. Medical diagnosis for the student and practitioner. particular part but the entire expression of the electrical wave accom-panying the contraction of the ventricle (Samojlojf, Straub, Hoffman), (e) adiminution of the intracardial short-circuiting at the end of systole when theventricle is empty. The U wave (not lettered) is a diastolic event, due to (a) the last relaxationof the fibers of the ventricle (Einthoven), (b) the electrical variation of the arteries(Hering). The Phonocardiograph.—By a relatively simple combination of a secondgalvanometer, microphone, stethoscope, rheostat, accumula
. Medical diagnosis for the student and practitioner. particular part but the entire expression of the electrical wave accom-panying the contraction of the ventricle (Samojlojf, Straub, Hoffman), (e) adiminution of the intracardial short-circuiting at the end of systole when theventricle is empty. The U wave (not lettered) is a diastolic event, due to (a) the last relaxationof the fibers of the ventricle (Einthoven), (b) the electrical variation of the arteries(Hering). The Phonocardiograph.—By a relatively simple combination of a secondgalvanometer, microphone, stethoscope, rheostat, accumulator, and a trans-former, simultaneous electrocardiograms and phonocardiograms are obtain-able which are capable of showing both the volume and pitch of the murmurtogether with its exact place in the cardiac cycle and relation to the eventsof the electrocardiogram. * Modern Aspects of the Circulation in Health and Disease, Carl J. Wiggers, admirable exposition of the most recent work in this field. Registers timepitch and vol-ume Fig. 224.—Simple apparatus forregistration of heart sounds andmurmurs when attached to theelectrocardiograph. It consistsmerely in the bringing of a micro-phone into circuit with the stringgalvanometer. ELECTROCARDIOGRAPHIC RECORDS 525 MARKING AND INTERPRETATION OF ELECTROCARDIO-GRAPHIC RECORDS Systematic Procedure Indispensable.—The absolute necessity forproceeding in a systematic and orderly manner in the marking and inter-pretation of the polygram was emphasized in that chapter. While it is important there, it is even more important in regard to themarking and interpretation of electrocardiographic records. Time Record.—In all instruments the time is indicated in hundredths of asecond. In the Hindle instrument, used by the author, it is indicated bymain divisions of seconds with sub-divisions of seconds. General Description of Waves.—The important deflections in the electro-cardiographic record have been arbitr
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectdiagnos, bookyear1922
