A Left Ventricular Assist Device (LVAD) is a battery-powered mechanical pump designed to support the function of a failing heart. It is a form of mechanical circulatory support surgically implanted in the chest to take over the work of the heart’s main pumping chamber. The device works alongside the weakened native organ to ensure sufficient blood flow throughout the body. By maintaining circulation, the LVAD helps restore the delivery of oxygen and nutrients to vital organs, improving a patient’s strength and overall well-being.
What is an LVAD and Its Purpose
The primary medical context for receiving an LVAD is end-stage heart failure, a condition where the left ventricle has become too weak to function effectively. When standard medical therapies no longer adequately manage symptoms, an LVAD provides immediate and sustained circulatory assistance. The mechanical support aims to alleviate symptoms such as severe fatigue and shortness of breath, which result from insufficient blood flow.
LVADs are used in two distinct clinical scenarios. The first is “Bridge to Transplant” (BTT), where the device supports the patient while they wait for a suitable donor heart to become available for transplant. This application allows the patient to regain strength and health. The second is “Destination Therapy” (DT), which is a long-term treatment option for patients who are not eligible for a heart transplant due to other health factors. In the DT scenario, the LVAD is intended to provide permanent, ongoing circulatory support.
The Physical Components of the Device
The LVAD system consists of internal and external components working together to maintain circulation. The internal pump itself is a small, implanted device, often no larger than the size of a golf ball, which sits near the heart. This pump is connected to the heart and a major artery by two specialized tubes, known as cannulas or grafts.
Internal Components
The inflow cannula draws blood directly from the apex, or tip, of the left ventricle. The outflow cannula receives the pumped blood and directs it into the aorta, the body’s largest artery. Connecting the internal pump to the external system is the driveline, a cable that passes through a small opening in the skin, typically in the abdomen. This driveline transfers power and operational data.
External Components
The external system must be worn by the patient constantly and includes a controller and a power source. The controller is a small, computerized unit that monitors the pump’s speed, flow, and power consumption. It also displays alerts and critical information for the patient and care team. The power source consists of rechargeable lithium-ion batteries or an AC power adapter.
How the Pump Circulates Blood
The core function of the LVAD is to create a parallel path for blood flow, bypassing the failing left ventricle. After the inflow cannula draws blood, it enters the pump housing. Inside the pump, a spinning rotor generates the force required to propel the blood forward. The rotor spins at thousands of revolutions per minute, creating a powerful, constant flow.
Unlike the heart’s natural beating action, which creates a pulsatile flow—a rhythmic surge and drop in pressure—the LVAD produces a continuous, non-pulsatile flow of blood. This constant flow is highly efficient for circulating blood but results in a distinct physiological consequence: most patients with a modern LVAD do not have a conventionally palpable pulse.
Because the blood moves continuously, blood pressure cannot be measured with a standard cuff and stethoscope. Instead, a Doppler device is used to determine a mean arterial pressure (MAP). The continuous flow ensures that peripheral organs receive a constant, adequate supply of oxygenated blood, which reduces heart failure symptoms and improves organ function.
Daily Life and Management with an LVAD
Living with an LVAD requires adherence to a strict daily management routine to ensure the device operates without interruption.
Power Management
Power management is a continuous task, as the system must be powered twenty-four hours a day. Patients typically carry two sets of rechargeable batteries, each providing between 8 to 16 hours of power, depending on the device model and its settings. They must be vigilant about monitoring the controller display and promptly swapping batteries before they fully deplete. Patients must always carry spare, fully charged batteries and a backup controller when away from a main power source.
Driveline Care
Another critical component of daily management is the meticulous care of the driveline exit site, the small opening where the cable passes through the skin. This site is a potential pathway for infection. Patients must perform daily sterile dressing changes according to specific protocols provided by their LVAD team. This typically involves cleaning the site with an antiseptic solution and applying a fresh, sterile dressing to keep the area clean, dry, and protected from trauma or infection.
Lifestyle Adjustments
Patients must make significant lifestyle adjustments to safeguard the device and their health. Activities involving water immersion, such as swimming, bathing in a tub, or using a hot tub, are strictly prohibited. This prevents the external components from getting wet and avoids driveline site infection. Patients must also avoid contact sports or activities that risk a direct blow to the device or the driveline, which could cause internal damage or dislodgement. Carrying the external equipment, often in a specialized vest or harness, becomes a permanent part of the patient’s wardrobe, requiring careful planning for clothing and sleep positioning to prevent tension on the driveline.