Cardiovascular effects of an earthquake: direct evidence by ambulatory blood pressure monitoring.

The increased cardiovascular mortality during an earthquake has been related, among other factors, to a sympathetically mediated increase in heart rate 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 during an earthquake. In a patient undergoing 24-hour ambulatory blood pressure monitoring (Spacelabs 90207), we had the opportunity to directly record the acute blood pressure and heart rate changes induced by an earthquake (magnitude 4.7 according to the Richter scale) that struck central Italy in March 1998. Systolic blood pressure rose to 150 mm Hg, diastolic blood pressure rose to 122 mm Hg, and heart rate rose to 150 bpm at the time of the strongest tremor. Prequake blood pressure levels were restored only 1 hour later, but blood pressure remained characterized by a pronounced variability throughout the following 6 hours. Thus, a sympathetically mediated combined increase in blood pressure and heart rate may represent an important pathophysiological mechanism responsible for the increased frequency of cardiovascular events during an earthquake. The associated increase in blood pressure variability might further contribute to the increase in cardiovascular risk typical of this condition. Our case report further supports the usefulness of ambulatory blood pressure monitoring to assess the blood pressure and heart rate effects of sudden daily life events, the actual cardiovascular impact of which can hardly be quantified through traditional measurements.