4 | Summer 2017
shock from an implantable cardioverter
defibrillator (ICD) may trigger an increase
in healthcare needs for many people,
regardless of whether the shock was
medically necessary, according to a new
study published in Circulation: Cardiovascular Quality and
Outcomes, an American Heart Association journal.
ICDs save people from sudden cardiac death by
delivering a shock to restore a normal rhythm when the
lower chambers of their heart, or ventricles, beat erratically.
Inappropriate shocks occur with ICDs, most often when
the device mistakes a different heart rhythm problem
for ventricular arrhythmia—abnormal heart rhythms that
originate in the lower chambers of the heart.
“ICDs cannot assess patients the way a doctor can,”
said lead study author Mintu Turakhia, M.D., M.A.S.,
cardiac electrophysiologist and senior director of research
and innovation at the Center for Digital Health at Stanford
University in California. “The device doesn’t know, for
instance, if the patient is unconscious or has a pulse. We
wanted to see what happens after a shock, in terms of care
and cost, to help define the potential benefit of smarter
The authors analyzed the experience of 10,266 patients
implanted with an ICD in the U.S. between 2008 and 2010
by linking data transmitted to the device manufacturer
with the patients’ healthcare records. During that time,
963 patients, average age 61, experienced 1,885 shocks.
Thirty-eight percent of those shocks were determined to be
Researchers also found:
• Nearly half of all patients ( 46 percent) who experienced
a shock received health care related to the shock.
• One in three patients received emergency room or
outpatient care only.
• One in seven patients was admitted to the hospital.
• Invasive cardiovascular procedures, including
electrophysiology studies, cardiac catheterization and
cardiac ablation, were commonly performed following
both appropriate and inappropriate shock.
• The average cost of health care following a shock was
$5,592 for an appropriate shock and $4,470 for an
“Obviously, shocks that save people’s lives are a good
thing, but they are also very painful, can be traumatic and
often lead to more healthcare procedures and expenses,”
Turakhia said. “This is why strategies to make these ICDs
more selective so that they deliver fewer inappropriate
shocks is especially important. Fortunately, the industry has
made many advancements in this area.”
Turakhia added that newer programming strategies
reduce the number of inappropriate shocks, even among
older-generation ICDs. The devices can be programmed by
clinicians to deliver fewer inappropriate shocks by waiting
briefly to see if the ventricular arrhythmia resolves itself and
by cautiously avoiding triggering shocks for heart rhythms
with moderately fast rates.
“The quality of care is no longer just an issue of whether
an ICD was implanted in appropriate patients but also
whether it was programmed in the best way possible,” he
said. “We have the technology to do that today.”
“From this study, we cannot tell whether any patient
received appropriate or inappropriate care — only whether
they received an appropriate shock or not,” Turakhia said.
“We can say, however, that the costs associated with both
kinds of shock are substantial and that optimal device
programming that reduces shock events are likely to
decrease healthcare costs and improve patient health.”
Source: American Heart Association News
SHOCK FROM HEART DEVICE
OFTEN TRIGGERS FURTHER
HEALTH CARE NEEDS