National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine treatment outcome research support non-u.s. gov't female male aged middle aged Drug Administration Schedule Comparative Study randomized controlled trials as topic follow-up studies dose-response relationship drug risk assessment probability intravenous finland electrocardiography* infusions registries clinical trials phase iii as topic arrhythmias pmid:15204232 doi:10.1080/14017430410025783 jyrki lilleberg vesa ylönen lauri toivonen anti-arrhythmia agents / administration & dosage* anti-arrhythmia agents / adverse effects cardiac / complications cardiac / diagnosis cardiac / drug therapy* heart failure / complications heart failure / diagnosis heart failure / drug therapy* hydrazones / administration & dosage* hydrazones / adverse effects myocardial contraction / drug effects pyridazines / administration & dosage* pyridazines / adverse effects simendan