Source:http://linkedlifedata.com/resource/umls/id/C0001396
MSH: A condition of fainting spells caused by heart block, often an atrioventricular block, that leads to BRADYCARDIA and drop in CARDIAC OUTPUT. When the cardiac output becomes too low, the patient faints (SYNCOPE). In some cases, the syncope attacks are transient and in others cases repetitive and persistent.,NCI: An episode of sudden and transient loss of consciousness sometimes associated with seizures. It is caused by a sudden decrease of the cardiac output that results from a sudden cardiac dysrhythmia. Typically patients develop an initial pallor, followed by facial flush during recovery.