As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast track" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.
Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a
A. We now fully understand how risk factors trigger heart attacks.
B. We recently began to study how risk factors trigger heart attacks.
C. We have not identified many risk factors associated with heart attacks.
D. We do not fully understand how risk factors trigger heart attacks.
As heart disease continues to be the number-one killer in the United States, researchers have become increasingly interested in identifying the potential risk factors that trigger heart attacks. High-fat diets and "life in the fast track" have long been known to contribute to the high incidence of heart failure. But according to new studies, the list of risk factors may be significantly longer and quite surprising.
Heart failure, for example, appears to have seasonal and temporal patterns. A higher percentage of heart attacks occur in cold weather, and more people experience heart failure on Monday than on any other day of the week. In addition, people are more susceptible to heart attacks in the first few hours after waking. Cardiologists first observed this morning phenomenon in the mid-1980, and have since discovered a number of possible causes. An early-morning rise in blood pressure, heart rate, and concentration of heart stimulating hormones, plus a
A. aware of
B. affected by
C. accustomed
D. prone to
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