Low atrial rhythm – ECG

Low atrial rhythm Brief Review Abstract: Low atrial rhythm manifests with inverted P waves in inferior leads. It may be seen in sinus venosus atrial septal defect. Low atrial rhythm (Click on the image for an enlarged view) This ECG shows inverted P waves in inferior leads (II, III and aVF). This indicates that the atrial activation is spreading from below upwards. It is suggestive of a focus either in the low atrium or high junction. A mid junctional rhythm will have no visible P waves as the P wave will be within the QRS due to simultaneous activation of the atria and ventricles. In low junctional rhythm the P wave occurs after the QRS, in the ST segment and is inverted in inferior leads. In left atrial rhythm originating from the lower part, the P waves are inverted in inferior leads as well as lateral leads. There is notching of the QRS complex in the inferior leads which suggest the crochetage sign in atrial septal defect. Low atrial rhythm can occur with sinus venosus atrial septal defect as the sinus node may be defective so that alternate focus arising in the low atrium gives the dominant rhythm. The PR interval is also shorter in low junctional and low atrial rhythm, more in the former than in the latter, due to obvious reasons. Low atrial rhythm has been reported in acute amlodipine intoxication.1 A rare autosomal dominant disorder in four generations of a family with congenital heart diseases (atrial septal defect, tetralogy of Fallot and persistent left superior...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: ECG / Electrophysiology Source Type: blogs