The Mariana Islands are shown, with the territory of Guam to the extreme south, and the Commonwealth of the Northern Mariana Islands (14 islands) to the north. Active volcanoes are shown with triangles. The Mariana Islands (also the Marianas) are a crescent-shaped archipelago comprising the summits of fifteen mostly dormant volcanic mountains in the western North Pacific Ocean, between the 12th and 21st parallels north and along the 145th meridian east.
People with congestive heart failure are often given pacemakers to help their hearts pump more efficiently. But doctors have been puzzled by about 40 percent of people given those devices who don't get any better. They often wind up in the hospital, or they die. Now researchers say they've got the problem figured out.
Who Needs an Implantable Device? An implantable device may be appropriate for your heart condition if: Your heart beats too slowly and is often irregular; Your heart beats normally but is sometimes too fast or too slow; Types of Implantable Devices. Your UNC Medical Center doctor may suggest one of these three types of implantable devices to treat your heart condition: Pacemaker â Helps maintain heart rate when itâs too slow by delivering small electrical impulses to the heart; single-chamber pacemakers connect to one chamber in the right side of the heart, while dual-chamber pacemakers connect both the upper and lower right chambers