Heart rate at rest is usually between 60-80 beats per minute; males tend to have a lower rate than females, and the resting rate tends to fall with age. Resting heart rate is also generally lower in those who are physically fit; rates of less than 50 beats per minute are relatively common in endurance athletes. A sharp increase in resting heart rate is usually a sign that something is wrong. It may indicate illness, injury, emotional stress, or overtraining. Many elite athletes regularly monitor their resting heart rate and stop or reduce training if it increases significantly. This method of assessing fitness is not, however, very reliable.
During exercise, heart rate rises dramatically, and is a good indicator of exercise intensity. Maximal heart rate is usually assumed to be 220 minus the person’s age in years, but actual measurements indicate a wide variation (see maximal heart rate).
They also reference the interesting observation that:
Miguel Indurain, a cyclist and five time Tour de France winner, had a resting heart rate of 28 beats per minute, one of the lowest ever recorded in a healthy human.
Lance Armstrong has a rate in the lower 30s.
And Answers.com also references a study that relates heart rate and heart problems:
An Australian led international study of patients with cardiovascular disease has shown that heart beat rate plays a key role in the risk of heart attack. The study, published in The Lancet (Sept 2008) studied 11,000 people, across 33 countries, who were being treated for heart problems. Those patients whose heart rate was above 70 beats per minute had significantly higher incidence of heart attacks, hospital admissions and the need for surgery. University of Sydney professor of cardiology Ben Freedman from Sydney’s Concord hospital, said “If you have a high heart rate there was an increase in heart attack, there was about a 46 percent increase in hospitalisations for non-fatal or fatal heart attack.”
But a study is not a double-blind clinical trial…
Maybe there is a common cause: poor nutrition and lack of exercise could cause the higher heart rate and would also lead to heart health problems. The heart rate might be associated with heart problems, but would not be the cause.