Dr. Louis Teichholz MD is a leading cardiologist, researcher, and chief of cardiology at Hackensack University Medical Center in New Jersey. In 1977, he was a Head of Cardiology at Mount Sinai Hospital in New York, when, on the holiday of Shmini Atezers in 1977, the Rebbe suffered a massive heart attack. He was asked to join a team of doctors treating the Rebbe at 770. It was there that he merited to converse with the Rebbe about many fascinating topics.