Ambulatory electrocardiogra phy incarworkers

A previous studyina carassembly plant showedthatproduction-line workers hada lower incidence rateofheart attacks thanexecutive staff. Inthepresentstudy some major coronary riskfactors and24-hour ambulatory electrocardiograms were investigated intwo age-matched samples of30middle-aged men drawnfromthese occupations. Menwith a knownhistory ofheart disease wereexcluded. Comparedwithproduction-line workers, executive staff on average hada higher diastolic blood pressure(P< 0-05) andfewer tookheavyexercise during their leisure time (P< 005). Ventricular premature beats (VPB)occurred insimilar numbers ofmen inbothgroups (35%)andthefrequency ofVPB was alsosimilar foreachoftheperiods ofwork,leisure and sleep. Apartfromisolated ectopic beats, disturbances ofrhythm were uncommon, andneither VPBnorother arrhythmias appeared tobeinduced byoccupational factors. Inastudy ofmenemployed inanOxford carfactory (Baxter etal., 1976), production-line workers were foundtohavea significantly lowerage-adjusted incidence ofheart attacks comparedwithother workers inthefactory andwiththerates derived by Kinlen (1973) formenintheOxfordcommunity. Staff workers withexecutive responsibilities hadthe highest incidence, almost three times higher thanthe community. Thestudy described here compared some majorcoronary riskfactors andthefrequency of ventricular premature beats(VPB)and other arrhythmias intheambulatory electrocardiogram (ECG)ofsamples ofmiddle-aged mendrawnfrom these twooccupations. Employees withahistory of heart disease wereexcluded, asoneoftheaimsof this study wastoexplore thevalue ofambulatory ECG monitoring infit workers. Subjects andmethods