Land mark concepts in cardiology : How to localise focal atrial tachycardia with P wave morphology in ECG ? Land mark concepts

What is the simplest and accurate way to predict  the   origin of Right atrial tacycardia(RAT)  from left atrial tacycardia(LAT) ?

Look at the P waves in V 1 ( Don’t look further ! )

• A  negative  or  a biphasic (+/- ) P wave in V 1  is 100% specific  for a right atrial tachycardia
• A positive P in V1 or  a biphasic ( –/+ ) P-wave in lead V ₁   has 100%  sensitivity  for a left atrial tachycardia 

What are the incidence of left and right atrial tachycardia ?

RA- 75%

LA -25%

What are the common focus of right atrial tachycardia ?

1. Crista terminalis (60% of all RAT)
2. Tricuspid annulus
3. Coronary sinus ostium
4. Perinodal tissue
5. Right side of IAS
6. Right atrial appedage

What are the left atrial focus in Left atrial tachycardia ?

1. Right & left pulmonary vein (50% of all LAT)
2. Superior mitral annulus
3. LAA
4. CS body
5. Left septum

 (Please note  this rule is not applicable for reentrant tachycardias, atrial flutter, AV nodal tachycardias)

Source :  

P-Wave Morphology in Focal Atrial Tachycardia

Development of an Algorithm to Predict the Anatomic Site of Origin

  This paper  from  Melburne, Australia is a rare gem of  an article for understanding

atrial tachycardia .This  paper won the  the Eric and Bonny Prystowsky Heart Rhythm

Society Fellows Clinical Research Award, New Orleans, Louisiana, 2005.

Click on the Link  to reach the article

  http://content.onlinejacc.org/cgi/content/full/48/5/1010