As heart disease continues to be the number-one killer in the United States, researches havebecome increasingly interested in identifying the potential risk factors (33)­­­­­­­­­­____trigger heart attacks. High-fat diets and life in the fast lane have long been known to contribute to the high incidence of heart (34)_____ . 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 ...

As heart disease continues to be the number-one killer in the United States, researches havebecome increasingly interested in identifying the potential risk factors (33)­­­­­­­­­­____trigger heart attacks. High-fat diets and life in the fast lane have long been known to contribute to the high incidence of heart (34)_____ . 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. (35)____ , people are more susceptible to heart attacks in the first few hours after walking. Cardiologists first observed this morning (36)____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 (37)____hormones, plus a reduction ofblood flow to the heart, may all contribute to the higher incidence ofheart attacks between the hours of 8:00 AM. and 10:00 AM.

Điền vào số 34