Cardiomyopathies * Flashcards
What is cardiomyopathy?
It’s a heart disorder in which the major abnormality is related to the myocardium.
What are the 3 categories of cardiomyopathies?
Dilated, hypertrophic and restrictive
What’s dilated cardiomyopathy?
It’s ventricular enlargement with impaired systolic contractile function
What happens with dilated CM?
There’s enlargement of all 4 chambers. There’s also extensive fibrosis.
What’s the pathophysiology of DCM?
Ventricular dilation with impaired contractile function. The stroke volume and CO initially decline. Also leads to reduction of renal blood flow, so there’s increased renin release. Systemic and pulmonary congestion occurs as well.
Regurgitation due to DCM has what effects?
- Volume and pressure overload in atria
- Regurgitation further reduced ventricular ejection (ie; stroke volume)
- Causes volume overload in ventricles.
What’s hypertrophic cardiomyopathy?
It’s asymmetric left ventricular hypertrophy and a common cause of sudden mortality in young athletes.
It is characterized by a very stiff thickened muscle that results in impaired relaxation and high diastolic pressure.
What’s the cause for hypertrophic cardiomyopathy?
Reduced contractile function leads to increased stress, which leads to hypertrophy.
What are the 2 categories of HCM?
- HCM without outflow tract obstruction.
2. HCM with outflow tract obstruction
What is HCM without outflow obstruction characterized by?
Strong systolic contractions, but results in increased stiffness and impaired filling.
What’s HCM with outflow obstruction characterized by?
It invokes abnormal motion of anterior mitral valve leaflet.
The ejection of blood is more rapid due to narrowed outflow tract by hypertrophied septum.
What’s restrictive cardiomyopathy?
It’s rigid ventricles that aren’t thickened. Impaired diastolic filling occurs with normal systolic function.
Fibrosis or scarring occurs, and so does infiltration of myocardium by an abnormal substance.
What’s the most common cause of restrictive cardiomyopathy?
Amyloidosis (when amyloid builds up in your organs)
What does RCM result in with respects to the passive filling curve?
There’s an upward shift due to:
- Elevated systemic and pulmonary venous pressure
- Theres reduced ventricular cavity size with decreased stroke volume and cardiac output.
What happens with increased rigid myocardium?
There’s increased diastolic ventricular pressure decreased ventricular filling, venous congestion, decreased CO
