Heart palpitations are often described as the sudden, noticeable feeling of the heart fluttering, pounding, or skipping a beat. These sensations can be unsettling, especially for individuals who have an implanted cardiac device. The primary function of a pacemaker is to manage a slow or irregular heart rhythm by delivering small electrical pulses to the heart muscle. Despite the presence of this regulating technology, it is entirely possible to experience palpitations even with a functioning pacemaker.
Understanding the Pacemaker’s Function
A pacemaker is designed to treat bradycardia (a slow heart rate) or correct blocks in the heart’s electrical conduction system. The device acts as an electrical safety net, ensuring the heart does not drop below a programmed minimum rate. It typically works only on demand when the natural heart rhythm fails.
However, the device is not a cure for all rhythm disorders and has specific limits. A standard pacemaker is not programmed to prevent or stop fast heart rhythms, known as tachycardias, which often cause palpitations. While it ensures a minimum rate, it does not stop the heart’s electrical system from generating rapid or disorganized rhythms. This limitation allows other arrhythmias and non-cardiac triggers to continue causing symptoms.
Palpitations Caused by Other Heart Conditions
The most frequent causes of palpitations are heart rhythm issues the device is not intended to treat. Arrhythmias originating in the upper chambers, such as Atrial Fibrillation (AFib) or Atrial Flutter, can still occur. These conditions involve rapid, disorganized electrical activity that feels like a chaotic fluttering or racing in the chest.
Extra heartbeats, known as premature atrial contractions (PACs) or premature ventricular contractions (PVCs), are also common. These cause the sensation of a skipped or extra beat. Since the pacemaker only steps in if the heart rate drops too low, it generally ignores these premature beats unless they lead to a significant pause. Although often benign, these beats are easily felt as a palpitation.
Many external factors can trigger palpitations regardless of the implanted device. High levels of emotional or physical stress and anxiety can cause a noticeable increase in heart rate and force of contraction. Common stimulants, including caffeine or certain medications, can also increase the heart’s excitability. These external triggers override the pacemaker’s specific role in preventing slow rhythms.
Symptoms Related to Pacemaker Operation
Palpitations can sometimes relate directly to the device’s function or placement, requiring a device check and possible reprogramming. One condition is “Pacemaker Syndrome,” which occurs when the atria and ventricles contract without proper coordination. This lack of synchrony leads to inefficient blood flow and can cause symptoms like lightheadedness, fatigue, and palpitations, often described as a pounding in the neck.
Another device-specific issue is Pacemaker-Mediated Tachycardia (PMT), a re-entry rhythm that the pacemaker itself helps sustain. This occurs in dual-chamber devices when an impulse travels backward from the ventricle to the atrium. The pacemaker senses this impulse and responds by pacing the ventricle again at a rapid rate. This results in a fast, regular rhythm experienced as significant palpitations.
Physical issues with the device or its leads can also cause symptoms. If a lead (the thin wire connecting the device to the heart muscle) becomes dislodged or fractured, the pacemaker may sense or pace inappropriately. This malfunction can lead to sensations of fluttering or skipped beats if the device fails to deliver an impulse or delivers one at the wrong time. These functional problems are typically detected during a routine device check.
Recognizing When Medical Attention is Needed
While many palpitations are harmless, certain accompanying symptoms signal the need for prompt medical evaluation. New or worsening palpitations accompanied by severe shortness of breath, significant chest pain, or dizziness require immediate emergency attention. Fainting (syncope) combined with palpitations is a serious warning sign of inadequate blood supply to the brain.
For non-life-threatening symptoms, a consultation with a cardiologist is necessary if palpitations become more frequent, last longer, or change in character. It is helpful if the patient keeps a diary, noting the time, duration, and any associated activity. Reporting symptoms that occur during exercise or while lying down can provide important clues about the issue’s relation to the heart’s electrical system or the pacemaker’s settings.