Ophto hypertension cats Flashcards
According to the study on ocular fundus abnormalities in cats with systemic hypertension, what percentage of the study population presented with some degree of fundus abnormality at the time of diagnosis?
58.6%
In the study by Cirla et al. (2021), what grade of ocular fundus lesion corresponds to severe retinal hemorrhages and partial retinal detachment in hypertensive cats?
Grade 3
1: increased arterial vascular tortuosity with minimal to moderate narrowing of the retinal arteries
2: grade 1 + mild retinal hemorrhages and/or subretinal exudation (bullous retinal detachment)
3: 1+2+ partial retinal detachment and moderate/severe retinal and/or vitreous hemorrhages
4: 1+2+3+ subtotal/total retinal detachment
Which method is considered the gold standard for blood pressure measurement?
Intra-arterial catheterization
In the management of systemic hypertension in cats, which antihypertensive drug is considered first-line therapy?
Amlodipine besylate
According to consensus: 3 types of hypertension. Waht are those?
situational, secondary, idiopathic
What is the recommended course of action if a patient’s elevated blood pressure is thought to be ‘situational hypertension’?
Take the blood pressure at home or in a stress-free environment and repeat measurements
What is the most common underlying condition associated with systemic hypertension in cats?
chronic renal failure
What other diseases can lead to systemic hypertension in cats?
hyperthyroidism (HT), hyperaldosteronism,
diabetes mellitus, and hypertrophic myocardiopathy
(HCM)
What are the recommendations/protocol when taking BP with Doppler?
width of the cuff should be 30%-40% of the circumference of the
extremity at the site of cuff placement.
First measurement should
be discarded and the average of 5-7 consecutive consistent indirect
measurements should be obtained
Can you think of any dog breed with higher BP?
hounds (eg, Greyhounds, Deerhounds) = BP is
higher than in mongrel by approximately 10-20 mm Hg
T/F: The term systemic hypertension is applied to sustained increases in
SAP, MAP and DAP
F: only systolic according to consensus
According to consensus: 3 types of hypertension. Waht are those?
situational, secondary, idiopathic,
How common is idiopathic hypertension in cats?
13-20%
What are the main organs affected by TOD?
kidneys (=progression of CKD), eyes (Retinopathy/choroidopathy), brain (Encephalopathy
Stroke), heart and blood vessels (Left ventricular hypertrophy
Left-sided congestive
heart failure (uncommon)
Aortic aneurysm/dissection (rare))
In hypertensive cats, what is the most common severe ocular lesion observed according to the 2021 study?
tot retinal detachment
After how many days of treatment with amlodipine did 50% of hypertensive cats in Cirla et al.’s study show significant improvement in their fundic lesions?
21d
What is the estimated prevalence of systemic hypertension in cats with chronic kidney disease (CKD), according to the ACVIM consensus statement?
50-65%
According to Cirla et al. (2021), what is the prognosis for visual recovery in cats that present with severe hypertensive ocular lesions?
Limited visual recovery despite retinal reattachment.
In most cases, tx lead to
retinal reattachment and hemorrhage reabsorption. However, at the last clinical evaluation (365d after diagnosis) only 71/132 cats had maintained their visual function, while 61/132 cats showed no or inconsistent visual function.
What is the primary mechanism of action of amlodipine?
Ca-channel blockade -> vasodilation
specifically acts on the L-type Ca channels in smooth muscle of blood vessels:
L-type calcium channels, which are responsible for the entry Ca²⁺ into the cells of smooth muscles in the arterial walls-> reduces the influx of Ca into vascular smooth muscle cells. Ca is key factor that facilitates muscle contraction. Without sufficient calcium inside the cells, the ability of the smooth muscle to contract is diminished.
Vasodilation:
The reduced contraction of vascular smooth muscles leads to vasodilation, or the relaxation and widening of blood vessels, particularly in the arteries. This results in a decrease in systemic vascular resistance (SVR).
Preferential Action on Arteries (Minimal Cardiac Effect):
Amlodipine predominantly affects arterial smooth muscle without significantly impacting cardiac muscle contractility or conduction. This is because it has a higher affinity for vascular smooth muscle than for cardiac muscle, making it especially useful in managing hypertension without directly affecting heart rate or causing significant bradycardia.
Renal Effects and Proteinuria:
By lowering systemic blood pressure, amlodipine helps reduce the glomerular capillary pressure in the kidneys, thus protecting the glomeruli from damage. This mechanism is beneficial in reducing proteinuria in hypertensive cats, especially those with chronic kidney disease (CKD).
What are the reported side effects of amlodipine?
peripheral edema
and gingival hyperplasia - uncommon
What are ophthalmoscopic signs of hypertensive optic neuropathy?
Papilledema (Swelling of the Optic Disc), retinal hemorrhage, retinal detachment, retinal edema, vascular tortuosity, pallor of optic disc, subretinal and intraretinal exudates
According to the study on systemic hypertension (SHP) in cats, amlodipine therapy was effective in reducing SHP damage to the fundus. However, what percentage of cats maintained their visual function after 365 days of treatment?
54%
according to the paper, what is a critical factor
for the restoration and maintenance of visual function?
Duration of retinal detachment:
the shorter the period of detachment, the better the prognosis
for the restoration and maintenance of visual function
What is the pathophys of gingival hyperplasia as side effect of amlodipine?
Compared with other parts of the body, gingiva has the highest activity of transglutaminase,
which is a Ca-dependent enzyme involved in apoptosis.
Decreased intracellular Ca levels caused by amlodipine
(Ca channel blocker) reduces normal apoptosis and, hence, deregulation of tissue overgrowth contributes to gingival
enlargement
