Pacemaker Syndrome

Pacemaker syndrome is an iatrogenic disease, meaning it is an adverse effect and direct result of medical treatment. It may affect those who have implanted pacemakers used to regulate and synchronize an irregular heartbeat, causing a lack of synchronization between the atrium and ventricle, weakening overall cardiac output.

Causes

• A pacemaker is commonly implanted into the chests of patients who have trouble with a consistently irregular heartbeat, so as to synchronize the activation of the upper and/or lower chambers of the heart, allowing normal cardiac output to occur. At times, the pacemaker may stimulate only the lower chambers (ventricles), activating that part before the upper chambers (atria), effectively reversing the order in which a heart beats. This causes blood to be pumped against closed valves, resulting in the symptoms typical of pacemaker syndrome.

Symptoms

• Symptoms of pacemaker syndrome include decreased cardiac output, caused by an out-of-sync atrium not filling the associated ventricle. This can lead to numerous other symptoms, including shortness of breath, chest pain, heart palpitations, and in extreme cases sporadic and brief losses of consciousness (syncope). These symptoms often mimic those that required a pacemaker implant in the first place, and can also be present after the cessation of the original symptoms that prompted the implant.

Diagnosis

• Pacemaker syndrome is generally diagnosed without special clinical tests or investigation, but at times it is necessary to rule out other possible culprits, such as infection or heart disease. A physician may use a monitor to connect the symptoms experienced by the patient to an irregular cardiac rhythm, and the physician must take care to rule out a defective pacemaker or a pacemaker at the end of its battery life.

Treatment

• Pacemaker syndrome is treated in several ways, depending on various factors. If the pacemaker paces only the ventricle, a lead is attached to the atrium and resynchronized, resolving the desynchronization that led to the symptoms. In patients with a pacemaker that paces other parts of the heart, or both the ventricle and the atrium, reprogramming the pace and resynchronizing the pace usually resolves the symptoms.

Prognosis

• Barring an underlying cause that is not related to the installation of a pacemaker, such as heart disease or infection, prognosis is excellent and a vast majority of all patients recovery completely once the pacing of the pacemaker is properly synchronized.