Diseases of the chest and the principles of physical diagnosis . chief branches of thebundle of His, , in the arborization of the Purkinjefibers. Like bundlebranch block, this condition shows the notching and prolonged durationof the initial deflections; but differs in the low amplitude of the initialdeflections in all leads and in the absence of typical diphasic curveswith huge T waves. This form of electrocardiogram is probably morefrequent than that due to block of the main branch, and is important onaccount of its serious prognosis (Willius), and frequent association withcoronary throm
Diseases of the chest and the principles of physical diagnosis . chief branches of thebundle of His, , in the arborization of the Purkinjefibers. Like bundlebranch block, this condition shows the notching and prolonged durationof the initial deflections; but differs in the low amplitude of the initialdeflections in all leads and in the absence of typical diphasic curveswith huge T waves. This form of electrocardiogram is probably morefrequent than that due to block of the main branch, and is important onaccount of its serious prognosis (Willius), and frequent association withcoronary thrombosis. Sino-auriadar.—In the rare condition of sino-auricular block, oc-casional cycles are entirely absent {, there is no evidence of eitherauricular or ventricular activity). It is assumed in these cases that thesinus impulse has been blocked before reaching the auricle. Auricular Flutter.—This relatively common form of arrhythmia wasdiscovered by means of the electrocardiograph, and it is still impossible T^bctdbuu- AxA*^ ^A/j7^Ti. ^-^^ Fig. 159.—Alternation of initial deflections. Taken during an attack of paroxysmaltachycardia. Note the alternating height of i? (this is further modified by changes due torespiration). Note also in each cycle that the bigger R is associated with a smaller Q anda bigger .S. After the paroxysm alternation was no longer found. (—Alternation mayalso cause a similar difference in height of the T waves.) definitely to diagnose the condition without its aid. The ectopic originin the auricle of the rapid stimulus production is usually shown by theinversion of P in one or other lead. If due allowance is made for thebreaks caused by R and T, a regular rapid succession of P sum-mits can be traced through the record. As the ventricle cannot respondto all the impulses from the auricle, a state of partial block is 2 or 3 to 1, the ventricular rhythm will be regular; if a 3 to 2 rhythmexists, the ventricular response will of c
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectdiagnos, bookyear1920
