Development of a Customizable Pacing Protocol to Induce Persistent Atrial Fibrillation in Swine

IntroductionPersistent atrial fibrillation (AFib) research is dependent on large animal models to understand pathogenesis and test new treatments and therapeutic techniques. While various methods have been established to induce persistent AFib in large animals, including electrical, surgical, pharmacological, and genetic approaches, each has distinct limitations. The most recent being the device industry no longer providing off-target rapid atrial pacing programs for use in animals. This challenge requires the development of a new accessible model of inducing atrial fibrillation in large animals. Methods UsedWe developed a wireless pacing system using a Raspberry Pi Pico W microcontroller (Pico) programmed for variable pacing frequencies. The device is powered by a subcutaneously implanted 9V battery. The Picos built-in Wi-Fi capabilities enable remote connection and real-time adjustment of pacing frequency output. This protocol describes a prospective study in which swine will undergo chronic right atrial pacing for 3-4 weeks to induce persistent AFib. We tested our device in a domestic swine. Vascular access was established through the left jugular vein and an active fixation pacing lead (Medtronic 5076) was implanted under fluoroscopic guidance in the right atrium. Proper lead positioning and pacing function were confirmed through electrocardiographic monitoring of both atrial and ventricular capture. Preliminary ResultsOscilloscope testing demonstrated frequency and voltage output concordant with the programmed frequencies while real-time adjustments were made through the Wi-Fi interface. A cardiac pacing wire was placed in the right ventricle then relocated to the right atrium and successful pacing with capture was verified using an electrocardiogram. ConclusionsThis protocol will provide a system capable of capturing atrial tissue with confirmed wireless power transfer capabilities that has minimal tissue heating and is physiologically safe. Combined with our literature review findings that electrical atrial pacing methods are most effective for inducing persistent AFib, our device provides researchers with the potential for an improved tool for creating large animal models of persistent AFib.