100 QUESTIONS IN CARDIOLOGY

58 What are LVADs and BIVADS, and who should

have them?

Brendan Madden

Over the past 30 years, there have been efforts to produce a

mechanical device that can replace the human heart. Extracorporeal

univentricular and biventricular implantable devices are available,

which can support the failing heart following conventional cardiac

surgery, or while awaiting transplantation. The number of

potential recipients already far exceeds the number of available

donor organs, however, and temporary holding measures that

increase the size of the recipient pool only increase the number of

patients that die awaiting transplantation.

Devices available include:

• Left Ventricular Assist Device (LVAD)


• Right Ventricular Assist Device (RVAD)


• Biventricular Assist Devices (BIVADS)

At present they are used for selected patients as a bridge to

transplantation or occasionally to support patients with

cardiomyopathy or myocarditis or those who cannot be

successfully weaned from cardiopulmonary bypass following

conventional cardiac surgical procedures. An LVAD or RVAD is

used depending on which ventricle is failing. These devices

consist of extracorporeal pumps, which remove blood from the

atria bypassing the ventricles, and deliver it to the aorta and

pulmonary circulation. The output of each assist device can be

gradually reduced if the patient’s heart recovers. Indeed, in

some patients, successful weaning from artificial circulatory

support has been described. Others have been successfully

bridged to cardiac transplantation using an assist device. These

devices are, however, expensive. They are associated with

numerous complications, which include infection with

Aspergillus species, haematological complications and multiple

organ failure. It is not yet known whether the devices are

sufficiently free of long term complications to be an effective

treatment modality.