Pulmonary Vascular Diseases Flashcards
(44 cards)
What is the definition of pulmonary hypertension (PH)? What is the gold standard for its diagnosis?
Mean pulmonary artery pressure >= 25 mmHg measured by right heart catheterization
-> Right heart cath required for definitive diagnosis
How can you tell if pulmonary hypertension is due to left ventricular disease or not? What are these two subsets of pulmonary hypertension called?
Pulmonary venous hypertension (postcapillary): If PCWP > 15 mmHg, LAP must be elevated, and thus it is likely due to LV disease
Pulmonary arterial hypertension (precapillary): If PCWP < 15 mmHg, LAP must not be elevated, and thus it is likely cor pulmonale
What are Groups I and II Pulmonary Hypertension?
Group I - Pulmonary Arterial Hypertension, can be idiopathic or have a known gene / cause behind it
Group II - Pulmonary Venous Hypertension - generally due to left heart failure
How is group II PH treated?
Treat the underlying cause
-> usually LV failure
What is the cause of Group III pulmonary hypertension?
Pulmonary diseases causing chronic hypoxemia, and pulmonary vasoconstriction results. Can be irreversible over time.
Causes include:
COPD, interstitial lung disease, high altitude exposure, alveolar hypoventilation disorders
How is Group III pulmonary hypertension treated?
Treat the underlying cause, give supplementary O2 if needed.
What is Group IV pulmonary hypertension?
Chronic Thromboembolic Disease
-obstruction of proximal or distal pulmonary arteries by PE’s from DVT’s, tumor, parasites, or foreign material leads to obstruction of blood flow or reorganization.
How is Group IV pulmonary HTN managed?
Anticoagulants, surgical removal of PE’s, and Riociguat (nitric oxide mechanism)
What is Group V pulmonary hypertension?
HTN due to miscellaneous or multifatorial issues, such as hematologic disorders, systemic disorders (sarcoidosis), glycogen storage diseases, tumor obstruction, chronic renal failure
-> treat underlying cause
What are the classical causes of Group I pulmonary hypertension?
- Idiopathic pulmonary hypertension
- Familial pulmonary hypertension (may be related to gene mutations)
- Associated with other conditions
etc
What are some “associated conditions” which PH is found with? Why are these important?
Congenital heart disease, collagen vascular disease (CT disease or autoimmune), HIV, drugs / toxins, portal hypertension (cirrhosis), Schistosomiasis, sleep disordered breathing
Important because these need to be ruled out as causes by various tests (i.e. LFT’s for suspected portal hypertension) when diagnosing idiopathic pulmonary hypertension
What is the proposed pathogenesis of idiopathic pulmonary hypertension and the prognosis?
Imbalance of humoral mediators:
increased TXA2, endothelin, and 5-HT which vasoconstrict
Decreased prostacyclin and NO which vasodilate
This decreases luminal size of pulmonary arteries and eventually results in medial proliferation and right heart failure
-> survival is less than 2-3 years untreated
What specific histological changes can be seen in idiopathic pulmonary hypertension? Who tends to get this disease?
More common in women. Think of girl holding two tennis rackets in sketchy
- Hyperplasia of intima with fibrosis
- Hypertrophy of the media -> SM cells
- In situ thrombi from endothelial / platelet dysfunction
What are the telltale symptoms of pulmonary hypertension?
Early on, patients have no symptoms.
Later, develop dyspnea or fatigue with heavy exertion. Then at rest.
RV will begin to fail, and they complain about leg edema / abdominal swelling
What is the most ominous symptom that PH has progressed very far?
Patient starts fainting (syncope) due to lack of blood flow to left heart and then brain
-> RV can not push against this high afterload
What are classic signs of pulmonary hypertension?
Loud P2 due to high backpressure causing closing of the pulmonic valve to sound very loud.
Tricuspid regurg murmur may be heart if RV has dilated enough
Signs of right heat failure
What will ECG show in pulmonary hypertension?
Enlarged P waves due to RA hypertrophy
Large R in V1, and T-wave inversion in V1-V3 showing RV strain and hypertrophy
Why are pulmonary function tests and ventilation perfusion (V/Q) scans important when diagnosing PH?
Pulmonary function tests - can rule out a Group III disorder
Ventilation perfusion scan - can rule out thromboembolic disease (Type IV) as a cause
Why is ECG important for PH diagnosis?
Looks for LV function
-> can differentiate from Group II disease
What is the treatment of pulmonary hypertension based on, and what test is used to determine this?
Treatment is based on functional classes: level of dyspnea with physical activity (Class I-IV)
Six minute walk test while measuring oxygen saturation and heart rate
-> prognosis is worse in patients with short walking distances
What is the general treatment used for ALL groups of PH?
Supplemental O2 (keep above 90%) and diuretics
What classes of drugs are used to treat Group I pulmonary artery hypertension?
Know everything on this
- Endothelin receptor antagonists (bosentan) - end of the line for boss man Stan
- PDE5 inhibitors (sildenafil, tadalafil)
- Guanylate cyclase stimulators (riociguat, also used for Type IV)
- Prostacyclin derivatives - i.e. think iLow to ePro! epoprostenol, iloprost
- DHP calcium channel blockers (rarely) - almost never works
What are the clinical sydromes associated with venous thromboembolism (VTE)?
Remember the 7 P’s
- Proximal DVTs / pelvic thromboses
- Post-thrombotic syndromes - venous insufficiency / swelling
- Predisposition to future VTE
- Pulmonary embolism
- Pulmonary hypertension - (Group 4)
- Paradoxical emboli
- Perish - sudden death
What is Virchow’s triad which can predispose to DVT’s?
- Stasis
- Endothelial injury
- Hypercoagulable states
