Cardiovascular effects of an earthquake - Direct evidence by ambulatory blood pressure monitoring

The increased cardiovascular mortality during an earthquake has been relate d, among other factors, to a sympathetically mediated increase in heart rat e and blood pressure. However, this is supported only by indirect evidence collected after an earthquake, whereas for obvious technical difficulties, no data are available on the acute blood pressure and heart rate effects du ring an earthquake. In a patient undergoing 24-hour ambulatory blood pressu re monitoring (Spacelabs 90207), we had the opportunity to directly record the acute blood pressure and heart rate changes induced by an earthquake (m agnitude 4.7 according to the Richter scale) that struck central Italy in M arch 1998. Systolic blood pressure rose to 150 mm Hg, diastolic blood press ure rose to 122 min Hg, and heart rate rose to 150 bpm at the time of the s trongest tremor. Prequake blood pressure levels were restored only 1 hour l ater, but blood pressure remained characterized by a pronounced variability throughout the following 6 hours. Thus, a sympathetically mediated combine d increase in blood pressure and heart rate may represent an important path ophysiological mechanism responsible for the increased frequency of cardiov ascular events during an earthquake. The associated increase in blood press ure variability might further contribute to the increase in cardiovascular risk typical of this condition. Our case report further supports the useful ness of ambulatory blood pressure monitoring to assess the blood pressure a nd heart rate effects of sudden daily life events, the actual cardiovascula r impact of which can hardly be quantified through traditional measurements .