Skip to Main Content

++

The term cardiomyopathy is used to indicate myocardial dysfunction in the absence of an obstructive lesion or sustained hypertension. Cardiomyopathy is either an isolated abnormality (ie, confined to the heart) or is associated with a multisystem disorder. Neonates who have an unrecognized underlying cardiomyopathy may come to medical attention with a life-threatening response to an otherwise minor illness. Alternatively, evidence of cardiomyopathy may be noted on an echocardiogram performed for evaluation of an unrelated problem.

++

Mutations in genes encoding multiple proteins of the sarcomere, cytoskeleton, sarcoplasmic reticulum, nucleus, and cell membrane of the myocardial cell are now known to cause cardiomyopathy (Figure 9-1). More information regarding the structure and function of these proteins is available in Chapter 2.

++
Figure 9-1.
Graphic Jump Location

Myocyte cytoarchitecture. Various forms of cardiomyopathy may result from mutations in genes encoding multiple proteins within the cardiac myocyte. Different mutations in the same gene may cause different forms of cardiomyopathy. Abbreviations: EYA4, eyes absent homolog 4; MLP, cardiac LIM domain protein; MYBPC, myosin binding protein C; T-cap, telethonin; ZASP, muscle LIM-binding protein 3 (cypher). Adapted from Olson TM, Hoffman TM, Chan DP. Dilated congestive cardiomyopathy, In: Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, eds. Moss and Adams’ Heart Disease in Infants, Children and Adolescents. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:1197.

++

Classification of cardiomyopathies is problematic and has evolved as new information has become available regarding causation. Classification based on phenotype (ventricular morphology and physiology) is practical in that this information is what is most readily available after initial evaluation of the patient (Table 9-1). Phenotypic groups can be subdivided based on etiology (Tables 9-2, 9-3, 9-4). Some congenital heart defects or systemic hypertension can cause phenotypes that mimic various forms of cardiomyopathy and are included in text and tables as they need to be included in the differential diagnosis when evaluating patients. Phenotypic classification is certainly not perfect as it does not define causation; moreover, it may be misleading because some myopathic processes may be classified as more than one type or may change from one type to another during the course of the disease.

++
Table Graphic Jump Location
Table 9-1. Phenotypic Classification of Cardiomyopathy 
++
Table Graphic Jump Location
Table 9-2. Conditions Associated with Phenotypic Appearance of Hypertrophic Cardiomyopathy 

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessPediatrics Full Site: One-Year Subscription

Connect to the full suite of AccessPediatrics content and resources including 20+ textbooks such as Rudolph’s Pediatrics and The Pediatric Practice series, high-quality procedural videos, images, and animations, interactive board review, an integrated pediatric drug database, and more.

$595 USD
Buy Now

Pay Per View: Timed Access to all of AccessPediatrics

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.