Defibrillation Efficacy and Pain Perception of Two Biphasic Waveforms for Internal Cardioversion of Atrial Fibrillation

Abstract

Despite a 66% lower peak voltage and a 40% lower energy, the 40% tilt, 500-microF capacitor biphasic waveform did not change the pain perceived by the patient during delivery of internal cardioversion shocks. Pain perception for internal cardioversion probably is not influenced by peak voltage alone and increases with the number of applied shocks.

Psychophysiologic and Affective Parameters Associated With Pain Intensity of Cardiac Cardioverter Defibrillator Shock Discharges

“…This finding is in line with several other studies showing that a second delivered intracardiac shock is generally perceived as more uncomfortable than the first one, even when the second shock was delivered with less energy (13)(14)(15). Repetitive delivery of shocks also enhances the amplitude of startle responses in nonhuman (29,30) and human subjects (31) and may lead to sensitization in particular in ICD patients (32).…”

“…Nevertheless, the strength of the perceived pain among the ICD patients assessed in the present study varied considerably over the entire value spectrum of the 100-point VAS scale. Consistent with data from other studies dealing with pain from extreme short duration, these findings prove that a nociceptive stimulation resulting from the heart and the perceived pain intensity are only poorly correlated (11)(12)(13)(14)(15). What makes subjects perceive the same amount of nociceptive stimulation as unbearable on the one hand or almost not perceived on the other hand?…”

“…In the first place, characteristics of shock discharge, mainly the cumulative effect of repetitive shock delivery, may account for the degree of perceived pain intensity (13)(14)(15). However, reasons for this phenomenon have not been sufficiently elucidated so far.…”

Innovations in Clinical Cardiac Electrophysiology: Challenges and Upcoming Solutions in 2018 and Beyond

“…While the threshold for pain with ICD shocks is suggested to be o 0.1 J, 27 other commonly cited articles provide unconvincing evidence that shocks o 0.1 J are perceived as painless. [28][29][30][31] Current approaches to reducing DFTs, while promising, have not consistently reduced DFTs lower than this 0.1 J threshold.…”

“Beauty is a light in the heart”: The transformative potential of optogenetics for clinical applications in cardiovascular medicine1

“…In contrast, researchers working in the cardiovascular field have been relatively slow in embracing the idea that optogenetics might be a valuable tool for new clinical applications (6,7). Light-based stimulation could overcome several limitations of conventional electrotherapy for arrhythmia treatment; for example, since optogenetics enables selective stimulation of tissue targeted for opsin expression, optical defibrillation could circumvent the excitation of skeletal muscles surrounding the heart during high-energy shocks, thus alleviating the pain associated with it (8). Moreover, the amplitude and duration of electrical stimuli are limited by electrochemical reactions at the pacing site (9); since optogenetics-based control of membrane behavior does not involve Faradaic charge transfer, novel and potentially useful stimulation regimes are possible, such as continuous low-amplitude depolarization.…”