Heart Arrhythmia TypesIn a healthy heart, electrical impulses follow precise pathways or connections so that the heart beats properly and blood pumps in and out. When these pathways or signals get interrupted, they can cause abnormal heart rhythms (arrhythmias).They can start in the sinus node, ventricles and atria. Doctors group arrhythmias by where they start and how they affect your resting heart rate.Ventricular tachycardia, also known as V-tach, is a rapid heart rhythm starting from the lower chambers of your heart. When this happens, the heart cannot adequately fill with enough blood, which can cause problems, such as weakness and dizziness.Supraventricular tachycardia, or SVT, starts in the upper chambers of your heart above your ventricles and can cause a sudden, rapid heartbeat that may last several minutes or longer. This can be more serious than other types of arrhythmias, and it may increase your risk of stroke.Accessory pathway tachycardia, or APTA, is caused by extra pathways through the atria that allow the heart to beat more quickly than normal. This condition can lead to heart palpitations, fainting and heart failure.AV nodal reentrant tachycardia, or AVNRT, is caused by an extra pathway through the atrioventricular node, which sends impulses to your ventricles.Premature ventricular contractions, or PVCs, are early extra beats that may feel like your heart skipped a beat. They are generally harmless, but can trigger longer-lasting arrhythmias in people with heart disease or who have a history of heart attacks.