Intermittent preexcitation in children does not connote a lower risk AP by EP criteria or reduced symptoms. The low number of pediatric WPW patients who develop preexcited atrial fibrillation or sudden death warrants larger studies to investigate these outcomes.

Surgical scars secondary to the placement of pacemakers or internal cardioverter/defibrillators in the infraclavicular area can be unsightly. This report describes a novel cosmetic approach for the placement of pacemakers or internal cardioverter/defibrillators. The approach involves a small infraclavicular incision for placement of the leads and then a larger incision hidden high up in the axilla. The theoretical advantages of this approach are improved cosmetic outcome, ease of subsequent surgeries for device generator changes, and potentially improved defibrillation thresholds.

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We used the whole cell open-patch or perforated-patch technique to characterize μ-opioid modulation of Ca2+ current ( I Ca) in nodose sensory neurons and in a specific subpopulation of nodose cells, aortic baroreceptor neurons. The μ-opiate receptor agonist Tyr-d-Ala-Gly-MePhe-Gly-ol enkephalin (DAGO) inhibited I Ca in 95% of neonatal [postnatal day (P)1–P3] nodose neurons. To the contrary, only 64% of juvenile cells (P20–P35) and 61% of adult cells (P60–P110) responded to DAGO. DAGO-mediated inhibition of I Ca was naloxone sensitive, irreversible in the presence of guanosine 5′- O-(3-thiotriphosphate), absent with guanosine 5′- O-(2-thiodiphosphate), and eliminated with pertussis toxin; DAGO’s inhibition of I Ca was G protein mediated. Incubation of neurons with ω-conotoxin GVIA eliminated the effect of DAGO in neonatal but not in juvenile cells. In the latter, DAGO reduced 37% of the current remaining in the presence of ω-conotoxin. In the subset of nodose neurons, aortic baroafferents, the effect of DAGO was concentration dependent, with an IC50 of 1.82 × 10−8 M. DAGO slowed activation of I Ca, but activation curves constructed from tail currents were the same with and without DAGO (100 nM). In summary, μ-opiate modulation of I Ca in nodose neurons was demonstrated in three age groups, including specifically labeled baroafferents. The demonstration of a mechanism of action of μ-opioids on baroreceptor afferents provides a basis for the attenuation of the baroreflex that occurs at the level of the nucleus tractus solitarii.

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