The electrical system within the heart is responsible for ensuring that the heart beats correctly so that blood can be transported throughout our the body. Any malfunction of the electrical system in the heart malfunction can cause a fast, slow, or irregular heartbeat. Types of heart disease that affect the electrical system are known as arrhythmias. They can cause the heart to beat too fast, too slow, or irregularly. These types of heart disease include: 1. Sinus tachycardia Sinus tachycardia occurs when the sinus rhythm is faster than 100 beats per minute therefore it increases myocardial oxygen demand and reduces coronary blood flow, thus precipitating an ischemia heart or valvular disease. 2. Sinus bradycardia Sinus bradycardia occurs when a decrease of cardiac output results in regular but unusually slow heart beat less than 60 beats per minute. Symptoms of sinus bradycardia includes a feeling of weightlessness of the head, dizziness, low blood pressure, vertigo, and syncope. 3. Atrial fibrillation Atrial fibrillation is an irregular heart rhythm that starts in the upper parts (atria) of the heart causing irregular beating between the atria and the lower parts (ventricles) of the heart. The lower parts may beat fast and without a regular rhythm. Symptoms of atrial fibrillation include dizziness, light-headedness, shortness of breath, chest pain and irregular heart beat. 4. Atrial flutter Atrial flutter is an abnormal heart rhythm that occurs in the atria of the heart causing abnormalities and diseases of the heart. Symptoms of atrial flutter includes shortness of breath, chest pains, anxiety and palpitation. 5. Supraventricular tachycardia Supraventricular tachycardia is described as rapid heart rate originating above the ventricles, or lower chambers of the heart causing a rapid pulse of 140-250 beats per minute. Symptoms of supraventricular tachycardia include palpitations, light-headedness, and chest pains. 6. Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardia is described as an occasional rapid heart rate. Symptoms can come on suddenly and may go away without treatment. They can last a few minutes or 1-2 days. 7. Ventricular tachycardia Ventricular tachycardia is described as a fast heart rhythm that originates in one of the ventricles of the heart . This is a potentially life-threatening arrhythmia because it may lead to ventricular fibrillation and/or sudden death. Symptoms of ventricular tachycardia include light headedness, dizziness, fainting, shortness of breath and chest pains. 8.Ventricular fibrillation Ventricular fibrillation is a condition in which the heart's electrical activity becomes disordered causing the heart's lower chambers to contract in a rapid, unsynchronized way resulting in little heart pumps or no blood at all, resulting in death if left untreated after in 5 minutes. There are many heart diseases affecting electrical system such as premature arterial contractions, wolf parkinson, etc. If you need more information of the above subject, please consult your doctor **edited by moderators**