Cardiomyopathy Flashcards
What are some causes of dilated cardiomyopathy?
Answer: , including
alcohol abuse, beriberi (wet), Coxsackie B myocarditis,
chronic cocaine use, Chagas’ disease, doxorubicin toxicity, peripartum cardiomyopathy,
**Takotsubo cardiomyopathy, **
tachycardic cardiomyopathy, and arrhythmia.
What is the mnemonic for remembering the causes of dilated cardiomyopathy?
Answer: A Bunch of stuff Can Cause Cardiac Dilation
oAlcohol abuse
oBeriberi (wet)
oCoxsackie B myocarditis
oChronic cocaine use
oChagas’ disease
oDoxorubicin toxicity
What are the three other causes of dilated cardiomyopathy?
Answer: The three other causes are
peripartum cardiomyopathy,
Takotsubo cardiomyopathy, and
tachycardic cardiomyopathy.
What is the most common cause of dilated cardiomyopathy?
Answer: idiopathic (unknown origin).
What are the causes of hypertrophic cardiomyopathy?
Answer: is usually caused by genetic mutations in
* HCM (heavy chain myosin),
* Frederick ataxia, and
* familial inheritance.
What is the characteristic feature of hypertrophic cardiomyopathy?
Answer: is asymmetric hypertrophy of the interventricular septum.
What are the causes of restrictive cardiomyopathy?
Answer: Girl PLEASH
* by post-radiation therapy,
* Loeffler’s syndrome (eosinophilic infiltration),
* endocardial fibroelastosis (in patients < 2 years old with congenital heart diseases),
* amyloidosis,
* sarcoidosis, and
* hemochromatosis.
What is the most common cause of restrictive cardiomyopathy?
Answer: The most common cause is idiopathic (unknown origin).
Can sarcoidosis and hemochromatosis cause both restrictive and dilated cardiomyopathy?
Answer: Yes, sarcoidosis and hemochromatosis can cause both restrictive and dilated cardiomyopathy.
What are the pathologic mechanisms in dilated cardiomyopathy?
Answer: In dilated cardiomyopathy, ventricular dilation occurs,
-> leading to thinner ventricular walls.
-> Sarcomeres are added in a linear fashion or in a series (eccentric hypertrophy).
-> This results in bigger ventricular chambers with a thinner wall.
What is eccentric hypertrophy?
Answer:
- is the increase in the size of muscles in a lengthening fashion.
- In dilated cardiomyopathy, it leads to the enlargement of ventricular chambers in diameter.
What are the pathologic mechanisms in hypertrophic cardiomyopathy?
Answer: I
- , the interventricular septum is thicker than normal,
- resulting in a smaller ventricular diameter.
- Sarcomeres are added in a parallel fashion or on top of one another,
- leading to an increase in the size of muscle cells in a concentric fashion.
- However, this tends to favor the interventricular septum.
What is concentric hypertrophy?
Answer:
* is the increase in the size of muscles in a thickening fashion.
* Sarcomeres in “parallel”
- In hypertrophic cardiomyopathy, it causes the thickening of the interventricular septum.
What are the pathologic mechanisms in restrictive cardiomyopathy?
Answer:
- In restrictive cardiomyopathy, normal interstitial spaces in healthy cardiac tissues are replaced with fibrosis and infiltrative substances.
- This destruction and infiltration of cardiac tissues lead to non-compliant (stiff) cardiac tissues, resulting in restrictive filling of the ventricles.
What are the clinical features and complications of dilated cardiomyopathy?
Answer:
1. ventricular dilation with thinning of the walls leads to poor contractility,resulting in systolic heart failure or systolic dysfunction.
2. Patients may exhibit signs and symptoms of left heart failure, including paroxysmal nocturnal dyspnea, orthopnea, and dyspnea at rest or with exertion.
3. They may also present with signs of right heart failure, such as jugular venous distension, ascites, hepatomegaly, and pedal edema.
What are the pathophysiological mechanisms that contribute to decreased contractility in dilated cardiomyopathy?
Answer:
1. Decreased contractility in dilated cardiomyopathy is secondary to ventricular dilation, which stretches sarcomeres beyond their optimal length and reduces contractility.
2. Additionally, thinning of the ventricular walls also contributes to decreased contractility.
What is the Frank-Starling law and its relevance to dilated cardiomyopathy?
Answer:
1. The Frank-Starling law states that stroke volume increases as ventricular volume increases due to myocyte stretch, resulting in a more forceful systolic contraction.
2. In dilated cardiomyopathy, the dilated ventricles do not obey the Frank-Starling law, leading to decreased contractility.
What are the clinical features and complications of hypertrophic cardiomyopathy?
Answer: by
* asymmetric thickening of the interventricular septum, leading to diastolic dysfunction.
- This can cause a decrease in cardiac output, which may result in symptoms such as angina (chest pain), dyspnea on exertion, and syncope.
- In severe cases, decreased coronary artery perfusion can lead to sudden death through the acute onset of ventricular tachycardia or ventricular fibrillation.
What is the Venturi effect in hypertrophic cardiomyopathy?
Answer:
* In hypertrophic cardiomyopathy, the contracting interventricular septum creates a Venturi effect,
- causing a decrease in pressure when blood flows through a stenosis at high velocity.
- This can lead to decreased cardiac output and compromised coronary artery perfusion.
What are the symptoms and complications associated with restrictive cardiomyopathy?
.
Answer:
1. Rigid ventricles that cannot stretch, leading to diastolic dysfunction. Symptoms predominantly manifest as right heart failure,
2. including jugular venous distension, hepatomegaly, pedal edema, and ascites.
3. Left heart failure may also occur, leading to pulmonary edema
What are the characteristic heart sounds associated with dilated cardiomyopathy?
Answer:
- Dilated cardiomyopathy is associated with the presence of an S3 heart sound, which occurs early in systole.
- Additionally, mitral and tricuspid regurgitation can be heard as a holosystolic murmur due to the dilation of all chambers.
What are the heart sounds typically heard in hypertrophic cardiomyopathy?
Answer:
- the presence of an S4 heart sound, which is caused by the rigid ventricles and low distensibility.
- Additionally, a crescendo-decrescendo systolic ejection murmur can be heard at the left lateral sternal border. But not at the carotid
How does the presence of interventricular septum contraction affect the heart sounds in hypertrophic cardiomyopathy?
Answer:
- When the interventricular septum contracts and bows inward in hypertrophic cardiomyopathy, it narrows the left ventricular outflow tract (LVOT), leading to the development of mitral valve regurgitation.
- This contributes to the characteristic heart sounds associated with the condition.
What maneuvers can affect the intensity of the murmurs in hypertrophic cardiomyopathy?
Answer: The intensity of murmurs in hypertrophic cardiomyopathy can be affected by certain maneuvers.
For example,
* the Valsalva maneuver, standing, and leg lifts can decrease preload and intensity,
* while squatting and hand grips can** increase preload and intensity.**
What are the heart sounds and signs associated with restrictive cardiomyopathy?
Answer: In restrictive cardiomyopathy, the
* presence of S3 and S4 heart sounds can be observed.
* Additionally, mitral and tricuspid regurgitation occur due to the dilation of the atria, leading to stretching and pulling of the valve leaflets.
*
* Kussmaul’s sign, characterized by jugular venous distention that worsens or remains the same during deep inspiration, is also prominent in restrictive cardiomyopathy.
What is the gold standard diagnostic tool for cardiomyopathies?
Answer: Echocardiogram
What are the characteristic findings of dilated cardiomyopathy on an echocardiogram?
Answer:
* decrease in wall thickness,
* an increase in ventricular cavity diameter, and reduced contractility leading to decreased stroke volume and ejection fraction.
* Mitral and tricuspid regurgitation can also be observed using Doppler to assess blood flow.
How does hypertrophic cardiomyopathy appear on an echocardiogram?
Answer:
- increased wall thickness of the interventricular septum and asymmetric thickening of the ventricular myocardium.
- Ventricular cavity diameter may be reduced, and there is an increase in contractility.
- Mitral regurgitation can occur due to systolic anterior motion (SAM) of the mitral valve.
What are the echocardiographic findings in restrictive cardiomyopathy?
Answer:
- There may be varied wall thickness, with some cases showing symmetric wall thickening.
- The ventricular diameter may be normal or reduced due to increased thickness.
- Ejection fraction is typically normal, but
- ventricular compliance is decreased.
- Mitral and tricuspid regurgitation can occur due to bilateral arterial enlargement
How do chest X-rays (CXR) help in diagnosing cardiomyopathies?
Answer
* In dilated cardiomyopathy, cardiomegaly (enlarged heart) and pulmonary edema due to left-sided heart failure can be observed.
* In hypertrophic and restrictive cardiomyopathies, the chest X-ray findings are usually normal.
What ECG findings are commonly seen in all types of cardiomyopathies?
Answer:
Atrial fibrillation, characterized by an increased size or thickness of the atrium, is a common finding in all types of cardiomyopathies.
This is due to the stretch and remodeling of the atria.
Additionally, all types of cardiomyopathies carry an increased risk of ventricular tachycardia and ventricular fibrillation.
What is the characteristic sound associated with constrictive pericarditis?
The characteristic sound associated with constrictive pericarditis is a “pericardial knock.”
Q2. What are the heart sounds typically heard in restrictive cardiomyopathy?
A2. The heart sounds typically heard in restrictive cardiomyopathy are mitral valve (MV) and tricuspid valve (TV) regurgitation.
Q3. What is the cause of low voltage QRS complex in both constrictive pericarditis and restrictive cardiomyopathy?
A3. The cause of low voltage QRS complex in both constrictive pericarditis and restrictive cardiomyopathy is deposition in the AV node and bundle branches.
Q4. Why does a ventricular septal bounce occur during diastole in constrictive pericarditis?
A4. A ventricular septal bounce occurs during diastole in constrictive pericarditis because when blood comes to a rigid pericardium, the ventricles cannot distend and are pushed contralaterally.
Q5. What is a common echocardiographic finding observed in both constrictive pericarditis and restrictive cardiomyopathy?
A5. A common echocardiographic finding observed in both constrictive pericarditis and restrictive cardiomyopathy is bi-atrial enlargement.
Q6. What is the difference in pericardial thickness between constrictive pericarditis and restrictive cardiomyopathy?
A6. Constrictive pericarditis is characterized by a thickened pericardium, while restrictive cardiomyopathy has a normal pericardium without any problems.
Q7. How does cardiac catheterization help differentiate between constrictive pericarditis and restrictive cardiomyopathy?
A7. Cardiac catheterization helps differentiate between constrictive pericarditis and restrictive cardiomyopathy by comparing ventricular pressures.
In constrictive pericarditis, the left ventricular end-diastolic pressure (LVEDP) is usually greater than the right ventricular end-diastolic pressure (RVEDP).
Q8. What is the relationship between end-diastolic pressures on both ventricles in constrictive pericarditis?
A8. Equal end-diastolic pressures on both ventricles are observed in constrictive pericarditis.
Q9. How does the compliance of the ventricles differ between constrictive pericarditis and restrictive cardiomyopathy?
A9. The compliance of the ventricles is reduced in constrictive pericarditis due to the rigid and non-distensible pericardium, while in restrictive cardiomyopathy, the ventricles have slightly reduced compliance but can still distend.
Q10. What is the primary difference in the involvement of the pericardium between constrictive pericarditis and restrictive cardiomyopathy?
A10.
- The pericardium surrounds the heart and is rigid in constrictive pericarditis, causing limited expansion during diastole.
- In restrictive cardiomyopathy, there is no problem with the pericardium, and the condition is primarily related to the compliance and function of the ventricular myocardium.
Q1. What is the management approach for dilated cardiomyopathy with a focus on controlling volume and venous return?
A1.
The management approach for dilated cardiomyopathy involves
1. diuretics to control hypervolemia, fluid restriction, and
2. compression stockings to enhance venous return.
Q2. How can afterload be reduced in dilated cardiomyopathy?
A2.
1. using medications such as ACE inhibitors/ARBs and
2. direct vasodilators like hydralazine and isosorbide dinitrate.
Q3. What medication can be used to increase contractility in dilated cardiomyopathy?
A3. Digoxin can be used to increase contractility of the heart in dilated cardiomyopathy.
Q4. What is the recommended treatment for dilated cardiomyopathy patients at high risk of ventricular tachycardia or ventricular fibrillation?
A4.
with an ejection fraction (EF) less than 35% should receive an
* automated implantable cardioverter-defibrillator (AICD).