Techniques of Bedside Pacing

In temporary pacing the primary approach is transvenous--either percutaneous or via a cutdown in the jugular or brachial vein system. Tripolar and quadripolar pacemaker catheters which have been used for His bundle recordings are now obtainable as well as the bipolar variety. Among the latter is the floating catheter which may also be used as an intracavitary electrocardiogram. Doctor Furman of New York City has been extremely successful with this type in approximately 500 patients

Electrocardiographic Recognition of the Various Pacemaker Types and Dysfunction

This discussion deals with electrocardiographic interpretations of the various types of pacemakers as well as with their dysfunction which may be due to pulse generator failure, wire breakage, change in threshold, or polarization of the ventricle. Hemodynamic problems may also arise concerning placement of the pacemaker leads particularly in those patients who lack atrial contribution

Mechanisms of A-V Block

Determination of the varieties of A-V block is predicated on the precise identification of the site(s) of conduction delay as prognosis, and therapy must follow on this basis. Further electrophysiologic and pharmacologic studies will undoubtedly reveal other mechanisms on the nature of A-V transmission

Clinical Significance of Exit Block

Clinical features of exit block were shown and its probable electrophysiological mechanisms discussed. Based on recent electrophysiological studies, it is emphasized that exit block is a result of depressed conduction surrounding the ectopic pacemaker