In March, at Long Island Jewish Medical Center in New Hyde Park, a cardiologist fastened a device about the size of a grain of rice to the inside wall of a 43-year-old man's heart. Hospitals around the world have implanted that device before. None of them had ever implanted it in a patient like this one, a man born with his heart's two great arteries connected to the wrong chambers, and that is what made the procedure at LIJ a world first.

Northwell Health announced the milestone on September 1, after the patient came back for the six-month checkup that confirmed what he had been telling everyone since the spring: he can breathe again, and he is back at the gym.

A heart plumbed in reverse

The patient, Michael Chaves, is an intermediate school paraprofessional from Staten Island who was born with transposition of the great arteries, one of the most serious congenital heart defects there is. In a heart like his, the aorta and the pulmonary artery are swapped. The aorta rises from the right ventricle instead of the left, and the pulmonary artery rises from the left instead of the right, so blood that should be heading to the lungs to pick up oxygen can instead be sent back around the body without it.

Children born with the condition have their first operations before they can walk. Chaves had open heart surgery at five months old and received his first pacemaker at 13, and he has spent the four decades since inside cardiology offices, living with hardware that had to be custom-fit to an anatomy the hardware was never designed for.

That anatomy is the whole story here. A standard pacemaker lead is a thin wire threaded through a vein and into the interior of the heart. In many patients whose hearts formed differently, that route simply does not exist in usable form. The wall the wire would need to cross, the chambers it would need to reach, are not where the wire expects them to be. So Chaves's original pacing lead was not threaded anywhere. Surgeons stitched it directly onto the outside of his heart muscle.

A lead sewn to a beating heart lives a hard life. The muscle contracts around 100,000 times a day, every day, for years, and scar tissue slowly builds around the attachment point. Over the decades, Chaves's lead wore out, his heart function declined, and he was left needing something his doctors could not give him by any conventional route: a second pacing point on his left ventricle, so the two sides of his heart could be brought back into rhythm together.

A pacemaker with no wire at all

The answer was a system called WiSE, made by EBR Systems, and its design reads like an end run around every obstacle in Chaves's chest. There is no wire. The part that touches the heart is a tiny receiver electrode, roughly rice-grain sized, placed against the inner wall of the left ventricle. A separate transmitter, implanted nearby and run by its own battery pack, aims pulses of ultrasound at that electrode. The electrode converts the sound energy into electrical energy, and that electricity paces the chamber.

The device does not work alone, and that is the clever part. It listens for the patient's existing pacemaker and fires in sync with it, so the left ventricle contracts together with the right. Cardiologists call the result cardiac resynchronization therapy, and it is the standard of care for hearts whose chambers have fallen out of step. Until now, patients whose anatomy ruled out a conventional left-sided lead were largely shut out of it.

The implant was performed by Dr. Haisam Ismail, the hospital's associate chief of cardiology and its director of electrophysiology, and the case took a bench of specialists that few hospitals can seat at one table: adult congenital heart cardiologists, pediatric cardiothoracic surgeons, electrophysiologists on both the pediatric and adult sides, and interventional cardiologists, all planning one procedure for one patient whose heart matched no diagram.

Six months on, a treadmill

On August 27, Chaves came back to New Hyde Park for his six-month checkup. By Northwell's account he noticed the difference almost immediately after the procedure, in his breathing and in his heart rate, and the checkup bore it out. A lifelong exerciser, he is back to cardio on the treadmill and easing into lifting weights again now that his chest has fully healed. He described the strange experience of his body adjusting to what a synchronized heart actually feels like, something he had gone without for long enough to forget.

Why this matters beyond one patient

There is a growing population that this procedure speaks to directly. Surgeons have gotten so good at repairing congenital heart defects that most children born with them now live well into adulthood, which means there are more adults walking around with surgically rebuilt hearts than ever before, on Long Island and everywhere else. Many of them will eventually need pacing, and many of them have exactly the kind of nonstandard anatomy that makes conventional leads impossible.

What happened at LIJ in March is proof that the newest generation of leadless devices can reach those patients. And for readers keeping local score: the first time in the world that it was done for an adult congenital heart patient, it was done in New Hyde Park, by a Long Island team, on a patient who crossed two boroughs to get here because this is where it could be done.