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Cardiac Electrophysiology?

041813 Ys Men Dhruvakumar Balch Dr. Sandhya Dhruvakumar, a cardiovascular specialist at Stamford Hospital was introduced to Y’s Men or Westport-Weston on Thursday as a Cardiac Electrophysiologist. A what? The doctor explained, in a clear, though complex introduction to an emerging specialty that heralds a new era in the treatment of heart disease.

Dr. Dhruvakumar studies the electrical properties of the heart to develop protocols that treat an underlying problem, in contrast to legacy approaches that act largely to control symptoms.

Historically, cardiology has been largely about the chemical and biological properties. In the future it will be increasingly about electrical properties.

Her field is so new that there may not be enough cardiac electrophysiologists practicing in Fairfield County to fill a bridge table. Perhaps in part because Dr. Dhruvakumar has completed medical school, her residency and been awarded two fellowships – 12 years of post-undergraduate education.

Using a PowerPoint presentation entitled The Beat Goes On: Atrial Fibrillation, Pacemakers and Other Problems of the Heart, the doctor began by explaining – briefly – the heart’s structure and and how it works. From there she introduced arrhythmia and discussed its treatments.

From a cardiac electrophysiologist’s perspective the sinus node is the heart’s essential component. This tissue is located in the right atrium (upper chamber). As “the heart’s own pacemaker” it generates the heart’s electrical impulses. The sinus node stimulates the heart’s contractions and pumps blood returning from the venous system into the right atrium, which pumps it to the right ventricle. From there it goes to the lungs to get re-oxygenated and is then pumped first to the left atrium, then to the left ventricle and, finally, out into the arteries.

Arrhythmias, Dr. Dhruvakumar called “irregular beating of the heart.” If the heart beats too slowly the typical corrective is a pacemaker. This titanium enclosed electronic pulse generator is about the size of a matchbook and is implanted under the collarbone. It has a small wire going to the heart and batteries with a life of up to eleven years. The pacemaker reads the heart’s rhythms and generates beats missing when it slows or skips one. If a heart beats too rapidly the typical treatment is medication.

She then discussed atrial fibrillation, the most common type of irregular heartbeat, and described treatment alternatives. While the heart normally beats 60 to 100 times per minute, A-fib can produce “chaotic” rates of 300 beats per minute in the atria, and push the atria out of sync with the ventricles.

“It is not itself life threatening, but causes other problems.” One such is strokes – those with atrial fibrillation are up to seven times more likely to have strokes than the population as a whole. And its incidence is age related. Ten percent of the Medicare population exhibits its symptoms as do 15 percent of those over age 80.

Atrial fibrillation occurs when disorganized electrical pulses, generally originating in the pulmonary veins, overwhelm the sinus node and prevent the ventricles from contracting at normal rates and so failing to pump the necessary volume of blood back into the arteries. This leads to blood pooling and allows clots to form. If a clot escapes and blocks a blood vessel in the brain it denies oxygen to the brain. The result is a stroke.

Its symptoms include palpitations, lack of energy, dizziness, chest pain or shortness of breath. It can be caused by high blood pressure, arterial blockages (high cholesterol), heart valve problems, even previous heart surgery.

Dr. Dhruvakumar described three treatments. The first two, medication and a surgical procedure, seek to prevent strokes but do not address the fibrillation, the stroke source. The third, and newest, the electrophysiological treatment, seeks to eliminate the fibrillation itself.

The oldest treatment is taking blood thinners – “tried and true” Coumadin to prevent strokes. But it “interacts with everything else in your body,” and necessitates monthly blood checks. Newer medications such as Pradaxa and Xarelto don’t require monthly tests, but each has its concerns, and none repairs the heart.

A stroke prevention treatment for people who cannot take blood thinners is the LARIAT procedure. This approach uses two catheters to loop a fine filament around the base of the left atrial appendage to permanently seal it off and block the part of the heart in which 90 percent of clots form.

Ablation is a third option and the electrophysiologist’s “preferred treatment.” It offers a “permanent cure without needing chronic medication.” To perform the procedure the electrophysiologist inserts two catheters to identify the area of the arrhythmia, then cauterizes it, using radio waves to create heat, cryoablation (extreme cold) or a laser, to eliminate the arrhythmia. The result is a more normal heart rate and a reduced, if not eliminated risk of stroke.

The heart is a small electrical plant whose workings are only now being understood, and electrophysiology, Dr. Dhruvakumar told Y’s Men, holds the key to better enabling medicine to cure its problems rather than treating its symptoms.

Photo by Bill Balch

Roy Fuchs