Cardiomyopathies Flashcards
What is cardiomyopathy?
- Disorder within the cardiac myocytes themselves which results in abnormal cellular and hence cardiac performance
- Typically leads to irreversible decline in cardiac function
T/F Patients with a cardiomyopathy are often candidates for transplantation
True
What is the primary cause of cardiomyopathy?
Pathologic processes intrinsic to cardiac myocytes themselves
What is the secondary cause of cardiomyopathy?
Result of a pathological change in cardiac myocytes brought on by a systemic disease process
What are the 3 types of cardiomyopathies? Describe them briefly.
- Dilated - enlarged ventricles and thinned walls
- Hypertrophic - thickened, stiffened walls
- Restrictive - stiffened walls
What is the most common form of cardiomyopathy?
Dilated
Describe common characteristics of dilated cardiomyopathy? (3)
- Impaired systolic function with cardiac enlargement
- Hypertrophied myocytes with mitochondrial abnormalities
- Fibrosis is common – reduced ROM
Causes of dilated cardiomyopathy? (5)
- Toxic substances
- Poor nutrition (B1 deficiency)
- Idiopathic, family hx
- AIDs
- Cancer therapies
symptoms of dilated cardiomyopathy? (4)
- Fatigue
- Dyspnea on exertion, shortness of breath, cough
- Orthopnea (SOB while lying down), paroxysmal nocturnal dyspnea
- Increasing edema, weight, or abdominal girth
Signs of dilated cardiomyopathy? (3)
- Tachypnea: Increased respiratory rate
- Tachycardia: Increased heart rate
- Hypertension or hypotension
Other pertinent findings of dilated cardiomyopathy?
- Signs of hypoxia (eg, cyanosis, clubbing)
- Jugular venous distension (JVD)
- Pulmonary edema (crackles and/or wheezes)
- Enlarged liver
- Ascites (fluid in peritoneal cavity) or peripheral edema
Nonpharmacologic management of dilated cardiomyopathy?
- Sodium diet restricted to 2g/day
2. Fluid restriction
Describe overstretching of LVEDV on Frank starling law.
Overstretching (↑ LVEDV) leads to failure of the myocardial contractile unit Frank Starling law becomes compromised.
What type of CARDIOMYOPATHY is the single most common cause of death in young people?
HYPERTROPHIC CARDIOMYOPATHY
What is HYPERTROPHIC CARDIOMYOPATHY characterized by?
- a thick LV wall with a non-dilated cavity
- resulting cardiac hypertrophy is out of proportion to the hemodynamic load
- 9 gene defects which cause defects in sarcomeric proteins
What is genetic HYPERTROPHIC CARDIOMYOPATHY with autosomal (not sex linked) dominance?
- Normal blood pressures perceived as excessive by defective myocytes
- Hypertrophy occurs as a compensatory mechanism
- Ultimately heart decompensate (decrease functional capacity
T/F Majority of cases of HYPERTROPHIC CARDIOMYOPATHY are symptomatic and are caught before death.
False, Majority of cases are asymptomatic
First clinical manifestation is often sudden death
Describe effect of septal wall thickening on O2 delivery.
Thickening of septal wall -> Myocytes less effective -> blood flow reduced (ejection fraction/stroke volume compromised) -> O2 delivery compromised
Restrictive/infiltrative cardiomyopathy is characterized by what?
- restrictive diastolic filling/loss of compliance (ventricles stiffer – more difficult to fill up or incapable of doing so)
- idiopathic fibrosis
T/F Systolic function if normal in Restrictive/infiltrative cardiomyopathy
True
In Restrictive/infiltrative cardiomyopathy what volume/s are diminished? What volume/s are normal?
- EDVs are diminished (chambers cannot expand and therefore filling pressures are very high)
- ESVs and EFs are normal
What are symptoms of Restrictive/infiltrative cardiomyopathy?
- Dyspnea with exertion
- abdominal swelling
- ankle edema
- fatigue
What are causes of Restrictive/infiltrative cardiomyopathy?
- Scleroderma
- Diabetes
- Amyloidosis (abnormal protein builds up in your organs and interferes with their normal function)
- Sarcoidosis (fibrotic scarring secondary to myocardial infiltrates)
- Hemochromatosis (excessive deposition of iron)
- Metastatic cancers
- Secondary to Anthracycline treatment (antibacterial
- Radiation (mediastinal)
General Cardiomyopathy review:
Hypertrophic -
- Diastolic dysfunction
- Risk of sudden death in young athletes
- Thickened left ventricular wall
