July 27, 2000 -- Add another thing to the list of woes related to women's menstrual periods: Women with heart disease are at greater risk for having chest pains and heart attacks during certain phases of their cycles.
At times of the month when less estrogen is circulating in their bloodstreams, these women tend to have worse chest pain, or angina, and to perform more poorly on treadmill tests designed to look for low blood flow to the heart, according to a small study published in the journal Heart.
Angina is a temporary chest pain caused by reduced blood flow to the heart. It has been described as a feeling of tightness, heaviness, numbness, burning, or pressure that can be felt behind the breastbone. It can spread to the arms, neck, and jaw, and is often caused by exercise or stress.
Angina attacks usually last for less than five minutes, but can be anywhere from 30 seconds to 30 minutes. An angina attack is not a heart attack, but angina can progress into a heart attack, and it does require attention from a physician -- especially if the attacks start occurring more often, last longer, or are caused by less strenuous activities than usual. Doctors may test for angina by putting patients on a treadmill, then monitoring their hearts for signs that they are not getting enough blood.
The study was done in nine women, with an average age of 39 years, who had heart disease, chest pain, and had tested positive for low blood flow on exercise tests. They did treadmill testing each week for four weeks, always at the same time of day. The researchers also measured the women's levels of estrogen and progesterone.
The worst results were seen in the week during or immediately after menstruation, when levels of estrogen and progesterone are lowest. Exercise performance was poorest during this time, as compared with the phase just before the period began, when levels of the hormone estradiol are highest. Also during this phase, it took less time for signs of angina to begin after the women begin exercising.
The best results, both in total exercise time and time to onset of angina, came in the phase just before menstruation began, a time when both estradiol and progesterone levels are high. Progesterone levels did not seem to have any effects on these results, the researchers say.
Study author, Guy Lloyd, MBBS, MRCP, says that although the study was small, the results may bear consideration. Lloyd is with the Cardiothoracic Centre at St. Thomas' Hospital in London.
"Premenopausal women with heart disease are often poorly investigated and treated because of the infrequency of the diagnosis," he says. "Their symptoms are often difficult to explain and may be frightening."
And when a woman is menstruating, he says, the symptoms may be even more likely to dismissed. But patients should be aware that these symptoms may be a sign of heart disease, he says.