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
General Cardiomyopathy review:
Dilated -
- Enlargement of all cardiac chambers
- Systolic dysfunction
- Most common type
General Cardiomyopathy review:
Restrictive -
- Rigid ventricular walls
- Diastolic dysfunction
- Least common type
Other cardiac pathologies:
Stenosis -
- Valve doesn’t open properly
Other cardiac pathologies:
Regurgitation -
- Valve doesn’t close properly
- Permits backward flow of blood.
- Functional and anatomic Implications (decreased SV)
Other cardiac pathologies:
Arrhythmias -
Disturbance of rate and/or rhythm of heart beat
Arrhythmias:
Bradycardia rate -
Caused by what type of injury?
< 50 BPM
SA node injury
Arrhythmias:
Tachycardia rate -
Caused by what?
> 100 BPM
- Fear, pain, emotion, exertion, Fever, CHF, infection, anemia, hemorrhage, hyperthyroidism
Other cardiac pathologies:
Pericardial effusion -
buildup of fluid -> more difficult for heart to beat against increase pressure
What is pericarditis?
A swelling and irritation of the thin saclike membrane surrounding the heart (pericardium).
pericarditis caused by what?
- Viral infection
- Heart attack
- Idiopathic
Describe pain experienced with pericarditis? When is it worsened? What decreases pain?
- Sharp chest pain-pleural membrane rubbing against one another
- Pain is worsened by lying supine, inhaling deeply, or crouching.
- Leaning forward decreases the pain.
What is myocarditis? Caused by what? Can lead to what?
- Inflammation of the myocardium
- Usually caused by a viral infection
- Can lead to HF, arrhythmia, sudden death
What is an aneurysm?
An abnormal stretching (dilation) in the wall of an artery, a vein, or the heart with a diameter that is at least 50% greater than normal.
T/F Aneurysm named according to the specific site of formation.
True
- Aortic
- Thoracic aortic aneurysms
- Abdominal aortic aneurysms
- Femoral and popliteal aneurysm
In a true aneurysm, layers of the vessel dilate in one of the following 3 ways?
- Saccular: a unilateral outpouching
- Fusiform: a diffuse dilation involving the entire circumference of the artery wall
- Dissecting: a bilateral outpouching in which layers of the vessel wall separate, with creation of a cavity.
What is a false aneurysm?
the wall ruptures, and a blood clot is retained in an outpouching of tissue.
What is the most common aneurysm? What type of pain?
Abdominal aortic aneurysm (AAA) - fusiform in shap extending from below renal arteries to involve the entire infrarenal aorta and often involved the common iliac arteries
- Pressure causes lower abdominal pain and dull lower back pain
4 Causes of diabetic heart disease?
- Metabolic effects due to FFA, insulin resistance
- Structural - myocardial fibrosis and ECM changes
- Reduced perfusion due to small vessel disease
- Autonomic dysfunction reduced HRR
