Pacemakers, ICDs, and ICMs – oh my! Implantable heart detection devices

Janae Aune, MJLST Staffer

Heart attacks and heart disease kill hundreds of thousands of people in the United States every year. Heart disease affects every person differently based on their genetic and ethnic background, lifestyle, and family history. While some people are aware of their risk of heart problems, over 45 percent of sudden heart cardiac deaths occur outside of the hospital. With a condition as spontaneous as heart attacks, accurate information tracking and reporting is vital to effective treatment and prevention. As in any market, the market for heart monitoring devices is diverse, with new equipment arriving every year. The newest device in a long line of technology is the LINQ monitoring device. LINQ builds on and works with already established devices that have been used by the medical community.

Pacemakers were first used effectively in 1969 when lithium batteries were invented. These devices are surgically implanted under the skin of a patient’s chest and are meant to help control the heartbeat. These devices can be implanted for temporary or permanent use and are usually targeted at patients who experience bradycardia, a slow heart rate. These devices require consistent check-ins by a doctor, usually every three to six months. Pacemakers must also be replaced every 5 to 15 years depending on how long the battery life lasts. These devices revolutionized heart monitoring but involve significant risks with the surgery and potential device malfunctioning.

Implantable cardioverter defibrillators (ICD) are also surgically implanted devices but differ from pacemakers in that they deliver one shock when needed rather than continuous electrode shocks. ICDs are similar to the heart paddles doctors use when trying to stimulate a heart in the hospital – think yelling “charge” and the paddles they use. These devices are used mostly in patients with tachycardia, a heartbeat that is too fast. Implantation of an ICD requires feeding wires through the blood vessels of the heart. A subcutaneous ICD (S-ICD) has been newly developed and gives patients who have structural defects in their heart blood vessels another option of ICDs. Similar to pacemakers, an ICD monitors activity constantly, but will be read only at follow-up appointments with the doctor. ICDs last an average of seven years before the battery will need to be replaced.

The Reveal LINQ system is a newly developed heart monitoring device that records and transmits continuous information to a patient’s doctor at all times. The system requires surgical implantation of a small device known as the insertable cardiac monitor (ICM). The ICM works with another component called the patient monitor, which is a bedside monitor that transmits the continuous information collected by the ICM to a doctor instantly. A patient assistant control is also available which allows the patient to manually mark and record particular heart activities and transmit those in more detail. The LINQ system allows a doctor to track a patient’s heart activity remotely rather than requiring the patient to come in for the history to be examined. Continuous tracking and transmitting allow a patient’s doctor to more accurately examine heart activity and therefore create a more effective treatment approach.

With the development of wearable technology meant to track health information and transmit it to the wearer, the development of devices such as the LINQ system provide new opportunities for technologies to work together to promote better health practices. The Apple Watch series 4 included electrocardiogram monitoring that records heart activity and checks the reading for atrial fibrillation (AFB). This is the same heart activity pacemakers, ICDs, and the LINQ system are meant to monitor. The future capability of heart attack and disease detection and treatment could be massively impacted by the ability to monitor heart behavior in multiple different ways. Between the ability to shock your heart, continuously monitor and transmit information about it, and report to you when your heart rate may be experiencing abnormalities from a watch it seems as if a future of decreased heart problems could be a reality.

With all of these newly developed methods of continuous tracking, it begs the question of how all of that information is protected? Health and heart behavior, which is internal and out of your control, is as personal as information gets. Electronic monitoring and transmission of this data opens it up to cybersecurity targeting. Cybersecurity and data privacy issues with these devices have started to be addressed more fully, however the concerns differ depends on which implantable device a patient has. Vulnerabilities have been identified with ICD devices which would allow an unauthorized individual to access and potentially manipulate the device. Scholars have argued that efforts to decrease vulnerabilities should be focused on protecting the confidentiality, integrity, and availability of information transmitted by implantable devices. The FDA has indicated that the use of a home monitor system could decrease the potential vulnerabilities. As the benefits from heart monitors and heart data continue to grow, we need to be sure that our privacy protections grow with it.