| Two ECG strips obtained in the same patient simultaneously (each represents a different vector of the heart’s electrical conduction), demonstrating complete AV block (also called 3rd degree heart block). The solid arrows point to P waves, representing atrial electrical conduction originating from the sinus node. The dashed arrows denote electrical conduction in the ventricles (QRS complexes). Note that the P waves are not related to the QRS complexes, demonstrating that the atria are electrically disconnected from the ventricles. The QRS complexes represent an escape rhythm arising from the ventricle. [Source] |