Tetanizing prepulse: A novel strategy to mitigate implantable
cardioverter-defibrillator shock-related pain
#MMPMID26767423
Hunter DW
; Tandri H
; Halperin H
; Tung L
; Berger RD
Heart Rhythm
2016[May]; 13
(5
): 1142-1148
PMID26767423
show ga
BACKGROUND: Skeletal muscle activation has been implicated as the source of pain
associated with implantable cardioverter-defibrillator shocks. We hypothesized
that the skeletal muscle response to defibrillatory shocks could be attenuated
with a tetanizing prepulse immediately before biphasic shock delivery. OBJECTIVE:
The purpose of this study was to test the ability of tetanizing prepulses to
reduce the skeletal muscle activation associated with defibrillation. METHODS:
Seven adult pigs were studied. A left ventricular coil and subcutaneous dummy can
in the right thorax were used to deliver either pure biphasic waveforms or test
waveforms consisting of a tetanizing pulse of high-frequency alternating current
(HFAC) ramped to an amplitude of 5-100 V over 0.25-1 second, immediately followed
by a biphasic shock of approximately 9 J (ramped HFAC and biphasic [rHFAC+B]). We
used limb acceleration and rate of force development as surrogate measures of
pain. Test and control waveforms were delivered in sinus rhythm and induced
ventricular fibrillation to test defibrillation efficacy. RESULTS: Defibrillation
threshold energy was indistinguishable between rHFAC+B and pure biphasic shocks.
Peak acceleration and rate of force development were reduced by 72% ± 7% and 71%
± 22%, respectively, with a 25-V, 1-second rHFAC+B waveform compared with pure
biphasic shocks. Notably, rHFAC+B with a 9-J biphasic shock produced
significantly less skeletal muscle activation than a 0.1-J pure biphasic shock.
CONCLUSION: A putative source of implantable cardioverter-defibrillator
shock-related pain can be mitigated using a tetanizing prepulse followed by
biphasic shock. Human studies will be required to assess true pain reduction with
this approach.
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