1 Sparrow Thoracic and Cardiovascular Institute, Michigan State University, 1200 East Michigan Avenue, Suite 580, Lansing, MI 48912, USA. Electronic address: thakur@msu.edu.
2 Texas Cardiac Arrhythmia Institute, at St. David's Medical Center, 3000 North I-35, Suite 720, Austin, TX 78705, USA. Electronic address: dr.natale@gmail.com.