TIMING IS EVERYTHING

TIMING

IS EVERYTHING

WHEN IT COMES TO CORRECTING HEART RHYTHM DISORDERS, SPECIALISTS AT TAMPA GENERAL HOSPITAL ARE AT THE FOREFRONT OF NEW SURGICAL TECHNIQUES

BY K.S. MEYER

Everyone has heard the stories: The promising young Navy recruit who can’t join up because of some less-than-optimal EKG readings. The healthy grandmother who collapses while pouring her morning coffee. The experienced marathoner who falls dead 10 miles into a race. Heart rhythm disorders, or arrhythmias, are far more common than many people realize, affecting more than 14 million Americans. They can either be present at birth or occur for no apparent reason. Unlike most other heart disease, they often are unrelated to a patient’s lifestyle, although age, smoking, and other factors, such as use of caffeine or other stimulants, can increase the risk of harm from an arrhythmia.

While most arrhythmias are as easy for a skilled physician with a stethoscope to diagnose as a speech impediment is to the common ear,

Dr. Bengt Herweg Dr. David Wilson Opposite page: Dr. Bengt Herweg reviews an image of a patient’s heart. TGH is implementing cutting-edge treatments to correct arrhythmias, including cardiac resynchronization and cardiac or catheter ablation.

the underlying conditions giving rise to the symptom are notoriously diffi cult to fl ag and treat. Fortunately, the team at Tampa General Hospital is a leader in more modern approaches to treating arrhythmias that are more effective and carry fewer risks.

“The electrical activation of the heart is a major determinant of cardiac function,” said Dr. Bengt Herweg, medical director of the Electrophysiology Center of Excellence in the TGH Heart & Vascular Institute and professor of medicine at the USF Health Morsani College of Medicine at the University of South Florida. “A heart rate either too slow or too fast can result in fainting spells, and diseases of the electrical conduction system can result in heart failure, manifesting itself by lack of energy, volume overload, and premature death. Fixing electrical problems in the heart is, therefore, ‘low-hanging fruit’ when it comes to making a quick and lasting difference for patients.”

In decades past, treatment meant either fl ooding the heart muscle with medication or performing open-heart surgery.

“That’s a hallmark of what we were doing,” Dr. David Wilson, medical director of the electrophysiology laboratory in the TGH Heart & Vascular Institute and assistant professor of medicine at the USF Health Morsani College of Medicine, said of using medication to treat arrhythmias. “You’re manipulating the chemistry of the heart cells to make arrhythmias less likely. And that manipulation can, unfortunately, actually trigger arrhythmias under a certain set of circumstances, so those patients require closer follow-up and monitoring.”

The most frequent treatment for correcting symptomatic or dangerous arrhythmias in recent years has been catheter ablation, or insertion of devices including pacemakers and defi brillators with leads inserted into the heart muscle to force it to work properly.

“The preferred management may entail pacemakers, depending on the type of rhythm,” Wilson said. “It may entail ways to mitigate sudden cardiac death, like implantable defi brillators. It may involve the use of catheter ablation, which is an endovascular technique where we go in and try to fi nd the specifi c foci or triggers for cardiac arrhythmias and seek to modify the heart’s natural electrical system or destroy tissue that may be causing arrhythmias in order to prevent them from happening.”

While the insertion of electric leads does eliminate most symptomatic arrhythmias, it also may create problems down the road, with most leads becoming worn out after a certain amount of time and requiring extraction. Electrophysiologists have developed new ways to solve this issue as well.

“Five, 10 years ago, patients who had dysfunctional leads may have only been offered the option to have those leads abandoned, and then forced to have redundant, old hardware left in place while adding new hardware, which carries its own risks for vascular occlusion and infection or compromise of heart valves,” explained Wilson. “Whereas nowadays, we’re able to offer them transvenous lead extraction, where we go in and remove malfunctioning leads and replace them with brand new, serviceable leads.”

Herweg described another procedure to help regulate the heart’s rhythm.

“Another novel treatment option is cardiac resynchronization by stimulation of the specialized conduction system of the heart,” Herweg said. “We gain access to the venous system of the heart, usually through the left shoulder area; we come down through a small vein and that leads down to the heart. Under fl uoroscopic guidance and electrical recordings from inside the heart we then place leads in millimeter-thin fi bers of the conduction system and institute pacing, once we’re in the right spot.”

Once the pacing leads are in place, the electrophysiologist can adjust their output until the heart muscle is “fi ring” in total synchronicity and producing maximal cardiac output.

Now that more sophisticated interventions are available, electrophysiologists can use the heart’s own natural electrical system to create a more immediate, less sluggish fi ring of the muscle. The results have been promising, and TGH physicians have participated in clinical trials and published research to share their successes in this area.

“We now know, according to observational preliminary data, that pacing the conduction system of the heart not only does not have any ill side effects but can, even in selected patients, improve cardiac function and treat congestive heart failure,” Herweg said. “It’s a formative sort of cardiac resynchronization therapy. We have been involved in this from the beginning here at TGH.”

Some situations might require more intensive measures to correct a faulty heart rhythm. One of these treatments is cardiac or catheter ablation, which blocks the misfi ring electrical signals in the heart and restores a normal rhythm. Once considered a riskier procedure, various measures have been implemented to ensure such procedures are

For more information about the TGH Heart & Vascular Institute, please call (813) 844-3900 or email heart-vascular@tgh.org

quickly executed and less invasive.

“If we’re doing catheter ablation, we do have equipment that [enables us to] use multiple modalities to correct for things like cardiac motion and the complexities of working on a beating heart,” said Wilson. “Those include ultrasound, advanced computer 3D-mapping techniques, and fl uoroscopy. All those systems can, in some form, talk to each other and allow us to integrate all modalities in order to correct for things like respiratory motion in order to give us the most stable appearance of cardiac structures as possible.”

When a more aggressive intervention is needed to correct a more severe arrhythmia, such as atrial fi brillation—which dramatically increases the risk of both heart attacks and strokes—catheter ablation has shown signifi cant promise with less risk and a shorter hospital stay than conventional open-heart surgery.

“Catheter ablation for atrial fi brillation is still a relatively new procedure,” Wilson said. “The very fi rst one was performed around 1997, and it’s really become ubiquitous over the last 10 to 15 years. When I started performing these, about 10 years ago, it wouldn’t be unusual for a patient to be sent to an ICU afterwards—they’d be in the hospital for one to three days after that, and maybe require IV medications like diuretics in order to remove excess fl uid, or in order to monitor for signs and symptoms of heart failure. The procedure itself could sometimes take up to six to eight hours to perform. Nowadays, with modern techniques and improved technology, just physician time can be two hours or less, and patients can go home the same day.”

The same day. Even fi ve years ago, this would have been unheard of for patients, let alone coupled with the news that their arrhythmia had been treated in full, with almost no chance of relapse. This is now reality.