Heart Failure and Hypertension

Question 1

what two things is blood pressure determined by?

Answer 1

1. cardiac output

2. peripheral resistance

Question 2

How does angiotensin II increase blood pressure?

Answer 2

1. causes vasoconstriction
2. promotes vascular hypertrophy
3. stimulates aldosterone release → sodium and water retention

Question 3

What is poiseulle’s law?

Answer 3

resistance is inversely proportional to the fourth power of the radius

Question 4

1. What is primary/essential hypertension?
2. What are the two potential causes of primary hypertension?
3. Why are current treatments for primary hypertension not ideal?

Answer 4

1. hypertension that does not have a particular cause
2. genetic predisposition
   salt and water intake
3. underlying cause is not known/understood, therefore we are not treating the underlying cause

Question 5

1. What happens in the early phase of primary hypertension?
2. What drives the chronic phase of primary hypertension?
3. In the chronic phase of primary hypertension, is blood volume and cardiac output normal or raised?
4. What changes in endothelial function occur in the chronic phase of primary hypertension?

Answer 5

1. increased blood volume and cardiac output
2. irreversible tissue changes - thickening of walls of resistance vessels (leading to reduction in lumen diameters)
   increased vascular tone
3. normal
4. endothelium produces less NO; smooth muscle is less sensitive to NO

Question 6

1. What is secondary hypertension?

2. What are often the causes of secondary hypertension?

Answer 6

1. Hypertension with an identifiable cause

2. Renal or endocrine causes

Question 7

1. How does renal artery stenosis lead to secondary hypertension?
2. How does chronic renal disease lead to secondary hypertension?
3. What is Conn’s Syndrome?
4. What is Phaeochromocytoma?
5. How does Coarction of the aorta cause secondary hypertension?

Answer 7

1. poor perfusion of the kidney, means that it produces a lot of renin
2. increase in BP in attempt to restore GFR
3. overproduction of aldosterone due to adrenal tumour/adrenal hyperplasia
4. adrenal medullary tumours which produce catecholamines
   - alpha mediated vasoconstriction
   - beta mediated cardiac stimulation
5. kidneys are hypoperfused.

Question 8

What changes occur in the heart due to hypertension (2)

Answer 8

1. accelerated coronary atheroma formation
2. concentric left ventricular hypertrophy (due to increased afterload)
   - increased metabolic demands on heart
   - compression of cardiac vessels

Question 9

What changes can occur in the aorta due to hypertension (3)

Answer 9

1. atheroma
2. aneurism
3. dissecting aneurism
   - intima is stripped away from the media, creating a false lumen

Question 10

Name 4 hypertensive retinopathic changes

Answer 10

1. AV nipping
2. Hard Exudates
3. Flame Haemorrhage
4. Papilloedema

Question 11

1. What is accelerated hypertension?
2. What retinal change indicates accelerated hypertension?
3. What causes accelerated hypertension?

Answer 11

1. recent significant increase over baseline BP that is associated with target organ damage
2. Papilloedema
3. loss of autoregulation in the brain, leading to dilation of cerebral arteries

Question 12

1. What is acute heart failure?
2. What is chronic heart faiure?
3. What is heart failure usually initiated by?
4. What are people with heart failure at risk of?

Answer 12

1. patient experiences sudden onset of symptoms or rapid worsening of symptoms of existing heart failure
2. symptoms of heart failure are ongoing and long term
3. initial cardiac insult, such as MI
4. sudden death, usually from rhythm disturbance

Question 13

Name the two types of fluid accumulation that can occur in acute heart failure

Answer 13

Pulmonary oedema

Ansarca - systemic oedema, which usually affects peripheries

Question 14

1. Why does pulmonary oedema occur in heart failure?
2. What are the CXR findings in pulmonary oedema
3. How does a patient with pulmonary oedema present?

Answer 14

1. increase in end diastolic pressure so that it exceeds oncotic pressure in the pulmonary vessels
2. enlarged heart (>1/2 size of thorax)
   curly B lines
3. Breathlessnes, orthopnea, PND, pink frothy sputum

Question 15

Name 2 physiological consequences of LV failure, and how these can worsen the problem

Answer 15

1. decreased renal perfusion → RAAS activation → Water retention → increased preload
2. Decreased BP → sympathetic activation → vasoconstriction → increased afterload

Question 16

How does heart failure result in ansarca?

Answer 16

fall in cardiac output → fall in renal perfusion → RAAS activation → increase ADH and aldosterone → Na and H2O retention

Question 17

1. What is the law of laplace?
2. What does wall tension represent?
3. How does ventricular dilation lead to worsening heart failure?

Answer 17

1. wall tension = (pressure inside the chamber x radius of chamber) / thickness of wall
2. the amount of work the heart has to do, even before it starts to contract
3. dilaition of the ventricles causes the radius of the ventricles, therefore, wall tension increases. Increased tension increases the work of the heart

Question 18

1. How does skeletal muscle change in heart failure?

2. How does ventilation change in heart failure?

Answer 18

1. switch from slow twitch aerobic fibres to fast twitch anaerobic fibres
2. increased

Question 19

1. Why is diamorphine given to those with acute pulmonary oedema?
2. Which diuretic is given in acute pulmonary oedema?
3. What are the most beneficial treatments of acute pulmonary oedema?
4. What drug is given for inotropic support?

Answer 19

1. relief of anxiety; possible role as vasodilator
2. IV furosemide
3. treatments that reduce hydrostatic pressure in the pulmonary capilaries - IV nitrate
4. dobutamine (Beta 1 agonist)

Question 20

How is ansarca managed?

Answer 20

1. bed rest
   daily weighing
   diuretics
   inotropic support

Question 21

1. How are diuretics used to treat ansarca?

2. how are diuretics administered and why?

Answer 21

1. add thiazide diuretic
   change the loop diuretic if already on diuretic
2. intravenous infusion to bypass the oedematous gut

Question 22

What is the triple therapy for management of chronic heart failure

Answer 22

1. ACE inhibitors/AngII blockers - reduced vasoconstriction and aldosterone production
2. Aldosterone Antagonist (spironolactone) - reduces water retention
3. beta blockers - positive inotropic effects and sympathetic blockade

Question 23

1. What is the “ACE Escape Phenomenon”?

2. Name 1 advantage that ACE inhibitors have over Angiotensin II receptor antagonists

Answer 23

1. Other enzymes that convert Ang I to Ang II are not blocked by ACE inhibitors, therefore Ang II can still be produced.
2. ACE also breaks down kinins, which are involved in vasodilation. ACE inhibitors prevent the breakdown of kinins, therefore mediate vasodilation. AngII antagonists don’t have this positive effect