What is measured when the heart contracts?

To identify common heart conditions you'll need to have some tests. These could include:

• blood pressure tests
• checking your pulse
• X-rays
• stress tests

Checking your pulse

Taking a pulse is a very important part of heart health checks. It measures the number of heart beats per minute, assesses if the pulse is regular or not, and identifies the strength of the pulse. Your nurse or doctor may check your pulse, or you can check it yourself.

More about atrial fibrillation

Watch NHS Fife's video on how to check your own pulse, and how important it is to go and talk to your doctor or nurse if you notice that your pulse isn't regular.

Blood pressure is an important measurement that can be taken by your doctor, nurse or healthcare assistant. It’s recorded as two readings:

• systolic pressure (higher reading) – this records the pressure within the blood vessels as the heart contracts and forces blood out into the arteries
• diastolic pressure (lower reading) – this records the pressure when the heart fills up with blood again

Your blood pressure fluctuates throughout the day, depending on what you’re doing. The "white coat effect" is when your blood pressure rises at the thought of having your blood pressure taken. To prevent this when you get your BP taken, try to relax. You might be asked to sit quietly for at least five minutes beforehand. Tell the person taking your blood pressure about any prescribed medicines you’re taking.

Sometimes your doctor may want you to monitor your blood pressure at home over a period of time. This can be either by 24-hour ambulatory monitoring or by home monitoring.

Read more from the British Hyperternsion Society on home blood pressure testing

British Heart Foundation have information on measuring your blood pressure at home

Echocardiogram

An echocardiogram - or "echo" - is an ultrasound scan of the heart. It uses high frequency sound waves to create an image of your heart.

This is a painless procedure that is usually performed in hospital or in an outpatient clinic. You’ll have jelly applied to your bare chest, and an experienced operator will move the probe around your chest to get good views of your heart.

It can check:

• the size of the heart
• how well the heart muscle is contracting and relaxing
• how well the valves are working

More about having an echocardiogram

Electrocardiogram

An electrocardiogram (ECG) is a test that records the electrical activity of the heart. The ECG reflects what’s happening in different areas of the heart and helps identify any problems with the rhythm or rate of your heart. The ECG is painless and takes around 5-10 minutes to perform.

More about having an electrocardiogram

24-hour or ambulatory electrocardiogram

In this test, electrodes are connected to a small box and attached to a belt. You wear this belt for 24 hours, as you go about your normal daily activities. The ECG will be monitoring and will be able to record any abnormalities over the day. You’ll also be asked to record any symptoms. Then this can be assessed by the electrophysiologist or cardiologist.

Stress test

This stress test - or exercise tolerance test (ETT) or treadmill test - is similar to an ECG but records the activity of the heart as it works harder, for example while you’re walking on a treadmill. This "exercise" ECG records how the heart responds to exercise.

Watch this video by British Heart Foundation of someone being prepared for, and undertaking, an ETT.

A tilt test allows the doctor to monitor your blood pressure and heart rate when you’re lying down and standing up.

This test is designed to assess symptoms you may have been experiencing, like light-headedness or dizziness, and to see if your symptoms are related to your blood pressure or heart rate.

The test will normally be done as an outpatient appointment in an electrophysiology department.

Watch this British Heart Foundation video of a tilt test being performed.

This painless scan uses a magnetic field inside a scanning machine to produce images of the heart and blood vessels.

It’s useful for checking problems with structure of heart and blood supply.

It’s very helpful in getting images from people whose vessels and heart anatomy are difficult to see using angiography.

Cardiac CT uses a special X-ray machine, which moves around your body and takes detailed 3-D images of your heart.

Thallium scan (myocardial perfusion scintigraphy)

This scan shows how well blood is reaching the heart muscle through your coronary arteries. A small amount of thallium (radioactive substance) is injected into a vein, and a special camera moves around your heart. The camera picks up traces of thallium and produces pictures.

As thallium doesn’t travel well to areas where there’s a poor blood supply, the pictures can be used to see how well blood is reaching your heart. It’s a useful alternative to an exercise test if this can’t be done or when specific information on your heart muscle is needed which a treadmill exercise test can’t provide.

This is done at rest and during exercise.

The very low levels of radiation used are considered to be safe.

Coronary angiogram

A coronary angiogram is a type of X-ray used to examine the coronary arteries supplying blood to your heart muscle. It's considered to be the best method of diagnosing coronary artery disease - conditions that affect the arteries surrounding the heart.

During the test, a long, flexible tube called a catheter will be inserted into a blood vessel in either your groin or arm. The tip of the catheter will then be fed up to your heart and coronary arteries.

Special dye will then be injected through the fine catheter into your coronary arteries, and X-ray images will be taken. These images created during angiography are called angiograms.

These images will be used to identify narrowing or blockage of the arteries that may be responsible for your symptoms. This test is also sometimes required to reach a diagnosis for patients with heart valve and muscle disease.

More about cardiac catheterisation and coronary angiography

Watch a short video where Dr Peter Henriksen, Consultant Cardiologist for NHS Scotland, provides an outline and explanation of the coronary angiogram procedure.

There are a number of blood tests that can be done to rule out other causes of heart symptoms, and to measure different levels within the body that can affect the heart. You may also get blood tests done if you begin a new heart medicine. 

The most common are:

• Full Blood count (FBC) - this test measures the levels of red blood cells, white blood cells and platelets. It also measures the haemoglobin (oxygen carrying component of red blood cells).
• Urea and Electrolytes (Us and Es) - urea levels help to monitor how the kidneys are working. Electrolytes help to stabilise the heart rhythm.
• Glucose - this test measures the level of sugar in the blood.
• Liver and thyroid function - these tests measure liver function and the thyroid function.
• Troponin blood test - troponin is a protein which is released into the blood stream when the heart muscle is damaged. The troponin level provides a quick and accurate measure of any heart muscle damage. It’s used to help in the assessment following suspected heart attack. It may be taken on admission to hospital and/or 12 hours from the onset of symptoms.
• Cholesterol level and lipid profile.
• Natriuretic peptides - an indicator of heart failure.

More about having a blood test

Chest X-ray

A chest X-ray is useful for showing the size and shape of the heart and detecting chest disorders. This can provide doctors additional information about your symptoms (which can often relate to both chest and heart conditions) and can also show any fluid in the lungs, which may be caused by heart disease.

More about having an X-ray

Blood pressure is the force of the blood pushing against the artery walls. The force is generated with each heartbeat as blood is pumped from the heart into the blood vessels. The size and elasticity of the artery walls also affect blood pressure. Each time the heart beats (contracts and relaxes), pressure is created inside the arteries.

The pressure is greatest when blood is pumped out of the heart into the arteries. When the heart relaxes between beats (blood is not moving out of the heart), the pressure falls in the arteries.

Two numbers are recorded when measuring blood pressure.

• The top number, or systolic pressure, refers to the pressure inside the artery when the heart contracts and pumps blood through the body.

• The bottom number, or diastolic pressure, refers to the pressure inside the artery when the heart is at rest and is filling with blood.

Both the systolic and diastolic pressures are recorded as "mm Hg" (millimeters of mercury). This recording represents how high the mercury column in the blood pressure cuff is raised by the pressure of the blood.

Blood pressure is measured with a blood pressure cuff and stethoscope by a nurse or other healthcare provider. You can also take your own blood pressure with an electronic blood pressure monitor. These are available at most pharmacies.

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) has determined 2 levels of high blood pressure for adults:

• Stage 1

  • 140 mm Hg to 159 mm Hg systolic pressure—higher number

and

• 90 mm Hg to 99 mm Hg diastolic pressure—lower number

• Stage 2

  • 160 mm Hg or higher systolic pressure

and

• 100 mm Hg or higher diastolic pressure

The NHLBI defines prehypertension as:

• 120 mm Hg to 139 mm Hg systolic pressure

and

• 80 mm Hg to 89 mm Hg diastolic pressure

The NHLBI guidelines define normal blood pressure as follows:

• Less than 120 mm Hg systolic pressure

and

• Less than 80 mm Hg diastolic pressure

Use these numbers as a guide only. A single elevated blood pressure measurement is not necessarily an indication of a problem. Your healthcare provider will want to see multiple blood pressure measurements over several days or weeks before making a diagnosis of high blood pressure and starting treatment. If you normally run a lower-than-usual blood pressure, you may be diagnosed with high blood pressure with blood pressure measurements lower than 140/90.

What are the risk factors for high blood pressure?

Nearly one-third of all Americans have high blood pressure, but it is particularly prevalent in:

• People who have diabetes, gout, or kidney disease

• African Americans (particularly those who live in the southeastern U.S.)

• People in their early to middle adult years; men in this age group have higher blood pressure more often than women in this age group

• People in their middle to later adult years; women in this age group have higher blood pressure more often than men in this age group (more women have high blood pressure after menopause than men of the same age)

• Middle-aged and elderly people; more than half of all Americans age 60 and older have high blood pressure

• People with a family history of high blood pressure

• People consuming a high salt diet

• Overweight people

• Heavy drinkers of alcohol

• Women who are taking oral contraceptives

• People with depression

How does blood pressure increase?

The following conditions contribute to high blood pressure:

• Being overweight

• Excessive sodium intake

• A lack of exercise and physical activity

How is high blood pressure controlled?

These steps can help you control your blood pressure:

• Take prescribed medicine exactly as directed by your healthcare provider

• Choose foods that are low in sodium (salt)

• Choose foods low in calories and fat

• Choose foods high in fiber

• Maintain a healthy weight, or losing weight if overweight

• Limit serving sizes

• Increase physical activity

• Reduce or omit alcoholic beverages

Sometimes daily medicine is needed to control high blood pressure. If you have high blood pressure, have your blood pressure checked routinely and see your healthcare provider to monitor the condition.