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