Rarely, pacemakers can cause new symptoms even though other symptoms have gotten better. These new symptoms are called pacemaker syndrome.
Proper pumping by the heart depends on a number of things. It needs good blood flow from the veins, a proper rate of beating, and heart muscle that squeezes well. The heart also needs to squeeze in the correct pattern. Each heartbeat should start with squeezing (contraction) of the upper heart chambers (atria). A short pause is then followed by contraction of the lower heart chambers (ventricles). If the pattern is changed even slightly, the heart does not pump efficiently and this can affect how you feel.
Artificial pacemakers may help the ventricles, the atria, or all of the chambers to contract at the right time. Pacemakers are designed to follow the heart's normal rhythm. They can be fine-tuned to maintain the normal pattern of the heartbeat. However, sometimes a pacemaker impulse may travel backward. This may cause the atria to contract at the wrong time. Also, a pacemaker that fires at a constant rate may be just fine for someone at rest but may not work well for exercise. Either of these situations may cause symptoms.
Your healthcare provider will ask about your symptoms and may examine you, including a check of your pulse. You may have an electrocardiogram (EKG, or ECG) or a 24-hour tape recording of your heart's electrical activity.
Pacemakers can be reprogrammed to change their pattern. Your healthcare provider may change heart rates, the strength of the impulses, and the timing of the pauses. Most of the symptoms can be made better by changing these settings. Several tries with different settings may be needed. In some cases the pacemaker may need to be replaced with one that can pace both the atria and ventricles, or with a pacemaker that can respond to exercise by increasing its beating rate during exercise.
With the right pacemaker and the right adjustments, pacemaker syndrome can almost always be treated or prevented.
