St George Cardiology

02 8580 1649

Suite 7H, Level 5, 1 South St
Kogarah NSW 2217

Holroyd Heart Centre

02 8604 0933

Suite 7H, Level 5, 1 South St
Kogarah NSW 2217

Holter monitor/Event monitor



A holter monitor is a tests used to diagnose abnormalities in heart rhythm and blackouts. It can detect forms of a fast heart rhythm (tachycardia) and slow heart rhythm (bradycardia or pauses). The monitor is worn for 24 hours and any symptoms e.g. chest pain, shortness of breath, lightheadedness or palpitations (racing heart sensations) are recorded including the specific symptom and time. 


We also provide an event monitor - a week long monitor which is especially useful in a patients with only occasional symptoms. 



What is it? A Holter Monitor is a continuous twenty four hour recording of your heart rhythm. There are two common reasons why your Doctor may have referred for this test are: 

  • 1. If you have been feeling dizzy, having blackouts or palpitations, then this test can be used to try to find out if the cause of these symptoms is coming from your heart.
  • 2. If you have been started on a new medication or other treatment because you have had an arrhythmia, this test can be used to determine if a new medication/treatment has had the desired effect.

Preparation: Please shower on the morning of the test, and preferably wear a two-piece outfit. The electrodes are placed near your collarbone so it may be more comfortable for you to wear a high necked shirt.


What happens during the tests? The monitor consists of a digital recorder with up to 7 leads attached to it. A  Technician will attach the leads to your chest using sticky electrodes. If you have an allergy to any type of adhesive, please inform the Technician prior to the test so that a protective gel can be applied prior to the application of electrodes, and a hypo-allergenic tape can be used. You will be given a diary to fill in over the 24 hour period of the test. This will be used by you to let us know any relevant activities and symptoms such as exercise and bed time. There is a clock on the outside of the monitor, and you should use this to time and document the events in the diary as your watch and the clock on the monitor may not be synchronised.


During the monitoring period During the time that you are wearing the Monitor, you are asked to go about your day as normal including attending work. The only restriction on activity is that the monitor cannot get wet, so you cannot bath, shower or go swimming. Please record in your Diary any symptoms that you may feel and the activity you were doing AND the time of the symptoms. Normal electronic equipment and mobile telephones will not interfere with the recording.


What happens after your test? The Technician will write a report, which will be reviewed by a Cardiologist. The results will be sent to the Doctor who requested the test. The Technician will not be able to give you any results on the day of the test. Allow up to 5 working days for your Doctor to receive the results.




BP Monitoring


A 24 hour blood pressure monitor is a very useful test in heart medicine. The monitor is worn for 24 hours with hourly blood pressures through the day and 5 to 7 measurements over night. Why is this investigation so useful?


1. To assess blood pressure control on current medical therapy

2. To exclude white coat hypertension


White coat hypertension is a very important condition to detect. These patients have signficant elevations in blood pressure in the office but normal, near normal or only mild hypertension on 24 hour monitoring. These patients should not be treated with antihypertensive therapy, as they are at increased risk of hypotension. This condition is more common than one might expect. If you are getting dizzy on only low doses of blood pressure medication, then there is a real possiblity that you have white coat hypertension.


Hypertension during sleep on 24 hour montoring can also be a sign of obstructive sleep apnea. 



What is it? Ambulatory Blood Pressure Monitoring records your blood pressure intermittently during a normal day. Common reasons why your doctor may have referred you for the test are:

  • To monitor borderline hypertension (high blood pressure).
  • Monitor the effect of anti-hypertensive medication during a normal day.
  • To discount ‘White Coat hypertensive Syndrome’.
  • To diagnose Low blood pressure Syndromes.

Preparation: No preparation is required. You will not be able to bath or shower during the monitoring period.


During the monitoring period: When you are wearing the monitor, you are asked to go about your day as normal including attending work. The machine does give a soft audible noise immediately prior to inflation. In a normal working environment this is frequently not heard. However, as soon as the cuff begins to inflate you are required to keep the arm, including the fingers still until the cuff has deflated. If you are driving or operating machinery safety comes first. The machine will repeat the reading within the following 3 minutes affording time for you to pull over (if driving) and improve the comfort, safety and accuracy of the recording. The Blood Pressure cuff will inflate every half hour during the day and hourly at night. If the reading does not register, a repeat inflation may occur. To ensure the monitor is working the initial readings are displayed however data for all subsequent readings is stored but not displayed. Whilst the cuff continues to inflate and deflate at regular intervals the monitor is working.


Hypertension (high blood pressure) usually has no symtpoms unless very severe. Patients are much more likley to have symptoms with low blood pressure. The blood pressure can be quite high after a low blood pressure episode. Taking blood pressure after symptomatic "fuzzines" can be misleading as it may be elevated as a response to low blood pressure. Diagnosing hypertension and increasing medication can be very harmful as it will cause more hypotension (the primary problem). 24 hour BP monitoring can be very useful in these cirumstances as often reducing medications will help the problem. 


Unfortunately, ABP is not covered by medicare, despite being one of the most useful tests in cardiology.