diastole.
- Acute vs. chronic effusion: This large effusion caused tamponade because it accumulated relatively rapidly. Slowly accumulating effusions allow pericardial stretch and may exceed 1 liter without hemodynamic compromise.