Diagnostic Tests

Cardiology  

Electrocardiogram (ECG) 

What it is and how it works: An electrocardiogram (ECG) is one of the most common heart tests performed. It is used to record the electrical activity of the heart during each beat, which is done by placing a number of electrodes, or sticky pads, onto the chest, wrists, and ankles. These are then connected by wires to an ECG recording machine. It is important that the patient remains as relaxed as possible during the ECG recording to help ensure a reliable result. Normally, the test will last for only a few minutes. 

What it detects: An ECG can help to identify various heart problems. It can be used to detect unusually fast or slow heart rates, irregular heart rhythms (also called arrhythmias), and areas of reduced blood supply to the heart. 

Blood pressure 

What it is and how it works: A blood pressure test is used to measure the strength, or pressure, of blood against the walls of the arteries of the body. This pressure is caused by the pumping action of the heart. Blood pressure is usually recorded as two numbers – the systolic pressure, which is the maximum pressure generated when blood is pumped out of the heart during a single beat, and the diastolic pressure, which is the minimum pressure between beats, or when the heart is at rest. For example, a blood pressure of 140 systolic over 90 diastolic is recorded as 140/90mmHg. When a recording of your blood pressure is made, a cuff will usually be wrapped around the upper arm and filled with air until tight – this can feel a little uncomfortable. The cuff is connected to a blood pressure machine which will help to record the result. It is important to remain as relaxed as possible and not to talk during the test. This helps to ensure a reliable result. Normally, the test will last for only a few minutes. 

What it detects: Blood pressure recordings help to detect abnormally high or abnormally low results. High blood pressure is typically linked to unhealthy lifestyles, consuming too much alcohol, smoking, or being overweight. If left untreated, it can lead to problems with the heart and kidneys. Low blood pressure can be caused by certain medicines, dehydration, and heart failure.  

24-hour blood pressure monitoring 

What it is and how it works: As with a blood pressure recording, an inflatable cuff is secured around your arm. However, for 24-hour blood pressure monitoring, this cuff is then connected to a small monitoring device that is worn around your waist. The cuff will inflate and deflate at regular intervals over a 24-hour period to help monitor your blood pressure. You will not need to stay in the hospital or clinic for this to be done, and you can continue with your normal day-to-day activities during this. 

What it detects: As with blood pressure assessment, blood pressure recordings help to detect abnormally high or abnormally low results.  

Blood tests 

What it is and how it works: A blood test is where a sample of blood is taken for analysis in a laboratory. This is done by inserting a needle into a vein, usually at a site that is located inside the elbow or on the back of the hands. Before the needle is inserted, a tight band (tourniquet) is placed above the site from which the blood is due to be drawn. The skin is then cleaned with an antiseptic wipe. Once the required number of samples have been taken, these will then be sent to a laboratory for tests. 

What it detects: Several blood parameters can be looked at during a blood test. These include a Full Blood Count (FBC – to look for infection or anaemia), Urea and Electrolytes (U&Es – to look for any electrolyte imbalances), Liver Tests (to look for any liver problems), Lipid Profile (to look for any abnormalities in cholesterol, good and bad fat levels, as well as performing an advance lipid profile for e.g., familiar hypercholesterolaemia), Thyroid Function Tests (TFTs – to look for an over or underactive thyroid which can cause problems with the heart, or that might be resulting in palpitations), Clotting Screen (to monitor medicines such as warfarin), Cardiac Enzyme Tests such as troponin (to diagnose or rule out a heart attack), B-type Natriuretic Peptide (BNP – to look for signs of heart failure), and inflammatory markers such as ESR/CRP (for pericarditis and myocarditis)