Cardiomyopathies Flashcards
Cardiomyopathy
Disease of the heart muscle where walls of the heart have become thickened or stiff
What is the thickest layer of the heart wall
Myocardium
Which cells make up the myocardium
Cardiomyocytes
Which filaments are involved in cardiomyocyte contraction
Myosin
Actin
Compensatory reflexes to cardiomyopathies
Sympathetic nervous system activation
RAAS activation
Atrial natriuretic peptide
3 types of cardiomyopathies
Dilated
Restrictive
Hypertrophic
What happens in Dilated cardiomyopathy
Ventricular dilation and stretching of muscle fibres
What happens in Restrictive cardiomyopathies
Restricted/ stiff walls and impaired ventricular filling
What happens in Hypertrophic cardiomyopathy
Excessive wall thickening of cardiac muscle with disorganised muscle and fibrotic plaques
Cardiomyopathy symptoms
May not be signs or symptoms in early stages
Fatigue
Shortness of breath
Dizziness
Light headedness
Fainting
angina
Palpitations
Leg and feet Oedema
Abdomen swelling
Cough
Chest congestion
Sleeping difficulty
Weight gain
Why do cardiomyopathies cause palpitations
Arrhythmias
Why do cardiomyopathies cause chest pain
Reduced oxygen
Why do cardiomyopathies cause breathlessness
Pulmonary oedema
Why do cardiomyopathies cause dizziness and fainting
Reduced oxygen and blood flow to brain
Why do cardiomyopathies cause tiredness
Reduced cardiac output
Why do cardiomyopathies cause peripheral oedema
Reduced cardiac output
What type of cardiomyopathy is caused by left or biventricular dilation and systolic dysfunction
Dilated cardiomyopathy
How does dilated cardiomyopathy effect stroke volume and cardiac output
Decrease
Why is ventricular filling impaired in cardiomyopathy
Disorganised myofibrils and sarcomeres,
Fibrotic plaques
How does dilated cardiomyopathy affect preload
Increase
How does the cardiovascular system compensate for a reduction in CO
frank starling mechanism
Neurohormonal mechanism
RAAS activation
What can compensatory mechanisms to dilated cardiomyopathies cause
Heart failure
How can increased preload and afterload lead to heart failure
Reduced ejection fraction
Increased wall stress
How can angiotensin II and aldosterone lead to heart failure
Lead to Pathogenic cardiac remodelling
Gene abnormalities in which proteins can increase dilated cardiomyopathy risk
Myofibril
What observations may appear on examination of a patient with dilated cardiomyopathy
Tachycardia
Tachypnoea
Raised JVP
displaced apex beat
Peripheral oedema
What testing is used in cardiomyopathy diagnosis
ECG
echocardiogram
Cardiac MRI
Genetic testing
What does increased total peripheral resistance lead to
Increased Na+ and H2O retention
Oedema
Pulmonary system congestion
What drugs are used in dilated cardiomyopathy management
Beta blockers
Anticoagulants
Dupiuretics
ACE inhibitors
angiotensin II receptor blockers
What do ACE inhibitors and angiotensin II receptor blockers do
Lower blood pressure
Which devices are used to control arrhythmias
Pacemaker
Implantable cardioverter defibrillator ICD
Surgeries for dilated cardiomyopathy management
Remove areas of heart muscle that affect blood flow from heart
Heart transplant
What causes hypertrophic obstructive cardiomyopathy from hypertrophic cardiomyopathy
Asymmetrical septal hypertrophy tightens aortic valve space
What does hypertrophic cardiomyopathy cause
Increased left ventricular wall thickness
Interstitial fibrosis
Arrhythmia
Cardiomyocyte hypertrophy and disarray
How is ventricular volume effected by hypertrophic cardiomyopathy
Unaffected or decreased
What can lead to left ventricular outflow tract obstruction and mitral valve obstruction in hypertrophic cardiomyopathy
Septal thickening
Hypertrophic obstructive cardiomyopathy
Obstructed blood flow from heart to body
Which ventricle is more likely to be affected by hypertrophic cardiomyopathy
Left
Which type of myopathy is the most frequent cause of sudden death in young people
Hypertrophic
What is the major cause of hypertrophic cardiomyopathy
Genetic mutations in sacromeric proteins and myofilament elements
What is the basis of hypertrophic cardiomyopathy diagnosis
Otherwise unexplained left ventricular hypertrophy identified by echo or MRI
Alcohol septal ablation
Using alcohol to kill septal enlargement
Hypertrophic cardiomyopathy management
Implantable cardioverter/defibrillator
Surgical myectomy
Drugs
Anti coagulation
Antiarrhythmics
Ablation
