Lin WC et al, 2010: Impact of shock wave lithotripsy on heart rate variability in patients with urolithiasis
Lin WC, Ho CY, Chen YH, Chen IC, Chen HY, Tsai FJ, Shen JL, Man SS, Huang PH, Chen YL, Man KM, Chen WC
Department of Urology, China Medical University Hospital, Taichung, Taiwan
The physiological response of the cardiac autonomic nervous system during shock wave lithotripsy (SWL) remains unclear. Heart rate variability (HRV) is an index of cardiac autonomic balance. This study aimed to analyze HRV during SWL in patients with urolithiasis. Electrocardiograms of patients who underwent SWL were obtained. Recordings were obtained before and after SWL. For each time point, the recordings were obtained continuously for 6 min, after which R wave-to-R wave (RR) intervals were extracted. The time digital sequence derived from RR intervals was the HRV signal. Time-domain analysis revealed that the mean of RR intervals (MRR) and standard deviation of normal beat-to-normal beat (NN) intervals (SDNN), but not the square root of the mean squared difference of successive NNs (RMSSD) or triangular interpolation of NN intervals (TINN), significantly increased during SWL. The increase in SDNN persisted after SWL but MRR returned to the initial level. Frequency-domain analysis revealed that very low frequency (VLF), low frequency (LF), and LF/high frequency (HF) ratio significantly increased after SWL, while there was no statistically significant difference in HF. Thus, the patients had significantly high MRR and SDNN during SWL and significantly high SDNN, VLF, LF, and LF/HF ratio after SWL. SWL could alter the functioning of the cardiac autonomic nervous system, resulting in reduction in sympathetic activity and increase in parasympathetic activity. Further studies with larger samples are required to confirm these findings and understand the underlying mechanisms.
Urol Res. 2011 Apr;39(2):135-40. doi: 10.1007/s00240-010-0312-3. Epub 2010 Oct 6
PMID: 20924572 [PubMed - in process]
In the early days of HM3 SWL was ECG triggered because of arrhythmias. But nowadays this is of minor importance. With new generation lithotripters (Zanetti et al . Cardiac Dysrhythmias Induced by Extracorporeal Shockwave Lithotripsy J. Endourol 13, (6), 1999; 409 – 412) SWL without ECG triggering did not lead to dysrhythmia of clinical significance.
Küfer et al. (Reference 20) using the same lithotripter type observed clinically relevant bradycardia in only one of > 400 applications (Küfer R, et al. New-generation lithotripters for treatment of patients with implantable cardioverter defibrillator: experimental approach and review of literature. J Endourol 15, 2001 :479–484).
This 12 authors publication has to be read with caution. There is no control group with sham treatment that would help to rule out that the described effects of SWL on ECG recordings of patients are really an effect of shock waves or not of pethidine or circumstances. Not “Long-term studies with larger samples are necessary to evaluate whether these findings have clinical implications regarding mortality and morbidity“ but trials on healthy volunteers could solve the questions.
Something is wrong with the references. 16 and 18 which should refer to cardiac side effects of SWL deal with hematoma after SWL due to garlic consumption and ureteroscopy respectively.