- Syndrome X
:"The terms Syndrome X or Metabolic syndrome X may also be referring to
metabolic syndrome ."(Cardiac) syndrome X is angina (chest pain) with signs associated with decreased blood flow to heart tissue but with normal coronary arteries. It occurs more often in young women. Some studies have found increased risk of other vasospastic disorders in syndrome X patients, such as
migraine andRaynaud's phenomenon . It is treated withcalcium channel blocker s, such asnifedipine , and usually carries a favorable prognosis.This is a distinct diagnosis from
Prinzmetal's angina .Cardiac syndrome X is sometimes referred to as microvascular angina when there are findings of microvascular dysfunction.
Features
While there is no formal definition for Syndrome X, the general consensus is that it entails all of the following:
* Angina: This usually does not cause dysfunction onechocardiogram and can last longer than that of heart disease.
* AbnormalCardiac stress test : ST changes are typically similar to those ofcoronary artery disease and opposite of those withPrinzmetal's angina . Myocardial perfusion imaging can be abnormal in 30% of patients.
*Coronary angiogram : Normal* Other causes of chest pain must be ruled out, including:
**Prinzmetal's angina
**Esophageal spasm Diagnosis
Syndrome X is a diagnosis of exclusion. Typically this will necessitate both a clinical diagnosis, appropriate stress testing, and a coronary angiogram that meet the above criteria.
Pathophysiology
In a large percentage of patients, there is a finding of systemic microvascular abnormalities, causing reduced blood flow in the microvasculature of the
cardiac muscle s.While numerous physiological mechanisms have been proposed, none have been proven.
Treatment
*
nitrates - can reduce chest pain
*calcium channel blockers - specificallynifedipine anddiltiazem can be effective.
*beta blockers - also work.
*aminophylline - may work by inhibiting adenosine receptors.
*estrogen - may work in women.ee also
*
Takotsubo cardiomyopathy References
*cite journal | author=Botker HE, Sonne HS, Sorensen KE | title=Frequency of systemic microvascular dysfunction in syndrome X and in variant angina | journal=Am J Cardiol | year=1996 | pages=182–6 | volume=78 | issue=2 | pmid=8712140
* [http://www.ncbi.nlm.nih.gov/pubmed/10689391 Cardiac Syndrome X: An Overview]
* [http://heartdisease.about.com/cs/coronarydisease/a/CSX.htm Cardiac Syndrome X]
* [http://www.texasheartinstitute.org/HIC/Topics/Cond/CardiacSyndromeX.cfm Texas Heart Institute]
* [http://content.nejm.org/cgi/content/full/347/17/1377 New England Journal of Medicine Editorials]
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