“…the Technomed Sonolith, Direxl, and in the Siemens Lithostar machine using an electromagnetic device to create the shock wave. In the Wolf and EDAP machines, where the shock waves are created using piezoelectric energy, the heart rhythm is not thought to be affected and nc triggering from the ECG is considered necessary (Zwergel et al, 1987;Merberg et al, 1988;Ziegler et al, 1988;Kim et al, 1989;Miller et al, 1989;Tung et al, 1990).…”