1. Pulmonary Embolism and Infarction

2. Pulmonary Embolism Falls under the spectrum of diagnosis called VTE
600,000 episodes occur yearly causing 200,000 deaths
Death is uncommon after proper dx and treatment is initiated
Majority of PE’s are from LE’s but only 30% have leg symptoms

3. Pathophysiology
Dislodged thrombi travel through Rt heart and lodge in pulmonary arterial circulation
Small emboli vs. large emboli

5. Risk Factors Age (advanced) Cigarette smoking Extended travel history
History of VTE**
HTN
HRT
Immobilization**
Recent joint replacement
LE bone fx
Malignancy**
Obesity
OCP’s
Trauma
Pregnancy
Surgery w/in past 3 months**
Stroke**

6. Risk Factors, cont. Anticardiolipin syndrome
Antithrombin III deficiency
Factor V Leiden
Lupus Anticoagulant
Protein C or S deficiency
Prothrombin G20210A mutation
(Evaluation for above causes should be limited to pt’s with recurrent or FHx of VTE)

7. Signs and Symptoms Dyspnea (73%) Tachypnea (70%) Pleuritic Pain (66%)
Rales (51%)
Cough (37%)
Tachycardia (30%)
S4 (24%)
Hemoptysis (13%)

8. Diagnosis What do you order first? CXR EKG ABG Chem 7 CBC Ddimer
Troponin
BNP

9. EKG’s

10. CXR

11. Definitive Imaging Studies
Pulmonary Angiography
Requires right heart catheterization and 4 injections of iodinated contrast
Associated with 5% morbidity and 0.5% mortality rate
Reserved when other tests are all inconclusive

13. Figure 1.Massive pulmonary thromboembolism, seen at pulmonary angiography
in a patient with recent resection of colonic cancer, undergoing chemotherapy,
who had suddenly collapsed in the ward.

14. V/Q scans 97% specific when “high probability”
95% predictive value when high clinical probability
14% false positive rate
Normal perfusion scan excludes PE
Intermediate requires further work-up

15. Normal perfusion images
Normal ventilation on the left with abnormal perfusion scan on the right

17. Findings: A large mismatch defect is present in the anterior segment of the right upper lobe. Additionally, there are unmatched perfusion defects in the apicoposterior segment of the left upper lobe and the anteromedial basilar segment of the left lower lobe.

18. Helical CT scan
CTPA (CT pulmonary angiography) is considered first line modality by some clinicians
Specificity (87-97%)
Sensitivity (53-60%)
Added benefit of suggesting alternative dx
Neg result is insufficient to exclude PE in mod to high risk patients (need to perform NIV of LE’s)

20. CT Pulmonary Angiography
CT Pulmonary Angiography. Arrow points to thrombus in right upper lobe pulmonary artery.

21. Multiple lower lobe segmental pulmonary emboli
Thrombus at the bifurcation of the right interlobar pulmonary artery
Thrombus within the origin of the right interlobar pulmonary artery

22. Other Studies Magnetic Resonance pulm angiography LE evaluation
minimal value in dx
LE evaluation
useful when clinical suspicion is high and V/Q scan is unequivocal
ultrasound is 90% sensitive for DVT

23. Other Studies, cont. Echocardiogram
used for risk stratification when pts are hemodynamically unstable
Common findings include RV dysfunction, RV dilation, and patent foramen ovale
McConnell Sign:
normal contraction of RV apex despite moderate to severe RV free wall hypokinesis
94% specific for PE

24. Treatment
Heparin
Coumadin
LMWH
IVC filters

25. IVC or Greenfield filters

26. Heparin vs. LMWH LMWH developed in the 90’s 1-2x daily, SQ
no monitoring needed
provides immediate anticoagulation
can be used in outpatients
2004 American College of Chest Physicians:
LMWH has therapeutic equivalence to unfractionated heparin in proximal DVT’s and VTE

27. Coumadin INR goal of 2-3 Duration is controversial
2004 ACCP consensus statement provides the guidelines for long-term treatment

28. ACCP guidelines
1. Pts with first epidode caused by reversible risk factor should have 3 months of warfarin treatment.
2. Pts with first episode of idiopathic PE should have 6-12 months of warfarin and be considered for indefinite therapy.
3. PE and cancer should have LMWH for 3-6 months and then warfarin indefinitely.

29. ACCP guidelines, cont.
4. Pts with first PE with antiphospholipid Ab’s or 2+ thrombophilic conditions should be treated for 12 months or indefinitely.
5. Two or more episodes of PE should be considered for indefinite treatment.
See for full consensus guidelines.

30. Treatment, cont. Thrombotic therapy Pulmonary Embolectomy
reserved for hemodynamically unstable patients
many contraindications
Pulmonary Embolectomy
unstable pts with contraindications to thrombolysis
severe RV dysfunction
catheter based procedure