Hypertension Flashcards
is systemic arterial hypertension usually a primary or secondary disease
secondary disease
what is systemic hypertension
persistently elevated systemic blood pressure
why is systemic arterial pressure saved during LCHF
compensation from the SNS keeps the pressure normal
What systolic and diastolic pressures warrant further investigations
systolic >160mmHg
Diastolic >100mmHg
how can kidney disease lead to systemic (arterial) hypertension
Areas of ischaemia of the kidneys leads to activation of RAAS
Reduced sodium excretion with subsequent volume expansion and increased CO
what are some initiating causes of systemic (arterial) hypertension
chronic fluid accumulation
persistently increased heart rate
chronic vasoconstriction
What are some perpetuating causes of systemic (arterial) hypertension
small artery changes: hyaline arteriosclerosis, vascular smooth muscle hypertrophy
renal disease
What is hyaline arteriosclerosis
High pressure fluid hitting the walls of the arteries resulting in the thickening and hardening of the walls
What 4 conditions in systemic (arterial) hypertension commonly secondary to
Renal disease
Hyperadrenocorticism
Hyperthyroidism
Diabetes mellitus
How can hyperadrenocorticism lead to systemic (arterial) hypertension
increased renal retention of salt and water
overproduction of renin –> vasoconstriction
How can hyperthyroidism lead to systemic (arterial) hypertension
increased sensitivity of myocardium to cathecolamines
How can diabetes mellitus lead to systemic (arterial) hypertension
volume expansion due to hyperglycaemia
overproduction of renin –> vasoconstriction
At what point does end organ damage occur
systolic >180mmHg
30mmHg rise within 48 hours
What are some examples of end organ damage and their clinical findings
Eye- Hypertensive retinopathy- acute onset blindness, intraocular haemorrhage
CNS- Hypertensive encephalopathy - Ataxia, seizures, strokes
Renal- proteinuria, PU/PD
Cardiac- left ventricular hypertrophy- murmurs arrhythmias
What is the difference between Doppler and oscillometric measurement of BP
Doppler only gives systolic
Oscillometric gives systolic, diastolic and mean
How is cuff size for blood pressure measurement selected
Cuff width size 40% of cuff site circumference
At what systolic blood pressure should treatment be started
systolic 160 to 179mmHg is repeatable findings of evidence of end organ damage
systolic >180mmHg even if no clinical signs
How is high systemic (arterial) blood pressure treated
treat underlying cause
beta blockers
ACE inhibiters
Ca channel blockers
In what hypertensive patients are Beta blockers the treatment of choice
Hyperthyroid cats
In what hypertensive patients are ACE inhibiters the treatment of choice
Patients that have proteinuria
Which pathologies causing hypertension are ACE inhibitors better in the treatment of
Those that lead to elevated renin levels
Renal failure
Cushings
Diabetes
What is the first choice for treatment of systemic (arterial) hypertension in cats
Ca channel blockers
List 3 examples of ACE inhibitors
Benazepril
Enalapril
Imidapril
What are the goals of treatment of systemic arterial hypertension
Reduce blood pressure
- <150/95 mmHg
reduce end organ damage risk
decrease proteinuria
prevent further deterioration of organ function
How are increases in pulmonary blood flow accommodated by the pulmonary circulation with minimal increases in pulmonary pressure
Highly distensible thin walls of pulmonary vasculature
Recruitment of under perfused vessels
Large pulmonary capillary SA
How is pulmonary hypertension defined
systolic pulmonary arterial pressure >35mmHg
diastolic pulmonary arterial pressure >10mmHg
List the 5 causes of pulmonary (arterial) hypertension
- Alveolar hypoxia with pulmonary vasoconstriction/ remodelling
- Pulmonary vascular obstructive disease
- Pulmonary over circulation
- High pulmonary venous pressure
- Idiopathic
How can severe respiratory disease lead to pulmonary (arterial) hypertension
Arterial vasoconstriction due to hypoxia increasing pulmonary vascular resistance which increases pulmonary hypertension
Pulmonary hypertension inducing angioproliferative changes
What are some examples of pulmonary vascular obstructive disease
pulmonary thromboembolism
Herat worm disease
How can congenital shunts lead to pulmonary (arterial) hypertension
increased volume of blood in pulmonary circulation
Raised perfusion pressure damaging pulmonary vessels and leading to remodelling
How does pulmonary (arterial) hypertension effect the Right ventricle?
Hypertrophy and dilation
What is meant by cor pulmonale?
Right sided changes induced by pulmonary (arterial) hypertension caused by pulmonary vascular/parenchymal changes
How does decline in RV function lead to decreased cardiac output?
Reduced blood into pulmonary circulation
Reduced LA preload
Reduced LV stroke volume
Reduced CO
What breeds is pulmonary (arterial) hypertension more commonly seen in?
Breeds predisposed to airway/valvular disease: WHWT, CKCS
What age of dog is pulmonary (arterial) hypertension more commonly seen in?
Middle to older age
When should you suspect pulmonary (arterial) hypertension?
See the following without an obvious cause:
Persistent respiratory difficulty
Fatigue
Exercise intolerance
What are the most common clinical signs of pulmonary (arterial) hypertension?
Exercise intolerance
Cough
Respiratory difficulty
Syncope
Ascites
What heart sounds can severe pulmonary (arterial) hypertension result in?
Split S2 due to pulmonic valve closing earlier than aortic valve
What are some thoracic radiography findings indicative of pulmonary (arterial) hypertension?
Cardiomegaly (esp R sided)
Enlarged pulmonary arteries
R sided heart failure signs: hepatomegaly, large CVC, pleural effusion
Where are veins located on thoracic DV radiographs?
Ventral and central
What are some echocardiograph findings indicative of pulmonary (arterial) hypertension?
RV hypertrophy (>1/2 thickness of LV wall) and dilation
Pulmonary artery dilation
RA enlargement
Flattened IVS
How is pulmonary (arterial) hypertension treated?
Treat underlying disease
Sildenafil (viagra)
Pimobendan
Oxygen therapy
