Heart block: symptoms, types, causes and treatment

The NHS says symptoms of heart block may include dizziness, fainting or feeling like you are about to faint, chest pain, tiredness and shortness of breath. They range from mild to severe depending on the type of heart block and how it affects you, and you may have no symptoms at all.

The British Heart Foundation (BHF) says first-degree heart block does not usually cause symptoms or need treatment, whereas second- and third-degree heart block can cause feeling faint or dizzy, tiredness and sometimes confusion, pressure or pain in the chest and shortness of breath. Some people have a very low heart rate. In some the block is always there, while in others it comes and goes.

The BHF adds that AV heart blocks might turn into higher-degree blocks if they are left untreated, which is why new symptoms should be checked.

Electrical impulses move through the heart and make it beat. The BHF says a heart block happens when these impulses are blocked or delayed. Some heart blocks do not cause symptoms, but others are more serious.

An AV (atrioventricular) heart block happens when impulses are delayed or blocked as they travel between the atria, the top chambers, and the ventricles, the bottom chambers. The BHF also describes bundle branch blocks, where impulses travelling through the ventricles are slower than normal, and tachy-brady syndrome, where the sinus node does not work properly and the heartbeat can be too fast, too slow or switch between the two.

The NHS says heart block is most often caused by a heart condition such as coronary heart disease, or a heart attack. Some babies are born with heart block, known as congenital heart block. Other possible causes of AV heart block include taking some types of medicine, infection and inflammation of the heart caused by another condition, and having heart surgery. Sometimes there is no obvious cause.

The BHF adds congenital heart disease, cardiomyopathy, ageing of the electrical pathways in the heart and thickening of the heart muscle to the list, and says heart block can also happen naturally in people with a normal heart. If it is due to medicines or an electrolyte imbalance, you are monitored closely in hospital and given treatment to reverse the medicines or correct the imbalance.

The NHS says treatment depends on what is causing heart block and whether you have symptoms. If you have no symptoms you will not usually need any treatment. If you have severe symptoms you may need a pacemaker, which keeps your heart beating regularly and not too slowly, for a short time or permanently depending on the cause.

The BHF says that if you are diagnosed with second- or third-degree heart block you may need a pacemaker fitted. If the block is caused by a heart attack you may only need a temporary pacemaker in hospital, and if the rhythm does not return to normal soon afterwards you might need a permanent one.

The NHS describes a pacemaker as a small device put under the skin of the chest that sends out an electrical signal to help control the heartbeat. It is fitted in hospital by a cardiologist and usually takes about an hour. You have local anaesthetic, sometimes with sedation, and the wires are guided through a vein to the heart. You will usually stay overnight. If you have a slow heartbeat you may be offered a leadless pacemaker placed directly in the heart through a vein, which usually means going home the same day.

After the procedure you will feel tired for a few days and the left side of your chest will be sore. The NHS advises not to drive for at least the first week and not to carry heavy objects, do vigorous exercise or lift the elbow above shoulder height for 4 to 6 weeks. You must tell the DVLA and your insurer. Follow-up is about 6 weeks later at the pacemaker clinic, then at 3 to 6 months, and at least every 12 months. The battery usually lasts 6 to 7 years.

Contact your pacemaker clinic or NHS 111 if the wound becomes more swollen, tender or red, leaks, you have a very high temperature, or your earlier symptoms return. Call 999 for severe breathlessness, a tight or heavy chest, pain spreading to the arms, back, neck or jaw, very pale, blue or grey skin or sudden confusion.

The NHS says the main test is an electrocardiogram (ECG), which measures the electrical activity of the heart. It usually takes a few minutes, though you may be asked to wear a portable ECG for 1 or 2 days. The BHF says the ECG can show the type of heart block you have.

Other tests the NHS lists include an echocardiogram or cardiac MRI scan to picture the heart, exercise tests that check your heart while you use a bike or treadmill, and blood tests. The BHF notes that heart block is often noticed during routine tests for other conditions when there are no symptoms.

The NHS says to get help from NHS 111 if you feel dizzy all the time or it keeps coming back, if you have fainted, or if you have shortness of breath that gets worse during normal activities or when lying down. It stresses that you are not wasting anyone’s time by getting it checked.

Call 999 if you have been diagnosed with heart block and have chest pain, severe difficulty breathing (gasping, choking or unable to get words out), feel sweaty, sick or lightheaded, or someone faints and is not breathing or cannot be woken within 1 minute. Do not drive yourself to A&E.

On the NHS a GP arranges an ECG and refers you to cardiology if heart block is found. Pacemakers are fitted by cardiologists in hospital, and follow-up happens in a pacemaker clinic. Emergency heart block with fainting or collapse is dealt with through 999 and A&E.

Private cardiology appointments can speed ECG, monitoring and echocardiograms, and private hospitals fit pacemakers. The same follow-up and device checks apply, so ask who will run your pacemaker clinic checks and what happens if you move area.