(CNN) -- Cautious doctors replacing former Vice President Dick Cheney's heart defibrillator in 2007 modified it so it couldn't be hacked by terrorists who might try to kill him, Cheney told CNN's Sanjay Gupta in an interview that aired Sunday night on CBS' "60 Minutes."
Cheney's cardiologist, Dr. Jonathan Reiner, was interviewed along with his famous patient.
"It seemed to me to be a bad idea for the vice president of the United States to have a device that maybe somebody ... might be able to get into, hack into," Reiner said. Turning to Cheney, the cardiologist added: "I worried that someone could kill you."
So, when Cheney needed his implanted defibrillator replaced in 2007, Reiner ordered the manufacturer to disable the wireless feature, thus preventing anyone from sending a signal to the device and shocking the vice president into cardiac arrest.
Gupta's interview with Cheney and Reiner will air Tuesday on CNN's "Anderson Cooper 360."
Cheney is the author of a new book, "Heart: An American Medical Odyssey," co-written by Reiner.
It's described as a medical tale that looks at breakthroughs in cardiac care over the past 40 years. It's also a story about how Cheney's heart disease overlapped with key moments in history.
Case in point: Around 9/11, Cheney said, there was no time to worry about his health. He'd already had several heart attacks by that point.
"I didn't think about my health. I was thinking about the problem we were dealing with," Cheney said.
But life has a persistent way of intruding -- and intrude his heart problems did -- many times over Cheney's long political career.
Just about two months after taking the oath as vice president, Cheney wrote a secret letter of resignation. It was pending for the entire time he served.
Cheney wrote the letter because he saw a gap in the U.S. Constitution. If a vice president is alive but incapacitated, there's nothing in the Constitution that allows for that person's removal. Worried that he might find himself in that position, he penned the letter.
The 72-year-old Cheney suffered his first heart attack in 1978, at age 37, while campaigning for Congress.
It was the first of five heart attacks. He suffered subsequent heart attacks in 1984, 1988, 2000 and 2010. Cheney also underwent an open heart surgery and had a pacemaker implanted.
In 2010, Cheney had a left ventricular assist device, or LVAD, implanted to help his heart pump.
The LVAD, a battery-operated heart pump, is basically used to buy people time -- a last resort, if you will -- while they await a new heart. Cheney waited 20 months for a transplant, undergoing the procedure last year.
After appearing frail and weak, he now seems full of energy and is back to a normal weight. His color has returned and he has no shortness of breath.
Asked by Gupta how he is feeling, Cheney said "fantastic."
"Now I'm to the point where -- I literally, you know, feel like I have a new heart, a lot more energy than I had previously. There aren't any real physical limits on what I do. I fish, I hunt. And -- I don't ski, but that's because of my knees, not my heart. So it's -- it's been a miracle," he sahttp://www.secure-medicine.org/public/publications/icd-study.pdfid.
It's like having a new lease on life.
"You wake up every morning with a smile on your face because you've got a new day you never expected to have. And there's a sense, well, of wonderment. Nothing short of magical," Cheney said.
But back to that potentially hacked defibrillator. SPOILER ALERT: Fans of the Showtime series "Homeland" might find it a familiar scenario. The vice president in that series died after terrorists hacked his heart pacemaker and instructed it to emit a lethal jolt of electricity.
Hacking a defibrillator may sound improbable, but researchers have demonstrated that it is possible. Tadayoshi Kohno, associate professor of computer science and engineering at the University of Washington, and colleagues showed in a 2008 study that they could use their own hardware to communicate with an implantable cardioverter deﬁbrillator.
"We wanted to get ahead of any potential threat," Kohno said. "We knew that medical devices were advancing, and we wanted to get the medical device community focused on understanding the risks, so that future medical devices with more wireless communication capabilities, and so on, were adequately secured."
It wasn't easy, Kohno said, but by studying the signals that hospital equipment would normally send to the device, researchers were able to figure out how to generate their own signals to communicate with it. From a few centimeters away from the device, they could change the defibrillator's settings and turn its therapies on and off, Kohno said. The device was the current model at the time, but now represents an older generation of such devices.
The FDA considers the security of medical devices to be an important issue, Kohno said, and the medical community is working on figuring out how to improve them. In the meantime, though, the risk for most people is incredibly low, Kohno said.
"If I had any medical reason to get an implantable defibrillator or a pacemaker, I would have no hesitation in doing so, even the one that we studied," Kohno said. "These are lifesaving devices and truly the benefits outweigh the risks."
The Federal Trade Commission is holding a workshop on November 19 to discuss privacy and security issues that arise from the increased connectivity of devices with each other and with people -- the so-called "Internet of Things" -- including in the health arena.
CNN's Chelsea J. Carter, Victor Hollingsworth and Elizabeth Landau contributed to this report.