SCIENTIFIC JOURNAL of the Hungarian Society of Cardiology

Rapid and simultaneous increasing of the impedance and the pacing threshold in the shock and CS electrode of a CRT-D device

█ Case report

DOI: 10.26430/CHUNGARICA.2019.49.6.427

Miklós Márton, Sághy László
SZTE ÁOK, II. sz. Belgyógyászati Klinika és Kardiológiai Központ, Szeged


Introduction: During the procedure of cardiac resynchronisation therapy, positioning of the CS electrode can be challenging. According to this observation, implantation of a new CS electrode should only be reserved for the completely fractured or broken leads.
Case: Left ventricular no capture has been detected during regular follow-up in a CRT-D device patient caused by significantly increased pacing threshold and impedance of the shock and left ventricular electrode simultaneously at the same time. The fluoroscopy showed shock lead damage at the level of the clavicle however the LV electrode seemed to be intact. Changing the pacing polarity from LV tip → RV coil to LV tip → Case led to normalization of the impedance and threshold values. During the follow-ups the patient became asymptomatic and the biventricular capture remained constant.
Discussion: Ten years after the failure of the pace/sense part of the shock electrode, the high voltage part has been broken, which resulted in the absence of the left ventricular capture. Changing the configuration of the pacing vector excluding the right ventricular shock coil, the left ventricular capture could be restored. The previous situation showed the fracture of the left ventricular electrode falsely.


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