People who are wakened by repetitive leg movements during sleep may more than double their chance of having a brief episode of ventricular tachycardia soon afterwards, researchers report.

US researchers investigated the association of periodic limb movement disorder and episodes of discrete non-sustained ventricular tachycardia in more than 2900 older men (mean age 76) participating in an ongoing sleep study.

They homed in on 49 of the men, who had a total of 141 episodes of non-sustained ventricular tachycardia.

Non-sustained ventricular tachycardia – classified in this study as an episode of less than 30 seconds’ duration with three or more consecutive beats at rate of 100 bpm – was known to double the risk of sudden cardiac death in men without heart disease, the authors noted.