Time-related changes in the Q-T interval in acute myocardial infarction: possible relation to local hypocalcemia.
In 63 patients with either acute transmural or nontransmural myocardial infarction, the Q-T interval was prolonged beyond normal limits on at least 1 of the 5 days after infarction in 27 patients (8 with transmural and 19 with nontransmural infarction). The time-related changes in the corrected Q-T (Q-Tc) interval were defined for the entire sample and showed significant expansion, maximal on day 2, from a preinfarction control value. By day 5, the Q-Tc interval was no longer significantly prolonged and was not expanded beyond normal limits in any patient. Various possible causes of Q-T prolongation in myocardial infarction are local hypothermia, local conduction delay, neurogenic effect and local hypocalcemia. Collateral evidence suggests that the letter may contribute significantly to prolongation.
D000200:Action Potentials; D002118:Calcium / Q000378:metabolism*; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology*; D013997:Time Factors; D014882:Water-Electrolyte Balance
D002118:Calcium