Cardiology information.

Here is some useful information on conditions, investigations and treatments.

Heart Rhythm Issues

The heart is an amazing muscle in your body. It functions as a pump to move blood to your lungs to receive oxygen, and then move that oxygen rich blood around your body. We have valves within the heart that open and close to stop the blood moving the wrong way through the system.

The heart muscle itself receives blood through the coronary arteries, small blood vessels that branch out and ensure the muscle can work hard in response to effort.

In order for the pump to work in a coordinated way, there is an electrical network running through it. This is what creates your heart rhythm, which describes how ordered and regular those electrical signals are, and the heart rate, describing how fast your heart is beating. Many factors can affect this, including normal day to day activity.

Electrocardiogram - ECG (or electrokardiogram EKG)

You can get an idea about your heart rate and rhythm by feeling your pulse. We tend to do this at your wrist. We measure this in beats per minute, and it should feel regular and steady.

There are medical and consumer devices, including your smartphone, perhaps using the phone camera and an app (fibricheck) or an inbuilt green light in your smartwatch to look at pulse flow (photoplesmography). Exercise monitors on gym equipment or chest straps work in a similar way. 

These methods are useful to measure the pulse rate, but don’t tell us anything accurate about the rhythm. For this we need to record the actual tiny electrical signals (in millivolts) as they flow through the heart. We do this with a device which can detect this between two or more skin electrodes, and the difference in signal between various pairs of electrodes gives us an ECG lead.

The gold standard ECG uses 10 electrodes to create 12 leads. This is the type of recording that you would have in clinic, and is generally used to look at the heart over just 10 seconds, and will give us information about preexisiting conditions.

We can use an ambulatory ECG to create a dynamic recording of the heart rhythm too, and this helps to detect problems occurring only intermittently. These devices can record for a day or longer, and even longer term with tiny devices that can put inserted under the skin.

You may also have a smart watch which does also record your ECG (as well as pulse), typically by placing a finger from one hand on the watch crown of the other wrist. There are also electrode devices which work with your smartphone or tablet. Be aware that not all of these have received medical regulation approval, although Kardiamobile has.

Echocardiogram

The structure of the heart muscle, pumping function and valve movements can be assessed in a variety of waves, traditionally through examination. Abnormalities of the heart valves can cause turbulent or noisy blood flow, and this can be picked up as a murmur when listened to with a stethoscope.

The most common method of visualising these features is with ultrasound. This is a harmless and painless type of imaging test which “bounces” sound waves off structures in the body.

A specialist ultrasound for the heart is called an transthoracic echocardiogram, and this can look at the structure and function. This is usually done by a cardiac physiologist, a specially trained technician, who reports the findings which can then be interpreted by your cardiologist. 

Your cardiologist may recommend using ultrasound in other ways, but this would also be explained in detail before arranging. Sometimes an echocardiogram is done following exercise, or with medication to speed up the heart. This is known as a stress echocardiogram and can be used to look at how well the muscle receives blood.

There are also occasions where we need to scan areas of the heart in more detail, and we may use an ultrasound probe passed into the gullet. This is known as a transoesophageal echocardiogram and is usually done as part of heart surgery.

Angiogram

The blood vessel supply of your heart can be visualised with X-rays. This is usually done to calculate your risk of future problems like a heart attack, by looking for hardening of the arteries (atherosclerosis), or we can inject a dye which outlines the arteries and shows us if there is any narrowing which might restrict blood flow and cause angina.

There are various treatments to deal with atherosclerosis, generally focussed on modifying your risk factors. Sometimes we may recommend unblocking the artery with angioplasty.

MRI

We can also get a very detailed picture of the heart by using MRI, or magnetic resonance imaging. This is a painless scan which uses a strong magnetic field and radio waves to create a moving image of your heart pumping.

We often use a dye to show up areas of scar tissue within the heart, and sometimes this is combined with medication to make your heart beat faster and see how it performs under stress.

This gives us very useful information about why the heart muscle might be weakened, and whether any narrowing of the heart arteries is important.

Arrhythmia

Your heart rhythm is normally initiated from the top of the heart from the “sinus” node. This generally varies between 50 and 100 beats per minute when resting. It can be faster when exercising, but also if you are anxious, in pain or if you have a fever. The heart rate can also slow, typically when you are resting or asleep.

These are normal reactive, or physiological, changes that happen in response to your body’s needs, in a similar way that your blood pressure, temperature or breathing rate can change. Sometimes these normal changes can happen in an exaggerated or unhelpful way, such as the feeling you may have when you feel nervous, but they are still normal findings.

Palpitations

Your heart beats around 100,000 times in a day, but you don’t generally notice it! When you have an awareness of it bearing, perhaps a thud, vibration or fluttering in your chest or neck, we call that a palpitation.

It may happen with a normal heartbeat, perhaps if it is faster than you are used to, but can be because of any arrhythmia.

It does not in itself indication any serious problem, but can help to describe the symptoms and help reach a diagnosis.

Ectopic beats

Whilst a normal heart beat is initiated from the top chambers, other areas of the heart can trigger a beat, a bit like a muscle twitch. This is often followed by a brief pause whilst the heart fills again before the next beat, and so this beat tends to be a bit more forceful.

Some people might feel these as a skipped or missed beat or as an extra beat which is slightly out of rhythm. These are usually entirely harmless, although we may recommend tests to look for related conditions.

Atrial fibrillation

The upper chambers of the heart (atria) can develop an irregular and chaotic rhythm called atrial fibrillation (AF). This conducts quite quickly to the main pumping chambers (ventricles) and causes an irregular pulse. This can cause symptoms such as palpitations, breathlessness or dizziness. For some people the AF does not cause any symptoms at all. 

This is an important condition because it can increase the risk of blood clots forming in the heart, which can then travel elsewhere in the body and cause problems such as stroke.

The absolute risk of this happening is determined according to your overall health, affected by things like your age and problems like diabetes. The good news is that a simple blood thinner medication, known as an anticoagulant, can reduce that risk. 

For some people AF comes and goes (paroxysmal AF), whereas for others it is there the whole time, or persistent. As long as the risks of stroke are managed, treatment of symptoms depends on how much they affect your day to day living. This can include medication to slow the heart rate down or keep you in a normal rhythm, or procedures to reset or control the rhythm.

Atrial flutter

Sometimes a regular short circuit rhythm can develop in the upper chambers. This causes the upper chambers to beat quite quickly, and the main pumping chambers (ventricles) respond by beating quite fast too. This can cause symptoms such as palpitations, breathlessness or dizziness.

This is an important condition because it can increase the risk of blood clots forming in the heart, which can then travel elsewhere in the body and cause problems such as stroke.

The absolute risk of this happening is determined according to your overall health, affected by things like your age and problems like diabetes. The good news is that a simple blood thinner medication, known as an anticoagulant, can reduce that risk. 

Atrial flutter is usually caused by a specific short circuit within the right atrium, and it can often be cured with a procedure known as ablation to cauterise the fibres causing it.

Supraventricular tachycardia

Supraventricular tachycardia or SVT is a term used to describe a number of faster rhythms that can occur. In most cases they are harmless, but can cause intermittent problems such as palpitations, breathlessness or dizziness.

They occur when the normal electrical signal travels through a short circuit between the top and bottom of the heart and continues to do so for several minutes. It usually starts and stops very quickly.

There are many types of SVT, but the commonest is known as AV nodal re-entrant tachycardia (AVNRT) where the signal short circuits between fibres travelling to and from the atrioventricular node (“junction box” connecting the top and bottom on the heart). Less commonly there may be additional electrical connections between the upper and lower chambers, and this can cause AV reentrant tachycardia. An example of this Wolff-Parkinson-White syndrome

 Treatment is based on a few factors but a cure is often possible. An electrophysiology study and ablation, offers the chance to confirm the cause of the arrhythmia, and cauterise the fibres causing the problem.

Ventricular tachycardia and fibrillation

Fast heart rhythms originating from the ventricles are known as ventricular tachycardia (VT). These can be harmless, but in people with heart disease, VT or ventricular fibrillation (VF) may cause fainting or cardiac arrest where the heart fails to beat properly.

Bradycardia

A slow heart rate is termed bradycardia. This is often a heart rate below 50 beats per minute, although resting heart rates as low as 40bpm can be entirely normal. The pulse, or heart rate monitor, can detect a slow rate, although the rhythm causing this can only be determined by an ECG. 

Sinus bradycardia is usually a normal finding. Sometimes the sinus node fails to initiate a heart beat, and this can cause a pause in the heart beat. This may happen normally when sleeping, but if it happens in association with symptoms such as dizziness or fainting, it is often a sign of an underlying problem.

There are also conditions in which the sinus beat doesn’t get through the atrioventricular node (“junction box” connecting the top and bottom on the heart) and this can cause a slow heart rate, or intermittent pauses which can be quite serious, even if they don’t cause symptoms like fainting. 

Pacemaker

A pacemaker is a permanent device which helps to control the heart rhythm. It is usually implanted as a minor surgical procedure under local anaesthetic, sited under the skin near your collar bone, with one or more electrode wires passing through a vein down to your heart.

The device is a sealed unit containing a battery and computer circuitry, a flat oval about 5cm across. The outline of the device may be visible under the skin. 

The pacemaker is set to monitor the heart rhythm continuously, and may stimulate the heart muscle to beat if the rate drops below a certain level. You don’t feel the electrical impulse required to do this. Some pacemakers are used to coordinate the heart rhythm between the left and right ventricles.

Implantable cardioverter defibrillator

An implantable cardioverter defibrillator or ICD is a device similar to a pacemaker, implanted as a minor surgical procedure under local anaesthetic, sited under the skin near your collar bone, with one or more electrode wires passing through a vein down to your heart.

The device is a sealed unit containing a battery, capacitor and computer circuitry. It is about the size of a matchbox. The outline of the device may be visible under the skin. 

The ICD is set to monitor the heart rhythm continuously, and similarly to a pacemaker it may stimulate the heart muscle to beat if the rate drops below a certain level. It will also detect dangerous fast heart rhythms, such as ventricular tachycardia or fibrillation, and automatically deliver a shock to the heart to reset this rhythm.

Heart attack

If there is a sudden blockage to the blood supply of the heart (perhaps from atherosclerosis), the muscle supplied by that artery will be starved of oxygen and would eventually die and become permanently damaged.

This can happen very quickly, and so heart attack is a medical emergency you should call 999 for an ambulance immediately.

Angina

The heart is a muscle and requires oxygen to beat normally. This is carried by the blood through vessels called arteries. Narrowing of the arteries caused by atherosclerosis can restrict this blood flow, causing symptoms known as angina. This can be a cramp like discomfort felt in the chest, neck, arms or stomach, but sometimes may just cause breathlessness. 

The symptoms are typically felt when the heart is under strain, such as physical exertion, and usually relieved by resting. Pain or discomfort which is not worse with exercise is unlikely to be angina. 

Angina is usually investigated by imaging the arteries with an angiogram. If there is atherosclerosis then treatment to relieve the symptoms and prevent progression of the disease is usually recommended. Sometimes opening up the artery with a scaffold to stent it open, known as angioplasty, is needed.

Symptoms that happen with progressively less effort, or then start happening at rest, may require more urgent medical attention. If there is a sudden blockage to the blood supply of the heart (perhaps from atherosclerosis), the muscle supplied by that artery will be starved of oxygen and would eventually die and become permanently damaged.

This can happen very quickly, and so heart attack is a medical emergency you should call 999 for an ambulance immediately.

Heart failure

Heart failure is a term used to describe any condition in which the heart fails to pump blood efficiently. The main symptoms are breathless during exertion, and fluid retention leading to swollen feet, ankles or abdomen. 

Investigations for heart failure include ECG, some blood tests, and an imaging test, usually an echocardiogram.

It usually results from weakness in the muscle, but can be due to arrhythmia or problems with the anatomy of the heart. There are a range of conditions that can cause heart failure, some of which are reversible, although it is usually a long term condition for which there is no cure. Treatments mean that it is often possible to live a normal life.

Electrophysiology study and ablation

The rhythm of the heart can be investigated in a number of ways, the commonest being a resting ECG. Sometimes we need to look at how the electrical signals travel through the heart.

We can do this by recording an ECG from inside different areas of the heart during an electrophysiology study (EPS). This is done by passing fine recording electrode wires up through the vein at the top of the leg, and using x-ray guidance to place them in defined locations. The time it takes for signals to travel around can tell us a lot about what is happening, and we would usually take the opportunity to try and reproduce any suspected or confirmed arrhythmia.

We would aim to confirm the location of the short circuit causing this, and if it was accessible, ablation can be used to freeze or heat the fibres causing it.

Ready to get in touch?

For appointments and other enquiries, get in touch today