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

Abstract

Shock waves delivered by a spark-gap generator during extracorporeal shock wave lithotripsy (ESWL) for kidney stones frequently cause cardiac arrhythmias. However, detailed data about the arrythmogenicity of this therapy using a piezoelectric lithotriptor are not available even though this type of machine is generally not considered to induce cardiac arrhythmias. The prevalence and nature of cardiac dysrhythmias during piezoelectric ESWL were assessed in 34 patients with kidney stones in whom cardiac disease other than dysrhythmias had been excluded. Each patient underwent 24-hour ambulatory electrocardiography (ECG) recording 2 to 3 days before ESWL. On the day of ESWL, ECG was performed continuously from 4 hours before and throughout the procedure. The relationship between ESWL-related dysrhythmias 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 or ventricles or both in 20 patients (59%), atrial premature contractions in 4, ventricular premature contractions in 7, both types in 7, atrial and ventricular premature contractions plus extreme sinus bradycardia in 1, and neurally mediated sinus bradycardia and hypotension in 1. However, piezoelectric ESWL-related dysrhythmias were not related to the dysrhythmias seen in the usual life. Heart rate spectral analysis suggested that changes in autonomic neural activity were involved in the mechanism(s) of ESWL-related dysrhythmia. Although lethal dysrhythmias have not yet been encountered at our institution, patients at risk of sustained life-threatening cardiac dysrhythmias should be monitored closely even if ESWL for kidney stones is undertaken using a piezoelectric lithotriptor.