Pulmonary Vascular Diseases Flashcards
Pulmonary hypertension refers to elevated pulmonary ________ (arterial/venous) pressure
arterial
Inc. pressure in pulmonary a.
List the 3 pathophysiologic mechanisms that cause pulmonary hypertension
- Increased pulmonary blood flow
- Increased pulmonary vascular resistance
- increased pulmonary venous pressure
List the 6 groups/classifications of pulmonary hypertension
- Pulmonary arterial hypertension
- PH secondary to L-CHF (Inc. PVP)
- PH secondary to respiratory dz and/or hypoxia
- Pulmonary emboli/thrombi/thromboemboli
- Parasitic dz (HW, lungworm)
- PH with multifactorial or unclear mechanisms
List the causes of pulmonary hypertension secondary to respiratory disease
- Tracheobronchial dz (Bronchitis)
- Pulmonary paranchymal disease (pulmonary fibrosis, pneumonia)
- Airway obstruction
- Low inspired O2 (hypoxia @ high altitude)
List heart disease causes that can result in pulmonary venous hypertension
L-sided heart dz (Increased pulmonary venous pressure)
- DCM
- DMVD
List heart disease causes that can result in pulmonary arterial hypertension
- PDA
- VSD
Pulmonary hypertension is more common in _________ (dogs/cats)
Dogs
Pulmonary hypertension is more common in ___________ (small breeds/large breeds)
Small breeds
What clinical signs might be observed in a patient with pulmonary hypertension?
- Syncope, often exercise induced
- Tachypnea, dyspnea
- Cough
- Exercise intolerance
- Ascites if R-CHF present
PE findings on a patient with pulmonary hypertension?
- Abnormal lung sounds
- Cyanosis
- Normothermic, normal to inc. HR
If severe PH:
- Murmur due to TV regurg
- Ascites, jug distension due to R-CHF
- Systemic hypotension
What findings can be seen on a thoracic radiograph of a patient with pulmonary hypertension?
- Enlarged pulmonary arteries
- +/- R-side cardiomegaly
- +/- Enlarged main pulmonary arter
- +/- Pulmonary infiltrates
What findings can be seen on an echo of a patient with pulmonary hypertension?
- Tricuspid valve regurg
- RV hypertrophy
- Dilated many pulmonary a. & branches
- RA dilation
Explain how pulmonary hypertension can result in systemic hypotension
- Increased resistance in pulmonary a
- RV can’t pump enough blood to L-side of the heart
- Volume underloaded LV resulting in dec. CO, SV, and systemic hypotension
What is the treatment protocol for a patient with pulmonary hypertension?
- Tx not indicated unless moderate or severe PH
- Tx of underlying cause is most IMPT
- Give pulmonary vasodilators: Sildenafil
- Supplemental O2 (helps dilate pulmonary a.)
What is the prognosis for a patient with pulmonary hypertension?
- Severe PH: poor long term, guarded short term
- Sudden death can occur with severe PH
- Good to fair prognosis if underlying cause is treated
What diagnostics should be done on a patient with suspect pulmonary hypertension?
- HWT
- Thoracic rads
- Echo (gold standard)
True or False: Most patients with pulmonary hypertension present with clinical signs
False
mild PH does not cause CS, Severe PH always causes CS
What conditions are associated with PTE?
- IMHA
- PLN / PLE
- Hyperadrenocorticism / Corticosteroids
- Diabetes mellitus
and more
If pulmonary hypertension is severe enough, a ____________ murmur can be heard
Right apical systolic murmur (due to TV regurg)
List the more widely available tests that may provide evidence in support of or against PTE
- Thoracic rads (may be normal)
- Arterial blood gas
- D-dimers
- Coag panel (PT/PTT)
- Thromboelastography
Which of the following tests, if normal, generally rules out acute signs of PTE?
A. D dimers
B. PT/PTT
C. Thoracic radiographs
D. Absent right apical systolic murmur
A. D dimers
What is the acute vs chronic treatment protocol for a patient with PTE?
Acute:
- Heparin
- Supplemental O2
- IV fluids
Chronic: antithrombotic
- Anticoag
or
- AntiPLT (Clopidogrel, Aspirin)
What is the prognosis for a patient with PTE?
Fair to guarded if mild-mod
Poor for severe PTE
What are features and clinical consequences of HWD?
- Pulmonary artery and parachymal injury
- pulmonary hypertension
- R- CHF
- Glomerulonephritis
- Thrombocytopenia
- DIC
- Caval syndrome
HWD can cause _________ hypertrophy due to ________ overload
RV concentric, pressure
What is the drug of choice for eliminating Wolbachia during HW treatment?
Doxycycline
What is caval syndrome?
Mechanical obstruction (by worms) of blood flow in the R side of the heart and vena cava
Results in hemolytic anemia and cardiogenic shock
Annual screening should be done on dogs > ______ of age for HWD
over 7 months
What tests should be ran on dogs when screening for HWD?
Antigen test and microfilaria test
What is the preferred treatment protocol for a dog with HWD?
- Macrocyclic lactone preventative
- Doxycycline
- Exercise restriction
- Adulticide therapy with 3-dose melarsomine (1-2 months after diagnosis of HW)
- +/- corticosteroids
Why is exercise restriction an imperative measure taken when treating a patient with HWD?
Reduces risk of thromboembolic complications
What MCL should be avoided in microfilaremic dogs if possible?
Milbemycin - can cause obstruction and anaphylaxis
How is corticosteroid therapy beneficial in treating dogs with HWD?
- Anti-inflamm tx for symptomatic patients
- Prevention and tx of adverse rxns to microfilaricides
- TX of pneumonitis, pulmonary granulomas, or PTE
- Provides analgesic for melarsomine injections
- Mf + dogs should be pretreated with corticosteroids before 1st dose of MCL
What is the treatment protocol for caval syndrome?
Emergency worm extraction via jug vein
(delay melarsomine tx for atleast 30 days)
Differences in HWD in cats compared to dogs?
- Never develop mature infection (no adult worms)
- Pulmonary disease develops even tho mature adults never exist
- Rarely mf+
- Develop HARD (HW ass resp disease)
What can develop as a consequence of HWD in cats?
HARD (HW ass resp disease)
(ashthma like symptoms)
What tests should be ran in symptomatic cat with suspect HWD?
- Antigen and Antibody test (BOTH!!)
