Sinus bradyarrhythmias in acute period of myocardial infarction (differential diagnosis, prognosis)

Frequencies of vegetative dysfunction of the sinus node and of different va riants of the sick sinus syndrome and their impact on immediate (inhospital ) and remote prognosis were studied in 1427 patients with acute myocardial infarction (MI). patients with sinus bradyarrhythmias were subjected to atr opine test in acute and to transesophageal sett atrial pacing - in subacute period of infarction. Sick sinus syndrome and vegetative dysfunction of We sinus node were found in 2,5 and 3,9% of patients, respectively Hospital m ortality in patients with sick sinus syndrome was 5%. There were no inhospi tal deaths among patients with vegetative dysfunction of the sinus node, Si ck sinus syndrome often coexisted with proximal atrio-ventricular block and combined alterations of sinus and atrioventricular nodes were found in 31, 7% of cases. Among all clinico-electrocardiographical variants of sick sinu s syndrome bradycardia-tachycardia syndrome was mast stable. This syndrome either persisted during follow-up or transferred to constant atrial fibrill ation. Sinus bradycardia or sino-atrial block during follow-up were sporadi c. pacemaker implantation was required only in 1 patient.