Cardiomyopathies Flashcards
Define preload and afterload xx [2]
Preload: cardiac myocytes in ventricles are filling with blood and stretching. Creates end diastolic volume
Afterload: force or pressure need to contract to eject blood out of aortic valve
Define cardiomyopathies
Group of diseases of the myocardium that affect the mechanical or electrical function of the heart because the walls of the heart chambers have become stretched, thickened or stiff. This effects the hearts ability to pump blood around the body
Which of the following is dilated cardiomyopathy?
A
B
C
D
Which of the following is dilated cardiomyopathy?
A
B
C
D
Which of the following is restricted cardiomyopathy?
A
B
C
D
Which of the following is restricted cardiomyopathy?
A
B
C
D
Which of the following is hypertrophic cardiomyopathy?
A
B
C
D
Which of the following is hypertrophic cardiomyopathy?
A
B
C
D
Cardiomyocytes are subdivided into which type of cells? [3]
pacemaker cells [1]
atrial cardiomyocytes [1] (force producing)
ventricular cardiomyocytes [1] (force producing)
What can be 3 consequences of cardiomyopathies? [3]
Thrombus / PE [1]
Arrhthymias [1]
Heart failure [1]
What are the three types of cardiomyopathies? [3]
1. Dilated cardiomyopathy: dilated left ventricle which contracts poorly/has thin muscle.
2. Restricted cardiomyopathy: Impaired relaxation due to stiff wall making it difficult to stretch
3. Hypertrophic cardiomyopathy: ventricular thickening causing disorganied muscle mass and reduced volume in ventricles
Which of the following is the most common?
Dilated cardiomyopathy
Hypertrophic cardiomyopathy
Restricted cardiomyopathy
Which of the following is the most common?
Dilated cardiomyopathy
Hypertrophic cardiomyopathy
Restricted cardiomyopathy
Name 5 symptoms of cardiomyopathies [5]
Extreme fatigue
Shortness of breath
Dizziness
Chest pain / Angina
Heart palpitations
Peripheral oedema
Ascites
Fluid in flungs
Difficulty sleeping
Weight gain
Early stages: May not present with signs or symptoms – need mutli modal investigations
But as the condition advances, signs and symptoms usually appear as severity increases
Why would cardiomyopathy cause:
i) chest pain? [1]
ii) breathlessness? [1]
Why would cardiomyopathy cause:
i) chest pain? [1]
reduced o2
ii) breathlessness? [1]
pulmonary oedema
Dilated cardiomyopathy carries what type of inheritance pattern? [1]
Autosomal dominant
What are features of dilated cardiomyopathy? [1]
What are the physiological consequences of dilated cardiomyopathy? [3]
Left or biventricular dilation & systolic dysfunction in absence of CAD, hypertension valvular disease or congenital heart disease. Dilated left ventricle which contracts poorly/has thin muscle
Causes:
- Reduced stroke volume and therefore CO
- Disordered myocytes: impaired ventricular filling
- Increase in preload / end diastolic pressure
How does the heart compensate for a reduction in CO due to dilated cardiomyopathy? [2]
Frank Starling Mechanism:
- Sympathetic nervous system activates increase in HR and contractility
- Subsequent activation of RAAS
What is the effect of increased aldosterone on blood potassium levels? [1]
Increasde aldosterone causes reduced potassoim levels in blood
Describe the pathology behind hypertrophic cardiomyopathy (HCM)
The hypertrophic, non-compliant ventricles impair diastolic filling resulting in reduced stroke volume and thus cardiac output
Septum can also be affected: causes left ventricular outflow tract obstruction or mitral valve dysfunction. Significant thickening of septum causes tightening of aortic valve – reduced ejection fraction
Causes a disarray of cardiac myocytes so conduction is affected
