The pattern and prognostic features of QT intervals and dispersion in patients with acute ischemic stroke

Ischemic stroke, which is perhaps the commonest subtype of stroke, is associated with electrocardiographic (ECG) changes. Some of these changes have been thought to be due either to the stroke state itself or pre-existing heart disease. Some, particularly QT intervals, have been associated with increased mortality.

The aim is to investigate the pattern of QTcmax, QTd and QTcd in patients with ischemic stroke and to compare these changes in patients without pre-existing heart disease in order to determine their prognostic importance.

Sixty-four patients with acute ischemic stroke were compared with 60 controls observing the various ECG changes. Patients without pre-existing heart disease were isolated and compared with the total cohort.

Thirty-five (54.7%) of the patients had ischemic-like ECG changes made up of ST depression (29.7%), T-wave inversion (21.8%) and U wave (9.3%). Twenty-eight (43.8%) had QTcmax prolongation. Twenty-four (37.5%) of the patients had no pre-existing heart disease. The QT was similar when compared with the total cohort except in QTcmax, where there was significant difference (447.3+/-72.2 vs. 408.6+/-40.3 msecs). Mortality rate of the total cohort at 28.1% was significantly higher than in those without pre-existing heart disease at 8.3%, suggesting that presence of pre-existing heart disease contributed to mortality. QTcmax (r=0.293 p=0.045) and days on admission (r=-0.543 p=0.001) were the other variables that correlated with mortality in the total cohorts.

Ischemic-like and repolarisation ECG changes are common in our patients with acute ischemic stroke. These changes tend to be due to pre-existing heart disease rather than the stroke state.