If no P waves can be seen and the QRS complexes are irregularly irregular, then atrial fibrillation is present. ST segment elevation from pericarditis is diffuse (all leads except aVR and V1 ...

The QRS complex consists of the Q wave, the R wave and the S wave. The QRS complex comes after the P wave when the SA nodal action potential travels through the AV node to the ventricles to cause ...

These ECG voltage attenuations are of extracardiac mechanism, and impact the amplitude of QRS complexes, P-waves, and T-waves, occasionally resulting also in shortening of the QRS complex and QT ...