Dick Cheney’s heart problems were never a national secret. I was Cheney’s cardiologist for 27 years, including his two terms as vice president. During his time at the White House, he needed stents, a defibrillator and medical treatment for an arrhythmia and a thrombus in his leg. After he was implanted with the defibrillator in his chest in 2001, he used to frequently show visitors to his office in the West Wing a sample device provided by the m…