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ECG OF THE WEEK
DR.Prof.K.H.Noorul Ameen’s unit(M4)
Dr.S.Dhileepan
History
• 70 yr old male,• k/c HT,CAD for 20 years,• Had cardiac transplantation 6 months back.
ECG shows
• HR-140/min,• Rhythm –regular,• PR interval -0.28 sec,• Axis +60-90 degree,• Incomplete RBBB• Two sets of P waves, independent to each
other and one being always conducted.
DIAGNOSIS
ATRIAL DISSOCIATION
Atrial dissociation
• First reported by Wenkeback in 1906. It has been suggested that inatrial dissociation each atrium beats separatelyand independently as a result of blockage orinterruption of an interatrial pathway (Bachmann'sbundle). The sinus pacemaker controlsone atrium and the ectopic pacemaker controlsthe other atrium. The two pacemakers donot interfere with each other as a result of interatrial block or presence of preferential exit block
Differential diagnosis
1)Atrial parasystole-conducted, - normal P wave.2)Artefact –rhythmic muscular twitchings, electrical disturbance from adjacent person.
causes
• RHD• SHT• CCF• Sudden neurogenic stimuli• Uremia• Diphtheria
Atrial dissociation in transplanted heart
• Heart transplantation- orthotropic, - heterotropic . • In orthotropic transplantation posterior wall
of recipient heart is retained but denervated.• It produces impulse but not conducted as it is
blocked by suture line.• In heterotrophic transplantation 2 sets of
complexes are produced.
Orthotropic transplantation
Heterotropic transplantation
Heterotrophic transplantation
ECG shows
• Varying PP,PR,RR interval,• P wave inverted and gradually become normal
when heart rate speeds up.
Wandering pacemaker
causes
• Phyisiologic-deep sleep• Young adults with high vagal tone• Digitalis • Sick sinus syndrome
WANDERING PACEMAKER.
• This variant of sinus arrhythmia involves passive transfer of the dominant pacemaker focus from the sinus node to latent pacemakers that have the next highest degree of automaticity located in other atrial sites (usually lower in the crista terminalis) or in AV junctional tissue. The change occurs in a gradual fashion over the duration of several beats; thus, only one pacemaker at a time controls the rhythm, in sharp contrast to AV dissociation.
• Precursor of MAT
THANK YOU