The relative importance of physical activity and emotional stress among the occupational factors leading to heart disease has been difficult to determine from a review of published data. There is also a lack of reliable tests for evaluating the work capacity of cardiac patients. In order to assess the strain of a given job it is necessary to consider not only the average energy requirements but also the peak loads. Experience has shown, however, that workers who return to properly selected productive employment after recognition of their cardiac disability have at least as good a prognosis as those who do not return and that with respect to efficiency, regularity of attendance, freedom from accidents, and adaptability they compare favorably with other groups of workers.
Benton JG. EVALUATION OF THE CARDIAC PATIENT FOR WORK CAPACITY. JAMA. 1960;172(8):790-793. doi:10.1001/jama.1960.03020080020006