By Michael Dabaie Medtronic PLC said the first procedures were performed in the investigational device exemption pivotal trial of the PulseSelect Pulsed Field Ablation System. PulseSelect uses pulsed electric fields to treat atrial fibrillation. The first procedure in the PULSED AF pivotal trial was performed this week at Southcoast Health in Fall River, Mass., with the second procedure also at Southcoast Health. The PULSED AF Trial aims to establish the safety and efficacy of the PulseSelect System. Atrial fibrillation is one of the most common and undertreated heart rhythm disorders, affecting more than 37 million people worldwide. The disease involves an irregular quivering or rapid heart rhythm in the upper chambers of the heart.