HRS: Heart failure patients benefit from leadless pacing
Leadless pacing in heart failure patients with ultrasound-mediated stimulation energy is feasible, according to a study published in the June issue of HeartRhythm.

Kathy L. Lee, MBBS, and colleagues from the Queen Mary Hospital in Hong Kong, and colleagues sought to apply ultrasound-mediated leadless pacing technology in heart failure patients and to evaluate the effects of respiration and body posture on the acoustic window.

Ten patients underwent diagnostic testing with coronary angiography and left ventriculography. Patients who were 18 years or older, had an ejection fraction of less than or equal to 35 percent and were in N.Y. Heart Association functional class III or IV were eligible to participate. An electrophysiology catheter incorporating a receiver-electrode to deliver ultrasound-mediated pacing was positioned in the left ventricle to determine the thresholds, the authors wrote. The acoustic windows on the chest wall were determined based on the effects of respiration while the patients were lying on their back, tilted 30 degrees leftward, rightward and upward.

"It was our objective to conduct a study that would demonstrate the feasibility of leadless pacing in patients with advanced heart failure," said Lee. "We believe our study will generate further interest in leadless pacing and encourage future technological advancements in this area."

The results of the study found ultrasound-mediated pacing to be successful in all 10 patients who participated, showing a 100 percent success rate, the investigators said. The acoustic window size was adequate for ultrasound transmission from the chest surface to a receiver electrode in the left ventricle, regardless of patient position or respiratory phase. Thus, the ability to perform leadless left ventricular pacing in heart failure patients using the technology proves to be feasible. 

The authors wrote that "leadless pacing is a potential breakthrough in pacing technology that provides the advantage to avoid all complications related to the insertion and existence of a pacing lead, such as infections and lead dysfunction, which can lead to severe cardiac problems or death."