General practitioners play an important part in the management of cardiac arrhythmias with regard to both diagnosis and monitoring. They are responsible for liaising with cardiologists and deciding when referral is necessary. Management of some arrhythmias is difficult and confusing, even for cardiologists. Arrhythmias may present with chest pain, syncope or 'dizzy turns', or breathlessness. Symptoms are generally unreliable for diagnosing arrhythmias. They depend on the haemodynamic consequences of the arrhythmia, which are a result of the type of arrhythmia, its anatomical origin, duration, the resulting heart rate, the underlying cardiac function, coexisting valve abnormalities and the age, medical condition and activities of the patient. Anti-arrhythmic drugs may result in proarrhythmia, particularly in patients with structural heart disease, coronary heart disease and left ventricular hypertrophy. Radio-frequency ablation of ventricular arrhythmias originating from the right ventricular outflow tract and a focal point in the left ventricle may be treated with ablation.