Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
Why do the lungs have low pressure in normal pulmonary circulation?
|
Vasodilators>>>Vasoconstrictors
Allows recruitment of under-perfused vessels Distention of thin-walled vessels |
|
|
Resistance is inversely proportional to _________.
|
Radius^4
|
|
|
What is the most important determinant of pulmonary vascular resistance?
|
Arterial lumen area (RADIUS)
|
|
|
Causes of Pulmonary Arterial Hypertension
|
Idiopathic
Heritable Drug, Toxin (Fen Fen) Assocd w/CT Dz, Congenital Heart Dz, HIV, Schistosomiasis |
|
|
Pathophysiologic cause of pulmonary hypertension.
|
Vasoconstrictors (Thromboxane A2, Endothelin, Angiotensin II) >> Vasodilators (Prostacyclin NO, ANP, Symp Tone)
|
|
|
Changes involves in pulmonary vascular remodeling.
|
Intimal thickening
Medial smooth muscle hypertrophy Adventitial thickening Thromboses Plexiform lesions Note: all parts of arterial wall affected |
|
|
Physical exam findings in pulmonary arterial hypertension.
|
Loud P2
RV Heave TRICUSPID MURMUR Peripheral EDEMA |
|
|
Hallmark hemodynamic signs of pulmonary arterial hypertension.
|
Severely increased PA pressure and Pulm Vasc Resistance
|
|
|
Genetic cause of familial PAH
|
BMPR2 mutation (bone morphogenetic protein receptor II)
|
|
|
Treatment of Pulmonary Arterial Hypertension
|
Anticoag (PAH can cause thromboses)
O2 for hypoxia Diuretics, digoxin x R-HF Pulm vasodilators |
|
|
Epoprostenol:
MOA Use |
Pulmonary vasodilator (but can act systemically)
Pulm CAD |
|
|
Role of endothelin in PAH.
|
Endothelin binds SM to induce vasoconstriction
Inc'd endothelin expression in PAH |
|
|
Why is sildenafil used in PAH?
|
NO induces cGMP broken down by PDE-5
Block PDE-5 with sildenafil to induce vasodilation |
|
|
Bosentan:
MOA Use |
Blocks endothelin binding
PAH |
|
|
Causes of pulmonary hypertension in patients with COPD.
|
Alveolar hypoxia-->vasoconstriction
Enhanced by respiratory acidosis (lower pH-->higher PVR) Chronic hypoxia-->vasc remodeling Loss of blood vessels Hyperinflation-->mechanical compression of arteries Polycythemia-->Inc blood viscosity |
|
|
When does thromboembolism result in pulmonary hypertension? Why?
|
Recurrent or unresolved thromboemboli result in vascular remodeling and obstruction of vessels
|
|
|
Pulmonary Thromboembolism:
Treatment |
Anticoag
Surgical removal of unresolved clot |
|
|
How does cor pulmonale arise in pulmonary hypertension?
|
Pulm HTN-->Inc'd RV afterload-->RV HTN-->RV Dilation/failure
|
