An uncommon case of complete AV block.

Background: Granulomatosis with polyangiitis (GPA) is a rare systemic inflammatory disorder characterized by vasculitis of the small vessels, as well as necrotizing granulomatous lesions, affecting mainly upper and lower respiratory tracts, lungs and kidneys. Cardiac involvement has traditionally been a rare manifestation of GPA, with misleading clinical presentation until late stages. Cardiac conducting tissue involvement is a rare and potentially life-threatening complication.

Dobutamine potentiates arterial chemoreflex sensitivity in healthy normal humans.

beta-Adrenergic agonists may increase chemosensitivity in humans. We tested the hypothesis that the beta1-agonist dobutamine increases peripheral chemosensitivity in a double-blind placebo-controlled randomized and crossover study. In 15 healthy subjects, we examined the effects of dobutamine on breathing, hemodynamics, and sympathetic nerve activity (measured using microneurography) during normoxia, isocapnic hypoxia (10% O2), posthypoxic maximal voluntary end-expiratory apnea, hyperoxic hypercapnia, and cold pressor test (CPT).