Signs and symptoms can arise suddenly and may resolve without treatment. Stress, exercise, and emotion can all result in a normal or physiological increase in heart rate, but can also, more rarely, precipitate<unk> . Episodes can last from a few minutes to one or two days, sometimes persisting until treated. The rapid heart rate, if fast enough, reduces the opportunity for the "pump" to fill between beats decreasing cardiac output and consequently blood pressure. The following symptoms are typical with a rate of 150–270 or more beats per minute * Pounding heart * Rapid Heart beat * Shortness of breath * Chest pain * Rapid breathing * Dizziness * Sweating * Loss of consciousness For infants and toddlers, symptoms of heart arrhythmias such as<unk>  are more difficult to assess because of limited ability to communicate. Caregivers should watch for lack of interest in feeding, shallow breathing, and lethargy. These symptoms may be subtle and may be accompanied by vomiting and/or a decrease in responsiveness.
Supraventricular tachycardia
Tachycardia
Sinus arrhythmia
Ventricular tachycardia
Junctional tachycardia
Ectopic beat
Inappropriate sinus tachycardia
Ventricular flutter