HOUSTON -- There's new fear that people with the swine flu could be at risk for heart failure, KPRC Local 2 reported Monday.

Dr. Barry Diner works in emergency medicine at St. Luke's Hospital, where in the last week they've seen a disturbing trend.

"There's been three cases that also developed into heart failure," said Diner.

It's the first we've heard of swine flu potentially causing such a risk, and the doctor said he hasn't seen heart failure with the regular flu.

"It's kind of concerning because we don't necessarily see that unless we have overwhelming infection," said Diner.

With only three cases, Diner said there's not enough evidence for a direct link between swine flu and heart failure yet, but there is reason for concern.

Of the three patients, one was a teenager and one was a pregnant woman. Doctors delivered the baby early and the new mother is in critical condition.

Doctors said one of the swine flu patients died after heart failure within 24 hours of coming into the hospital.

This comes as Harris County health officials said there have been an additional six swine flu deaths in the county since June.

Three men and three women, all adults over the age of 19 and one over the age of 65, have died. The county said that at least half had pre-existing medical conditions.

"While sadly these deaths are truly tragic for the families, we're not surprised that we're having deaths," said Rita Obey with the Harris County Health Department.

Doctors now are saying if you get flu-like symptoms, you have to judge for yourself if a trip to the hospital is necessary.

"When someone's not feeling well and they feel like they can't handle themselves at home, they need to come to the hospital for an evaluation," said Diner.