Cardiac Testing
(SA)

Attached in under 30 seconds, the lightweight, showerproof myPatch Holter provides patients with the freedom to continue their daily routines while delivering greater clarity and superior results. With no battery recharging or patch changes required during testing, myPatch is both easy and comfortable for patients.  

What are the benefits of multi-day monitoring? 

Data shows that longer monitoring periods increase the likelihood of detecting first occurrences of various significant arrhythmias. With increasing evidence of atrial fibrillation's contribution to stroke, a multi-day Holter can detect more subtle arrhythmias. It also provides peace of mind, as arrhythmias are less likely to go unnoticed compared to shorter studies.  

Our myPatch Multi-Day Holter Monitor Report 

The report summarises the study, highlights any significant events and provides a conclusion. Results are analysed by specialist reporting software and a cardiac physiologist, with report sign-off and recommendations by a cardiologist. For complex cases requiring specialist review, a cardiologist is available to explain the results if needed. 

Our myPatch Multi-Day Holter Monitor reports are available to digitally download from Clinical Labs’ eResults. Click here to log in or register. 

An electrocardiogram (ECG) only provides a snapshot of cardiac rhythm at a specific moment, whereas arrhythmias may be short-lived, paroxysmal, and even asymptomatic, making documentation challenging in many patients. Holter monitoring has been developed to record cardiac rhythm over a set period in patients suspected of having arrhythmias. Holter monitors are the preferred method as they offer a 24-hour window of heart rate changes and can be correlated with symptoms. 

Generally, cardiologists prefer that patients presenting with common warning signs, such as palpitations, unexplained dizziness, and slow heart rhythms, undergo Holter monitor testing through their GP before being referred to a specialist. By having the patient undertake the Holter test while waiting to see a cardiologist, the necessary data and results are already available at the time of specialist consultation. This approach shortens the diagnostic process, enabling the cardiologist to make the most informed decision from the outset. 

Arrhythmia indications for ambulatory ECG monitoring:  

• Cardiac palpitations 
• Unexplained syncope or dizziness 
• Suspected slow heart rhythms 
• Hereditary ‘‘electrical” abnormalities 
• Evaluation of an abnormal ECG with ectopy and heart block 
• Cryptogenic stroke evaluation to document paroxysmal atrial fibrillation 
• Evaluation of success of either antiarrhythmic or ablative therapy 
• Paediatric ambulatory monitoring 
• Following acute myocardial infarction 
• Potentially lethal arrhythmias with congestive and hypertrophic cardiomyopathy 
• Monitoring cardiac implantable electronic device therapy 
• Chest pain or dyspnoea thought to be associated with arrhythmias or ST changes 

Our Holter Monitor Report 

The report summarises the study, highlights any significant events and provides a conclusion. Results are analysed by specialist reporting software and a cardiac physiologist, with report sign-off and recommendations by a cardiologist. For complex cases requiring specialist review, a cardiologist is available to explain the results if needed.  

Our Holter Monitor reports are available to digitally download from Clinical Labs’ eResults. Click here to log in or register.

Recognised as a gold standard test for blood pressure assessment, ABPM provides interval measurement over 24 hours for a full diagnostic assessment of blood pressure, while allowing for circadian rhythm and white coat or masked hypertension concerns. It is also effective in assessing drug effects, patient activity, and work influence, while providing better correlation with end-organ damage than isolated BP readings. 

Automatic cuff inflation occurs every 30 minutes during the day and every hour overnight, with ambulatory pulse waves, peripheral blood pressure, central haemodynamics, and arterial stiffness measured over a 24-hour period to create a haemodynamic day/night profile. It is recommended that at least 14 recordings be performed during the daytime period.  

Our ABPM Report 

Results are analysed by specialist reporting software, with report sign-off and recommendations by a cardiologist. The interpretation of results requires a clinical assessment, taking into consideration well-established risk factors for cardiac disease. Consequently, the referring doctor can modify the report conclusions to suit the patient’s individual circumstances, such as a young diabetic with renal disease who requires optimal control. The referring doctor, and not the reporting physician, should review the patient diary with the patient. For complex cases requiring specialist review, a cardiologist is available to explain the results if needed. 

Our ABPM reports are available to digitally download from Clinical Labs’ eResults. Click here to log in or register.   

Despite the vast improvements in cardiological investigations, the resting 12-lead ECG remains the first cardiology investigation performed during a consultation or hospital visit.  

Indications for 12-lead ECG: 

• Heart health 
• Pre-operative evaluation 
• Palpitations/skipped beats 
• Bradycardia 
• Chest pain 
• Dizziness and syncope 
• Familial sudden death syndromes, including athletes 
• Hypertension 
• Cardiomyopathy 
• Dyspnoea 
• Stroke 
• Pacemaker evaluation 

Our ECG Report 

Results are analysed by specialist reporting software and a cardiac physiologist, with report signoff and recommendations by a cardiologist. For complex cases requiring specialist review, a cardiologist is available to explain the results if needed.  

Our ECG reports are available to digitally download from Clinical Labs’ eResults. Click here to log in or register.  

A wide range of biochemical tests can be useful in the assessment and treatment of heart disease. Click here to view our summary infographic. 

Heart Failure 

Patients with suspected or known heart failure can now be investigated with a B-type natriuretic peptide (BNP) measurement.  An item for NT-proBNP or BNP testing, is available on the Medicare Benefits Schedule, broadening the range of clinical situations in which NT-proBNP or BNP testing can be ordered. 

B-type natriuretic peptides (BNP) are primarily synthesised and released by the heart's ventricles in response to ventricular stretch and pressure overload, reflecting myocardial wall tension. This makes BNP an important biomarker for the diagnosis, evaluation, and management of heart failure. It is particularly useful for distinguishing heart failure from other causes of dyspnoea. 

In our laboratories, an NT-proBNP level of less than 125 ng/L makes a diagnosis of congestive heart failure unlikely. 

Chest Pain 

Investigating chest pain is best done in a setting where resuscitation facilities are available. Initial investigations include a troponin measurement and a 12-lead resting ECG. These tests are usually then repeated after a period of several hours, depending on local protocols. 

Hypertension (BP) 

Besides repeated blood pressure measurements or a 24-hour ambulatory recording, investigations for secondary causes of hypertension can also be appropriate. These are best done before the patient commences treatment. Typical tests include investigations for: 

• Adrenal causes 
  • Hyperaldosteronism (renin-aldosterone ratio) 
  • Pheochromocytoma (urine catecholamine or metabolites) 
  • Cushing’s syndrome (cortisol) 
• Liver disease (liver function tests) 
• Renal disease (urea and electrolytes) 
• Thyroid disorders (thyroid function tests) 

Cardiac Arrhythmias and Palpitations 

The initial investigation for arrhythmias and palpitations is a resting 12-lead ECG, followed by 24-hour ambulatory ECG monitoring (Holter monitoring). Biochemical testing for electrolyte imbalances (potassium, calcium, magnesium), digoxin levels and thyroid disorders can also be useful. 

Atherosclerosis 

Serum lipids (cholesterol, triglycerides, HDL cholesterol, LDL cholesterol and non-HDL cholesterol) have an important association with atherosclerosis and measuring levels is useful in diagnosing and managing lipid disorders. Some more specialised investigations, such as apolipoprotein (a) and high-sensitivity C-reactive protein (hs-CRP), can be helpful in selected patients.