title: Clinical study of QT interval syndrome.
mesh_terms: D000328:Adult; D000368:Aged; D005117:Cardiac Complexes, Premature / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007008:Hypokalemia / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000503:physiopathology; D013577:Syndrome