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Posts Tagged ‘inter atrial block’

Knowledge and wisdom check in pace maker therapeutics !

Posted in cardaic physiology, cardiac physiology, Cardiology - Electrophysiology -Pacemaker, cardiology -Therapeutics, Cardiology -unresolved questions, tagged , , , , , , , , , , , , , , , , , , , , , , on February 10, 2013| Leave a Comment »

Answer

Each of the above can be important in diseased heart .The most important component seems to be Inter- ventricular  synchrony .This is closely followed by AV synchrony .In dysfunctional  ventricles Intra-ventricular  synchrony  also becomes important .In  structurally  normal hearts  none seems to be important  (This statement can be debated  )

VVI pacemakers causes  both AV  and Inter-ventricular (VV ) dys-synchrony

DDD pacemaker  may still  induce  Inter-ventricular ( VV ) dys-synchrony  whenever  RV is paced for any reason .This may happen up to 60 % of pace making time in real world.

Some more facts

*Chronic VVI pacing may  induce adverse  remodeling of both atria and may worsen LV dilatation. In contrast isolated chronic organic LBBB is well tolerated and with paradoxical septal motion rarely worsen the LV function.

**Please note the paradoxical septal motion , which is  noted in  all LBBBs is  same as inter-ventricular  dyssynchrony .

***Inter atrial synchrony is a less discussed issue .It becomes  important in diseased atria which manifest gross   intra atrial conduction blocks  , atrial inhomogeneity and AF .Onset and offset  of AF has a major impact in the way DDD pacing is going to fire .

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ECG suggests LAE . . . Echo reveals an absolutely normal Left atrium . . . what is your comment ?

Posted in Cardiology - Electrophysiology -Pacemaker, cardiology -ECG, Infrequently asked questions in cardiology (iFAQs), tagged , , , , on February 8, 2013| Leave a Comment »

This is an ECG of a 42 year old man .He was reported as  Left atrial  enlargement (LAE) and was referred for  echocardiography . His echo was normal . LA measured 2.5 X 3.1 cm .The consultant  called back the echo lab ,  to verify   the left atrial dimension .He thought he was very sure of LAE .It took  considerable time to convince him about the credibility  of the echocardiographer . He was  right after all  . . . still . . .  ECG was  also looked  convincing  for LAE !

left atrial enlargement by ecg limitations sensitivity

left atrial enlargement by ecg limitations sensitivity echo la dimension

                         Is this phenomenon  of wide P wave with normal atrial dimension  common ?

Yes it is . It  underscores  poor sensitivity of ECG in the  diagnosis  of LAE .The P wave abnormality in the above patient is due to Inter atrial block (IAB ) . This widens the p wave .

What  are the types of Inter atrial block ?

inter atrial block europace 1999 de luna

 

P wave widening is not synonymous with LAE .(Here P waves  widened   due to sluggish inter nodal pathway and inter atrial pathway .It is something like QRS widening in  bundle branch blocks  )

Final message

IAB is an important differential diagnosis for LAE . The significance of which is not entirely clear . It  is possible  IAB   precede LA enlargement  .It can even trigger AF due to  inhomogeneity.

Even though IAB was reported in 1950s  (Puech P* ) ,  it was  rarely  considered important With  increasing incidence of atrial arrhythmia in aging population , IAB is expected to  come into the lime- light again . The sophisticated electro anatomical mapping  can unravel the mysteries surrounding this entity .

Reference

INTER ATRIAL BLOCK

*Puech P. L’activite´ electrique auriculaire normale et pathologuique. Paris: Masson, 1956; 206.

http://www.jecgonline.com/article/S0022-0736%2812%2900227-0/abstract

http://europace.oxfordjournals.org/content/1/1/43.full.pdf

Bachman bundle branch block

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