title: Sick sinus syndrome and AV node re-entry.
abstract: A 69-year-old man presented with recurrent palpitations since childhood. Electrophysiology studies performed on two separate occasions revealed the combination of sick sinus syndrome and AV node re-entrant tachycardia. The case is reported because it illustrates marked temporal variability in the electrophysiological properties of the dual AV node pathways, and also deleterious effects of verapamil on sinoatrial node function.
mesh_terms: D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology*; D001919:Bradycardia / Q000139:chemically induced; D002036:Bundle of His / Q000503:physiopathology; D004562:Electrocardiography; D004594:Electrophysiology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012804:Sick Sinus Syndrome / Q000150:complications*; D012849:Sinoatrial Node / Q000187:drug effects; D013610:Tachycardia / Q000150:complications; D014700:Verapamil / Q000009:adverse effects
chemical_list: D014700:Verapamil