Angina is pain or discomfort in the chest which is usually caused by coronary heart disease. The pain may also spread to the arm, stomach, neck and jaw. Angina occurs when the arteries that supply blood and oxygen to the heart muscle become narrowed, restricting blood flow.

Angina can be split into two categories:

Stable angina: angina symptoms are caused by an obvious trigger, such as exercise, and improve with medication and rest.

Unstable angina: angina attacks are more unpredictable, occurring with no obvious trigger and continue despite rest.

If you suffer from angina it is important to minimise any risk factors that can cause further narrowing of your arteries. These include:

  - Stopping smoking
 - Being physically active
  - Maintaining a healthy weight
 - Ensuring that cholesterol is within healthy limits
 - Controlling  high blood pressure

Your heart is governed by an electrical system that tells your heart when to beat and push blood around the body. An arrhythmia is an abnormal heart rhythm when your heart is beating too fast, too slow or with an irregular pattern.

Fast heart rhythms are known as tachycardias and include supraventricular tachycardia, atrial flutter, atrial fibrillation, ventricular tachycardia and ventricular fibrillation.

Slow heart rhythms are called bradycardias and include rhythms such as AV heart block, bundle branch block and tachbrady syndrome. 

The most common causes of arrhythmia are that the electrical impulses are not coming from the sinus node as they should and are instead being generated from another part of the heart. Occasionally the electrical impulses can originate from the sinus node but are travelling to the lower chambers of the heart by an unusual path.

Depending on the arrhythmia that you are experiencing, medications may be used to stop, prevent or control it. Alternatively a procedure such as a cardioversion or ablation may be performed or an implantable cardioverter defibrillator (ICD) or pacemaker may be inserted via surgery. ​

It is not always possible to remove a blockage using a stent. This can be the case if there are multiple blockages, or if the blockages are in inaccessible areas. Sometimes a coronary artery bypass graft (CABG) is the best option.

Arteries from the chest wall (internal mammary artery) or arm (radial artery), or veins from the leg (saphenous veins), are used to bypass blockages in the coronary arteries. The number of bypasses needed depends on how many arteries are narrowed. The coronary arteries are located on the outside of the surface of the heart, so the surgeon does not need to open up the heart. However, in order to access the heart, the surgeon will need to cut through the sternum (breastbone).

Recovery time varies from person to person, but most people find that it takes between two and three months to make a full recovery. Older people, or those who were particularly unwell before surgery may take longer to recover than others. ​

Pacemakers

If your heart's natural pacemaker (the sinus node) isn't working properly, or there is an abnormality with the electrical conduction system in the heart a pacemaker may be required.

The job of a pacemaker is to artificially take over the role of the sinus node. Electrical impulses are sent to stimulate the heart to contract and beat. Most pacemakers work on demand (when they are needed, e.g. if the heart has a missed beat or is beating too slowly). However, some work all the time.

ICD (implantable cardioverter defibrillator)

An ICD is used to pace the heart in the same way as a pacemaker. However, it can also deliver a shock if it detects the heart is beating in an abnormal or life-threatening rhythm.

They are usually fitted in patients who have suffered from, or are at risk of developing life-threatening arrhythmias (abnormal heart rhythms).

The most common ventricular arrhythmias are: ventricular tachycardia (VT) and ventricular fibrillation (VF). These can happen suddenly and can be life-threatening.

Driving

After having a device fitted it is important that you inform the DVLA and your insurance company. If you have had a pacemaker you can usually start driving again after one week. However if you have an ICD you are usually not allowed to drive for the first six months after it has been implanted (provided it has not delivered any shocks or pacing treatment).

If you have had a device fitted it is important that you avoid lifting anything too heavy, and lifting the arm (on the same side) above head height for the first six weeks. Gradually return to normal daily activities and keep the shoulder mobile by gently moving the arm.​

Heart failure means that the heart is no longer pumping the blood around the body as effectively as it used to and the pumping action of the heart isn't as forceful as it should be. The most common causes of heart failure are heart attack, high blood pressure and cardiomyopathy (diseases of the heart muscle). Heart failure can also occur as a result of heart valve problems, excess alcohol or drug misuse or uncontrolled, irregular heart rhythms.

Symptoms of heart failure include:

 - Shortness of breath
 - Fluid retention and swelling (mainly in the ankles, stomach and lower back
 - Fatigue

Symptoms occur because the heart does not have the strength to pump the blood efficiently all the way around the body. This can cause fluid to pool in the feet and legs. If this is left unmanaged it can spread to the stomach and lungs. This will lead to shortness of breath and breathing difficulties.

If you suffer with heart failure you will usually see a specialist heart failure nurse. It is important to comply with medications, keep an eye on weight and fluid retention and cut down on your salt intake.​

'Myocardial' refers to the myocardium or heart muscle; infarct refers to cell death as a result of lack of oxygen.

Causes

Heart attacks are caused by a blockage in one or more of the coronary arteries. Plaques can form in the coronary arteries due to coronary heart disease. If a plaque cracks or ruptures a blood clot forms to try to repair the damaged artery wall. This blood clot can totally block the artery, causing part of the heart muscle to be starved of oxygen. If this happens the affected part of the heart muscle will begin to die unless blood-flow is restored (either by angioplasty/stent/bypass/medical management).

Symptoms

Symptoms can vary from person to person, but commonly include:

· Central crushing chest pain
· Pain in one or both arms
· Pain in the neck, throat and/or jaw
· Shortness of breath
· Sweating
· Nausea or vomiting
· Feelings of indigestion
· Weakness

The valves within the heart ensure that blood flows in one direction. Occasionally valves can become diseased or damaged; this can cause a valve to not open fully or not close properly.

If a valve is unable to fully open, blood flow through that valve will become restricted. This will result in extra strain being placed on the heart as it has to work harder to push blood through the narrowing. This is referred to as 'valve stenosis' or 'narrowing'.

If a valve is not able to close properly it will allow blood to flow backwards. This is often referred to as a 'leaky valve' or 'regurgitation'. As a result of blood flowing the wrong way through a valve, extra strain will be placed on the heart as it will have to work harder to pump the required volume of blood.

Individuals with heart valve disease may not necessarily display any symptoms, however some of the most common symptoms include being out-of-breath, swelling in the feet and ankles and being unusually tired.

Treatment may not always be required for heart valve disease; however regular check-ups will be required to ensure that function has not decreased further. Most valve problems are treated through medication or by having heart valve surgery.