Linda Munoz had been rushed to Stanford Hospital & Clinics on a
Flight helicopter. The 28-year-old pregnant woman was suffering
mysterious heart problems, and doctors feared that they could make
delivery not only more difficult, but potentially fatal —for both her
and her unborn child.
In the late third trimester of her pregnancy, Munoz's heart had
started racing and would not relent. Mintu
Turakhia, MD, MS, a cardiac electrophysiologist, was on call for
Arrhythmia Service on the day she arrived. "It was quite
scary," he said. "She was having palpitations that had
gotten much worse over the course of her pregnancy. The arrhythmia
was becoming more sustained and more rapid.
"The normal changes in the body's blood circulation during
pregnancy made her even more vulnerable to losing blood flow to the
brain, which made her lightheaded," added Turakhia, an instructor
of medicine." To complicate things, we also worried that the
arrythmia was affecting the circulation of her baby.
Turakhia diagnosed an irregular heart beat — right ventricular
outflow tract tachycardia — that was interfering with her heart's
ability to pump blood. Working with a range of colleagues at the
hospital, he prescribed medications that were safe and suppressed the
arrhythmias. Under the care of the Stanford obstetrics team, the
patient gave birth to her first child, and mother and baby did well.
While ventricular tachycardia often occurs in patients with heart
disease, the form Turakhia identified can occur in otherwise healthy
individuals, and is sometimes referred to as a "nuisance
arrhythmia." But in periods of stress, like pregnancy, the
arrhythmia can become pronounced and potentially life-threatening."
Before her pregnancy, Munoz had felt extra heartbeats and occasional
palpitations, but nothing like this. "I was short of breath,
light-headed and I could feel my heart racing," she recalled.
"Sometimes I felt like I might lose consciousness."
Munoz went to see her obstetrician, and he recommended that she be
admitted to a community hospital for an electrocardiogram. There her
heart arrythmias were detected, and Munoz was transferred by Life
Flight to Stanford.
According to Turakhia, her pregnancy had unmasked her tendency to
have this VT. "I was concerned that it was going to damage her
heart in the long term," he said. "To further complicate
things, she wanted to have another child, and we couldn't let her go
into another pregnancy without addressing this condition."
After the birth, Turakhia continued to monitor the young mother's
condition for another four months, when he determined that a cardiac
catheter ablation procedure was necessary to help his patient. During
that time, even simple tasks, like holding her daughter, caused her to
have sustained palpitations.
As a cardiac electrophysiologist who specializes in diagnosing and
treating heart rhythm disorders, Turakhia was able to identify the
specific site in his patient's heart where the arrhythmia was
occurring. He inserted a catheter in the femoral vein, at the right
groin, and then ran it into the heart with the help of fluoroscopy
(X-ray) and a sophisticated three-dimensional electronanatomic mapping
system. After identifying the cells that were causing the irregular
beats, Turakhia zapped them with radiofrequency energy.
"It was a risky procedure because for several months after
pregnancy, the tissue of the walls of circulatory vessels become more
delicate and can be easily injured," Turakhia said about the
ablation. The procedure heats up tissue in a directed burn of a few
millimeters on the surface of the heart and destroys the small number
of cells that are firing too fast.
"We had to be very careful, but we were able to find the site,
and on the first attempt we terminated the arrhythmia—and cured her."
Munoz said she felt better immediately. "There were no more
arrhythmias. I couldn't feel them anymore."
Paul Wang, MD,
Director of the Cardiac Arrhythmia Service, noted that although many
people have extra heart beats, fewer than 10 percent of them require
an ablation. "But for people who get ablated, it's
terrific," Wang added. "And this was an excellent case, with
an outstanding outcome."
Turakhia followed his patient closely after the procedure, and had
her wear a Holter monitor, a portable device to monitor cardiac
events, for three weeks.
"I was very pleased because this made an immediate impact on
her life," he said. "She was able to go back to work, she
could hold her child, and she could think about having another baby,
knowing she won't be at risk for having these arrhythmias again."