New Toys for the Electricians

Electrophysiology is the subspecialty of cardiology that deals with the electrical problems of the heart.  At times the heart develops rhythms that break down into the fast rhythms, the slow rhythms and the lethal rhythms.  I have blogged in the past about the development of ICDs or implantable defibrillators and now we are seeing the next generation of these devices.

This paper was published online at the NEJM website and presented at the Heart Rhythm Society Meeting in May.  It was presented by Dr. Bardy who is the founder of the company as well as one of the inventers of the device.  Dr. Bardy  works at the Cleveland Clinic in Cleveland Ohio.

A conventional ICD is implanted by placing a wire into the right top chamber of the heart known as the atrium and a “shocking catheter” into the right lower chamber of the heart known as the ventricle.  There are other ways to do this but the descriptions are outside the scope of this blog.  To do this, the wires are in contact with the blood of the body and special equipment and x-ray is need.  This new device uses a generator that is implanted in the top part of the chest underneath the skin as in a standard ICD.  The new part is an array shocking catheter which is placed under the skin near the heart alongside the sternum.  It is not in actual contact with the heart and is not in the blood stream.

The procedure requires no x-ray and can be done in any suitable surgical location.  This device requires much more energy to work, almost twice as much, and the device is capable of delivering an astounding 80 joules of energy.  Most ICDs deliver shocks in the range of 18 joules.

The study encompassed 55 patients followed for a short 10 months.  One hundren and thirty seven bouts of induced rhythm were terminated.  Twelve episodes of spontaneous rhythms were successfully treated by the device.  For one patient the device would not successfully work in the lab and the patient received a standard ICD.  One patient died of renal failure unrelated to the study.

This is an exciting advance but not ready for prime time.  The device lacks many of the standard features of ICDs; perhaps the most important one is that of tiered therapy.  What is meant by that is that the device delivers therapy in many ways and often terminates the rhythm without delivering a full shock.  In addition the ICDs often function as backup pacemakers for patients.

Not quite ready, but an exciting advance and I applaud the thought leaders here. 

Next: A new device for atrial fibrillation…

Tags: Electrophysiology, Heart Rhythm, Heart Rhythm Society, ICD, implantable defibrillator
Posted in Pacemaker / AICDs | No Comments »

Adult Stem Cell Research

NOGA mapping image

One of the primary purposes for the creation of the JMHVRI was to have Holy Cross Hospital involved with cutting-edge research. This has allowed us to participate in the most exciting research development in years.

In my 20 years of research at the clinical level, my team and I have had the privilege of being involved with important breakthroughs in the clinical and drug treatment of cardiac disease. We have participated in the development and approval process of most of the drugs I now use for the treatment of heart disease. Much of our work continues in this mode. Our work with adult stem cells portends an improved future for cardiac patients.

To date, we have been involved with two stem cell projects and one project utilizing a stem cell protein. We are the only site in south Florida and one of three sites in Florida.

Adult stem cells are undifferentiated cells that multiply by cell division to replenish dying cells and regenerate damaged tissue. They are derived from adult tissue samples. Although the process is unique, it is not strong enough to repair all the cells that die naturally or by accident. If you have a heart attack, the few adult cardiac stem cells in your heart are not numerous enough to repair the damage. The reasons are unknown and an active area of research. We have no way of obtaining adult cardiac stem cells because we cannot biopsy the heart adequately to obtain them.

Therefore, the studies utilize other stem cells to obtain the results we are clinically trying to obtain. These cells or protein material are then injected directly into the heart from the leg in a manner similar to angiography and angioplasty using an additional special machine known as NOGA. NOGA technology is similar to the technology used in electrophysiology studies to isolate and identify areas of the heart of interest; in our case, those areas of the heart which are scarred or lacking adequate blood supply. After identification, special catheters are used for the injections.

Next… The Baxter CD34+ stem cell study for the treatment of angina.

Tags: Electrophysiology, NOGA mapping
Posted in Adult Stem / Cell Treatment, Chronic Angina, Heart Failure | 3 Comments »