Ischemic cardiomyopathy is a type of
cardiomyopathy caused by a narrowing of the coronary arteries which supply blood to the heart.[4] Typically, patients with ischemic cardiomyopathy have a history of
acute myocardial infarction,[5] however, it may occur in patients with
coronary artery disease, but without a past history of acute myocardial infarction. This cardiomyopathy is one of the leading causes of
sudden cardiac death.[6] The adjective ischemic means characteristic of, or accompanied by,
ischemia — local anemia due to mechanical obstruction of the blood supply.[7]
Ischemic cardiomyopathy is the cause of more than 60% of all cases of
systoliccongestive heart failure in most countries of the world.[6][8] A chest
radiograph that demonstrates coronary artery
calcification is a probable indication of ischemic cardiomyopathy.[9] The following are causes of ischemic cardiomyopathy:[1]
Ischemic cardiomyopathy is caused by too little blood flow and hence oxygen reaching the
muscular layer of the heart due to a narrowing of coronary arteries in turn causing
cell death. This can cause different levels of tissue injury and affect large and intermediate arteries alike.[10][11][12]
Diagnosis
Ischemic cardiomyopathy can be diagnosed via
magnetic resonance imaging (MRI) protocol, imaging both global and regional function. Also the Look-Locker technique is used to identify diffuse
fibrosis; it is therefore important to be able to determine the extent of the ischemic scar.[2] Some argue that only left main- or proximal-left anterior descending artery disease is relevant to the diagnostic criteria for ischemic cardiomyopathy.[5] Myocardial imaging usually demonstrates left ventricular dilation, severe ventricular dysfunction, and multiple infarctions.[13] Signs include
congestive heart failure,
anginaedema, weight gain and fainting, among others.[6][14]
American Heart Association practice guidelines recommend
implantable cardioverter-defibrillator (ICD) use in those with ischemic cardiomyopathy (40 days post-MI) that are (NYHA)
New York Heart Association functional class I. A
LVEF measurement (simply called LVEF alone among cardiologists) of greater than (>) 30% is often used to differentiate primary from ischemic cardiomyopathy, and as a prognostic indicator.[18][19]
A 2004 study showed the patients in that study who underwent ventricular restoration as well as a coronary artery bypass achieved greater postoperative LVEF than with the latter surgery alone.[20] Severe cases are treated with
heart transplantation.[21]
Prognosis
One of the most important features differentiating ischemic cardiomyopathy from the other forms of
cardiomyopathy is the shortened, or worsened all-cause
mortality in patients with ischemic cardiomyopathy. According to several studies,
coronary artery bypass graft surgery has a survival advantage over medical therapy (for ischemic cardiomyopathy) across varied follow-ups.[11][22][23][24]
^
abYatteau, Ronald F.; Peter, Robert H.; Behar, Victor S.; Bartel, Alan G.; Rosati, Robert A.; Kong, Yihong (1974). "Ischemic cardiomyopathy: The myopathy of coronary artery disease". The American Journal of Cardiology. 34 (5): 520–525.
doi:
10.1016/0002-9149(74)90121-0.
ISSN0002-9149.
PMID4278154.
^Louie HW, Laks H, Milgalter E, Drinkwater DC, Hamilton MA, Brunken RC, Stevenson LW (November 1991). "Ischemic cardiomyopathy. Criteria for coronary revascularization and cardiac transplantation". Circulation. 84 (5 Suppl): III290–III295.
PMID1934422.
^O’Connor, Christopher M; Velazquez, Eric J; Gardner, Laura H; Smith, Peter K; Newman, Mark F; Landolfo, Kevin P; Lee, Kerry L; Califf, Robert M; Jones, Robert H (2002). "Comparison of coronary artery bypass grafting versus medical therapy on long-term outcome in patients with ischemic cardiomyopathy (a 25-year experience from the Duke Cardiovascular Disease Databank)". The American Journal of Cardiology. 90 (2): 101–107.
doi:
10.1016/S0002-9149(02)02429-3.
ISSN0002-9149.
PMID12106836.
Likoff, Jessup Mariell, Chandler Sheryl L., Kay Harold R. (1987). "Clinical determinants of mortality in chronic congestive heart failure secondary to idiopathic dilated or to ischemic cardiomyopathy". The American Journal of Cardiology. 59 (6): 634–638.
doi:
10.1016/0002-9149(87)91183-0.
PMID3825904.{{
cite journal}}: CS1 maint: multiple names: authors list (
link)
Carmeliet Peter; et al. (1999). "Impaired myocardial angiogenesis and ischemic cardiomyopathy in mice lacking the vascular endothelial growth factor isoforms VEGF164 and VEGF188". Nature Medicine. 5 (5): 495–502.
doi:
10.1038/8379.
PMID10229225.
S2CID7536458.