ECG Monitoring

ECG Monitoring

We record the heart’s electrical activity in a variety of ways which include:

  •  12-lead electrocardiogram or ECG used to make a 30 second one off recording
  •  24 hour ECG (Holter Monitor) to make recordings continuously over 24 hours
  • Long term ECG (Event Monitor) to monitor the electrical activity over a longer period continuously & make recordings when symptoms occur or an arrhythmia is detected.

The electrical activity of a single heartbeat recorded from the surface of the chest

The first part of the ECG is called the p-wave and is a recording of a combination of the electrical activity of the right and left atria. After a slight delay due to travel of the electrical impulse from the top of the heart (atria) to the bottom of the heart (ventricles), the ventricles are electrically activated, generating the QRS portion of the ECG. The third wave in the ECG is the T wave, caused by the heart electrically recharging itself.

12-lead Electrocardiogram (ECG)

Mortara ELI10 ECG recorder

This is recorded during a visit to our office using disposable skin electrodes and a small, ultraportable paperless device (Mortara ELI 10). It connects to our ECG  Information Management System (EScribe) using WiFi. We can interpret the ECG from our desktop computer and compare ECGs between visits.

Using the same recorder with a 3G card, we can record record ECGs remotely and transmit the ECGs to the office for analysis.

24 hour ECG (Holter) recording

The Holter recorder is used to record the hearts electrical activity (ECG or Electrocardiogram) during daily life including sleep. It is a continuous recording of the ECG using 5 electrodes attached to the skin. The monitor we use is able to build a reconstruction of the 12 Lead ECG we do in the office as part of the consultation but gives us important additional information about heart rhythm which we can’t obtain during a visit to our Consulting rooms.

Why is it done?

Diagnosis of Heart Rhythm Disorders.  Patients may experience palpitations (awareness of the heart beating unusually including fast and irregularly). Dizzy spells can be heart related when the heart beats unusually quickly or slowly. We are able to record what the heart’s rhythm is at the time symptoms occur which aids diagnosis of the condition.

Detecting Asymptomatic Heart Rhythm Disorders. There is a range of normal changes in the heart’s rhythm but there are a number of heart rhythm changes which patients are not aware of such as atrial fibrillation (AF), atrial tachycardia and ventricular tachycardia (VT) which can be found during a 24hr ECG recording.

Monitoring Effects of Treatment. There are many reasons why the effect of drug treatment on heart rhythm needs to be examined – one common one is control of heart rate in those with atrial fibrillation during daily life. We sometimes look for silent angina (ischaemia) using the Holter recorder which is not a heart rhythm problem but one which shows on the ECG by changes in what is called the ‘ST-segment’.

How is it done?

The Holter Monitor is attached by a technician. The recorder has a button which the patient presses to record when experiencing symptoms such as palpitations, dizziness or chest discomforts, and needs to also record in a diary  what they felt, the time of day and what they were doing at the time they experienced the symptom.

Download a Patient Information Sheet for the Holter test here.

Long term ECG (Event Monitor)

This is a way of recording the heart’s rhythm over a long period of time such as 1 to 2 months and up to 6 months rather than 24 to 48 hours as is done with Holter recorders. This is a much simpler and less sophisticated recorder than a 24-hour ECG recorder but allows us to measure the heart’s rhythm during very infrequent or asymptomatic events. An alternative is to implant a loop recorder but this is an invasive procedure and designed for much longer recording periods of 3 or more years. The device is battery operated and sends recorded information via a standard telephone line to a website where the information is uploaded and transmitted to our practice.

Why is it done?

Diagnosis of Fits, Faints and ‘Funny Turns . Changes in heart function – either heart rhythm or blood pressure – can cause symptoms which lead to dizziness or loss of consciousness. This can result in falls and injuries and resemble non-heart related problems like balance disorders or epilepsy. Both fast and slow heart rhythms can disturb consciousness. Recording the heart rhythm from the ECG is valuable in making the diagnosis or excluding a heart related cause.

Diagnosis of the cause of palpitations.  Palpitations may be due to increased awareness of the normal beat of the heart, a sense of an irregular beat or fast heart beat due to a change in the heart’s rhythm (arrhythmia). Many disturbances of the heart’s rhythm are relatively harmless but others are not and detecting the type of heart arrhythmia is very important.
Monitoring for asymptomatic but infrequent arrhythmias . The test may be performed to look for arrhythmias like atrial fibrillation (AF), or complex ventricular arrhythmias such as ventricular tachycardia (VT). This includes before and after treatments such as drug treatment of AF, to confirm the effectiveness of procedures such as ablation of arrhythmias like atrial fibrillation (AF), atrial flutter or supraventricular tachycardia (SVT) and less frequently ventricular tachycardia.

How is it done?

This (heartEVENT) is lightweight and easy to use. The device flashes to indicate it has recorded an event (which may have been asymptomatic). The patient can activate a recording during symptoms by pressing a button. The battery lasts for up to 2,500 recordings. It can only record up to 4 events before it has to be downloaded via a landline.

Download Patient Information Sheet on Event Monitor test here.