A pacemaker is a small medical device designed to help manage certain heart rhythm conditions. This implanted technology works to ensure your heart maintains a regular beat. Many people wonder if a pacemaker delivers a sensation akin to an electric shock, a common misconception. This article clarifies what a pacemaker does and what, if anything, you might feel from its operation.
Understanding Pacemakers and ICDs
Pacemakers and implantable cardioverter-defibrillators (ICDs) are both implanted devices that help regulate heart rhythms, but they serve different primary functions and deliver distinct sensations. A pacemaker is a small, battery-powered device typically placed under the skin in the upper chest, just below the collarbone. Its main purpose is to treat bradycardia, a condition where the heart beats too slowly or irregularly. The device monitors the heart’s natural electrical activity and, if it detects a slow or missed heartbeat, sends a low-energy electrical impulse to stimulate the heart to beat at a normal rate.
An ICD is generally larger than a pacemaker and is designed for different heart rhythm problems. ICDs are primarily used for individuals at high risk of life-threatening arrhythmias, such as ventricular tachycardia or ventricular fibrillation, which involve dangerously fast or chaotic heartbeats. The ICD continuously monitors the heart and, if it detects such a dangerous rhythm, can deliver a high-energy electrical shock to restore a normal rhythm, a process known as defibrillation. Some ICDs also include pacemaker functions, allowing them to address slow heart rates. The sensation of a true “shock” is almost exclusively associated with an ICD, not a standard pacemaker.
How a Pacemaker Works and What You Feel
A pacemaker functions by delivering low-energy electrical impulses to the heart to maintain a steady rhythm. The device consists of a pulse generator, which contains a battery and a small computer, and thin, insulated wires called leads. These leads are inserted into a vein, typically in the shoulder, and guided into the heart chambers. Electrodes at the tip of the leads make contact with the heart muscle, delivering the electrical signals from the pacemaker and also sensing the heart’s natural electrical activity.
The pacemaker continuously “senses” the heart’s rhythm. If it detects that the heart rate falls below a programmed threshold or misses a beat, it will “pace” the heart by sending a small electrical signal. Most people do not feel these impulses when the pacemaker activates. If any sensation is perceived, it is usually described as a subtle flutter in the chest or no sensation at all, rather than a painful or jolting shock.
When a “Shock” Sensation Occurs and What to Do
While a standard pacemaker does not deliver a shock, a strong jolt or “shock” sensation can occur if a patient has an implantable cardioverter-defibrillator (ICD) and it delivers a therapeutic shock. An ICD shock is typically described as a strong kick to the chest or a sudden jolt. While startling, it is a sign the device is working to correct a life-threatening arrhythmia. This high-energy electrical discharge lasts less than a second. Some individuals may experience symptoms like dizziness or palpitations before an ICD shock, while others receive no warning.
If you experience an ICD shock, it is important to remain calm. Find a safe place to sit or lie down, as the shock can cause lightheadedness or dizziness. After a single shock, contact your healthcare provider or ICD clinic immediately, ideally the same day or the next, for a device check. If you experience multiple shocks within a short period, typically two or more, seek emergency medical attention by calling emergency services. Notify your doctor if the shock requires medication changes or impacts activities like driving, as driving restrictions may apply.