Sick sinus syndrome in older adults: symptoms, tests and pacemaker treatment

Every heartbeat starts with a tiny electrical signal. In a healthy heart that signal is produced by the sinus node, a small area of specialised tissue that acts as the heart's natural pacemaker. NICE explains that in sick sinus syndrome this node becomes unable to produce the electrical impulses at the rate the heart needs, so the pulse may be too slow, may pause, or may swing between slow and fast.

The condition is not one single rhythm. NICE lists several patterns that sit under the same heading. In sinus arrest or pause, the node occasionally fails to generate impulses for anything from a couple of seconds to several minutes. In sinoatrial exit block, the node produces its impulse normally but the signal is blocked before it leaves the node. In bradycardia-tachycardia syndrome, slow rhythms alternate with fast ones.

A slow heart rate, bradycardia, is defined by NICE as fewer than 60 beats per minute. The word syndrome matters here: it is the pattern of rhythm problems together with symptoms that makes the diagnosis, not a number on a monitor. Plenty of people, including fit older adults, can have a slow resting pulse without any illness.

Because the heart intermittently fails to keep up with the body's demands, the symptoms come and go. NICE's public information lists fainting, falls, dizziness, confusion, chest pain and difficulty breathing. The NHS page on heart rhythm problems adds palpitations, feeling lightheaded, tiredness and chest discomfort, and stresses that having these symptoms does not necessarily mean a rhythm problem.

In an older person the picture is often quiet and easy to explain away. A relative may simply notice that someone seems more tired, is less steady, has had an unexplained fall or has episodes of vagueness. Keeping a note of when these happen, what the person was doing and whether anyone checked a pulse can be genuinely useful to the doctor.

• Fainting or near-fainting, sometimes without warning.

• Dizziness or light-headedness, particularly on exertion.

• Unexplained falls.

• Unusual tiredness or reduced stamina.

• Palpitations, including a racing or irregular beat as well as a slow one.

• Breathlessness, chest discomfort or new confusion.

The NHS says to call 999 or go to A&E if you are having heart palpitations together with chest pain, shortness of breath, feeling dizzy or lightheaded, or fainting or feeling like you might faint. If those symptoms have already passed, it advises asking the GP surgery for an urgent appointment, calling 111 or using 111 online.

For palpitations that keep happening or are getting worse, without those added symptoms, the NHS advice is to see a GP. Do not drive yourself to A&E; ask someone to drive you or call 999 and ask for an ambulance.

For most people with sick sinus syndrome, NICE says the cause is unknown and the disease is progressive. It lists age, ischaemic heart disease, heart valve disorders and heart failure as the most commonly identified causes of abnormal heart rhythms in general. The NHS adds that medicines, viruses, caffeine, alcohol, smoking and drugs can also produce an abnormal heartbeat.

Sick sinus syndrome can sit alongside atrioventricular block, a separate problem in which the signal between the upper and lower chambers is slowed or blocked. NICE notes that people with sick sinus syndrome may also have, or go on to develop, atrioventricular block.

NICE states that the diagnosis is made using electrocardiograms. An ECG records the electrical activity of the heart, including rate and rhythm, and the NHS describes a resting ECG as quick and painless, with sticky patches placed on the arms, legs and chest. The difficulty is that a rhythm fault that comes and goes may be absent during a short recording.

That is why monitoring over time is used. NICE says Holter monitoring, which is ECG monitoring for 24 to 48 hours, or event recorders may be used. The NHS describes a portable ECG as a small recorder worn on a belt, usually for 24 to 48 hours but sometimes up to 7 days, during which you cannot bath or shower. The NHS says that before a pacemaker is fitted you may need blood tests, a chest X-ray or an echocardiogram.

NICE's guidance describes a pacemaker as a small device placed under the skin in a minor surgical procedure and connected to the heart by fine wires. It detects when the heartbeat is too slow, or when an impulse is not produced, and supplies the electrical signal to start or control the beat. Pacemakers may be single-chamber, connected to one chamber, or dual-chamber, connected to both the upper and lower chambers. Choosing between them is a specialist decision, and NICE has reviewed the evidence comparing dual-chamber and single-chamber atrial devices in people without atrioventricular block.

The NHS explains that before a pacemaker you will have an assessment at the hospital, which may include blood tests, a chest X-ray or an echocardiogram. A standard device is fitted by a cardiologist under local anaesthetic, a small cut is made on the left side of the chest and the wires are guided through a vein to the heart. It usually takes about an hour and you will usually stay in hospital overnight. If you have a slow heartbeat you may be offered a leadless pacemaker placed directly in the heart, with no wires and no chest cut, and you can usually go home the same day.

Medicines have a supporting role. The NHS notes that treatment for a heart rhythm problem depends on the type and cause and may include medicines to control rate and rhythm, ablation, cardioversion or a pacemaker, together with treatment of any condition behind it.

The NHS says you will feel tired for the first few days and the left side of your chest will be sore, and that full recovery can take a few weeks or months. Its advice is not to drive for at least the first week, and not to carry heavy objects, do vigorous exercise or lift your elbow above shoulder height for 4 to 6 weeks. You must tell the DVLA and your insurer that you have a pacemaker.

Follow-up is built in: about 6 weeks after fitting at the pacemaker clinic, 3 to 6 months afterwards with the cardiology team, and at least every 12 months after that. The battery usually lasts 6 to 7 years and checks become more frequent as it nears replacement. You will be given an ID card to show to healthcare professionals and at airport security, where a handheld metal detector must not be held over the device.

Contact the pacemaker clinic or NHS 111 if the wound becomes more swollen, tender or red, leaks blood, pus or clear fluid, or if you develop a very high temperature or feel shivery, or if your original symptoms return or worsen. Call 999 for severe breathing difficulty, a tight or heavy chest, pain spreading to the arms, back, neck or jaw, a very pale, blue or grey colour, or sudden confusion.

NICE says the prognosis of sick sinus syndrome is variable and difficult to predict, depending on the underlying cause and on other conditions such as ischaemic heart disease. It also notes that, if untreated, symptomatic bradycardia may lead to fatigue, fainting, palpitations, dizziness, heart failure and an increased risk of death, which is the reason treatment is offered once symptoms are clearly linked to the rhythm.

In the UK, assessment, monitoring and pacemaker implantation are provided through NHS cardiology services, usually after a GP referral. Some people choose to be seen privately for a faster appointment or monitoring; the tests and the device decisions are the same in principle, and the same follow-up arrangements apply.