Irregular Heartbeat, Reduced Lung Capacity Deadly Combo

FOR RELEASE: 4 p.m. EDT, MondayJune 25, 2001

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American Heart Association journal report:Irregular heartbeat, reduced lung capacity make deadly combo

DALLAS, June 26 -- A simple lung function test may help identify which individuals with irregular heartbeats are at increased risk of heart attack, researchers report in today's Circulation: Journal of the American Heart Association.

Researchers found an increased risk of heart attack for individuals who had ventricular arrhythmias in combination with low lung function. Ventricular arrhythmia is an abnormal, rapid heart rhythm that originates in the ventricles, the lower chambers of the heart. It is often associated with heart attack.

"A lung function test could be useful for the assessment of the individual's risk of heart attack and in determining a course of treatment for a cardiac arrhythmia," says Gunnar Engstr¥m, M.D., Ph.D., senior author of the Swedish study.

Lung function was measured by forced expiratory volume (FEV1) -- the maximum air volume one can blow in one second -- and vital capacity (VC) -- the maximum air volume one can breathe in and out. These values were adjusted to account for differences in height (since taller people have bigger lungs). Individuals were divided into quartiles based on their FEV1 and VC measurements. Men with the lowest FEV1 and VC -- and therefore poorest lung function -- were in quartile one, while those with the highest FEV1 and VC in quartile four. Rates of death and heart attack were compared among all four quartiles.

"The men were from the general population, so their lung function was normal on average," says Engstr¥m. "Thus, the men in quartiles one and two had very moderately reduced lung function. Nevertheless, there were strong associations with arrhythmia and the incidence of coronary events and death among these individuals."

Researchers tracked 402, 68-year-old men who participated in the population-based "Men Born in 1914 Study" in Malmo, Sweden, for up to 14 years. None had a history of heart disease or stroke. During the study, 143 men had ventricular arrhythmia.

Men with frequent or complex ventricular arrhythmia and FEV1 below the median (in quartile one or two) had a death rate of 71.5 per 1000 person-years, and a coronary event rate of 37.7. Men with the same type of arrhythmia and FEV1 above the median (quartile four or five) had a death rate of 26.8 and a coronary event rate of 18.0.

Co-authors include Per Wollmer, M.D., Ph.D.; Bo Hedblad, M.D., Ph.D.; Steen Juul-Moller, M.D., Ph.D.; Sven Valind, M.D., Ph.D.; and Lars Janzon, M.D., Ph.D.

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NR01-1305 (Circ/Engstr¥m)

Media Alert: Dr. Engstr¥m can be reached by phone at 46-40-332-670; or by e-mail at [email protected] (Please do not publish contact information.)