Pharmacological modulation of the hyperpolarization-activated current (If) in human atrial myocytes: focus on G protein-coupled receptors

Conclusions. - Our results provide the first functional evidence of the different G protein coupling of β1-AR, β2-AR and 5-HT4 receptors in HuAM. Further they support the view that If current might play an important role in triggering catecholamines and serotonin-induced atrial arrhythmias.