Effect of the Wenchuan Earthquake in China on Hemodynamically Unstable Ventricular Tachyarrhythmia in Hospitalized Patients

Earthquake may increase the risk of hemodynamically unstable ventricular tachyarrhythmias (HUSVTs). However, it was unclear how these arrhythmias were triggered during the period of earthquake. Medical records of patients in the Cardiovascular (CV) Department of West China Hospital, Chengdu, Sichuan, China, during the month after the Wenchuan earthquake and the 2 control periods (1 month before the earthquake and April 12 through July 11, 2007) were reviewed. The HUSVT event rate/10,000 person-days was higher during the month after the earthquake than during the 2 control periods (67 events/10,000 person-days vs 7 and 14 events/10,000 person-days; p = 0.000006 and p = 0.0004, respectively). Most HUSVT events in the earthquake month occurred in afternoon hours, consistent with the temporal trend of strong seismic activities and different from the pattern of diurnal distribution of HUSVT events occurring in the control periods. In the subpopulation consisting of patients admitted to the CV Department before the earthquake who continued to be treated the CV Department during the earthquake period, all HUSVT events occurred during the interval after the earthquake in comparison to no HUSVT event during the interval before the earthquake. Hypokalemia without identifiable cause, acute myocardial ischemia, and heart failure without evidence of ischemia were associated with HUSVT events in the earthquake month. In conclusion, the earthquake and its aftershocks could trigger the occurrence of HUSVT events in hospitalized patients with heart disease.