"More than 80 percent of all cases of sudden cardiac death occur in people who have significant coronary artery disease, but we currently do not have a medical test that consistently identifies patients at risk," said Sumeet S. Chugh, M.D., associate director of the Cedars-Sinai Heart Institute and director of Clinical Electrophysiology. Chugh is first author of an article in Circulation , now appearing online ahead of print. This research was conducted with colleagues in the Emergency Medicine and Pathology Departments at Oregon Health and Science University in Portland, as part of the ongoing Oregon Sudden Unexpected Death Study.
"Abnormal QT prolongation has significant potential for evaluating risk and developing prevention strategies, but there are many factors “ some known and some not known “ that contribute to QT prolongation. Diabetes and the use of certain medications were significant predictors of QT interval prolongation and sudden cardiac death risk in our study. However, the most interesting and somewhat unexpected finding was that abnormally prolonged QT interval of unknown etiology “ independent of diabetes, medications and other factors “ was an even more powerful predictor of sudden cardiac death, with a five-fold increase in odds," said Chugh, who holds the Pauline and Harold Price Chair in Cardiac Electrophysiology Research.
The researchers noted that several gene variations have been linked to prolonged QT intervals, and the discovery of new genetic associations are likely to improve risk-assessment and intervention strategies. "The continued identification of gene variants that determine QT interval duration has become an important scientific priority in the field," Chugh said.
"QT interval" refers to electrical activity that occurs in the main pumping chambers of the heart, the ventricles. It includes the Q, R, S, and T waves seen on an electrocardiogram. Unlike heart attacks, which are typically caused by clogged coronary arteries, sudden cardiac arrest is the result of defective electrical impulses.
csmc/
Recent clinical studies suggest that migraine may be a progressive disease with cardiovascular, cerebrovascular and long-term neurologic effects. Suffering from migraines may also be a risk factor for brain lesions. Additionally, studies following those who suffer from migraine with aura (sensory, motor or visual disturbances that can precede or accompany the headache) have shown these individuals to be twice as likely as the general population to develop major cardiovascular disease and suffer stroke. If such findings are confirmed, treatments, approaches and economic evaluations of migraine treatment may require major reconsideration.
Epidemiologic studies have recently indicated that 4 percent to 5 percent of the general population suffers from chronic daily migraine headache, a condition characterized by 15 or more headache days per month, and that transformed migraine ”the transformation of episodic migraine to the chronic form of the disorder ”accounts for approximately half of these patients.
Currently, most physicians do not think of migraine as they do illnesses such as diabetes, hypertension, asthma or rheumatoid arthritis. Nevertheless, migraine may need to be reexamined from a similar perspective as a chronic illness for which preventive therapy is important to delay or reduce more serious forms or complications.
wiley/wiley-blackwell