Objectives: To investigate whether shock wave lithotripsy (SWL) causes cardiac muscle injury that alters the levels of troponin I plasma, a cardio-specific enzyme shown to be useful in diagnosing cardiac muscle injury because of its high specificity.
Methods: Patients treated by SWL for renal stones participated in the study. They had undergone a baseline 12-lead electrocardiogram (ECG) a few days earlier. One day after SWL, they were queried about any chest discomfort, blood was drawn for evaluation of troponin I and creatine kinase with isoenzymes (CK-MB), and an ECG was carried out.
Results: Thirty-two patients (21 men and 11 women, mean age +/- SD 51.0 +/- 10.6 years) comprised the study group. Fourteen SWL treatments were on the right side and 18 on the left. The mean number of shock waves was 2859 +/- 202. The mean time to evaluation after SWL was 22.3 +/- 1.3 hours. None of the patients reported chest discomfort. The mean value was 6.6 +/- 9.2 mU/mL for CK-MB and 0.02 l +/- 0.04 ng/mL for troponin I. No ECG changes suggestive of myocardial injury were evident. None of the 5 patients who experienced ventricular extrasystoles during SWL had any evidence of cardiac muscle injury.
Conclusions: We evaluated the symptoms, perioperative ECG changes, and cardiac troponin I and CK-MB plasma levels in patients who underwent SWL for renal stones and did not identify any myocardial damage. Troponin I plasma levels were not elevated after this procedure and, therefore, remain suitable for evaluation of patients complaining of chest pain after SWL.