Relation of Early Changes of QT Dispersion to Changes in Left Ventricular Systolic and Diastolic Function after a First Acute Myocardial Infarction

Abstract

Following myocardial infarction low QT dispersion is associated with preserved left ventricular function, whereas persistently increased dispersion is associated with left ventricular dilation and deterioration of diastolic function.

QT Dispersion Correlates with Systolic Rather than Diastolic Parameters in Patients Receiving Anthracycline Treatment

“…Therefore, if these theories are true, greater QTcD could reflect diastolic dysfunction in various diseases. Indeed, several reports show that in patients with acute myocardial infarction or Behçet's disease, QT dispersion is associated with LV dilation and deterioration of diastolic function (20,25,28). However, Kors et al suggested an important point that at all electrode sites, repolarization potentials must have principally the same duration by simple electric field theory (29).…”

“…QT dispersion was then corrected with Bazett's formula (QTcD) (19). QTcD was not measured if there were less than eight electrocardiographic leads available for analysis (20 (4) 21 (29) 10 (14) 1 (1) 2 (3) 1 (1) Cumulative anthracycline dose <200 mg/m 2 201-400 mg/m 2 400 mg/m 2 <…”

“…Averaged QTcD values in all measurable beats for 15 seconds were employed as the QTcD of the patient. Like manual measurement, QTcD was not measured if there were less than eight electrocardiographic leads available for analysis (20).…”

Continuous Administration of Nicorandil Decreases QT Dispersion During the Chronic Phase of Acute Myocardial Infarction

“…Various hypotheses have been advanced regarding the relationship between AMI and QTd and its implications for left ventricular function, occurrence of arrhythmia, and mortality rates. [8][9][10][11] Nicorandil (NIC) exhibits a dual mechanism of action, functioning as both a nitrate and an adenosine triphosphate (ATP)-sensitive potassium channel opener. 12) Attention has focused on reperfusion injury prevention or myocardial protection resulting from its potassium channel-opening action.…”