Transcript Cardiomyopathy

Cardiomyopathy
Myra Lalas Pitt
Hypertrophic Cardiomyopathy
 Cardiomyopathy with hypertrophy of the LV (± RV) with
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histological features of myocyte hypertrophy, myofibrillar
disarray, and interstitial fibrosis.
The prevalence in young adults is approximately one in 500.
Frequent cause of sudden death, particularly in young
individuals and competitive athletes.
Usually AD- the genes affected code for proteins in the
sarcomere
Associated with Pompe Disease
Signs and Symptoms
 Systolic function is preserved; may have increased
contractility; symptoms are typically caused by diastolic
dysfunction (impaired ventricular relaxation) and sometimes
LVOT obstruction.
 May be asymptomatic
 Palpitationss, dizziness, syncope, sudden death.
 Age of symptom onset: from birth to middle age
Treatment
 Beta-blockers : mainstays of therapy.
 Combination therapy (Beta-blocker and CCB) may be
considered in patients with severe hypertrophy and severe
outflow obstruction.
 LVOTO myectomy: Children with severe LVOTO.
Dilated Cardiomyopathy
 Cardiomyopathy with increased ventricular size and reduced
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contractility in the absence of coronary, valvar, or pericardial
disease.
Highest rate of disease in newborns and infants.
M> F
1-yr mortality is about 50% without cardiac transplantation.
Genetics: 1/3 have familial form, AD (most common is
cytoskeletal protein involvement), X-linked (typically occurs
in boys with rapid progression; elevated CK-MM)
Signs and Symptoms
 Shortness of breath, fatigue, orthopnea, diaphoresis, chest
pain, palpitations, exercise intolerance, syncope.
 Tachypnea, tachycardia, diaphoresis, S3 or S4 gallop,
holosystolic murmur (MR), hepatomegaly, ± ascites or
peripheral edema.
Treatment
Outpatient Management
ACE inhibitors and beta-blockers
(metoprolol/carvedilol): Mainstays of
therapy
Diuretics: May be useful for symptomatic
edema; no proven long-term benefit
Digoxin: Now used less often, but may
improve symptoms in some patients
Inpatient Management
Inotropic medications avoided whenever
possible; reserved for compromised
hemodynamic states (milrinone ± lowdose dopamine)
Diuretics: Decrease pulmonary edema
acutely; may improve preload in
volume overload states
Mechanical circulatory support:
Ventricular assist devices and ECMO
for those who fail medical management
as a bridge to recovery or
transplantation
Cardiac transplantation
Restrictive Cardiomyopathy
 Definition: Cardiomyopathy with abnormal stiffness of the
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ventricular wall leading to impaired ventricular filling.
Rare type of cardiomyopathy
Has the worst outcome of all forms of cardiomyopathy
(especially in children)
Sudden death occurs within 2 to 5 years of diagnosis in more
than 50% of patients.
Genetics: inherited in <10% of patients, usually AD
Signs and Symptoms
 CHF (dyspnea, orthopnea, and abdominal pain), syncope, or
sudden death.
 S4; holosystolic murmur of AV valve insufficiency if the
patient has pulmonary hypertension, hepatomegaly.
Treatment
 Heart transplantation is the only definitive therapy and is
often recommended as primary therapy.
 May use antiarhythmics.
 In general, meds may cause acute hemodynamic changes and
are usually not effective.
Glycogen Storage Disease
 Inheritance: AR (except some forms of type VI and IX X-
linked).
 Clinical presentation: Pathologic glycogen storage (eg,
hepatomegaly) or organ dysfunction (eg, muscle weakness,
muscular atrophy, cardiomyopathy, renal tubulopathy) or
hypoglycemia.
Type
Deficiency
Main Tissue
Symptoms and
Treatment
I (von Gierke)
Glucose-6-phosphatase
Liver, kidney
Hypoglycemic seizures,
hepatomegaly, short
stature, truncal obesity,
full cheeks,
hyperlipidemia,
hyperuricemia
Tx: Avoid hypoglycemia:
feed often: uncooked corn
starch , continuous feeds
(lactose-free, sucrose-free
formula) at night;
allopurinol
II (Pompe)
Lysosomal -glucosidase
Generalized
Infantile: FTT, severe
(cardio)myopathy with
hypotonia, usually fatal by
1 year
Juvenile or adult:
Progressive muscular
weakness with minimal or
absent cardiac involvement
Tx: IV enzyme
replacement Q2wk
Type
Deficiency
Main Tissue
Symptoms and
Treatment
III (Cori/ Forbes)
Debranching enzyme
Liver, muscle
Hepatomegaly,
(cardio)myopathy, short
stature, hypoglycemia
Tx: Frequent PO
feeding to maintain
normoglycemia
V (McArdle*)
Myophosphorylase
Muscle
Myalgia, muscle
cramps, exercise
intolerance, muscular
weakness.
Tx: Encourage
moderate aerobic
exercise, oral sucrose
before exercise, ±
creatinine, vitamin B6
supplementation
PREP Question
 You are evaluating a 12-year-old boy who has been fatigued for 2 weeks.
His mother reports that he had an upper respiratory tract infection 2
weeks ago, and his appetite has been decreased since then. On physical
examination, he is afebrile and has a heart rate at rest of 110 beats/min.
His respiratory rate is 22 breaths/min. His lungs are clear, and he has a
gallop rhythm without murmurs on cardiac auscultation.You discern
hepatomegaly and mild jugular venous distention.
Of the following, the MOST likely diagnosis is
a. anemia
b. dilated cardiomyopathy
c. Kawasaki disease
d. primary pulmonary hypertension
e. pulmonary embolism
Answer: B
 The gallop rhythm, hepatomegaly, and jugular venous distention
described for the boy in the vignette support the diagnosis of congestive
heart failure (CHF), most likely due to myocardial dysfunction
associated with dilated cardiomyopathy.
 Laboratory support for the myocardial failure seen in patients who have
CHF can be demonstrated by an elevation in the brain natriuretic
peptide value. Results of this test almost always are abnormal in patients
who have significant CHF.
 Among the many causes of CHF are large-volume left-to-right shunts
with pulmonary overcirculation, pressure load on the myocardium,
inadequate blood flow to the myocardium, infection or infiltration of the
myocardium, or genetic or idiopathic diseases of the myocardium.
References
Lowry AW, Bhakta KY, Nag PK, "Chapter 8. Cardiology" (Chapter). Lowry AW, Bhakta KY, Nag PK: Texas Children's
Hospital Handbook of Pediatrics and Neonatology:
http://www.accesspediatrics.com/content/7434509.
Lowry AW, Bhakta KY, Nag PK, "Chapter 17. Genetics" (Chapter). Lowry AW, Bhakta KY, Nag PK: Texas Children's
Hospital Handbook of Pediatrics and Neonatology:
http://www.accesspediatrics.com/content/7439230.
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