NH cares

Heart Pacemakers:
Understanding how they work

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1.What is a Pacemaker?

What is Pacemaker

A healthy heart beats at a regular rhythm as determined by the current condition of the body such as whether it is in motion or rest, or if it is unwell or in a stressful situation. The heart is signalled through a series of electrical impulses that is sent by a cluster of cells called the sinoatrial (SA) node which is the body's natural pacemaker.

In conditions where the heart is unable to maintain a steady rhythm, a small titanium device that functions as an artificial pacemaker is placed under the skin in a patient's chest. This pacemaker, which is powered by a battery, creates painless electrical impulses simulating those of the AV node, that signal the heart to beat with a regular rhythm so that blood is pumped correctly throughout the body.

One of three types of heart pacemakers may be suggested by doctors depending on the condition of the heart:

  • Pacemakers that use one wire lead to thread into the veins of the heart in any of the upper or lower chambers of the heart are called single chamber pacemakers
  • A dual chamber pacemaker uses two leads; one in the atria or the upper chamber, and another in the ventricle or a lower chamber of the heart
  • A BVT or a biventricular pacemaker has three wires leading to the right atrium (right upper chamber), the right ventricle (right lower chamber), and the left ventricle (left lower chamber). This kind of artificial pacemaker is usually prescribed in more severe cases and helps the two ventricles of the heart to beat in sync.

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2.When is a pacemaker used?

Monitoring heartbeat for pacemaker implantation

A pacemaker implantation may be recommended by your doctor if a case of erratic heartbeat is diagnosed. This is medically termed arrhythmia, and a pacemaker painlessly sends signals to the heart to ensure that the heart beats and pumps blood at the required pace.

Bradycardia is the most common form of arrhythmia that is addressed by the use of a cardiac pacemaker, and means that the heart beats slower than it should. Tachycardia means that the heart beats faster than normal, and in such cases, the pacemaker implantation helps with stabilizing the heart to beat more slowly. In patients with more severe heart disease, a dual chamber pacemaker or a BVT pacemaker may be used to connect two chambers of the heart, so that both beat with the right rhythm and the blood pumping action is synchronized.

Arrhythmia may happen due to a few underlying causes:

Congenital heart defects (CHD): When a child is born with a heart defect such as a heart block, a pacemaker may be used as part of the treatment. Even as a patient with CHD grows into adulthood, a cardiac pacemaker may be inserted and helps with several symptoms of the condition.

Symptomatic sinus node disease: Permanent pacemakers have become more common over the last two decades, especially as the engineering behind them have become more sophisticated, and as more recommendations for pacemaker implantation as a preventative measure for further heart health complications from sinus node dysfunction causing arrhythmia, oftentimes of the tachy-brady variation.

Hypertrophic cardiomyopathy (HCM): A condition where the heart walls become abnormally thick and unable to contract and release at the right time, indications of HCM is helped by a cardiac pacemaker which is shown to reduce mortality and symptoms in patients.

Syncope (fainting): Syncope may be caused due to many varied health conditions, and is a result of lowered blood flow to the brain. If this is determined to be happening due to erratic heartbeat, a pacemaker surgery may be suggested by doctors to ensure a steady pumping action by the heart to ensure adequate blood supply to the brain. More prescriptions for a heart pacemaker for syncopes are happening today because of the low pacemaker cost and its simpler implantation.

Congestive heart failure: Heart failure is an inefficient beating of the heart that prevents the blood from carrying adequate nutrition, sugar and oxygen to the body, and is due to a weakening of the heart muscles. The pumping action can be steadied by a permanent pacemaker.

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3.What does a pacemaker do?

Simply put, a pacemaker prevents mortality and symptomatic concerns arising from heart disease. It is used to stabilize the rhythm of the heart on a permanent or a temporary basis.

Temporary pacemakers may be used sometimes in case of heart attacks, termed acute myocardial infarction, to stabilize the pace of pumping when drugs and other interventions fail. A transvenous pacemaker, which is one of the types of a temporary pacemakers commonly used in emergency situations, is used on the right side of the heart due to ease of reach, unlike a permanent pacemaker which is more often implanted to the left. It is threaded into the right atrium or the right ventricle, and sometimes into both to stabilize the heart pumping action as the heart fails, especially due to near-complete blockage.

The complications arising out of such a pacemaker operation is still minimal compared to other invasive surgeries due to the improvement over time in the precision surgery techniques, as well as in the improvement of pacemaker quality.

However, it is not usual to recommend transvenous pacemakers to patients who might have a pacemaker surgery for a permanent pacemaker at a later time. The transvenous pacemakeris the more commonly prescribed temporary pacemaker, although transcutaneous pacing wherein electrical impulses are sent through the chest, and transesophageal pacing may also be used in acute situations.

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4.Types of pacemakers

Natural Pacemaker: The heart already has a pacing system that signals the correct rhythm of beating and this is the AV node. In a healthy body, the heart takes directions from this and maintain regular blood flow and pressure. In case of a heart concern that does not allow the AV node to function efficiently, an artificial pacemaker is used.

Artificial Pacemaker: These are of different types and can be classified majorly as permanent and temporary pacemakers.

Permanent pacemaker: A permanent pacemaker can be attached to either a single heart chamber, two chambers, or even three heart chambers, and are respectively called single chamber pacemakers, dual chamber pacemaker and triple chamber (biventricular pacemaker). The last one syncs both lower chambers of the heart, and the lead wires connect the pacemaker to both of them as well as an upper chamber, and so the biventricular pacemaker nomenclature is commonly used for it.

Depending on the severity of condition, and which heart atria or ventricle are most affected, a doctor would recommend a pacemaker surgery using one of these devices.

Permanent pacemaker is a suggestion offered for chronic conditions in cases where heart health is often deemed irreversible due to blockage, or arrhythmia is recurrent despite lifestyle changes or therapy. Bradyarrhythmia is the more common concern where permanent pacemaker implantation is recommended and the insertion of the device happens just below the subcutaneous fat, while the lead wires connect to the heart muscles to be stimulated.

Nowadays, leadless pacemaker is also available and becoming more recommended by doctors. Medtronic pacemakers can be leadless and have undergone all regulatory approvals, and may be recommended by doctors in certain less severe conditions. The pacemaker risks associated with insertion of this device is typically very low, since the pacemaker is very small and the implantation does not require cutting near the chest area. It is usually pushed through a minor cut through the large femoral artery that connects to the heart and inserted into the right atrium.

Temporary Pacemaker: A temporary pacemaker is always inserted under medical observation and the pacemaker operation happens under controlled clinical conditions when the patient's requirement for an artificial pacemaker is understood to be temporary and the dysrhythmia is to be resolved soon after. A temporary pacemaker may also be implanted before a permanent one is provided.

Transvenous pacemakers are the more commonly used devices, and a patient remains under observation in a hospital until the time the temporary pacemaker is in the body, after which the catheter is drawn out. Transcutaneous pacing devices are also called external pacemakers, and are placed under the skin and delivers electrical impulses to make the heart contract faster. Transesophagal pacing was developed since the upper heart chambers are close to the esophagus, making it a reasonable location for temporary pacemaker devices. The endocardium is the lining of tissue closest to the heart, and epicardial pacing, which is commonly used after cardiac surgery, taps into this. The lead wires inserted into the endocardium during heart surgery are affixed to a box device that generates the pulses required to stimulate heart contraction in this type of cardiac pacemaker.

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5.Are you the right candidate for a pacemaker?

Patient monitoring pacemaker surgery

If you have any of the indications below, you should consider getting a doctor's appointment to determine if you need a permanent pacemaker of heart. A heart pacemaker surgery is commonly recommended for heart patients who show these symptoms:

  • Fainting
  • Dizziness
  • Lightheadedness
  • Shortness of breath
  • Fatigue

A majority of patients today who have had pacemaker surgery are able to live healthier, more active lives, and with the ease of pacemaker implantation today, more doctors have become comfortable recommending it as a simple solution to prevent further damage to the heart and other vital organs which may be damaged through incorrect supply of blood, oxygen, sugar and other nutrients, as is common with various forms of heart disease.

Pacemakers implantations have become common with anyone, from newborns to geriatric patients, whenever abnormal heart function is detected. Although pacemaker operations are invasive, they are minimally so, and the body is very tolerant of the device. If you are someone who suffers symptoms such as dizziness and a lack of breath soon after beginning physical activity, it is not a sign of ageing only, and may be reason enough to undergo a pacemaker implantation to prevent further complications.

In case indications do not point to severe heart issues, a small, coin-size leadless pacemaker may be recommended to inserted in the heart. The leadless device is a single chamber pacemaker and cannot resynchronize more than one heart chamber, though, and is not suggested in case of severe blockages.

A pacemaker implantation may also be done in cases of drug overdose and may involve a temporary pacemaker to stabilize the heart rhythm especially as the body detoxes.

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6.How do I prepare for pacemaker surgery?

Especially in cases of temporary pacemaker insertion, no preparation is done by the patient, and it is immediately executed by doctors in a medical setting as it is an emergency situation, either in order for a permanent pacemaker placement later, or to be removed later in expectation of a steady heart rhythm after successful completion of the procedure.

Once the pacemaker surgery is performed successfully, the patient bearing the temporary pacemaker remains under careful clinical observation with heart rates monitored, and cannot be released.

If a permanent pacemaker is to be implanted, the doctor offers a complete checklist of things to be done and to be avoided by the patient in preparation for surgery after going through a detailed medical history of the individual.

Pacemaker risks remain low, and the preparatory steps are usually uncomplicated and may include:

  • Not eating or drinking for eight hours before the surgery. This stabilizes the blood pressure in most cases, lowering pacemaker risks further.
  • Using a special soap to disinfect the area of the body where the pacemaker surgery will happen.
  • Starting or stopping medication may be recommended by a doctor, depending upon your body's pathophysiology. Medicines that may interfere with pacemaker operation by heightening or subduing blood pressure may be monitored or stopped completely, and other medication to help the blood circulate more easily may be recommended.

Tests to be performed prior to pacemaker surgery include:

Electrocardiogram (ECG) test: To understand your heart's impulse generation condition.

Echocardiogram: Involves sound wave reflection to determine the heartbeat and provide the best pacemaker solution for your body

Holter monitoring is done in case the erratic heartbeat occurs outside the hospital, and involves the patient wearing the monitor outside the hospital so that abnormal heart rhythms can be picked up throughout the day, and all abnormalities reported.

Pacemaker precautions can include a stress test which is a commonly used test to determine heart and blood pressure conditions. An ECG is performed during exercise to determine if the pacemaker implantation is to correct erratic heartbeat only during heightened activity levels.

All these tests are non-invasive and help the doctor offer the most suitable suggestion for each individual, depending on the condition of their heart health. If necessary, a blood test may also be asked of the patient.

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7.How is a pacemaker surgery performed?

Pacemaker surgery

In most cases, the pacemaker operation is performed while the patient is conscious and under the effect of local anaesthesia. The commonly used pacemaker procedure is transvenous implantation is during which a heart specialist makes a small (around 2 inch) incision close to the heart and inserts the wires from the pacemaker device into a vein that leads to the heart. These lead wires are guided through to the heart atria / ventricles and attach to the heart tissue. Fluoroscopy or X-rays are performed to monitor the lead wires' journey through to the heart.

The lead wires are connected to the pacemaker at the other end that is then placed inside the body, usually the chest area. An IV drip with saline and sedative is also attached to another vein in the arm during the pacemaker procedure to relax the body.

A pacemaker surgery where the patient is made unconscious through the use of general anaesthesia is epicardial pacemaker implantation, and this is less commonly suggested today. The lead wires of the pacemaker, in this case, attach to the upper surface of the heart called the epicardium, and not to the heart chambers directly.

For both types of pacemaker implantation procedures, the lead wires are tested to see if they are properly working by the heart specialist or the electrophysiologist before they are attached to the pacemaker box. Small electrical signals are sent to the heart which is monitored continuously to see if the pacemaker leads are causing the required contraction. The pacemaker procedure is usually complete within an hour or so, although observation of the patient for 24 hours after the surgery is usually recommended.

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8.Complications and risks that may arise

Pacemaker complications are few, but may arise due to mechanical failure of the device. The risks of such an incident include:

  • Collapsing of the lung, medically known as pneumothorax. This may arise due to lead displacement and wrong lodging, and may require a further corrective surgical procedure.
  • The inflammation of the pericardium, which is the sac that protects the heart is called pericarditis, and may sometimes be noted after a pacemaker procedure. This is usually treated through medication such as pain medication and antibiotics.
  • Skin erosion due to faulty pacemaker battery is rare and would require pacemaker replacement and ongoing antibiotic treatment.
  • Blood clots in the vein are known to occur in some cases after the pacemaker operation is complete, and if under medical observation, it is resolved through the use of anticoagulation therapy.
  • Infections are not very common anymore considering the lowered pacemaker risks currently, but may occur and will then be treated through antibiotic usage.
  • Lead dislodgement may sometimes occur after a pacemaker procedure when the lead wires are dislodged and may move from the heart chamber or endocardium and become loose, causing internal injury.

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9.How do I recover from a pacemaker surgery?

Recovery after a pacemaker surgery requires rest for a few weeks and a diet may be recommended by your doctor. A few simple pacemaker precautions go a long way in aiding recovery after pacemaker implantation.

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10. Precautions to take after a pacemaker surgery

A pacemaker surgery usually requires the patient to be under medical observation for a day, after which a few precautions are suggested:

  • Heavy lifting and other strenuous activity should be avoided and a doctor will suggest this after a pacemaker operation
  • Regular health checks are recommended so that all signs that may or may not be obviously symptomatic are seen to with immediacy and are preventative in nature after a pacemaker operation
  • Be careful about medication, and recreational drug usage may be forbidden by your doctor
  • Light exercises such as walking may be recommended after 2 weeks of rest
  • Tight clothing over the pacemaker device should be avoided

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11. Pacemaker FAQs: All your concerns addressed

Q.  How long does a pacemaker battery last?

  1. A permanent pacemaker battery lasts for well up to 10-15 years, and a replacement will only be necessary in case of a mechanical failure of the device. A doctor will have prescribed for the pacemaker to last for a certain number of years, and it is advisable to schedule a check up during the time of suggested battery exhaustion, along with regular health check-ups.

Q.  Do metal detectors, microwaves or other appliances have any impact on my pacemaker?

  1. Metal detectors do not harm the pacemaker, but do detect metal. In case the detector signals metal in your body, please inform the security about your having undergone a pacemaker operation. Most household appliances have no effect on the pacemaker, but it is advisable to remain away from devices with strong electromagnetic fields such as large stereo systems.

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