Destruction of the sinoauricular node in dogs' hearts by radon

Borman, Milton C.; McMillan, Thomas A.

doi:10.1016/s0002-8703(27)90402-5

Cited by 9 publications

(2 citation statements)

References 7 publications

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“…Previous studies of subsidiary pacemaker function have used techniques ranging from radon destruction of the sinus node (Borman and McMillan, 1927), infusion of eserine into the sinus nodal artery (Urthaler et al, 1973), and exclusion of the sinus node (Sealy et al, 1973) to a partial or complete excision of the node , to unmask subsidiary pacemakers. Since distribution of the sinus node artery is extensive (Hardie et al, 1976), it was reasoned that blockade of sinus node artery distribution might be expected to produce a more reasonable model for pathological unmasking of subsidiary atrial pacemakers.…”

Section: Group I Dogsmentioning

confidence: 99%

Supraventricular pacemaker underdrive in the absence of sinus nodal influences in the conscious dog.

Loeb¹,

Murdock²,

Randall³

et al. 1979

Circulation Research

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The ability to reduce and maintain heart rate by electrical stimulation (underdrive) was tested in three groups of chronically instrumented dogs: sinoatrial node intact, ectopic atrial pacemaker produced by injection of rapidly hardening latex into the sinoatrial nodal artery, and idioventricular pacemaker produced by injection of formalin into the atrioventricular node. In the conscious unsedated state, underdrive of sinoatrial or idioventricular pacemakers resulted in competition between driven and intrinsic foci. However, the cycle length of ectopic atrial pacemakers could be increased by 148.4 +/- 30.7 msec (P less than 0.001) and maintained at that value. Cessation of underdrive resulted in a period of pacemaker suppression similar to that produced following overdrive. Single premature stimuli produced marked cycle length prolongations in dogs with ectopic atrial foci. Total autonomic blockade had no significant effect on the production of underdrive. Thus, the results of the present experiments provide evidence for maintained capture of cardiac pacemakers at rates significantly below intrinsic control and indicate that underdrive varies as a function of pacemaker site. Underdrive may explain the failure of junctional escape in the presence of slower atrial rhythms.

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Section: Group I Dogsmentioning

confidence: 99%

Supraventricular pacemaker underdrive in the absence of sinus nodal influences in the conscious dog.

Loeb¹,

Murdock²,

Randall³

et al. 1979

Circulation Research

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“…Life 2022, 12, 1895 2 of 10 After damaging the sino-atrial node in dogs with radon, Bormax and Meek [2] were able to generate a slow atrial rhythm in the animals. They observed the origin of the cardiac impulses in the low right atrium at the level of the inferior septum close to the coronary sinus.…”

Section: Introductionmentioning

confidence: 99%

Low Atrial Rhythm in a Large Cohort of Children from Transylvania, Romania

Henckell

Gușetu

Roşu

et al. 2022

Life

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Low atrial rhythm (LAR) is an ectopic rhythm originating in the lower part of the right or left atrium. Prior observational studies attempted to quantify the prevalence of low atrial rhythm in the pediatric population, but the observed prevalence was highly variable with relatively small sample sizes. We aimed to characterize low atrial rhythm and determine its prevalence in a large population of 24,316 asymptomatic children from northwestern Transylvania. We found a prevalence of 0.6% (145 children) for low atrial rhythm. Children with LAR had a significantly lower heart rate (mean 78.6 ± 8.3 bpm), than the control sinus rhythm group (85.02 ± 4.5 bpm). Furthermore, a shorter PR interval was seen in children with LAR (132.7 ± 12.7 ms) than in the children from the control group (141.7 ± 5.4; p = 0.0001).There was no significant association between gender and the presence of left LAR (LLAR) or right LAR (RLAR) (p = 0.5876). The heart rate of children with LLAR was significantly higher (81.7 ± 11.6 bpm) than that of the children with LRAR (77.6 ± 11.1 bpm) (p = 0.037). Pediatric cardiologists should recognize low atrial rhythm and be aware that asymptomatic, healthy children can exhibit this pattern, which does not require therapeutic intervention.

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