title: Evaluation of the state of the circulatory system in the officers of the Polish ocean lines. Part IV. Subperiods of the left heart-ventricle systole.
mesh_terms: D000328:Adult; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction; D009326:Naval Medicine; D009787:Occupational Medicine; D011044:Poland; D013599:Systole; D016276:Ventricular Function