What Is an Artificial Heart?

An artificial heart is a mechanical or electromechanical device implanted in the chest to replace or assist the pumping function of the natural heart. It maintains circulatory flow when the biological heart has failed irreversibly or requires temporary removal during surgery. The field sits at the convergence of cardiovascular medicine, mechanical engineering, and biomedical materials science, and its development has tracked closely with advances in miniaturized motors, blood-compatible surfaces, and implantable power systems.

The broad category of cardiac mechanical support devices includes total artificial hearts (TAHs), which replace both ventricles entirely, and ventricular assist devices (VADs), which supplement a failing native heart rather than replacing it outright. The TAH is used when both ventricles are so damaged that assist alone cannot sustain the patient; VADs are more commonly deployed as bridges to transplantation or, in some cases, as permanent destination therapy.

Total Artificial Hearts

A total artificial heart takes over the entire pumping workload by physically replacing the left and right ventricles. The CardioWest TAH, approved by the U.S. Food and Drug Administration as a bridge to transplantation, uses pneumatically actuated diaphragm pumps to generate pulsatile flow, closely mimicking the rhythmic output of the native organ. A newer design approach uses a single magnetically levitated rotor to pump blood simultaneously to both the pulmonary and systemic circulations, eliminating the friction and mechanical wear that historically limited device longevity. As IEEE Spectrum has reported, one electromagnetically actuated artificial heart achieved over 100 consecutive days of operation in a clinical setting, a milestone that illustrates how far reliability has advanced since the early Jarvik-7 trials of the 1980s.

Ventricular Assist Devices

Ventricular assist devices are implanted alongside the failing heart and take over much of the left ventricle's workload. The left ventricular assist device (LVAD) has evolved from bulky, pulsatile displacement pumps to compact, continuous-flow designs using fully magnetically levitated rotors. Magnetic levitation eliminates contact between moving parts and blood, reducing thrombosis and mechanical failure. As described in IEEE Spectrum's coverage of multiphysics simulation for LVADs, engineers now use coupled fluid-structure models to optimize rotor geometry, bearing forces, and washout flow patterns before committing to physical prototypes, compressing development cycles substantially.

Intraaortic balloon pumps and percutaneous ventricular assist catheters represent shorter-term mechanical support options used in intensive-care settings for acute decompensation. These devices are inserted without open-chest surgery and provide rapid stabilization while definitive therapy is arranged.

Power, Control, and Durability

Sustained operation of an implanted artificial heart requires a reliable power source and a control system capable of adapting output to the patient's changing metabolic demands. Current devices receive power transcutaneously through inductive coils embedded in the skin, avoiding the infection risk of percutaneous leads while accepting some energy transfer inefficiency. Onboard controllers monitor flow and pressure signals to adjust pump speed in response to exercise, posture change, and cardiac rhythm.

The IEEE Xplore paper on the current status of artificial heart and cardiovascular assist devices reviews the engineering and physiological constraints that have defined device design from early prototypes to the magnetically levitated systems used today.

Applications

Artificial heart technology has applications in a range of settings, including:

• Bridge-to-transplantation therapy for patients awaiting donor heart availability
• Destination therapy for patients who are not transplant candidates
• Postcardiotomy support following open-heart surgery
• Acute cardiogenic shock management in intensive care units
• Research platforms for studying circulatory physiology and device hemodynamics