Clinical and Electrocardiographic Features of Supraventricular and Ventricular Tachycardias

Abstract

One can make few useful generalizations about the clinical features of tachyarrhythmias, but the basic clinical tool used in their elucidation is the electrocardiogram; and, as we have heard during previous presentations, this is by no means the final diagnostic tool. Nevertheless it is the one that we most often use, and provided we have the necessary reservations about interpretation, it is a highly practical and indeed essential instrument. What we are here concerned with today are tachyarrhythmias, which can be irregular or regular, and which can be associated with two consequential features that may influence the clinical findings: atrioventricular block in the case of some supraventricular tachycardias, and atrioventricular dissociation as the hallmark, if not the invariable one, of ventricular tachycardias. Atrioventricular dissociation can of course occur in its own right under certain circumstances where the pulse rate is fast, but AV block in the presence of a normal sinus rate will require no further consideration because it will present as bradycardia.