Closs,+Michael

podcast: Obesity in America media type="custom" key="23301904"

podcast: ipad media type="custom" key="23304980"

Powerpoint:

=No Pulse: How Doctors Reinvented the Human Heart;=

The HeartMate II LVAS does not replace the natural function of the heart. it works with the patient’s own heart to pump blood. In a healthy heart, the left ventricle pumps blood through the body. In a heart weakened by heart failure, like a heart attack, the left ventricle is not strong enough to pump the blood. The HeartMate II LVAS helps the heart by taking over the function of the weak left ventricle and providing additional blood flow. The HeartMate II pump is implanted below the heart and is in valve of blood attached to the left ventricle and its outlet valve connected to the aorta. Blood flows from the heart into the pump. A small electric motor in the pump drives a rotor, like a propeller, inside the pump. That rotor pushes the blood into the aorta and out to the body. A flexible tube passes through the patient’s skin and connects the Heartmate ll pump to a small controller. This is worn outside the body. The controller is powered either by batteries or connected to a power supply to household electrical power outlet. The artificial heart is approximately 3 inches in length and weighing approximately 10 ounces. The HeartMate II can pump up to 10 liters of blood per minute. This will cover the full output of a healthy heart. The HeartMate II is designed to provide long term support for patients who have advanced stage heart failure. In total, more than 10,000 patients have been implanted with HeartMate II through trials and commercial use worldwide.

In November 2003, Frazier installed the newly approved HeartMate II to assist the failing heart of a young man from Central America. The man never cam back for check ups or follow up, he disappeared. When he finally showed up eight months later, Frazier held a stethoscope to his chest and was stunned to hear no heartbeat at all. The young man’s heart continued to work weakly, but it had pretty much shut down. Although the HeartMate II had been designed to assist the heart, not replace it, in this case it seemed to be doing all the work: not just helping the left ventricle push oxygenated blood to the body, but pushing the blood hard enough to flow through the body, then back through the useless heart to the lungs, through the useless heart again, and into the pump to complete the loop and begin the process all over again. The reason the young man had never come back for follow-up, he told Frazier, was that he’d felt perfectly fine.