Cardiac Dysrhythmias Related to Extracorporeal Shock Wave Lithotripsy Using a Piezoelectric Lithotriptor in Patients with Kidney Stones

It is well known that, during extracorporeal shock wave lithotripsy (ESWL) for kidney stones, shock waves delivered by a spark-gap generator frequently elicit cardiac arrhythmias. However, detailed data are lacking concerning the arrhythmogenesis of ESWL using a piezoelectric lithotriptor, even though this type of machine has generally been considered not to induce cardiac arrhythmia. Therefore, the prevalence and nature of cardiac dysrhythmias during piezoelectric ESWL were examined in 34 patients with kidney stones in whom cardiac disease other than dysrhythmia had been excluded. Each patient underwent 24-hour electrocardiographic recording 2 to 3 days before ESWL. On the day of ESWL electrocardiography was recorded continuously beginning from 4 hours before until the end of the procedure. The relationship between ESWL related dysrhythmia and autonomic neural activity was also evaluated by heart rate spectral analysis. Piezoelectric ESWL was found to elicit new or worsened tachyarrhythmia originating from the atria and/or ventricles in 20 patients (59%) and serious bradycardiac arrhythmia in 1. However, piezoelectric ESWL related dysrhythmias were not associated with the dysrhythmias in the daily life of the patients. Heart rate spectral analysis suggested that changes in autonomic neural activity were involved in the mechanism(s) of ESWL related dysrhythmia. Although lethal dysrhythmia has not yet occurred at this institution, it is considered that patients at risk for life threatening cardiac dysrhythmia should be monitored closely even if ESWL for kidney stones is done with a piezoelectric lithotriptor.