OBJECTIVE This study investigated the proportion of silent venous obstruction in patients who underwent pacemaker or lead reimplantation for various reasons. We also investigated independent predictors or risk factor of venous obstruction in this patient population. METHODS Seventy-three patients who underwent pacemaker pulse generator and/or lead reimplantation in our institution between 200...

We aimed to determine how age-associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23-25 months) and adult (3-4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL(-1) atropine + 1 mg mL(...

The heart's regular electrical activity is initiated by specialized cardiac pacemaker cells residing in the sinoatrial node. The rate and rhythm of spontaneous action potential firing of sinoatrial node cells are regulated by stochastic mechanisms that determine the level of coupling of chemical to electrical clocks within cardiac pacemaker cells. This coupled-clock system is modulated by auton...

Simultaneous recording of action potentials from cells in different parts of sinoatrial preparations from cat and rabbit hearts confirms the suggestion by Meek and Eyster that the dominant pacemaker site shifts during treatment with high [K] . The direction of die shift can be eidier upward or downward depending upon the location of the original dominant pacemaker site. In the majority of cases...

Breathing is a vital rhythmic behavior generated by hindbrain neuronal circuitry, including the preBötzinger complex network (preBötC) that controls inspiration. The emergence of preBötC network activity during prenatal development has been described, but little is known regarding inspiratory neurons expressing pacemaker properties at embryonic stages. Here, we combined calcium imaging and elec...

S1 File. Includes supplemental patient data; supplemental materials, methods, and patient selection methodology; supplemental results; supplement references, and 12 tables. Table A. Exclusion criteria for genetic testing in patients with a first degree relative with a pacemaker. Table B. HaloPlex NGS depth of coverage for Coriell and pacemaker samples.Table C. Selected HGMD and nonHGMDVUSs in p...

Somata of pacemaker and nonpacemaker neurons were isolated by ligatures tied around the axons between the somata and the synaptic regions, and the transmembrane potentials of the isolated somata were recorded. Isolated somata of pacemaker neurons had a spontaneous discharge while isolated somata of nonpacemaker neurons were quiescent. In addition, the time course of accommodation in isolated so...

CONTEXT Despite there being millions of pacemaker and implantable cardioverter-defibrillator (ICD) generator implants worldwide, little is known about device reliability. OBJECTIVES To perform a meta-analysis of prospective pacemaker and ICD registries to determine annual rates of pacemaker and ICD malfunction and to identify trends in these rates. DATA SOURCES MEDLINE (January 1966 to Apri...

Dynamic heart rate control by parasympathetic nervous input involves feedback mechanisms and reflex bursting of efferent cardiac vagal fibers. Periodic vagal bursting induces phasic changes in sinoatrial cycle length and can entrain the pacemaker to beat at periods that may be identical to those of the vagal burst. We investigated the electrophysiological basis of these phenomena in isolated si...