Having any degree of impaired heart function, known as left ventricular dysfunction (LVD), was almost five times more common in stroke patients than age-matched controls.
Although previous studies have linked heart failure to increased stroke risk, this is the first evidence that even mildly impaired heart function may be an independent risk factor for ischemic stroke. Ischemic strokes are caused by a blood clot that blocks blood flow to a part of the brain.
The finding raises the question of whether LVD should be included in the evaluation of a person's stroke risk. Mild, symptomless LVD is present in 3 percent to 6 percent of the general population, according to this study.
"Clinically overt heart failure has been associated with an increased risk of stroke," said Marco R. Di Tullio, M.D., senior author of the study and professor of clinical medicine at Columbia University in New York. "Mild and often asymptomatic LVD is not usually among the things we consider to predict stroke risk. These results suggest that maybe it should be."
In LVD, the heart fails to pump blood as effectively as a normal-functioning heart.
Associations between impaired heart function and stroke have come primarily from studies of patients who survived heart attacks. The association between LVD and stroke in the general population had not been as clearly evaluated in any large studies. Researchers compared rates of LVD in stroke patients and in controls enrolled in the Northern Manhattan Study (NOMAS).
The analysis focused on 558 NOMAS participants who underwent echocardiography, a test that uses soundwave technology to test heart functioning. The study group comprised 270 stroke patients with first time ischemic stroke (average age 70) and 288 stroke-free parti
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Contact: Bridgette McNeill
bridgette.mcneill@heart.org
214-706-1396
American Heart Association
1-Jun-2006