Teaching electrocardiogram interpretation.
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Cardiology↗
Biomedical subjects
Rory Childers
Publications and source records attributed to Rory Childers.
Consideration of pitfalls in and omissions from the current ECG standards for diagnosis of myocardial ischemia/infarction in patients who have acute coronary syndromes.
The ECG is the key clinical test available for the emergency determination of which patients who presenting with acute coronary syndromes indeed have acute myocardial ischemia/infarction. Because typically the etiology is thrombosis, the correct clinical decision regarding reperfusion therapy is crucial. This review follows the efforts of an AHA working group to develop new standards for clinical application of electrocardiology. The pitfalls in the current diagnostic standards regarding ischemia/infarction that have been identified by sufficiently documented studies are corrected in their report. This article focuses on the pitfalls for which new standards will emerge in future years.
Angina, Unstable↗
Electrophysiology of the electrocardiographic changes of atrial fibrillation.
The history of atrial fibrillation is described in terms of its electrocardiographic delineation, characteristics and clinical associations. The variant configurations are described and their relationship to rhythm duration and cardioversion success. The inter-relationship of fibrillation with flutter and their diagnostic differences are reviewed. The electrophysiologic basis of atrial remodeling is exemplified, together with its relationship to failure of rate adaptation of the atrial refractory period. Electric countershock causes an acute abbreviation of the atrial refractory period as does the induction of hyperthyroidism in the experimental animal. Current theories of the mechanism of fibrillation and the issue of originating pulmonary venous foci are reviewed. The lack of protection from ventricular fibrillation that exists with preexcitation via an accessory pathway is discussed in terms of the teleological role of orthograde downstream refractory periods.
Action Potentials↗
The infarct Q wave: foretaste and aftertaste; presentiment and recall.
Since acute myocardial infarction involves a progressive disturbance of intramyocardial propagation the process might be regarded as a conduction disturbance: incomplete in the evolving phase; complete with Q wave inscription. Premature atrial excitation (PAE) can induce fascicular or bundle branch conduction delay, or complete functional block. Considered here are the concepts of foretaste: in which PAE reveals the infarct Q before it has appeared in regular sinus beats, and aftertaste: in which, following the healing of the myocardial infarction, the Q wave is recalled by PAE after it has disappeared from regular beats. Foretaste was observed in a small number of acutely infarcted dogs. Aftertaste is substantially more problematic since Q wave inscription is known to occur, however uncommonly, in a small minority of noninfarcted aberration morphologies. Only lateral infarct Q waves appear to be recallable by PAE.
Animals↗