• People with the following conditions are at higher risk of developing Pacemaker Syndrome:
  • Left ventricular disease
  • Recipients of single-chamber ventricular pacemakers
  • Retrograde conduction
  • Decreased stroke volume
  • Decreased cardiac output
  • Decreased left atrial total emptying fraction
  • Elderly people

• According to most trials the only two variables that predict the development of pacemaker syndrome in the pre-implantation period are low sinus rate, and a higher programmed lower rate limit. Similarly in the post-implantation period, an increased percentage of ventricular paced beats is the only variable that significantly predicts the development of pacemaker syndrome.
• One major risk factor for the development of pacemaker syndrome is the presence of an intact VA conduction (retrograde ventriculo-atrial conduction).
• Intact VA conduction is present in as many as 90% of patients with preserved AV conduction, and in about 30-40% of patients with complete AV block. VA conduction may develop at any time after implantation of the pacemaker and may not be apparent at the time of implantation of the device.
• Patients with cardiomyopathy (hypertensive, hypertrophic, restrictive) and elderly individuals are particularly sensitive to the development of pacemaker syndrome because of the presence of noncompliant ventricles and diastolic dysfunction which lead to loss of atrial contribution to ventricular filling and in turn to pacemaker syndrome.

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