Overall, those who were current smokers had more than double the risk of sudden cardiac death. Those who had one to 14 cigarettes a day had a nearly doubling of risk. Those who smoked 25 or more a day had more than triple the risk of sudden cardiac death.
While some may think it surprising that even light smoking can increase risk of sudden cardiac death, Sandhu said it makes sense. "There are acute effects of nicotine,'' she said, and these may lead to the abnormal heart rhythms and other problems that boost risk.
The risk of sudden cardiac death decreased after the women quit smoking. For women without heart disease, the risk dropped in fewer than five years. For those with heart disease who quit smoking, their risk of sudden cardiac death dropped to that of a nonsmoker, too, but it took 15 or 20 years.
The findings provide valuable new information, according to Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles.
While the link between cigarette smoking and sudden cardiac death is well-established, he said, ''far less has been known about the relationship between number of cigarettes smoked, duration of smoking and the risk of sudden cardiac death."
"This new study demonstrates that even low-level use of cigarettes, in the range of one to 14 cigarettes a day, is associated with a substantial increase in risk of sudden cardiac death in women," Fonarow said. "Even occasional cigarette smoking in social circumstances may unnecessarily increase women's risk of sudden unexpected death."
Study author Sandhu said there's no one best way to quit smoking: Each person needs to have a strategy tailored to them.
While the study found an association between light smoking in women and sudden cardiac death, it did not prove a cause-and-effect relationship.
All rights reserved