St Jude Medical's HIFU cardiac ablation system gains EU and US
21 August 2008
St Jude Medical, Inc. (NYSE:STJ) has received European and US
clearance for its Epicor LP cardiac ablation system, a second generation
technology that uses HIFU (high intensity focused ultrasound) to
surgically ablate cardiac tissue to disrupt abnormal electrical impulses
in the heart.
The first patient to undergo treatment with the Epicor LP System was
a 73-year-old male with coronary artery disease and atrial fibrillation
(AF) at Derriford Hospital in Plymouth, United Kingdom. The patient, who
has suffered from persistent AF for more than three years, had a normal
heart rhythm upon completion of the ablation procedure.
“An increasing volume of published literature is demonstrating the
benefits of treating pre-existing AF in patients who are undergoing
valvular or coronary artery bypass surgery,” said Dr Dalrymple-Hay the
cardia surgeon who performed the operation. “The Epicor LP System
provides me with a technology that is flexible enough to treat AF
patients during either standard open chest procedures or minimally
invasive surgical procedures.”
About the procedure
Atrial fibrillation is the most common abnormal heart rhythm
condition, affecting millions of patients worldwide. With AF, the
heart’s upper chambers (the atria) do not beat effectively due to
abnormal electrical activity. As a result, the heart cannot effectively
pump blood, which can lead to shortness of breath, heart palpitations
If left untreated, AF increases the risk of stroke five fold,
according to a study reported in the journal Stroke in 1991 (Wolf
et al, Atrial Fibrillation as an independent risk factor for
stroke: the Framingham Study, Stroke 1991). AF is progressive and
increases in frequency and severity as patients grow older, and surgical
cardiac ablation has been found to provide relief from AF for a high
percentage of patients.
In surgical ablation performed with a HIFU energy source, energy is
focused from outside a beating heart. This treatment has been designed
to create precise and complete lines of cardiac tissue ablation to block
chaotic electrical impulses. The patient does not need to be placed on a
heart-lung bypass machine nor is the heart stopped. Because HIFU energy
is directed from outside the heart inward (instead of from the inside
out as is sometimes the case in ablations performed with other energy
sources), the risk of unintended peripheral damage is minimized.
In contrast, the traditional surgical approach requires that patients
be placed on a heart-lung bypass machine with their hearts stopped while
a cardiac surgeon cuts maze-like patterns in the atrial tissues and then
sews the incisions to encourage the formation of lesions, or tiny scars.
Surgeons may also use alternative energy sources, such as radiofrequency
or cryothermy, to create lesions in heart tissue. The lesions disrupt
the abnormal electrical impulses that cause AF.
St Jude Medical says the Epicor LP system has a lower profile
(smaller relative to the first generation technology) as well as other
features designed to facilitate easier device introduction and placement
around and on patients’ hearts. In addition, the Epicor LP System is
equally suited for use in both closed-chest procedures performed through
a single incision, and in open-chest procedures.