What determines the need for ongoing monitoring or pacemaker insertion versus watchful waiting in a patient with persistent ectopic atrial rhythm, supraventricular and ventricular ectopy, mitral valve prolapse, and dilated atrium, who develops bradycardia after minimally-invasive elective mitral valve repair?

From the Guidelines

The decision to pursue ongoing monitoring or pacemaker insertion versus a watch-and-wait approach for this post-mitral valve repair patient with bradycardia should be based on the severity and persistence of the bradycardia, with heart rates below 40 bpm or symptomatic bradycardia warranting more aggressive intervention, as suggested by the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. The presence of high-grade AV block, significant pauses (>3 seconds), or hemodynamic compromise would strongly favor pacemaker insertion. Key factors to consider include:

• The patient's baseline cardiac function, including ejection fraction and the degree of cardiac remodeling expected after valve repair
• Medication effects, as beta-blockers, calcium channel blockers, or antiarrhythmics might be contributing to the bradycardia and could be adjusted
• The likelihood of temporary bradycardia due to post-operative inflammation or autonomic dysfunction, in which case a conservative approach may be reasonable
• The patient's underlying ectopic atrial rhythm and frequent ectopy in the setting of structural heart disease (mitral valve prolapse with atrial dilation), which increases their risk for bradycardia progression Continuous telemetry for at least 48-72 hours post-stabilization would be prudent before discharge, with consideration of an event monitor for outpatient follow-up if no pacemaker is placed, as supported by the 2020 ACC expert consensus decision pathway on management of conduction disturbances in patients undergoing transcatheter aortic valve replacement 1. It is essential to weigh the risks and benefits of pacemaker insertion versus ongoing monitoring, considering the patient's individual circumstances and the potential for cardiac remodeling over time.

From the Research

Determining Factors for Ongoing Monitoring or Pacemaker Insertion

The patient's situation, with a persistent ectopic atrial rhythm on Holter and frequent supraventricular and ventricular ectopy, in the setting of mitral valve prolapse and a known dilated atrium on echo, undergoing a minimally-invasive elective mitral valve repair, and post-op experiencing bradycardia, prompts consideration of several factors to decide between ongoing monitoring or pacemaker insertion. These factors include:

• The presence of persistent atrioventricular block, which is an indicator for permanent pacemaker implantation after valvular surgery 2
• The occurrence of ventricular arrhythmias, which have extremely high in-hospital mortality and long-term mortality for those who survive the initial event 2
• The development of postoperative atrial fibrillation, which is associated with increased morbidity and mortality, and may require anticoagulation therapy and either a rate or rhythm control strategy 3, 4
• The patient's overall cardiac function and the presence of any reversible causes for the arrhythmias, such as hypoxemia, cardiac ischemia, catecholamine excess, or electrolyte abnormality 5

Considerations for Watch-and-Wait Approach

A watch-and-wait approach may be considered if:

• The bradycardia is transient and has reversible causes 2
• There is no significant or persistent atrioventricular block or sinus node dysfunction 2
• The patient's cardiac function is stable, and there are no signs of ischemia or other complications 5
• The patient is not experiencing any symptoms or hemodynamic instability due to the arrhythmias 3, 4

Role of Beta-Adrenergic Blockers

The use of beta-adrenergic blockers may be considered to reduce the risk of perioperative cardiac complications, but their effectiveness in reducing cardiac morbidity and mortality in people undergoing major non-cardiac vascular surgery is unclear 6. Additionally, beta-adrenergic blockers may increase the odds of intra-operative bradycardia and hypotension 6.