Cardiac conditions may be disparate, functional, or organic, with varying consequences. The lesions may involve the coronary system (the heart vessels), the endocardium (the internal membrane of the heart), the myocardium (the cardiac muscle), and pericardium (the serous envelope of the cardiac muscle). These lesions, or simple functional disorders, may induce symptoms such as palpitations, cardiac rhythm disorders, cardiac insufficiency, precordial pain, angina pectoris, and fainting fits. Injuries may result in heart valve ruptures or heart wounds.
Approximately 6% of all workers suffer from a heart condition, though the incidence is higher among elderly employees. Living and working conditions (hours of work, speed of work, nutrition, smoking) are factors at least as important in the aetiology of heart disease as physical work itself. Coronary diseases are found more frequently amongst sedentary workers or persons with heavy responsibility, such as manager's or executive's coronary disease.