Open thoracic surgical implantation of cardiac pacemakers in rodents

Abstract

Genetic engineering and implantable bioelectronics have transformed investigations of cardiovascular physiology and disease. However, the two approaches have been difficult to combine in the same species: genetic engineering is applied primarily in rodents, and implantable devices generally require large animal models. We recently developed several miniature cardiac bioelectronic devices suitable for mice and rats to combine the advantages of molecular tools and implantable devices. Successful implementation of these device-enabled studies requires microsurgery approaches that reliably interface bioelectronics to the beating heart with minimal disruption to native physiology. This protocol describes how to perform an open thoracic surgical technique for epicardial implantation of novel wireless cardiac bioelectronic devices in adult rats and has significantly lower mortality than transvenous implantation approaches. In addition, we provide the methodology for a full biocompatibility assessment of the physiological response to the implanted device. The surgical implantation procedure takes about 40 minutes to complete for an experienced operator, and up to 8 surgeries can be completed in one day. Implanted pacemakers provide programmed electrical stimulation for over 1 month. This protocol has broad applications to enable fully conscious in vivo studies of cardiovascular physiology in transgenic rodent disease models.

Wireless, fully implantable cardiac stimulation and recording with on-device computation for closed-loop pacing and defibrillation

“…These results show the potential for long-term studies that require heart rate measurements and stimulation. Adjacent results of chronic wireless battery-free neuromodulatory devices demonstrate operation over months and highlight the feasibility of this approach (52,53). In addition to wirelessly measurement of heart rate, the device is able to pace the heart for chronic therapy or induction of heart rhythm disorders.…”

Graphene Biointerface for Cardiac Arrhythmia Diagnosis and Treatment

“…In vivo rat study. Surgery procedures were performed as previously described 56 . All the surgical procedures were performed under general anesthesia with 3% (v/v) isoflurane inhalation until the animal no longer responded to a toe pinch.…”