Stavrakis S, Kem DC, Patterson E, Lozano P, Huang S, Szabo B, Cunningham MW, Lazzara R, Yu X. Opposing cardiac effects of autoantibody activation of ß-adrenergic and M2 muscarinic receptors in cardiac-related diseases. Int J Cardiol. 2011 May 05; 148(3):331-6.