[Clinical picture of pathological conditions with electrocardiographic features of the LGL syndrome].

Three cases of the LGL syndrome are reported. In the first case the syndrome was associated with hyperthyroidism, in the second case ECG abnormalities suggested focal myocardial ischaemia, in the third case pre-excitation coexisted with combined valvular heart disease. Attention is called to frequent occurrence of the pre-exitation syndrome with certain disease entities.