Cardiomyopathy

Question 1

what is cardiomyopathy characterized by? Results in? The cardiomegaly that occurs is from?

Answer 1

1. Characterized by poor myocardial systolic function of the left, right, or both ventricles in the absence of external pressure overload, volume overload, and coronary artery disease.
2. Loss of muscle function results in congestive heart failure.
3. Resulting cardiomegaly is more from dilatation than hypertrophy.

Question 2

what is the cause of most cardiomyopathies? What are some diseases linked to it?

Answer 2

1. The cause of most causes of congestive cardiomyopathy is unknown.
2. Viral infection has been implicated and the pathogenesis of this disease.
3. The following conditions have been linked to cardiomyopathy.

a. Prolonged ethanol abuse (most common).
(1) Alcoholic cardiomyopathy considered a separate category in England (2) May be reversible once alcohol removed and malnutrition corrected

b. Adriamycin (causes severe cardiac toxicity).
c. Exposure to toxins. (1) Cobalt. (2) Mercury. (3) Lead. (4) High dose catecholamines.
d. Familial (may account to up to 25% of cases)
e. Myocarditis (1) Infective (2) Autoimmune
f. Peripartum (1) Presents between 3 months before and 6 months after delivery
g. Endocrinopathies. (1) Thyrotoxicosis. (2) Hypothyroidism. (3) Acromegaly.
h. Metabolic disorders. (1) Hypophosphatemia. (2) Hyocalcemia. (3) Thiamine deficiency.
i. Hemoglobinopathies. (1) Sickle cell anemia. (2) Thalassemia.

Question 3

What are the symptoms and signs of cardiomyopathy?

Answer 3

1. Symptoms
   a. Symptoms of left sided failure. (1) Orthopnea. (2) Paroxysmal nocturnal dyspnea. (3) Dyspnea on exertion.
   b. Symptoms of right-sided failure. c. Chest pain.
2. Physical Signs
   a. Similar to those of “congestive heart failure”.
   b. Frequently a murmur of mitral insufficiency.

Question 4

What tests should we run to diagnose cardiomyopathy?

Answer 4

1. EKG
2. Chest x-ray
3. Echocardiography
4. Gated blood pool scanning
5. Cardiac cath

Question 5

Cardiomyopathy changes seen in EKG?

Answer 5

a. Left ventricular hypertrophy.
b. Nonspecific ST-T wave changes.
c. Left bundle branch block.

Question 6

Chest x-ray findings with cardiomyopathy?

Answer 6

a. Cardiomegaly.

b. Evidence of pulmonary vascular congestion.

Question 7

Echocardiography findings with cardiomyopathy?

Answer 7

a. Dilated and poorly contracting left and right ventricles.
b. Secondary left and right atrial enlargement.

Question 8

Gated blood pool scanning will show what with cardiomyopathy?

Answer 8

a. Reveals reduction of the ejection fraction of both ventricles.
b. Global dysfunction.
c. Regional contractile abnormalities may also exist.

Question 9

Cardiac catheterization with cardiomegaly?

Answer 9

a. Usually not necessary to ascertain diagnosis.

b. May be helpful to exclude or confirm ischemic heart disease as possible etiology.

Question 10

What is the therapy for cardiomyopathy?

Answer 10

1. Removal of offending agent (e.g. alcohol).
2. Correction of underlying endocrinopathy/metabolic disorder (e.g. hypothyroidism).
3. Supportive therapy. a. Salt restriction. b. Administration of cardiac glycosides (particularly in presence of atrial fibrillation) c. Diuretics. d. ACE-I and / or ARB and Beta-blockers e. Vasodilators.
4. Cardiac transplantation.

Question 11

What is restrictive cardiomyopathy?

Answer 11

1. Refers to a condition in which the composition of the myocardium has changed so that it becomes noncompliant.
2. The noncompliance of the myocardium restricts left ventricular filling, reducing stroke output and increasing left ventricular filling pressure

Question 12

What is the etiology of restrictive cardiomyopathy?

Answer 12

1. Infiltrative diseases of the myocardium.
   a. Amyloidosis.
   b. Hemochromatosis.
   c. Idiopathic eosinophilia.
   d. Carcinoid syndrome.
   e. Sarcoidosis.
   f. Endomyocardial fibroelastosis.

Question 13

What is the pathophysioloy of restrictive cardiomyopathy?

Answer 13

1. Systolic function is usually normal, however there is severe diastolic noncompliance.
2. Left ventricular pressure is above normal at any diastolic left ventricular volume.
3. Increase filling pressure produces pulmonary congestion.
4. As the infiltrative process progresses, systolic function is also compromised.

Question 14

What are the physical signs and symptoms of restrictive cardiomyopathy?

Answer 14

1. Symptoms. a. Symptoms of left and right sided congestive failure are usually present. b. Symptoms of right-sided failure usually more prominent.
2. Physical signs – include those present in left-sided and right-sided congestive heart failure.

Question 15

What are the tests we use to diagnose restrictive cardiomyopathy?

Answer 15

1. EKG
2. Chest X-ray
3. Echocardiography
4. Cardiac Catheterization

Question 16

What are the findings of EKG with restrictive cardiomyopathy?

Answer 16

a. P-mitrale or P-pulmonale
b. Atrial fibrillation
c. Low QRS voltages.
d. Poor R wave progression in chest leads
e. Nonspecific ST-T wave changes.

Question 17

What are the findings of chest x-ray with restrictive cardiomyopathy?

Answer 17

a. Signs of pulmonary vascular congestion. b. Normal or increased heart size. c. Pericardial calcifications (constrictive pericarditis)

Question 18

What are the findings of ECHO with restrictive cardiomyopathy?

Answer 18

a. Thickening of the left and right ventricles.
b. Left and right ventricular chamber sizes usually are normal.
c. Left and right atrial sizes are generally increased.
d. Myocardium may appear brighter than normal in amyloidosis.

Question 19

What are the findings of cardiac catheterization with restrictive cardiomyopathy?

Answer 19

a. Difficult to distinguish restrictive cardiomyopathy from constrictive pericarditis at cardiac catheterization. b. “Dip and plateau” in the left and right ventricular filling pressures may be seen in both disease.
c. In restrictive cardiomyopathy, left and right atrial pressures and left and right ventricular pressures usually are not identical as they are in constrictive pericarditis.
d. Endomyocardial biopsy during cardiac catheterization may help to establish diagnosis.

Question 20

What is the therapy for restrictive cardiomyopathy?

Answer 20

1. Generally limited.
2. Diuretics – reduced symptoms of congestion.
3. Vasodilators – use with caution since a reduction in preload causes a reduction in both left ventricular filling and cardiac output.
4. avoid digoxin in amyloidosis as patients are very digoxin sensitive; serious arrhythmias may occur

Question 21

What is hypertrophic cardiomyopathy?

Answer 21

1. Synonyms include idiopathic hypertrophic subaortic stenosis (IHSS) and asymmetric septal hypertrophy (ASH).
2. Disorder in which there is inappropriate myocardial hypertrophy that is usually asymmetric and diffuse.
3. Generally characterized by septal or localized hypertrophy without LV dilatation.

Question 22

What are the etiologies of Hypertrophic cardiomyopathy?

Answer 22

1. Genetic.
2. Catecholamine excess.
3. Mechanics of altered wall stress.
4. Calcium disorder.

Question 23

What is the gross pathology of hypertrophic cardiomyopathy?

Answer 23

a. Small ventricular cavity with flattened S shape from septal hypertrophy.
b. Mitral valve – intrinsically normal although distorted in shape from the myocardial hypertrophy.
c. Left atrium – dilated at autopsy.
d. Coronary artery disease – discovered in 25% of individuals (same as a normal population).
e. Bizarre arrangements of muscle fibers.

Question 24

What is the pathophysiology of Hypertrophic cardiomyopathy?

Answer 24

a. Ventricular hypertrophy with super normal systolic function.
b. Ventricular outflow gradient.
c. Abnormal diastolic relaxation and compliance.
d. Cardiac arrhythmias.

Question 25

Clinical features symptoms of hypertrophic cardiomyopathy?

Answer 25

1. Symptoms. a. Lack of correlation with gradient. b. Older patient – generally more symptomatic. c. Symptoms secondary to outflow obstruction. (1) Dyspnea – 90% (2) Angina – 70 to 80% (a) Small artery narrowing. (b) Intramyocardial compression. (c) Abnormal diastolic filling. (d) Coronary spasm. (3) Syncope/presyncope – 50 to 55% (a) Usually occurs after exercise due to reduction in afterload (peripheral vasodilatation), reduction in pre-load, an increased inotrope which all reduced left ventricular size and therefore increased the degree of left ventricular obstruction to outflow. (b) Arrhythmias.

Question 26

Physical signs of hypertrophic cardiomyopathy?

Answer 26

a. Carotid upstroke. (1) A “spike and dome” configuration. (2) Noted in 60 to 70% of individuals. b. Jugular venous pressures wave – generally normal. c. Heart sounds. (1) 20% paradoxically split resulting from either higher gradients or a left bundle branch block. d. Murmur. (1) Systolic ejection murmur heard along the left sternal border. (2) Not radiated to the carotids (as in aortic stenosis). (3) Murmur of mitral insufficiency may also be present.

Question 27

Tools to diagnose hypertrophic cardiomyopathy?

Answer 27

1. EKG 2. Echocardiogram 3. Cardiac Catheterization

Question 28

What does EKG of hypertrophic cardiomyopathy show?

Answer 28

a. Almost always is abnormal. b. Evidence of left ventricular hypertrophy. c. Nonspecific ST-T wave abnormalities. d. Left atrial enlargement. e. Atrial fibrillation (10% of patients); usually associated with clinical deterioration

Question 29

What does Echocardiography of hypertrophic cardiomyopathy show?

Answer 29

a. Increased septal thickness (septum to free wall thickness ratio of 1.3 or greater). b. Systolic anterior motion of the mitral valve. c. Early closure of the aortic valve. d. Two-dimensional echocardiography may demonstrate other areas of localized hypertrophy. e. Doppler echocardiography may demonstrate a left ventricular outflow tract gradient which is proportional to that measured in the catheterization lab; may also be helpful in evaluation for mitral regurgitation.

Question 30

What does Cardiac catheterization show with hypertrophic cardiomyopathy?

Answer 30

a. Initially contributed significantly to diagnosis and pathophysiologic delineation although with the advent of M-Mode/Two-Dimensional echocardiography and Doppler echocardiography it is now less often necessary. b. But still utilized to quantify the degree of obstruction prior to surgical consideration.

Question 31

What is the natural patient history seen with hypertrophic cardiomyopathy?

Answer 31

1. Highly variable. 2. 3% annual mortality. 3. Two populations described by Braunwald. a. Younger patient – stable but prone to sudden cardiac death. b. Older patient – gradual deterioration with increasing symptoms. 4. Infective endocarditis (4 to 5%). 5. Sudden cardiac death. a. Maybe first clinical manifestation. b. Most common in children/young adults age 10 to 35 (young athletes). c. Symptoms and gradient are not predictive; documented ventricular tachycardia (holter monitor) may be predictive.

Question 32

What classes of drugs are used in the medical treatment of hypertrophic cardiomyopathy?

Answer 32

1. Beta blockers 2. Calcium channel blocking drugs 3. Disopramide 4) . Digitalis 5. Anti-arrythmics

Question 33

Explain beta blocker use in hypertrophic cardiomyopathy?

Answer 33

(1) Generally helps prevent provocation of gradient. Does not abolish resting gradient. (2) Frequently effective in relieving symptoms in this disease. (3) Slows the heart rate, which increases left ventricular filling and size, and thereby, diminishes obstruction; also diminishes the vigor of left ventricular contraction and, thus, diminishes the velocity of blood flow which also reduces the degree of obstruction

Question 34

Explain the use of Calcium channel blockers to treat hypertrophic cardiomyopathy? Avoid use of?

Answer 34

(1) May also be of value in the treatment of obstructive myopathy. (2) Verapamil has been the calcium channel blocker used most frequently due to its minimal effect on afterload. (3) Have been shown to improve left ventricular relaxation (improved compliance). (4) Avoid the use of dihydropyradines (e.g., amlodipine) since vasodilating properties may actually worsen outflow tract obstructions; Verapamil has also been reported to worsen failure in a subset of patients with congestive heart failure and precipitate acute pulmonary edema; particularly in patients with severe obstruction.

Question 35

Explain the use of Disopramide in treating hypertrophic cardiomyopathy?

Answer 35

(1) Negative inotropic properties will often abolish the gradient (if not severe) or markedly reduced gradient (if severe) as demonstrated in the Catheterization Lab. (2) Most effective agent with obstruction at rest. (3) Usually added to beta-blocker and / or verapamil

Question 36

Explain the use of digitalis in treating hypertrophic cardiomyopathy? Contra-indicated?

Answer 36

(1) Contraindicated in the hyperdynamic phase of the disease when obstruction is present and the left ventricular cavity is small. 2) In the end stages of the disease when ventricular dilatation has occurred, standard therapy for congestive heart failure (e.g., digitalis and diuretics) may be beneficial.

Question 37

Other treatments for hypertrophic cardiomyopathy?

Answer 37

2. Dual-chamber pacing 3. Chemical septal ablation 4. Surgical Therapy. a. Improvement of subset of severely symptomatic patients but has not been shown to prevent sudden cardiac death and natural history. b. Myectomy – surgical reduction of the thickness of the left ventricular septum has been shown to be useful in relieving the outflow gradient and symptoms in those patients who have not responded to medical therapy. c. Mitral valve replacement – occasionally indicated for a severe mitral insufficiency due to distortion of valve from the myocardial hypertrophy.