It's enough to make your heart beat a little faster, this new study that suggests that your heartbeat rate when you are at rest can be used as a "death test" - a predictor of your chances of keeling over in the next two decades. Although doctors have known for some time that people who have low resting heart rates are usually fitter and more healthy, the new study is the first to quantify the risk of death.People who have a resting heart rate of 80 beats a minute (bpm) are 45% more likely to die of any cause in the next 20 years than those with the lowest measured heart rate, 45bpm.Most resting heart rates are between 60bpm and 100bpm but professional athletes have heart rates of about 40bpm.Researchers found that the risk of dying from any health condition rises by about 9% for every 10bpm increase. The chance of a fatal heart attack or stroke rises 8%."The link between resting heart rate and the risk of all-cause and cardiovascular mortality is independent of usual risk factors of cardiovascular disease," said Dongfeng Zhang, of the Medical College of Qingdao University in Shandong, China."This suggests that the resting heart rate is a predictor of mortality in the general population."To find the link between heart rate and death the research team reviewed 46 studies involving more than 1.2million people monitored for an average of 21 years. Just more than half were under the age of 50.In that time, there were 78349 deaths, 25800 of them from heart problems.The team found that when the heart rate reached 90bpm the chance of early death had almost doubled.They advise measuring the heart rate at night when the body is most relaxed to get a more accurate reading."The evidence does not conclusively establish resting heart rate as a risk factor but there is no doubt that an elevated resting heart rate is an indicator of a poor health status," said Zhang."Our results highlight the need for more attention to be paid to the resting heart rate and to the importance of physical activity in lowering resting heart rate."The Canadian Medical Association Journal published the research report. ..