dysrhythmia
Concise Oxford English Dictionary © 2008 Oxford University Press:
dysrhythmia /dɪsˈrɪðmɪə/
▶noun Medicine abnormality in a physiological rhythm, especially of the brain or heart.
– derivatives
dysrhythmic adjective,
dysrhythmical adjective.
dysrhythmic adjective,
dysrhythmical adjective.
'dysrhythmia' also found in these Oxford entries:

