Any tachycardic rhythm with a left or right bundle branch block that is NOT ventricular tachycardia is considered "supraventricular tachycardia with aberrancy". This would even include sinus ...

with aberrancy. 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 ...