Ectopic heart beats are excedingly common in the population - indeed just about everyone has them although not everyone notices them. They are defined as beats that occur before the next beat arising from the sinus node (the heart's own pacemaker).

The reason that they are so common is that it is not only the pacemaker area of the heart that can beat spontaneously but this is a property pocessed by all the heart muscle. At rest the usual rate of spontaneous electrical activity in the pacemaker area of the heart is about 70 beats a minute. In the atria it is about 50-60 beats a minute and in the ventricles about 30 beats a minute. This means that usually the frequency of electrical activity coming down from above doesn't give the lower areas of the heart the opportunity to discharge electricity spontaneously. However, if for any reason the areas above fail to maintain the heart rhythm, the lower areas in the heart can take over- all be it at a slower rate. These are called Escape Rhythms.

With Ectopics an area lower down in the pathway is active even before the next regular beat thereby causing a new heart beat to occur before the next regular beat was expected. If this occurs very soon after the last beat then there will be very little blood in the heart and typically the person will not feel this heart beat. The next beat to occur is likely to be a normal beat in its timing and there is likely to be a longer gap between the preceding ectopic and this next normal beat than between two normal beats. For this reason more blood has returned to the heart and therefore the ventricles are fuller and have to contract harder to pump out this extra blood and therefore the person tends to feel a harder and stronger beat. This is why so many people experience a sensation of a 'dropped beat' or 'pause' followed by a 'thump'.

Ectopic beats can arise from either the atria (top) or the ventricles (bottom) of the heart. If they arise from the atria, then other than for their timing in the heart rhythm, they look very similar on an ECG to the normal beats as their subsequent route through the heart is identical to that of the normal beats. If they originate in the ventricles then they look different as they start in the ventricular muscle and travel through it without using the His-Purkinje system which takes a little longer. This makes them a wider and a different shape on the heart tracing.

Below is an ECG recording showing an atrial ectopic. The typical features of it looking like a normal beat but occuring earlier can be seen.

Atrial ectopic

Atrial ectopic beats

Ventricular ectopics

Below is an ECG recording showing three ventricular ectopics. Here once again the ectopics occur early but in this case they are abnormal in shape.

Ventricular ectopic beats

With both the atrial and ventricular ectopics the following beat tends to occur when it would have done, had the ectopic beat not occurred, meaning there is a longer gap between the preceding ectopic and the normal beat than between any two normal beats. Similarly there is a shorter gap between a normal beat a subsequent ectopic beat.


The key to the diagnosis is a recording of the electrocardiogram during the symptoms and this can be either very easy or very difficult depending on the frequency of the symptoms. Explanations of the different tests and investigations can be found by following the links below. Tests and Investigations


Other than the irritation and inconvenience of the symptoms, ectopic beats are rarely of any significance. They should be viewed in the light of a full medical history and physical examination by an experienced doctor and often no further action is necessary. Sometimes it may be wise to carry out an exercise ECG Exercise electrocardiogram to exclude coronary artery disease and/or an echocardiogram to exclude valvular heart disease or a cardiomyopathy Echocardiogram. In the absence of a significant underlying cardiac disease most ectopic beats disappear with activity.