924 Your heart beats more than 100,000 times a day

1 00:00:07,754 --> 00:00:11,924 Your heart beats more than 100,000 times a day. 2 00:00:11,924 --> 00:00:16,846 In just a minute, it pumps over five liters of blood throughout your body. 3 00:00:17,513 --> 00:00:22,852 But unlike skin and bones, the heart has a limited ability to repair itself. 4 00:00:22,852 --> 00:00:25,605 So if this organ is severely damaged, 5 00:00:25,605 --> 00:00:29,692 there’s often only one medical solution: replacing it. 6 00:00:30,610 --> 00:00:35,740 Today, nearly 3,500 heart transplants are performed each year 7 00:00:35,740 --> 00:00:40,411 in a complex and intricate procedure with no room for error. 8 00:00:40,995 --> 00:00:44,499 The process begins by testing potential recipients 9 00:00:44,499 --> 00:00:48,377 to ensure they’re healthy enough for this demanding operation. 10 00:00:49,087 --> 00:00:54,634 Doctors are especially concerned with identifying immunocompromising illnesses 11 00:00:54,634 --> 00:00:59,305 or any other conditions that could compromise a patient's chance of survival. 12 00:00:59,931 --> 00:01:04,393 The next step is to match an eligible recipient with a heart donor. 13 00:01:04,852 --> 00:01:09,816 Donors are often comatose patients with no chance of being resuscitated 14 00:01:09,816 --> 00:01:14,320 or victims of a fatal event whose hearts are still healthy. 15 00:01:14,612 --> 00:01:18,950 In both cases, these patients need to be registered as an organ donor 16 00:01:18,950 --> 00:01:21,327 or have their families give consent. 17 00:01:21,702 --> 00:01:23,871 And even when a heart is available, 18 00:01:23,871 --> 00:01:27,708 surgeons can’t just pair any donor with any recipient. 19 00:01:27,959 --> 00:01:31,754 The recipient’s immune system will view a transplanted heart 20 00:01:31,754 --> 00:01:34,924 as a foreign organism that must be attacked. 21 00:01:35,216 --> 00:01:40,054 So doctors need to match recipients with donors that share their blood type 22 00:01:40,054 --> 00:01:42,014 and have similar antigens. 23 00:01:42,473 --> 00:01:45,476 If a match can be made, the surgery can begin. 24 00:01:45,852 --> 00:01:49,063 Once the donor's heart is confirmed to be healthy, 25 00:01:49,063 --> 00:01:51,649 the organ is immersed in an ice slush 26 00:01:51,649 --> 00:01:55,695 and injected with a solution to induce cardiac arrest. 27 00:01:56,070 --> 00:01:58,614 These treatments stop the heart from pumping 28 00:01:58,614 --> 00:02:00,950 to ensure it can be removed cleanly. 29 00:02:01,492 --> 00:02:05,204 Surgeons then place the organ in a mix of cold saline 30 00:02:05,204 --> 00:02:06,831 and preservation solution. 31 00:02:08,039 --> 00:02:10,208 This is when the clock starts. 32 00:02:10,209 --> 00:02:12,420 Disconnected from its blood supply, 33 00:02:12,420 --> 00:02:16,257 the heart’s cells start taking on damage from lack of oxygen. 34 00:02:16,465 --> 00:02:20,887 The organ will only remain viable outside the body for a few hours, 35 00:02:20,887 --> 00:02:24,223 so it needs to reach its recipient as fast as possible. 36 00:02:24,932 --> 00:02:29,145 Once the heart arrives, the recipient is put under general anesthesia. 37 00:02:29,478 --> 00:02:33,024 The surgeon makes an incision down the length of the chest, 38 00:02:33,024 --> 00:02:36,235 cutting through the breastbone to separate the rib cage 39 00:02:36,235 --> 00:02:37,695 and expose the heart. 40 00:02:37,695 --> 00:02:40,990 To keep blood flowing while they remove the damaged organ, 41 00:02:40,990 --> 00:02:44,911 surgeons use a cardiopulmonary bypass machine. 42 00:02:44,911 --> 00:02:46,871 This takes over the heart's job, 43 00:02:46,871 --> 00:02:51,626 generating enough force to push blood through the patient's circulatory system. 44 00:02:52,251 --> 00:02:54,503 After the old heart is removed, 45 00:02:54,503 --> 00:02:58,299 the surgeon begins sewing the donor heart into place. 46 00:02:58,299 --> 00:03:02,929 This is an incredibly precise process, where each blood vessel and artery 47 00:03:02,929 --> 00:03:06,140 must be carefully attached to avoid leaks. 48 00:03:07,099 --> 00:03:09,560 The procedure can last several hours, 49 00:03:09,560 --> 00:03:13,689 potentially longer if there’s scar tissue from previous surgeries. 50 00:03:13,689 --> 00:03:16,859 Once it’s finished, the bypass machine is turned off 51 00:03:16,859 --> 00:03:20,112 and blood is allowed to flow into the aorta. 52 00:03:20,112 --> 00:03:24,784 Doctors carefully monitor the new heart to ensure it’s beating on its own 53 00:03:24,784 --> 00:03:27,036 before sewing the recipient back up. 54 00:03:27,870 --> 00:03:31,874 Even after the procedure is complete, there's still work to be done. 55 00:03:31,874 --> 00:03:34,710 Surgeons are unable to directly connect the heart 56 00:03:34,710 --> 00:03:36,879 to the recipient’s nervous system, 57 00:03:36,879 --> 00:03:41,509 and it can take years for the body to fully innervate the new organ. 58 00:03:42,802 --> 00:03:47,223 During this period, the transplanted organ has a higher resting heart rate 59 00:03:47,223 --> 00:03:51,435 and risk of stroke, making exercise difficult and dangerous. 60 00:03:51,686 --> 00:03:54,814 And since it’s incredibly rare to find a perfect match 61 00:03:54,814 --> 00:03:56,691 between donor and recipient, 62 00:03:56,691 --> 00:04:00,611 the immune system will also have some response to the new heart. 63 00:04:00,611 --> 00:04:04,824 Immunosuppressive drugs can help manage the risk of rejection, 64 00:04:04,824 --> 00:04:09,412 but they also leave patients open to contracting dangerous infections. 65 00:04:09,412 --> 00:04:14,250 It requires constant monitoring and testing to balance these two concerns. 66 00:04:14,834 --> 00:04:19,964 Despite these challenges, about 70% of heart transplant recipients survive 67 00:04:19,964 --> 00:04:22,717 for at least five years after the operation, 68 00:04:22,717 --> 00:04:26,095 and just over 20% live another 20 years. 69 00:04:26,095 --> 00:04:30,099 So when this procedure is successful, it's truly lifesaving. 70 00:04:30,099 --> 00:04:33,853 Unfortunately, people in developing countries are often unable 71 00:04:33,853 --> 00:04:35,604 to access this surgery, 72 00:04:35,604 --> 00:04:41,068 and many viable hearts can’t be donated due to legal and regulatory issues. 73 00:04:41,527 --> 00:04:44,071 Thousands of people remain on waiting lists, 74 00:04:44,071 --> 00:04:47,658 and many are never able to find a suitable donor.