How many times does your heart beat per year?

Cecil replies:

Dear Faustino:

Your heartbeat, naturally, is by no means constant. The rate can vary from minute to minute, depending on stress and body temperature. In one famous, if rather grisly, experiment, a team of researchers in Utah in 1939 took an electrocardiogram of a man about to be executed by a firing squad. His heartbeat increased from 72 to 180 just before the shots were fired. Afterward, of course, the rate dropped sharply.

A rate of 72 to 80 beats per minute is generally considered normal for a healthy human being at rest. At birth, the rate is in the neighborhood of 130 beats per minute, with the figure decreasing through adolescence and then showing a slight upswing in old age. Women (and this seems to apply to the females of most species) have a faster heartbeat than men. Clams have the slowest heartbeats of all God’s creatures, varying from 2 beats per minute for a clam en repos to 20 for a clam in a state of extreme nervous excitement.

Since the solar year consists of 525,948 minutes and 48 seconds, a quick calculation at the rate of 80 BPM gives us a ballpark figure of 42,075,904 beats per year, give or take a couple mill. A reasonable estimate for the number of heartbeats in a lifetime is about three billion.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.