Fluid that builds up in other body tissues can cause weight gain and swollen ankles. In the trial, Kanter and his partners operated to insert the pacemaker into a patient's chest. Then they used a long narrow tube, called a catheter, to thread three delicate wires into the blood vessels around the heart. These wires send electrical signals to each side of the heart, prompting the muscles to contract more evenly. Kanter and his associates are now involved in a project to try to perfect those wires.
Patients remain awake during the procedure and can go home shortly afterward.
Doctors gauged the trial results in several ways. They measured how far patients could walk down a hallway in six minutes. They used ultrasound machines to measure how much blood was pumped out of the heart during each beat. All patients were given medications to improve their condition and all were implanted with pacemakers. Doctors switched on only half of the pacemakers in the first six months of the trial.