The AHA Guidelines and Scientific Statements Handbook

Chapter 14 Cardiomyopathies

envelope intermediate fi lament protein. Mutations
in this gene also cause Emery–Dreifuss muscular
dystrophy (EDMD). The X-linked gene responsible
for EDMD, emerin (another nuclear lamin protein)
also causes similar clinical cardiac features. Other
DCM genes of this type include desmin, caveolin,
and α- and β.b-sarcoglycan as well as the mitochon-
drial respiratory chain gene. X-linked DCM (XLCM)
is caused by the Duchenne muscular dystrophy
(dystrophin) gene, while G 4.5 (tafazzin) – a mito-
chondrial protein of unknown function – causes
Barth syndrome, an X-linked cardioskeletal myopa-
thy in infants.

Primary restrictive (nonhypertrophied)
cardiomyopathy
Primary restrictive cardiomyopathy as defi ned here
is a rare form of nonhypertrophied, nondilated
heart muscle disease and a cause of heart failure. It
is characterized by normal or decreased volume of
both ventricles associated with biatrial enlargement,
normal LV wall thickness and atrioventricular
valves, impaired ventricular fi lling with restrictive
physiology, and normal (or near normal) systolic
function. Both sporadic and familial forms have
been described and in one family a troponin I muta-
tion was responsible for both restrictive cardiomy-
opathy and HCM.

Acquired
Myocarditis (infl ammatory cardiomyopathy)
Myocarditis, an acute or chronic infl ammatory
process affecting the myocardium, is produced by a
wide variety of toxins and drugs (e.g., cocaine, inter-
leukin 2) or infectious agents – most commonly
including viral (e.g., coxsackie, adenovirus, parvovi-
rus HIV); bacterial (e.g., diphtheria, meningococ-
cus, psittacosis, streptococcus); rickettsial (e.g.,
typhus; Rocky Mountain spotted fever); fungal (e.g.,
aspergillosus, candidiasis); and parasitic (Chagas
disease, toxoplasmosis), as well as Whipple dis-
ease (intestinal lipodystrophy), immune (giant cell
myocarditis) and hypersensitivity reactions to drugs
such as antibiotics, sulfonamides, anti-convulsants
and anti-infl ammatories. Endocardial fi broelastosis
is a dilated cardiomyopathy in infants and children,
as a consequence of viral myocarditis in utero
(mumps) which has become quite rare.

Table 14.1 Secondary cardiomyopathies

Infi ltrative†

Amyloidosis (primary [AL]; familial autosomal dominant

[AF]*; senile [SSA]; secondary [AA] forms)

Gaucher disease*

Hurler’s disease*

Hunter’s disease*

Storage‡

Hemochromatosis

Fabry’s disease*

Glycogen storage disease*

(type II; Pompe’s)

Nieman-Pick disease*

Toxicity

Drugs; heavy metals; chemical agents

Endomyocardial

Endomyocardial fi brosis (EMF)

Hypereosinophilic syndrome

(Loeffl er’s endocarditis)

Infl ammatory (granulomatous)

Sarcoidosis

Endocrine

Diabetes mellitus*

Hyperthyroidism

Hypothyroidism

Hyperparathyroidism

Pheochromocytoma

Acromegaly

Cardiofacial

Noonan’s syndrome*

Lentiginosis*

Neuromuscular/neurologic

Friedreich’s ataxia*

Duchenne–Becker muscular dystrophy*

Emery–Dreifuss muscular dystrophy (EDMD)*

Myotonic dystrophy*

Neurofi bromatosis*

Tuberous sclerosis*

Nutritional defi ciencies

Beriberi (thiamine); pellagra; scurvy; selenium; carnitine;

kwashiorkor

Autoimmune/collagen

Systemic lupus erythematosis

Dermatomyositis

Rheumatoid arthritis

Scleroderma

Polyarteritis nodosa

Electrolyte imbalance

Consequence of cancer therapy

Anthracyclines: doxorubicin (adriamycin), daunorubicin

Cyclophosphamide

Radiation

* Genetic (familial) etiology.

† Accumulation of abnormal substances between myocytes (i.e., extracellular).

‡ Accumulation of abnormal substances within myocytes (i.e., intracellular).