Clinical presentation
54-year-old woman presenting with sudden dyspnoea, pleuritic chest pain, and syncope 8 days after total knee arthroplasty. HR 122 bpm, BP 88/54 mmHg, SpO2 89% on room air.
Investigation findings (CT Pulmonary Angiography (CTPA) & ECG)
CTPA demonstrates a large saddle filling defect straddling the main pulmonary arterial bifurcation extending into both right and left main pulmonary arteries. Right-to-left ventricular short-axis diameter ratio is increased at 1.45 with leftward bowing of the interventricular septum and contrast reflux into the inferior vena cava.
Final diagnosis
High-risk (massive) saddle pulmonary embolism
Case discussion
RV:LV ratio >1.0 and interventricular septal flattening on CTPA signify acute right ventricular pressure overload and correlate with higher short-term mortality.