Introduction: Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion, but the incidence and severity have never been quantified.
Materials and methods: Two hours after elective DC cardioversion in 83 sequential patients, we measured skin temperature, erythema index, and minimum sensory and pain detection thresholds at paddle sites and control sites on the contralateral side. Visual analogue pain score (VAS) was recorded at 2 and 24h post-cardioversion.
Results: Values for areas over paddle sites were higher (P < 0.05) than control site for all variables measured at 2h. Eighty-four percent patients experienced some pain and 23% patients experienced moderate to severe pain as assessed by VAS. Burns were greater at the edge than the centre of sternal sites and greater at sternal than apical sites. There were positive correlations between transthoracic impedance (TTI) and total energy delivered (r(2) = 0.048; P = 0.04); total energy and pain at 2 h (r(2) = 0.38; P < 0.0001) and 24 h (r(2) = 0.23; P < 0.0001); and number of shocks and pain at 2 h (r(2) = 0.36; P < 0.0001) and 24 h (r(2) = 0.19; P < 0.0001).
Conclusion: Elective DC cardioversion causes burns as measured by skin temperature, erythema index and sensory threshold to sharp touch. Pain experienced is related to the total energy and number of shocks delivered. To reduce burns, operators should apply optimal paddle force equally to both paddles, with the paddles applied so as to provide even contact along their edges. Burns may also be minimised by starting with lower energy shocks.