Atrial brillation is the most common pathologic supraventricular tachycardia.
It has many causes, is an expensive disease, impairs quality of life and leads
to an increased risk of death. Atrial dissociation is characterised by the
presence of two independent sets of P-waves. This peculiar abnormality may
give rise to the scenario where one atrium is in atrial brillation while the
other is in sinus rhythm. This is the rst published case of atrial dissociation
where the phenomenon is demonstrated by transmitral and transtricuspid
pulsed wave Doppler.