Heart rate and human survival has an inverse relationship. This is in fact true for all mammals.The tortoise which has a heart rate of 6/mt lives for over 200 years. The rat which has heart rate of 500 dies does not even celebrate it’s first birth day ! Human beings with an average heart rate of 70 lives for 70 years. 
There is a belief human heart is programmed to beat for certain trilion beats in it’s life time .It is possible , with evidence mounting this belief could indeed be true .
People with low heart rate simply outlive the ones with fast heart rate ! Is this due to simple fact they conserve their heart rate .Each human has a reserve of few trillion heart beats for usage in his or her life time .So if this is true what does regular vigorous exercise do to our longevity ! These are pure fantasy questions that need to be answered !
The truth may be regular excercise even though raises the heart rate to high levels it keeps our vagal tone high and maintain the basl heart rate low and there by conserving both heart rate and myocardial oxygen consumption.The other evidence for heart rate being vital in prolonging life is the proven benefits of beta blockers in patients with decompensated heart.
Read the excellent issue dedicated to the importance of heart rate for human survival especially in relation to cardiovascular disease .
From the publishers of dialogues in cardiology .This knowledge sharing comes free of cost
Courtesy of Servier
http://www.dialogues-cvm.org/pdf/19/DCVM19_05.pdf
Dr.S.Venkatesan MD 