From the Guidelines
Pacemaker syndrome is a condition characterized by adverse hemodynamics and overt symptoms, such as fatigue, chest discomfort, dyspnea, cough, confusion, presyncope, or syncope, resulting from loss of AV synchrony and ventriculoatrial conduction or atrial contraction against closed AV valves in patients with an implanted pacemaker. This condition typically occurs with ventricular pacing in the VVI mode in patients who are in sinus rhythm, as evidenced by a randomized clinical trial that compared symptoms and hemodynamic parameters among patients programmed to the VVI mode or the DDD mode 1. The symptoms of pacemaker syndrome include:
- Fatigue
- Chest discomfort
- Dyspnea
- Cough
- Confusion
- Presyncope
- Syncope These symptoms are caused by the disruption of normal cardiac contraction sequence, leading to reduced cardiac output and increased venous pressure. According to the study published in the Journal of the American College of Cardiology 1, patients with pacemaker syndrome may experience significant worsening of symptoms, with a mean symptom score of 29.0 ± 26.1 in the VVI mode. The treatment of pacemaker syndrome involves reprogramming the pacemaker to promote more natural heart rhythm coordination, often by upgrading to a dual-chamber pacemaker or using specialized pacing modes that minimize ventricular pacing, as suggested by the expert consensus statement on pacemaker device and mode selection 1. It is essential for patients experiencing symptoms to contact their cardiologist promptly, as simple pacemaker reprogramming can often provide immediate relief. Proper pacemaker selection and programming that maintains normal atrioventricular synchrony can help prevent pacemaker syndrome.
From the Research
Definition of Pacemaker Syndrome
- Pacemaker syndrome refers to symptoms and signs in pacemaker patients caused by inadequate timing of atrial and ventricular contractions 2, 3.
- The lack of normal atrioventricular synchrony may result in decreased cardiac output and increased atrial pressure, which elicits a systemic hypotensive reflex response 2, 3.
Causes and Risk Factors
- The pacemaker syndrome is encountered in a significant number of patients with ventricular (VVI) pacemakers, mostly when 1:1 retrograde ventriculoatrial conduction is present 2.
- The risk of occurrence of the pacemaker syndrome is minimized if pacemaker systems are used which restore or maintain the normal atrioventricular contraction sequence 2.
- The incidence of pacemaker syndrome is uncertain, and varies from 7% to 20% of all ventricular paced patients 3.
Symptoms
- Neurologic symptoms or symptoms suggesting low cardiac output or congestive heart failure are indicative of the pacemaker syndrome 3.
- These symptoms may vary from mild to severe, they are nonspecific and very common among cardiac patients with or without pacemaker 3.
- Symptomatic hypotension induced by VVI pacing is characteristic of the pacemaker syndrome 4.
Treatment
- Dual-chamber pacing is an effective approach for treatment of the pacemaker syndrome 4.
- Reprogramming to atrial-based pacing can improve quality of life and alleviate symptoms of pacemaker syndrome 5.
- The DDI mode provides the clinician increased utility and flexibility in the use of AV sequential pacing therapy and can eliminate pacemaker-related tachycardias and abolish pacemaker syndrome symptoms 6.