Notation System and Overlay Diagrams for the Analysis of Paced Electrocardiograms

With the advent of adaptive dual-chamber pacing, the interaction between the pacemaker and the heart is becoming increasingly complex and the interpretation of paced electrocardiograms more difficult. We have developed a set of notation conventions for use in teaching and rhythm-atrip analysis. Easily-drawn symbols delineate successful, unsuccessful, and inhibited pacing and sensing events as well as refractory and blanking periods. Another application is to generate movable transparent overlays after programming a pacemaker, to be used in interpreting subsequent rhythm strips.     

Pseudomalfunctions of Dual-Chamber Pacemakers

La prolifération de la stimulation auriculoventriculaire a crée de nombreux cas de "pseudo-dysfonctionnemenl" du stimulateur. En ce qui concerne ľinterpretation electrocardiographique, il est devenu parfois impossible de faire la distinction entre normal et anormal. La classification et les critères de ces phénomenes sont décrits. Il semble que seule la connaissance parfaite du fonctionnement de cheque stimulateur préviendra la fausse interprétation des tracés éléctrocardiographiques.
The proliferation of dual-chamber pacemakers has created a host of electrocardiography problems relating to interpretation. The term "pseudomalfunction" identifies an electrocardiographic finding that looks like pacemaker malfunction but is not. Several different models of dual-chamber pacemakers, which are either presently available or in clinical evaluation, produce different types of pseudomalfunc-tions. These are classified and described. Intimate knowledge of individual pacemaker characteristics is required for proper evaluation of these units.     

A possible role for mono(ADP-ribosyl)transferase in the signalling pathway mediating neutrophil chemotaxis

1 Mono(ADP-ribosyl)transferase activity has been identified on the external surface of human polymorphonuclear neutrophil leucocytes (PMNs). The enzyme is released from the plasma membrane by phosphoinositide-specific phospholipase C, suggesting a glycosylphosphatidylinositol (GPI) linkage of the enzyme to the plasma membrane. Partial sequence of cDNA encoding the enzyme suggests that it is identical to the GPI-linked mono(ADP-ribosyl)transferase identified previously on human skeletal muscle.
2 A panel of inhibitors of mono(ADP-ribosyl)transferase (including vitamins K₁ and K₃, novobiocin and nicotinamide) showed a rank order of inhibitory potency similar to that described for other mono(ADP-ribosyl)transferases. Furthermore, the mono(ADP-ribosyl)ation of agmatine was inhibited also by diethylamino(benzylidineamino)guanidine (DEA-BAG), another substrate of the enzyme related structurally to arginine.
3 There was a close linear correlation between the I C ₅₀ values for inhibition of mono(ADP-ribosyl)ation of agmatine by DEA-BAG or the enzyme inhibitors and their I C ₅₀ values for inhibition of receptor-dependent polymerization of cytoskeletal actin and chemotaxis.
4 These results suggest a role for mono(ADP-ribosyl)transferase in the transduction pathway involved in receptor-dependent re-alignment of the cytoskeleton during neutrophil chemotaxis.