This blog is written by our clinicians and aims to keep patients informed with up to date information on medical conditions.
According to the British Heart Foundation, Heart and Circulatory disease cause 26% of all deaths in UK. Coronary Heart Disease is the most common cause of a heart attack, with one hospital visit every 3 minutes.
It is estimated that there are 7 million people in UK (3.5 million men and 3.5 million women) living with heart and circulatory problems.
In UK, there are more than 30,000 out of hospital cardiac arrests each year with an overall survival rate of less than 1 in 10 in UK.
What is a cardiovascular Screen?
A cardiovascular screen aims at identifying early signs of heart and vascular disease and risk factors that may lead to heart attacks and strokes.
It usually consists of:
- Blood tests – such as cholesterol profile and diabetes check
- Screening tests such as ECG (electrocardiogram), ECG Stress Test, Carotid Doppler etc
In the following paragraph we shall focus largely on the heart screening tests available versus large vessels such as the carotids and the aorta.
This article will focus on the Imaging Screening tests, blood tests and other laboratory investigations will be described in a future article.
What Are The Main Screening Imaging Heart Tests Available And What Do They Do?
An ECG is a measurement of your heart activity whilst you are resting. Electrodes placed on your chest, arms and legs will pick up the electrical activity of your heart.
- Diagnoses heart attacks and angina if you have chest pains at the time of the test being taken
- May diagnose past unknown or silent heart attacks
- May diagnose abnormal heart rhythms and conduction disorders within the heart’s electrical system
- May diagnose abnormalities within the muscle of the heart
- May point to undiagnosed congenital heart problems
- It is the most basic test for the heart and may miss a large number of heart issues
- May not pick up an abnormality if at the time of recording you have no symptoms such as chest pain or palpitations
- Does not exclude ischaemic heart disease
- A normal ECG does not necessarily mean a healthy heart
ECG Stress Test
An ECG Stress test is undertaken in a similar way to an ECG but, rather than resting, you are required to walk at certain speeds on a treadmill. The speed and incline of the treadmill will go up gradually. During the test you are carefully monitored to see what your heart rate is and what your blood pressure is doing. An exercise treadmill test typically goes on for a maximum of 12 minutes. It will be stopped before this time if you experience any chest pain, or become too breathless.
- It can detect abnormal heart rhythms during exercise, and reduced blood supply to the heart due to blockages in the arteries.
- It does not reveal the extent of the reduced blood supply, or the specific area in the heart that is not receiving enough blood.
- It may not detect arterial wall thickening, as this condition does not always lead to a reduction of blood flow to the heart when exercising.
- The test is not suitable for patients who are unable to perform treadmill exercises, for example joint problems or poor mobility.
Holter ECG Monitoring
This is a battery-operated device that measures and records your heart’s activity (ECG) continuously for 24 to 48 hours or longer depending on the type of monitoring used. The device is the size of a small camera. It has electrodes that attach to your skin. After the recording period is over, the information is downloaded and reviewed by a cardiologist.
- It is completely safe.
- It is portable and can be worn whilst you go about your normal daily activities.
- It can help diagnose abnormal heart rhythms and check if pacemakers are working correctly.
- It can help with some diagnoses if symptoms are recorded at the same time as the palpitations.
- The monitor will not help your diagnosis if you do not have palpitations during the time of recording.
- You need to attend a hospital or clinic to have the device fitted.
- You will be unable to bathe, shower or swim while wearing the monitor. Some people find it slightly uncomfortable to sleep with and electrodes can be pulled off.
Alivecor Kardia Mobile ECG
This is a small device around 3 inches long. On the device there is a place to put your fingers if you feel symptoms (for example palpitations, dizziness or breathlessness). The device then transmits to the Kardia App on your smart phone to give you results of your ECG, which usually takes about 30 seconds.
- This is small enough to easily carry in your pocket, or even attach to the back of your smart phone.
- Once bought, you can monitor whenever you wish, which means it is useful for intermittent symptoms.
- It has been shown to be very effective for capturing atrial fibrillation – an arrhythmia that can lead to increased risks of strokes.
- The device costs around £100, with options for paying for a monthly subscription to store ECGs and other data.
- Users have reported getting “unclassified” rhythms that have required further interpretation by medical professionals.
- A smartphone is ideally needed to help obtain results.
- You may need to place the device on a table, as shaky hands may interfere with rhythm detection.
This is an ultrasound scan of the heart that produces live images. There are trans-thoracic Echos (TTOs) and trans-oesophageal Echos (TOEs). During TTOs, a probe is placed on your chest in order to obtain images. During TOEs, a doctor guides a much smaller transducer down your throat through a thin, flexible tube down the oesophagus (gullet). With the transducer behind your heart, your doctor can get often get a better view.
- It is very safe.
- This test can monitor how your heart and its valves are functioning. The images can help spot problems like blood clots in the heart, fluid in the sac around the heart, or infections present on heart valves.
- It is very useful for determining the health of the heart muscle, especially after a heart attack.
- It can be used to help diagnose heart failure.
- It is sometimes not possible to get adequate images by TTOs and patients are required to undergo the more invasive TOE. This may require fasting beforehand, sedation, and your throat may be sore afterwards.
- TOEs also carry very rare risks of chest pain or oesophageal perforation.
This is a transthoracic echo that is carried out during or just after a period of exercise on a treadmill or exercise bike, or after being given an injection of a medication that makes your heart work harder (pharmacological stress). The pharmacological stress echocardiogram is for patients who cannot exercise.
- A stress echocardiogram can identify the site of narrowed blood vessels, and the extent of reduced blood flow to the heart.
- It is useful if your symptoms are brought on by exercise.
- It is non-invasive.
- There is a small possibility of the patient experiencing chest pain, irregular heartbeat, blood pressure changes, or rarely, a heart attack during the test. The procedure is supervised to minimise these risks.
CT Coronary Calcium Score
This is a CT scan of your heart, and is a way of obtaining information about the presence, location and extent of calcified plaque in the coronary arteries—the vessels that supply the heart. Calcified plaque results when there is a build-up of fat and other substances under the inner layer of the artery. This material can calcify, which signals the presence of atherosclerosis – coronary artery disease (CAD).
- Useful for people who have risk factors for heart disease, but who do not yet have symptoms.
- It is quick (approximately 15 minutes), painless and non-invasive. No fasting is needed.
- This method can potentially pick up very early stages of coronary artery disease before any significant blockage has developed.
- The CT scan uses x-rays, so there is a small dose of radiation.
- A person who is very large may not fit into the opening of a conventional CT scanner or may be over the weight limit—usually 450 pounds—for the moving table.
- CAD, especially in people below 50 years of age can be present without calcium (non-calcified plaque) and may not be detected by this test.
CT Coronary Angiogram
This is another CT scan method that uses an injection of an iodine-rich contrast dye to assess the health of the coronary arteries by performing a CT scan whilst the dye flows through the coronary arteries that supply the heart. It can obtain detailed images of any narrowing or blockages in the arteries.
- It is quick, painless and non-invasive compared with other methods that require a catheter inserted into the wrist or groin.
- It is useful for investigating chest pain in people with low-intermediate risk for coronary artery disease who have normal or unclear results.
- There is a small dose of radiation.
- An intravenous drip generally needs to be placed in the arm to receive the dye material.
- There may be an allergic reaction to the contrast dye.
- People with advance kidney disease or kidney failure may not be suitable for the procedure – or may need a blood test prior to the procedure to ensure their kidney function is stable.
This is a test that measures the health of the inner lining of the arteries (the endothelium). The test uses a blood pressure cuff placed around a patient’s arm, which then inflates and deflates to measure the elasticity of the main artery in the upper arm (brachial artery). It is thought that loss of elasticity in the artery lining is one of the earliest signs of coronary artery disease. Along with other results (e.g blood pressure, cholesterol and blood sugar), the results from the device is then entered into an age calculator to give you a “vascular age” which ideally should be the same or lower than your actual age.
- The test is simple, non-invasive and takes only 20 minutes.
- It gives clear results on which aspects of your lifestyle need to be improved.
- It may give a good indication of coronary artery disease at an early stage before atherosclerosis or calcification has developed.
- Patients have to fast, abstain from coffee, nicotine and vigorous exercise before the test to ensure accurate results.
- Blood tests are needed to help calculate the vascular age.
- A high BMI may affect the accuracy of results.
Myocardial Perfusion Scanning
This is a test that uses a small amount of injected radioactive substance to create images that show blood flow to the heart muscle. The radioactive dye is picked up by a special camera. The myocardial perfusion scan looks at the pumping action of your heart and the flow of blood to your heart muscle. It can help diagnose coronary heart disease and may also be used by doctors to find out if you’d benefit from coronary bypass surgery. Scans can be done at rest, or under stress, whereby the patient exercises on a bike or treadmill – or medication given to make the heart work harder.
- The test itself takes only around 20 minutes – though it may take longer if you are having both a stress and a resting perfusion scan.
- It is one of the few tests that can give detail on both structure and function of the heart at the same time.
- You cannot take any caffeine-containing products for around 24 hours prior to the test.
- You are exposed to a small dose of radiation.
- You need to lie very still.
- There is a small risk of chest pain if you have known heart disease during the stress part of the test.
- There is a very small risk of reaction to the radioactive tracer.
Cardiac magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the structures within and around the heart. Cardiac MRI is used to detect or monitor cardiac disease and to evaluate the heart’s anatomy and function in patients.
- MRI images of the heart are better than other imaging methods for certain conditions. This advantage makes MRI an invaluable tool in early diagnosis and evaluation of certain cardiac abnormalities, especially those involving the heart muscle.
- It is noninvasive and there is no radiation.
- As the test involves an MRI scanner, it will not be suitable for those suffering with claustrophobia or people with any metal parts in their body, e.g. pacemakers.
- It can sometimes be difficult to get accurate pictures if there is an irregular heartbeat e.g atrial fibrillation, as the heart movement and rate are unpredictable.
Which Screening Heart Tests Should You Look Out For In A Screening Medical
As you can see there is a multitude of tests available on the market. You may look for a heart test because you have a specific concern or because you wish to get an assessment of your health.
It is always best to discuss your health with a doctor first as there is no one glove that fits all.
An ECG though is worth having as may highlight unknown current or past conditions.
If you are or you believe you are a healthy individual, an ECG Stress test is highly unlikely that is beneficial and one should not spend their monies on a health check that includes an ECG Stress Test. Patients tend to be reassured if they had a normal ECG Stress Test. However an ECG Stress Test is only abnormal in advanced heart disease. If you are looking to identify early changes than this is not the test for you. The ECG Stress Test has been around for a very long time and it is used primarily by the NHS as a way of risk grading patients with known/ suspected heart disease.
In October 2018, the American Heart Association published their guidelines for the prevention of heart disease. For the first time, it has been made clear that a CT Coronary Calcium Score should be utilised when assessing someone’s risk for future heart disease and when deciding for example to start someone on statins. This approach is recommended for those who are looking for a personalised approach to their health. At ROC, we have been utilising this test since 2010 specifically for this purposes.
A CT Coronary Calcium Score does have the downside of cost (approximately £600) and radiation though. The question of what else is available out there, that costs less, involves no radiation and can be repeated once lifestyle changes made, was a question posed by ROC for several years. This is how we started utilising the Angiodefender for the purpose of providing a personalised heart disease risk evaluation.
An Echocardiogram although good for evaluation the heart chambers, valves and function will not identify early cardiovascular disease. This, as well as the other tests mentioned above (MRI, CT Angiogram) may be recommended by doctors upon certain findings or history.
The ECG Holter Monitoring test has always been a source of dissatisfaction with patients primarily due to the fact that it can miss abnormal heart rhythms if one doesn’t have palpitations/ does not experience an abnormality during the recording. The Kardia Alivecor monitor (along with ZioPatch not described in this article) has revolutionised the diagnosis of abnormal heart rhythms, primarily as the patient can record their ECG themselves when they experience symptoms. Unfortunately, this test has been picked up by only some NHS trusts within UK, but ROC does recommend patients they buy it when is indicated.
If you have any questions about this article, your heart, screening tests or you have any concerns do get in touch.
In the meantime, the key point to take home is- an old fashion ECG Stress test as a way of health screening is unlikely to benefit your health, although many feel good when is normal.
Think Prevention. Think CT Coronary Calcium Score. Think Angiodefender.