Clinical electrocardiography / by Sir Thomas Lewis.

  • Thomas Lewis
Date:
1913
Catalogue details

Licence: Public Domain Mark

Credit: Clinical electrocardiography / by Sir Thomas Lewis. Source: Wellcome Collection.

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    Fig. 7. An electrocardiogram from a normal subject, showing the auricular summit (P) and the ventricular deflections (Q, R, S and T). In this and the remaining figures, the lead is marked in the upper left hand corner ; the time, at the bottom, is in one-thirtieth sec., the ordinates each represent one-tenth millivolt. Fig. 8. Simultaneous electrocardiograms and heart sound curve from a normal subject. The figure shows the time-relations of the electro¬ cardiogram to the beginnings of the 1st and 2nd heart sounds. All points on a vertical line are simultaneous. There would be little gain at present in discussing the causation of the individual deflections of the electrocardio¬ gram. We know that certain of them are auricular and that certain of them are ventricular ; the curves provide us with clear indications of the systoles of auricles and of ventricles, and enable us to establish within very small limits of error,