Pediatric Cardiac Teams at Holtz Children’s Hospital Use Internal Pacemaker Made for Adults to Save Premature Baby Born with Complete Heart Block

By: Krysten Brenlla

Andrea Limas, 36, and her husband always knew they wanted to start a family. What they didn’t expect was how challenging that journey would be.

“By the time we decided to have children, it took a very long time,” Limas said. “We had our first son about four years ago. With him, I had many complications due to conditions I didn’t even know I had.”

She learned she had a ventricular septal defect – a hole in the wall between the two lower chambers of the heart. Limas was also diagnosed with preeclampsia, a serious pregnancy complication marked by high blood pressure.

She was considered a high-risk pregnancy. However, despite the risks, she gave birth to a healthy baby boy.

A few years later, she became pregnant with her second child – a girl. Early on, she realized she would be having another high-risk pregnancy when she was diagnosed with an autoimmune disorder called Sjogren’s syndrome.

Sjogren’s syndrome attacks moisture-producing glands. During pregnancy, certain antibodies linked to Sjogren’s can affect the baby, increasing the chance of rare complications, like congenital heart block.

“In my case, my baby had a complete heart block – the worst kind,” Limas said. “Normally, a regular fetal heart rate is 150 or 160 beats per minute. Hers was at 30 to 40.”

When Limas was 24 weeks pregnant, her team noticed the baby was going into heart failure.

“I was told that I needed to act quickly, because the baby was at risk of multiorgan failure, and she could have passed away,” she said. “Because of the complexity, I needed to be transferred to Jackson Memorial Hospital.”

Once she arrived at Jackson, the UHealth Jackson Children’s Care pediatric cardiac team took her in and began multiple tests on her and the baby. They confirmed the baby was in an extremely critical state.

Limas needed to have the baby prematurely. Once the baby was born, she needed to undergo emergency heart surgery to place an external pacemaker– a vital step for temporary cardiac support.

“Hearing that was really scary,” Limas said. “The team said it was the only way to save her life.”

At 27 weeks, on March 6, 2025, Limas gave birth to a 2-pound baby girl, Rebeca Andrea Zaldaña Limas.

“The team at Jackson did everything possible to stabilize Rebeca once she was born. I told them to do whatever it took to save my baby,” Limas said.

After her initial surgery, Rebeca spent several weeks in Holtz Children’s Hospital’s neonatal intensive care unit (NICU),. For the first few days, she was intubated. Soon after, she was placed on continuous positive airway pressure (CPAP), a method of respiratory therapy.

Once Rebeca was off CPAP, she was ready for her second cardiac procedure.

“As Rebeca grew, it was time to place the Micra internal cardiac pacemaker,” said Steven Fishberger, MD, program director of pediatric electrophysiology at Holtz Children’s/UHealth Jackson Children’s Care. “Usually, these pacemakers are for adults, but it was adapted for premature babies. Rebeca was around 30 weeks when it was placed. She was still very premature, but she did remarkably well.”

On April 26, the team successfully placed the internal pacemaker on Rebeca.

Two days later, Limas was able to hold her daughter for the first time.

“There were really tough moments where Rebecca looked in really bad shape,” she said. “All I know is that she’s here for a reason – she’s a fighter. God gave her the grit to keep persevering for her life.”

After spending 130 days in the NICU, on July 14, 2025, Rebeca was ready to go home and meet her big brother.

“Being in the NICU is never a straight trajectory, there are ups and downs every day, but we gave complete confidence to the teams at Jackson who worked on Rebeca,” Limas said. “They were there to save her life.”

Today, Rebeca is living a healthy and normal life – growing bigger every day.

“The teams at Jackson, their passion for what they do in saving children’s lives, we’ll never forget it,” Limas said. “We bear witness to miracles unfolding every day. We’re so grateful for being one of those Jackson miracles.”