From the Guidelines
Yes, hypotension can be related to pacemaker dysfunction.
Pacemaker Syndrome
Pacemaker syndrome, a condition that incorporates many possible mechanisms for inducing hypotension, can occur due to pacemaker dysfunction, and device re-programming or replacement may be necessary to resolve the issue 1.
- The syndrome is characterized by episodic alternating AV synchrony and asynchrony, inadequate cardiac output associated with VA conduction, and patient awareness of beat to beat variations with absence of AV synchrony or with fixed asynchrony in cardiac contractile sequence.
- Pacemaker syndrome can be caused by loss of atrial contribution or negative atrial kick, and replacement of a single chamber ventricular pulse generator with an atrial-based pacing system may be required 1.
Management of Hypotension
Hypotension can result from several underlying physiological processes, including vasodilation, hypovolaemia, bradycardia, and low cardiac output, and treatment should be based on the presumed underlying cause 1.
- Bradycardia, which can be caused by pacemaker dysfunction, can be managed with anticholinergic agents such as atropine or glycopyrronium, or with a pacemaker in cases of profound bradycardia.
- Low cardiac output due to acute or chronic myocardial dysfunction can be treated with positive inotropic agents such as dobutamine or epinephrine.
Clinical Implications
In clinical practice, it is essential to consider pacemaker dysfunction as a potential cause of hypotension, particularly in patients with a history of pacemaker implantation or those experiencing symptoms such as syncope or lightheadedness 1.
- Device re-programming or replacement may be necessary to resolve the issue, and treatment of hypotension should be based on the presumed underlying cause.
From the Research
Relationship between Hypotension and Pacemaker Dysfunction
- Hypotension can be related to pacemaker dysfunction, as evidenced by studies that have investigated the pacemaker syndrome 2, 3, 4, 5.
- The pacemaker syndrome refers to symptoms and signs in pacemaker patients caused by inadequate timing of atrial and ventricular contractions, which can result in decreased cardiac output and increased atrial pressure, eliciting a systemic hypotensive reflex response 2.
- Pacemaker malfunction can occur due to failures of sensing, capture, and inadequate pacing, leading to severe hemodynamic consequences, including hypotension 6.
- The incidence of pacemaker syndrome varies from 7% to 20% of all ventricular paced patients, and is often associated with retrograde VA conduction 2, 5.
- Symptoms of pacemaker syndrome may include neurologic symptoms, low cardiac output, congestive heart failure, dizziness, lightheadedness, fatigue, and hypotension 2, 3, 4, 5.
Mechanisms and Clinical Manifestations
- The lack of normal atrioventricular synchrony may result in decreased cardiac output and increased atrial pressure, which can elicit a systemic hypotensive reflex response 2.
- Retrograde ventriculoatrial conduction is a common mechanism underlying pacemaker syndrome, and is often associated with hypotension and other symptoms 5.
- The frequency of ventriculoatrial conduction in patients with sick sinus syndrome is higher than in patients with A-V block, which may contribute to the development of pacemaker syndrome 5.
Diagnostic Approaches and Implications for Management
- Diagnostic approaches for pacemaker syndrome include electrocardiogram (ECG) and electrophysiologic studies to assess atrioventricular synchrony and ventriculoatrial conduction 2, 5.
- Management of pacemaker syndrome may involve reprogramming the pacemaker or switching to a different pacing mode to restore normal atrioventricular synchrony 2, 4.