Cardiovascular Dysfunction Hypertensive Heart Disease Flashcards
What are some areas of CVS dysfunction?
Failure of pump
Obstruction to flow
Regurgitant flow
Shunted flow (diversion of flow from one part of the heart to another (eg. patent ductus arteriosis))
Disorders of Cardiac conduction (eg. reentry or node problems and other arrhythmia)
Rupture of heart or a major vessel (gun shot wound for example)
What happens when you have a pressure overload?
Higher systolic blood pressure which results in thickening of the walls of the ventricles. and in turn this results in concentric hypertrophy
What happens when you have a volume overload in the heart?
Increase in diastolic pressure results in addition of new sarcomeres and chamber enlargement resulting in eccentric hypertrophy
What happens to the heart after hypertrophy?
Increased muscle fiber width
Nuclear enlargement
more mitochondria in cells
Possible fibrosis (due to lower blood supply associated with hypertrophy as well as lack of increase in blood vessel size)
Synthesis of abnormal protein and additional nuclear DNA
Molecular changes (Gene expression pattern resembling foetal pattern)
What is the aetiology of cardiac hypertrophy?
Pressure or volume overload or trophic signals.
What are the causes of cardiac hypertrophy?
Hypertension (pressure overload)
Vascular disease (pressure and/or volume overload)
Myocardial infarction (regional dysfunction with volume overload)
These factors result in the cardiac work increasing thus increasing stress on the cardiac walls and the stretch of walls.
What is cardiac hypertrophy characterized by?
Increase in heart size and mass
Increase in protein synthesis
Induction of immediate-early genes
Induction of foetal gene program
Abnormal proteins
Fibrosis
Inadequate vasculature
What is cardiac dysfunction associated with?
Heart failure
Arrhythmias
Neurohumoral stimulation
What does eosinophilic tissue show on slide?
pink colour
What are the types of heart failure?
Forward failure which is a failure in tissue perfusion and results from a diminished cardiac output.
Backward failure results when there is pooling of blood in the venous system and oedema.
Left heart failure result in backward failure in pulmonary circulation and in turn right heart failure as well.
Right heart failure is secondary to left heart failure.
Systolic failure is inability to contract normally and expel blood resulting in weakness, fatigue, reduced exercise tolerance, etc.
Diastolic failure is increased resistance to ventricular inflow and reduced ventricular diastolic capacity
High output failure results from hyperthyroidism, anaemia, pregnancy, AV fistulas
Low output failure results from IHD, HHD, Dilated CM, pericardial disease
Acute heart failure occurs after big infarct valve rupture or loss of blood and usually is a type of systolic failure and results in systemic hypotension without peripheral oedema
Chronic heart failure results in multi valvular heart disease and normal BP but with oedema
How does HF appear in patients?
Dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
Cachexia
Abdominal and Cerebral symptoms
Hepatomegaly
Splenomegaly
Jaundice
Hydrothorax and ascites
Peripheral oedema
What is forward heart failure?
Diminished cardiac output and reduced tissue perfusion
What is backward heart failure?
Pooling of blood in the venous system resulting in venous congestion and oedema
What is Left Heart Failure?
Congestion of pulmonary circulation causing stasis of blood in left sided chambers and hypoperfusion
What are the most common causes of Left Heart Failure?
Ischaemic heart disease (IHD), Hypertensive Heart Disease (HHD), Valvular Heart Disease (VHD), CardioMyopathy (CM)
What is the cause of right heart failure?
Secondary to LHF or primary lung disease, high pressure left to right shunt.
What does right heart failure result in?
Systemic congestion due to blood not being pumped away from the right ventricle fast enough
What is systolic heart failure?
Failure in expelling blood normally resulting in weakness, fatigue, and reduced exercise tolerance as well as symptoms of hypoperfusion
What is diastolic failure?
Increased resistance to ventricular inflow and reduced ventricular diastolic capacity (I.e inability to relax and fill)
What causes diastolic failure?
Anything that prevents the ventricle from stretching adequately to fill up. eg. Constrictive pericarditis, Cardiomyopathy, and myocardial fibrosis
What causes high output failure?
Hyperthyroidism, anaemia, pregnancy, AV fistulas, beriberi
What causes low output failure?
Ischaemic Heart Disease
Valvular Heart Disease
Dilated Cardiomyopathy
What is dilated cardiomyopathy?
Heart chamber is larger and weaker
What is acute heart failure?
The result of sudden events to the heart such as myocardial infarction, valve rupture, and loss of blood.
What type of failure typically is acute heart failure?
Systolic failure
What is chronic heart failure?
Normal BP but oedema due to slow movement of blood.
What causes chronic heart failure?
Dilated CardioMyopathy and multivalvular heart disaese