The Journal of laboratory and clinical medicine . of heart-block. In Fig. 9,A, the a-c in-irval measures fifths, exceeding slightly the normal of .2 seconds. This trac-ig also shows two premature auricular contractions. When there is an occasional failure of the ventricle to respond to the im-ulse coming from the auricle it is called the second stage of heart-block or the;age of dropped beats. Fig. 9,B illustrates the occurrence of dropped beats.[ote the prolongation of the conduction time up to the point of failure of theentricular response. Note that the period B measures less than A. In
The Journal of laboratory and clinical medicine . of heart-block. In Fig. 9,A, the a-c in-irval measures fifths, exceeding slightly the normal of .2 seconds. This trac-ig also shows two premature auricular contractions. When there is an occasional failure of the ventricle to respond to the im-ulse coming from the auricle it is called the second stage of heart-block or the;age of dropped beats. Fig. 9,B illustrates the occurrence of dropped beats.[ote the prolongation of the conduction time up to the point of failure of theentricular response. Note that the period B measures less than A. In complete heart-block the analysis of the tracing is carried out in thesual way. Having determined c we may proceed to fix v. We are at once;ruck by the variation in the general outline of v. We then see that there is 0 wave present having the constant time relation of a to c, but find a seriesf regularly recurring waves falling either before, with or after c and v 1 an apparently utterly haphazard relation to these two waves. \, i i t i. 4, *-. ?& ^v/. Fig. 8.—A. Paroxysmal tachycardia. B. Diagram illustrating the nature of the disturbance in paroxysmal tachycardia. The only possible source of a regularly recurring wave in the jugular curvet a higher rate of speed than c is auricular systole; if therefore these peaksan be shown to space accurately they are a waves. Note the difference in of a and c and a and v in Fig. 9,C. AURICULAR FLUTTER. Although the polygraphic records of auricular flutter are often difficult) interpret, there are many instances in which the analysis is so simple thatlere should not be the slightest question as to the nature of the disturbance,hilc without them or without electrocardiographic records the diagnosis is im-ossible. The jugular curve falls briefly into two types: one made up of a sequence 734 TJie Journal of Laboratory and Clinical Medicine
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