Low-energy optogenetic technique offers safer arrhythmia treatments

Sudden cardiac arrest is one of the leading causes of death worldwide and is often preceded by arrhythmias like ventricular tachycardia and ventricular fibrillation. In patients who chronically suffer from these disorders, treatments typically consist of implantable defibrillators, which deliver electrical shocks to return the heart to a normal rhythm. Though lifesaving, these repeated electrical shocks can cause pain, tissue damage, and other unpleasant side effects.

One possible alternative can be found through optogenetics, which employs light pulses to control cellular function in genetically modified cardiac tissue. Hussaini et al. explored how low-energy optically resonant feedback pacing can end ventricular arrhythmias before they develop into cardiac arrest.

Unlike conventional stimulation that involves a single high-energy pulse to reset all cardiomyocytes simultaneously, resonant feedback pacing applies multiple low-energy pulses to perturb the system and eliminate the spiral and scroll waves responsible for arrhythmia patterns.

“We sent a sequence of global optical pulses at times synchronized with the measured arrhythmic activity, and we observed a significant termination efficiency, which is desired to develop a low-energy defibrillation technique,” said author Sayedeh Hussaini.

The team demonstrated, both numerically and experimentally, that resonant feedback pacing is significantly more efficient than conventional single-pulse stimulation, terminating arrhythmias using over 40 times less pulse energy.

“We can achieve efficient termination of arrhythmias at intensities which are at or even below the excitation threshold,” said author Stefan Luther. “Below the excitation threshold, we are just modulating the excitability of the system. We have shown that, even by modulating excitability, we can remove the waves that drive the arrhythmia.”

Source: “Efficient termination of cardiac arrhythmias using optogenetic resonant feedback pacing,” by Sayedeh Hussaini, Aidai Mamyraiym-Kyzy, Johannes Schröder-Schetelig, Sarah L. Lädke, Vishalini Venkatesan, Laura Diaz, Raul Q. Uribe, Claudia Richter, Vadim N. Biktashev, Rupamanjari Majumder, Valentin Krinski, and Stefan Luther, Chaos (2024). The article can be accessed at https://doi.org/10.1063/5.0191519 .