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390 Section M: Pulmonary Arterial Disorders
arterial pressures using a cardiac catheter introduced mation from other species, identification of a treatable
through the jugular vein. Such measurements are not or reversible cause, positive response to such treatment,
routinely undertaken in cats both because diagnosis and and milder degrees of pulmonary hypertension should
treatment of an underlying cause appears to be more be associated with a more favorable prognosis. Since this
clinically applicable and rewarding, and because per- is a syndrome comprised of many different causes, the
forming such measurements may create a risk of sub- expected outcomes are likewise varied. In human patients
stantial iatrogenic problems (particularly as general with pulmonary hypertension, mean pulmonary arterial
anesthesia is generally needed for catheterizing the pul- pressure, right atrial pressure, and pulmonary vascular
monary arteries of cats). resistance are inversely proportional to survival.
Treatment REFERENCES
When pulmonary hypertension exists in association Pulmonary Thromboembolism
with a contributory or inciting cause, treatment of
the cause is indicated first. A common example is con- Davidson BL, Rozanski EA, Tidwell AS, Hoffman AM. Pulmonary
gestive heart failure, where treatment of cardiogenic thromboembolism in a heartworm-positive cat. J Vet Intern Med
2006;20:1037–1041.
pulmonary edema with diuretics and an ACE inhibitor Dickson BC. Venous thrombosis: On the history of Virchow’s triad.
may bring improvement or resolution of the pulmonary Univ Toronto Med J 2004;81:166–171.
hypertension. Dvorak LD, Preziosi DE, Hitchcock LS. What is your diagnosis? Acute
In the normal cat, pulmonary vasculature tone is pulmonary thromboembolism secondary to spontaneous death of
adult heartworms. J Am Vet Med Assoc 2000;217:180–181.
maintained as a balance between locally acting vasodila- Fedullo PF, Tapson VF. The evaluation of suspected pulmonary
tors prostaglandin I 2 and nitric oxide (NO), countered embolism. N Engl J Med 2003;349:1247–1256.
by vasoconstricting substances including thromboxane, Norris CR, Griffey SM, Samii VF. Pulmonary thromboembolism in
endothelin-I (ET-I), and angiotensin II (ATII). cats: 29 cases (1987–1997). J Am Vet Med Assoc 1999;215:
Endothelial dysfunction in pulmonary hypertension 1650–1654.
contributes to smooth muscle cell proliferation Pouchelon JL, Chetboul V, Devauchelle P, Delisle F, Mai W, Vial V.
Diagnosis of pulmonary thromboembolism in a cat using echo-
(increased ET-I, AT-II, reduced NO), increased produc- cardiography and pulmonary scintigraphy. J Small Anim Pract
tion of vasoconstrictor mediators including ET-1 and 1997;38:306–310.
AT-II, and decreased synthesis of vasodilating substances Schermerhorn T, Pembleton-Corbett JR, Kornreich B. Pulmonary
including PGI 2 and NO. Thus, treatment of pulmonary thromboembolism in cats. J Vet Intern Med 2004;18:533–535.
hypertension can address either of these two arms if Schober KE, Maerz I. Assessment of left atrial appendage flow velocity
and its relation to spontaneous echocardiographic contrast in
Pulmonary Arterial Disorders speculative; published reports of the outcomes of these Schwarz T, Crawford PE, Owen MR, Störk CK, Thompson H. Fatal
pulmonary hypertension persists despite control of its
89 cats with myocardial disease. J Vet Intern Med 2006;20:
inciting cause. In the cat, such treatment applications are
120–130.
pulmonary fat embolism during humeral fracture repair in a cat.
treatments are absent in the feline species, likely due to
J Small Anim Pract 2001;42:195–198.
the rarity of this disorder in the cat and the limited
Sottiaux J, Franck M. Pulmonary embolism and cor pulmonale in a
efficacy of treatment of pulmonary hypertension in
cat. J Small Anim Pract 1999;40:88–91.
many cases. Candidate drugs for treatment of pulmo-
Stokol T, Brooks MB, Rush JE, Rishniw M, Erb H, Rozanski E, Kraus
nary hypertension that persists beyond the treatment of
MS, Geltzer AR. Hypercoagulability in cats with cardiomyopathy.
J Vet Intern Med 2008;22:546–552.
its associated or underlying causes may include phos-
phodiesterase inhibitors such as sildenafil (extrapolated Thomas JS, Rogers KS. Platelet aggregation and adenosine triphos-
dose of 1 mg/kg PO q 8 h) or tadalafil, calcium channel phate secretion in dogs with untreated multicentric lymphoma. J
Vet Internal Med 1999;13:319–322.
blockers such as amlodipine, angiotensin converting Whitley NT, Stepien RL. Defaecation syncope and pulmonary throm-
enzyme inhibitors such as enalapril or benazepril, endo- boembolism in a cat. Aust Vet J 2001;79:403–405.
thelin antagonists such as bosentan, and prostaglandin Van Vleet JF, Ferrans VJ, Weirich WE. Pathologic alterations in hyper-
analogs such as beraprost and treprostinil. These treat- trophic and congestive cardiomyopathy of cats. Am J Vet Res
ments represent future possibilities, because reported 1980;41(12):2037–2048.
use in feline pulmonary hypertension is absent from the
veterinary literature. Pulmonary Hypertension
Connolly DJ, Lamb CR, Boswood A. Right-to-left shunting patent
Outcome and Prognosis ductus arteriosus with pulmonary hypertension in a cat. J Small
Anim Pract 2003;44:184–188.
The natural history of pulmonary hypertension in the Kittleson MD, Kienle RD. Small Animal Cardiovascular Medicine. St.
cat has not been properly documented. Based on infor- Louis, Mosby, 1998, 125.