Nurses must be able to recognize normal and abnormal ECG patterns: - Normal Sinus Rhythm: Regular rhythm with appropriate waveforms. - Bradycardia: Slower than normal heart rate. - Tachycardia: Faster than normal heart rate. - Atrial Fibrillation: Irregular atrial activity, leading to an irregular heartbeat. - Ventricular Fibrillation: Rapid, erratic electrical impulses in the ventricles; a medical emergency.