Symptoms of tachycardia include:Recurrent palpitations that may feel like a strong neck pulse or a fluttering, pounding, or racing beat in the chest
Chest discomfort
Weakness, fainting, shortness of breath, dizzinessSymptoms of bradycardia include:
Fatigue
Shortness of breath
LightheadednessSymptoms of an irregular heartbeat may be all of the symptoms for either tachycardia or bradycardia.