QT dispersion and heart rate predict the risk of sudden unexpected cardiac death in men: the Manitoba Follow-Up Study.

As many as half of all sudden cardiac deaths are unexpected, with no preceding symptoms or signs of cardiac problems. Since 1948, the Manitoba Follow-up Study has prospectively recorded routine medical information and resting electrocardiographic (ECG) findings from a cohort of 3983 men. During 58 years of follow-up, 180 men experienced sudden unexpected cardiac death (SUCD).