Flashcards in Pathophysiology Of Heart Disease Deck (25):
What is the basis of heart failure?
Abnormality of cardiac function
Failure to maintain adequate circulation
What is the primary cause of systolic heart failure?
Ischaemic heart disease
What are some other causes of systolic HF? (other than IHD)
What are the classes of heart disease?
Class I -> Class IV
Asymptomatic -> severe
What is the ejection fraction usually?
What happens in systolic dysfunction?
Increased LV capacity
Reduced LV output
Thinning of myocardial wall
Mitral valve incompetence
What is the main neuro-hormonal activation in HF?
Describe the baroreceptor mediated response at the start of HF
Early compensatory mechanism to increase cardiac output (SNS)
But has long-term negative effects
What negative effects does the increased SNS response at the beginning of HF lead to?
Beta receptors down-regulated
Up-regulation of RAAS
Which mediator can bradykinin increase the levels of?
Nitric oxide - vasodilation
Activation of angiotensin II type 2 receptors can increase the levels of which mediator?
How can the angiotensin II type 1 receptor contribute to organ damage?
Fibrosis and remodelling (in heart)
Increase aldosterone release
What are the effects of elevated angiotensin II?
Na+ and water retention
Left ventricular hypertrophy and myocyte dysfunction
(Can make fluid overload in HF worse)
What is the effect of natriuretic hormones?
Decrease reabsorption of Na+
Decrease fluid overload
Inhibit secretion of renin and aldosterone
Balances the effects of RAAS on vascular tone and fluid levels
What causes the release of natriuretic hormones?
Stretch or increase in cardiac chamber volume
What are the effects of endothelin?
Effects are like angiotensin II except more aggressive
What is the effect of prostaglandins?
Vasodilators on renal arterioles
Why shouldn't HF patients take NSAIDs?
NSAIDs block prostaglandin synthesis
Prevents prostaglandin-induced vasodilation
What happens in the kidney during HF?
GFR maintained during early HF by haemodynamic changes
In severe HF, blood flow falls, GFR falls and rise in serum urea and creatinine
Describe diastolic dysfunction
Concentric ventricular hypertrophy
Reduced ventricular compliance
Impaired diastolic filling
Low cardiac output
What are the 3 broad types of heart failure?
Congestive (both sides)
What are the signs/symptoms of left heart failure?
Dyspnoea on exertion
Gets up a lot at night
Can progress to: tachycardia, cardiomegaly, pulmonary oedema, peripheral oedema
What are the common causes of right heart failure?
Secondary to left heart failure
Chronic lung disease
Tricuspid/pulmonary valvular disease
Left tot right shunts
What are the signs/symptoms of right heart failure?