When most people think of the human heart, they envision a big beating muscle with multiple valves and arteries to help pump blood. What many don’t see is the complex electrical system of the heart that initiates the heartbeat and controls the timing of valve opening and muscle contraction in different parts of the heart. When this system of natural electrical wiring is working properly, the heart pumps blood with the right timing and sequence. When it wears out, it can develop arrhythmias—irregular rhythms that can cause serious health issues.
“When the heart's natural electrical system becomes defective, the heartbeat may go too fast, too slow, become irregular, or even stop,” said Alexei Shvilkin, MD, Cardiac Electrophysiologist at South Shore Hospital and an Assistant Professor of Medicine at Harvard Medical School. “Rhythm problems can cause shortness of breath, dizziness, passing out spells, or even death. Fortunately, the artificial pacemakers help alleviate a lot of these problems.”
Innovations in Artificial Pacemaking
Artificial pacemakers are one of the major discoveries in cardiology that have given a new lease on life to millions of patients suffering from irregular heartbeats. A pacemaker is a small device that sends electrical impulses to the heart through thin wires (leads) attached to the inside of the heart muscle. It helps maintain a suitable heart rate and rhythm when the natural electrical system of the heart fails. Though they do not cure heart disease or prevent heart attacks, by speeding up the abnormally slow heartbeat (bradycardia), pacemakers can often eliminate symptoms associated with it. Patients often experience more energy and less shortness of breath. Many patients fully depend on their pacemaker because their heart would stop if they did not have one.
A pacemaker most commonly has two wires (leads) attached to the top (atrium) and the bottom (ventricle) of the heart. The bottom lead is usually attached to the muscle of the right ventricle which has been the standard pacing site since the development of implantable pacemaker technology in the 1960s. It is the easiest place to attach the lead that provides reliable pacing. However, to reach the left ventricle (the main pumping chamber of the heart) the signal from the right ventricular lead has to slowly travel through the heart muscle all the way to the left side of the heart. It takes a long time and throws off the optimal timing of ventricular pumping. Over time, this can weaken the heart muscle.
“We have learned that while potentially saving the life in the short term, the long-term side effects of right ventricular pacing include pacing-induced heart failure and increased risk of death. Fortunately, there have been considerable advances in pacemaker technology,” said Dr. Shvilkin. “Unlike a traditional pacemaker that completely bypasses the natural electrical wiring of the heart, often it is possible to engage and take advantage of the remaining electrical fibers to preserve the natural path of electrical activation.”
Early last year, Dr. Shvilkin started performing an innovative, relatively new heart procedure known as His-Bundle Pacing (HBP) at South Shore Hospital—the first performed in the South Shore region. HBP has been shown to eliminate the risk of pacing-induced heart failure in patients who need pacemakers.
During the procedure, instead of the right ventricle, the lead is attached directly to His-bundle just below the level of the breakdown directed by special guiding catheters or thin plastic tubes. From there, the electrical signal travels quickly down the natural pathways using bundle branches to the right and left ventricles.
Hingham resident, Elizabeth Bradley was on the receiving end of Dr. Shvilkin’s first South Shore Hospital HBP procedure.
“I knew that something special was happening the moment Dr. Shvilkin came in smiling and clapping after the procedure,” Elizabeth recalls of that day. “Knowing that I received a state-of-the-art procedure like this right here on the South Shore without worrying about going into Boston makes me feel safe and well taken care of close to home,” she said.
Not everybody is a candidate for HBP, but having these options available at South Shore Hospital ensures that all South Shore residents have access to the highest quality cardiac care and services close to home, on par with major academic centers in Boston.
“I’m very excited to bringing the world-leading innovations in cardiac pacing to our local community—right here at South Shore Hospital,” said Dr. Shvilkin. “I am looking to expand the scope of the pacemaker procedures further. Soon, I am planning to start implanting 'leadless' pacemakers – devices with a completely new design. These small devices the size of a bullet are delivered inside the heart using a catheter through a vein in the leg similar to cardiac catheterization. They need no wires since they sit right inside the heart. Not everybody is a candidate for a His-Bundle or leadless pacemaker, but having these options available makes it easier to make the right choice of pacemaker for each patient.”
To learn more about advanced cardiac care on the South Shore, please visit our website or call (781) 624-8272.