A Left Ventricular Assist Device (LVAD) is a mechanical pump implanted in the chest to assist a failing heart. It is designed for patients with advanced heart failure whose heart muscle is too weak to effectively circulate blood throughout the body. The device is a form of mechanical circulatory support, not a full artificial heart replacement, that assists the heart’s main pumping chamber. This technology restores adequate blood flow, which improves the function of other organs and enhances the patient’s quality of life.
How the Device Supports the Heart
The LVAD is a continuous-flow pump that is surgically connected directly to the heart and the major artery leaving the heart. The pump component is typically placed near the bottom tip of the left ventricle, which is the lower-left chamber responsible for pumping oxygenated blood to the entire body. A tube, called an inflow cannula, draws blood out of this weakened ventricle and directs it into the pump mechanism itself.
Inside the LVAD, a rapidly spinning impeller or rotor continuously propels the blood forward. The blood then exits the pump through a second tube, the outflow graft, which is connected to the aorta. This process effectively bypasses the left ventricle’s weak pumping action, ensuring a steady stream of blood reaches the rest of the body, including the vital organs. The pump’s operation is powered by external batteries or a power module, managed by a portable computer called the controller.
Modern LVADs produce continuous, non-pulsatile blood flow, which differs from the rhythmic surges of a natural pulse. The pump rotates at a fixed speed, often between 8,000 and 10,000 revolutions per minute, generating a constant flow. Consequently, many patients with an LVAD do not have a palpable pulse or a measurable blood pressure using standard cuff devices. This constant blood flow reduces the workload on the failing heart, allowing the organ to rest and potentially recover some function.
Reasons for LVAD Implantation
Implantation of an LVAD is reserved for individuals with advanced heart failure who are no longer responding adequately to medical therapy. The decision to implant the device is linked to a long-term treatment strategy, which generally falls into one of two categories. The first strategy is known as Bridge to Transplant (BTT), where the device sustains the patient until a suitable donor heart becomes available for transplantation.
BTT therapy is used to stabilize patients who are at high risk of death due to heart failure while they wait on the organ transplant list. The LVAD helps the patient regain strength and improve their overall health status, making them better candidates for the demanding heart transplant surgery when the time comes. This temporary support can last for months or even years, depending on the availability of a donor heart.
The second primary purpose is Destination Therapy (DT), where the LVAD is intended to be a permanent, long-term solution. DT is typically offered to patients with end-stage heart failure who are not eligible for a heart transplant due to age, co-existing health conditions, or other medical factors. For these individuals, the device serves as a method to prolong life and improve their functional capacity and quality of life.
Daily Life and Managing the LVAD System
Living with an LVAD requires constant management of the external components that power and control the implanted pump. The driveline is a cable that exits the body, usually through the abdomen, and connects the internal pump to the external system. Careful and consistent sterile care of the driveline exit site is necessary to prevent infection, as this is an open pathway into the body.
The external system includes a controller, which functions as the device’s computer, monitoring the pump’s speed and function and alerting the patient to any issues. This controller is connected to the power source, which is typically a set of rechargeable battery packs. Patients must carry these batteries, often in a vest or holster, and continuously monitor their charge levels to ensure the pump never loses power.
Battery packs usually provide power for several hours, requiring the patient to have charged spares ready for immediate exchange. While the device allows for a return to many normal activities, certain lifestyle adjustments are necessary to safeguard the system. Activities involving full water immersion, such as swimming or bathing in a tub, must be avoided to protect the external components from water damage. Patients must also avoid activities that could cause undue strain or tension on the driveline connection, ensuring continuous, reliable function.