Aim: Our investigation examined the influence of regular physical activity and sudden extrenious situations on the incidence of sudden cardiac death (scd) in two different Berlin districts with a total population of 219,251 in the examined age-groups.
Patients and method: All cases of scd which occurred outside of the hospital and were documented as been induced from ventricular fibrillation were examined over a time period of 18 months. For each case the amount of and the intensity of their regular physical activity was determined. In addition the stress of the sudden extrenious situations was survived. The study population was divided into various groups depending upon their level of regular physical activity. For each group the incidence of sudden cardiac death was determined. Then the relative risk for scd during strenuous activity compared to inactivity was determined for each group. The influence of preexisting disease was calculated.
Results: 77 patients with scd induced from ventricular fibrillation were included in our study. In the sedentary group we found an incidence of 4.69 scd per 10(5) person-years, in the group with a low level of regular physical activity we found an incidence of 4.25, in the group with a middle level of regular physical activity an incidence of 2.63 and in the most active group 0.92 scd per 10(5) person-years. We found the relative risk for scd during highly strenuous activity compared with inactivity to be 150 in the sedentary group as opposed to 4.0 in the most active group. The preexisting illness status of the case-groups had no influence on the outcome.
Conclusions: The results show that the risk of scd for all persons regardless of their levels of regular physical activity and their preillness status is higher during strenuous activity than during inactivity. The increase of the risk for scd during activity is the highest for persons with sedentary lifestyles, whereas the risk increase for persons with active lifestyles is minimal. The protective effect of regular physical activity for scd by far exceeds the risk increase of the actual strenuous situation.