Pulmonary Hypertension & PTE

Question 1

what are the three mechanisms of pulmonary hypertension?

Answer 1

increased CO, increased PVR, increased PVP

Question 2

pulmonary vascular dz, left-sided heart dz, chronic pulmonary dz and/or hypoxia, thrombotic and/or embolic dz and miscellaneous are all underlying dz processes that can lead to what?

Answer 2

pulmonary hypertension

Question 3

T/F: pulmonary hypertension usually occurs secondary to another condition

Answer 3

TRUE, must investigate further

Question 4

clinical signs for pulmonary hypertension look similar to what cardiac dz?

Answer 4

L-CHF

Question 5

what is the typical signalment for PH?

Answer 5

dogs, middle-age to older, small breeds

Question 6

what major clinical sign might lead you to think a patient has PH?

Answer 6

syncope or pre-syncope (often exertion-induced)

Question 7

what murmur might you find in a patient with PH?

Answer 7

tricuspid regurgitation (PMI right apex)

concurrent DMVD > left apical systolic

Question 8

T/F: a patient with severe pulmonary hypertension may also have systemic hypertension

Answer 8

FALSE, systemic HYPOtension

Question 9

what is the gold standard test for diagnosing PH in small animals?

Answer 9

echocardiography

Question 10

what signs might you see in an echo of a patient with PH?

Answer 10

• right ventricular hypertrophy & dilation
• right atrial dilation
• diastolic flattening of ventricular septum
• dilated PA and branches

Question 11

what is the most commonly used drug to treat PH in small animals?

Answer 11

sildenafil

Question 12

what is the MOA of sildenafil?

Answer 12

phosphodiesterase V inhibitor (pulmonary vasodilator)

Question 13

obstruction of a PA by a thrombus that originated in systemic venous circulation (or w/in the RA/RV)

Answer 13

pulmonary thromboembolism

Question 14

what are the three components of virchow’s triad leading to thrombus formation?

Answer 14

hypercoaguability, endothelial injury, and blood stasis

Question 15

what tests would you conduct for a definitive diagnosis of PTE?

Answer 15

CT, angiography, or radionuclide ventilation/perfusion scan

Question 16

what would you expect to see in thoracic radiographs of a patient with PTE?

Answer 16

MAY APPEAR NORMAL

+/- focal interstitial/alveolar infiltrates
+/- lung lobe consolidation
**hypovascular area/lobe

Question 17

an arterial blood gas of a patient with PTE would show what?

Answer 17

hypoxemia, hypocapnia, increased A-A gradient

Question 18

snowy presents to you with dyspnea and tachypnea. the owner reports he’s been more lazy than normal and has been coughing. you think he may have a PTE. thoracic radiographs are normal as well as D-dimer levels. are you correct in your diagnosis?

Answer 18

NO, normal D-dimer levels in a patient with acute signs of PTE generally rules out PTE

Question 19

what are the goals of treating PTE?

Answer 19

1) prevent growth of pre-existing thrombi and formation of new thrombi
2) support the respiratory and CVS

Question 20

what is acute treatment for PTE?

Answer 20

• unfractionated heparin or LMWH
• O2
• fluids

Question 21

what anti-platelet drugs would you consider in a patient with PTE?

Answer 21

clopidogrel and aspirin