Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Dr. Kulick received his undergraduate and medical degrees from the University of Southern California, School of Medicine. He performed his residency in internal medicine at the Harbor-University of California Los Angeles Medical Center and a fellowship in the section of cardiology at the Los Angeles County-University of Southern California Medical Center. He is board certified in Internal Medicine and Cardiology.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
There are many causes of cardiomyopathy that can be categorized in several ways. One method of defining cardiomyopathy is based on the official definition by the American Heart Association
(see below), which are broken into two categories, primary and secondary. Another method of categorizing cardiomyopathy causes are extrinsic and intrinsic (which are more commonly used when discussing the disease with patients, family, and caregivers) and are discussed later in this article.
The official definition of cardiomyopathy of the American Heart Association
in 2006 is as follows:
"Cardiomyopathies are a heterogeneous group of diseases of the myocardium
associated with mechanical and/or electrical dysfunction that usually (but not
invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are
due to a variety of causes that frequently are genetic. Cardiomyopathies either
are confined to the heart or are part of generalized systemic disorders, which
may lead to cardiovascular death or progressive heart failure-related
The definition divides heart disease into
1) primary cardiomyopathies, those
that usually affect the heart alone (primary) and 2) secondary cardiomyopathies,
those that are a result of an underlying condition affecting many areas of the
body. The primary cardiomyopathies are further divided into inherited
(genetic) diseases, those that are acquired, and those that are a combination of
Some causes are listed below of primary and secondary cardiomyopathies are
As previously mentioned, another method of categorizing cardiomyopathy causes are extrinsic and intrinsic (which are more commonly used when discussing the disease with patients, family, and caregivers). Extrinsic and intrinsic causes of cardiomyopathies are discussed below.
Extrinsic cardiomyopathies: Extrinsic cardiomyopathies are
those that are due to diseases that are not uniquely due to heart muscle cell
Intrinsic cardiomyopathies: Intrinsic cardiomyopathies are due to abnormalities that
originate in the heart muscle cell.
Examples of extrinsic cardiomyopathies include:
Ischemic cardiomyopathy isa disease of heart muscle due to inadequate blood
supply to heart muscle and is a common cause of cardiomyopathy. When blood vessels
to heart muscle become blocked, heart muscle cells can be deprived of oxygen and
fail to function normally. An example of this is a
heart attack, where a complete blockage of a blood
vessel causes muscle cells to die, decreases the total amount of muscle that can
contract and cardiac output is compromised.
Poorly controlled high blood pressure (hypertension) can lead to abnormally
functioning heart muscle.
Examples of extrinsic cardiomyopathies include:
Amyloidosis can infiltrate heart cells with amyloid protein.
Sarcoidosis can cause heart cell
Viral infections may cause inflammation of heart muscle (myocarditis) with
temporary or potentially permanent damage to heart muscles cells leading to a
Dilated cardiomyopathies occur when the heart muscle fibers are abnormally
stretched when the heart chambers increase in size and volume. The stretched
muscles lose their ability to contract strongly, similar to a slinky or an
elastic band that has been overstretched and loses its shape and function. As
the heart walls continue to stretch, they can also cause damage to the heart
valves between the chambers of the heart causing blood to regurgitate or
backwash, and as a result there is decreased cardiac output and heart failure. There are many causes
of dilated cardiomyopathy including:
chemical poisonings (for example, lead and arsenic),
such as muscular dystrophy, and
a variety of genetic diseases.
Hypertrophic cardiomyopathy is a genetic or familial disease where muscle in
the left ventricle has a predisposition to thicken and prevent normal flow of
blood out of the heart. Hypertrophic cardiomyopathy is the most common
sudden death in young people, such as exercising athletes.