Pulmonary and Systemic Hypertension Flashcards
what are the clinical signs of pulmonary hypertension?
dyspnea
fatigue
syncope
is the right ventricle more adapted to increased volume or increased pressure?
increased volume more than increased pressure
what does right ventricle dilation lead to?
tricuspid regurgitation
what are the common causes of pre-capillary, pulmonary arterial hypertension?
idiopathic
congenital heart disease (with left to right shunt)
heartworm infection
what is affected by pulmonary arterial hypertension?
pulmonary arterial system alone
what is the general cause of pulmonary arterial hypertension (pre-capillary)?
disorders that cause the arterial system to remodel and imbalance between vasodilation and vasoconstriction (endothelial dysfunction)
what is endothelial dysfunction?
imbalance between vasodilators and vasoconstrictors produced by endothelial cells
why is poiseuille’s equation important?
change in radius of a vessel causes a giant change in pressure
radius is to fourth power
what makes up pulmonary arterial remodeling?
intimal hyperplasia
medial hypertrophy
adventitial proliferation
what is pulmonary hypertension from with left-sided heart failure (post-capillary)?
pressure in left atrium passively transmitted backwards to pulmonary veins, capillaries, and even arteries
what are some causes of pulmonary thromboembolism in dogs and cats?
neoplasia
metabolic disease
trauma
surgery
renal disease
what are some endothelin-receptor antagonists?
bosentan
ambrisentan
macitentan
what does phosphodiesterase 5 do?
breaks down cGMP (important in vasodilation)
how can we deliver nitric oxide to the patient?
nitroprusside
nitroglycerine paste
what are some phosphodiesterase 5 inhibitors?
sildenafil
tadalafil
vardenafil
what are the neural controls of vasodilation and vasoconstriction?
sympathetic and parasympathetic systems
what does right ventricle dilation lead to?
tricuspid regurgitation
what is group 2 of pulmonary hypertension?
post-capillary, pulmonary venous hypertension secondary to left-sided heart disease
what are some causes of chronic thromboembolism that lead to pulmonary hypertension (group 4)?
heartworm infection
pulmonary thromboembolism
neoplasia
what happens with arterial remodeling?
pilmonary arteriolar remodeling: intima, media, adventitia
thrombus formation
inflammation
plexiform lesions
imbalance between vasodilation and vasoconstriction
what are plexiform lesions?
capillary-like vascular channels within lumen of small muscular arteries
what are some lung diseases in dogs that can lead to pulmonary hypertension?
interstitial fibrosis
sleep apnea
chronic hypoxia
what do endothelin-receptor antagonists do?
block endothelin receptor: prevent vasoconstriction
what are the types of systemic hypertension?
situational
secondary (most common)
idiopathic
what humoral regulators vasodilate?
nitric oxide
histamine
prostacyclin
what does hydralazine do?
inhibits calcium release in smooth muscle cells: decreases systemic hypertension
what can be used to inhibit RAAS to decrease systemic hypertension?
ACE inhibitor or angiotensin receptor blocker: enalapril, benazepril, losartan
what are some things that cause pulmonary hypertension through lung disease or hypoxia (group 3)?
interstitial lung disease
chronic exposure to high altitude
what in heartworm leads to pulmonary arterial hypertension?
endarteritis
villous proliferation
why is it a problem that pulmonary arteries experience high blood flow in left-to-right shunting?
proliferative changes in arteries
increase in pulmonary vascular resistance
can pulmonary hypertension secondary to left-sided heart failure lead to pulmonary arterial remodeling?
yes
how can direct destruction of the vascular bed from lung disease happen?
stress from hyperinflation
inflammation
how does lung disease cause pulmonary hypertension?
chronic hypoxia: increased vascular resistance
direct destruction of vascular bed from lung disease
pulmonary artery remodeling
endothelial dysfunction
how can we treat pulmonary hypertension?
fix underlying cause if possible
try to dilate pulmonary vessels
what are some humoral regulators that vasoconstrict?
catecholamines
endothelin
ADH/vasopressin
renin-angiotensin-aldosterone system
