Systolic time intervals and heart sounds in left bundle branch block.
Systolic time intervals and heart sounds were studied in twenty patients with left bundle branch block. A definite cause for the organic heart disease was not ascertained. Abnormal duration of the electromechanical systole (Q-A2), due to a prolongation both of the preejection period (PEP) and of the Q-M1 intervals, was found to exist in all. Prolongation of Q-M1 was due to lengthening either of the electromechanical interval (EMI) or of the pre-isovolumetric contraction time (PICT). Isovolumetric contraction time (ICT) was prolonged in thirteen patients only. There was a good correlation between LVET/ICT ratio and the duration of ICT intervals. Six patients showed a first heart sound of normal intensity and duration. There was no correlation between the duration of the systolic time intervals and the characteristics of the first and second heart sounds.
D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000503:physiopathology*; D004562:Electrocardiography; D006326:Heart Auscultation; D006347:Heart Sounds; D006801:Humans; D007702:Kinetocardiography; D008875:Middle Aged; D009200:Myocardial Contraction; D010701:Phonocardiography; D013318:Stroke Volume; D013599:Systole