CT Pulmonary Angiography Confirms the Clot
Contrast CT locates the embolus and starts the severity workup.
- CTPA: First-line imaging (fast, widely available scan)
- ~95%: Sensitivity (for segmental-and-larger clots)
- V/Q scan: Alternative test (used when contrast contraindicated)
- Main/lobar/segmental: Clot location (affects downstream risk)
Why imaging comes first
Placeholder: confirms diagnosis before any severity grading begins.
What the scan cannot tell you
Placeholder: clot size alone does not predict hemodynamic outcome.
Sustained Hypotension Defines the Massive Category
Blood pressure and shock signs split massive PE from everything else.
- SBP <90: Massive threshold (sustained 15+ minutes)
- ~30–50%: Massive PE mortality (without prompt reperfusion)
- ~5%: Massive PE incidence (of all diagnosed PE cases)
- Cool skin, syncope: Shock signs (support the diagnosis)
Defining sustained hypotension
Placeholder: shock or pressor need marks the massive branch.
Why this split happens first
Placeholder: unstable patients skip straight to thrombolysis pathway.
RV Dilation and Hypokinesis Signal Submassive Risk
Echo or CT reveals whether the right ventricle is straining.
- >0.9: RV/LV ratio cutoff (on CT or echo view)
- ~25%: RV dysfunction found (of hemodynamically stable PE)
- Apex-sparing: McConnell sign (hypokinesis pattern on echo)
- ~3–15%: Submassive mortality (higher than low-risk group)
Reading the strained ventricle
Placeholder: dilation and free-wall hypokinesis mark RV strain.
Why RV status matters
Placeholder: RV failure predicts deterioration even if BP is normal.
Troponin and BNP Corroborate RV Strain
Elevated cardiac biomarkers confirm strain seen on imaging.
- Present: Troponin elevation (reflects RV myocyte stress)
- Present: BNP elevation (reflects RV wall tension)
- Higher risk: Both markers positive (strengthens submassive call)
- Reassuring: Both markers normal (supports low-risk category)
What biomarkers add
Placeholder: labs confirm imaging findings, refine risk further.
Combining imaging and labs
Placeholder: either finding alone can still flag submassive risk.
Three Classes, Three Treatment Intensities
Massive, submassive, or low-risk each route to different care.
- Thrombolysis: Massive (or catheter/surgical intervention)
- Monitor closely: Submassive (anticoagulation ± escalation)
- Anticoagulation: Low-risk (standard outpatient-eligible course)
- Ongoing: Reclassification (status can worsen over hours)
Treatment intensity follows class
Placeholder: higher-risk classes get more aggressive intervention.
Reassessment matters
Placeholder: stable patients can still decompensate and reclassify.
Placeholder: classification is a snapshot, not a one-time verdict.