A New Sock Electrode for Recording Epicardial Activation from the Human Heart: One Size Fits All

Simultaneous recording of epicardial activation from multiple sites during open heart surgery is essential for studying unstable ventricular arrhythmias. A previously described sock electrode array for this purpose requires custom‐woven nylon sock material and expensive machined button electrodes. The limited compiiance and elasticity of nylon requires that a new sock be individually fitted for each heart. Despite careful fitting, 17–20% of electrodes do not make satisfactory epicardial contact in dogs. Further, electrodes frequently dislodge from the sock and wires break at the button electrode solder joint. Recognizing these limitations, we formed a new sock from Xspan* tubular dressing material and devised electrodes that attach securely to the sock. In six dogs. 90%± 3% of electrodes made satisfactory contact using the same Xspan* sock. significantly (p < .01) more than with the nylon sock despite far less labor. The same size X span* sock with 60 snap electrodes was used to record from 27 human hearts of widely different dimensions. Satisfactory epicardial contact was obtained in 90%± 14% of electrodes in the 18 patients with Wolff‐Parkinson‐White syndrome (WPW) and 75%± 15% of electrodes in the nine patients with coronary artery disease. In no case did an accessory pathway fail to conduct following sock placement. The hemodynamic effect of the Xspan* sock was evaluated in four dogs and was found to be minimal. Both the Xspan* sock and the snap electrodes are easily made from inexpensive, readily available materials. The same Xspan* sock accommodates o wide range of heart sizes, and the electrodes supported by the Xspan* sock record significantly better and with less dislodgement and wire breakage than previous socks.