The loss of a loved one brings inexplicable grief, pain, and heartbreak, and not only the figurative kind.

A new study found a link between the death of a spouse or partner and the development of irregular heartbeats among grieving individuals, a condition which increases the person's risk of heart attack or stroke.

In other words, a literal heartbreak.

A group of researchers from Aarhus, Denmark investigated 88,612 people diagnosed with a condition called atrial fibrillation or irregular heartbeat, and compared them with 886,120 more from a healthy control group.

The Aarhus University research team found that for a grieving person, there was a 41 percent higher risk of developing atrial fibrillation for the first time compared to those who did not lose a spouse.

This increased risk occurred regardless of gender and underlying conditions such as diabetes or cardiovascular disease. It also peaked about a week or two after the death and then subsided after 12 months.

Surprisingly, scientists found that the risk for atrial fibrillation appeared to be greatest among people under 60 years old, a risk that was twice as high.

When the death of an otherwise healthy partner was least expected, the risk of developing atrial fibrillation was 57 percent higher.

The condition is associated with increased risk of stroke, heart failure, and death. The study said the lifetime risk of developing irregular heartbeat is somewhere in between 22 to 29 percent in Western countries.

Meanwhile, study authors emphasized that further research must be done and their findings do not indicate that the death of a partner causes irregular heartbeat.

One theory is that acute stress may interrupt normal heart rhythms and trigger the production of chemicals that cause inflammation.

Still, the findings offer insight on how a person's health can be affected by relationships. Interventional cardiologist Dr. Sahil Parikh compares it to the condition known as "broken heart syndrome," in which the heart malfunctions often after a tragic event.

"The fact that people get this [atrial fibrillation] after a stressful occurrence is not that surprising," said Parikh, in an interview by ABC News.

The findings of the study are featured in the journal The Open Heart.

Photo: James Case | Flickr