From the Guidelines
Junctional rhythm after mitral valve repair is most commonly caused by surgical trauma to the conduction system, and treatment should focus on correcting underlying causes and ensuring hemodynamic stability, with temporary pacing and electrolyte correction being primary interventions. The development of junctional rhythm post-mitral valve repair can be attributed to various factors, including surgical trauma to the conduction system, edema around the AV node, electrolyte imbalances, effects of cardiopulmonary bypass, hypothermia during surgery, or medication side effects 1. According to the 2014 AHA/ACC guideline for the management of patients with valvular heart disease, mitral valve repair is preferred over replacement when possible, due to lower operative mortality rates and better preservation of LV function 1.
Causes of Junctional Rhythm
- Surgical trauma to the conduction system
- Edema around the AV node
- Electrolyte imbalances (particularly hypokalemia and hypomagnesemia)
- Effects of cardiopulmonary bypass
- Hypothermia during surgery
- Medication side effects
Treatment of Junctional Rhythm
- Observation for stable patients with adequate heart rates (40-60 bpm)
- Temporary atrial or ventricular pacing at 70-90 bpm for symptomatic or hemodynamically unstable patients
- Correcting electrolyte abnormalities, particularly maintaining potassium >4.0 mEq/L and magnesium >2.0 mg/dL
- Discontinuing medications that may suppress the AV node (beta-blockers, calcium channel blockers)
- Using atropine 0.5-1mg IV or isoproterenol (2-10 mcg/min) or dopamine (5-10 mcg/kg/min) infusions for temporary rate increase or ongoing rate support
As noted in the guideline, the success of mitral valve repair increases with surgical volume and expertise, and repair is more likely to be accomplished in centers with surgeons who have expertise in this type of surgery 1. In cases where junctional rhythm persists beyond 7-10 days, evaluation for permanent pacemaker placement may be necessary, though this is uncommon as most cases resolve with conservative management.
From the Research
Causes of Junctional Rhythm Post-Mitral Valve Repair
- Systolic anterior motion (SAM) after mitral valve repair (MVR) can cause junctional rhythm, as it can exacerbate left ventricular outflow tract obstruction and mitral regurgitation 2
- The surgical approach used in mitral valve surgery can also be a predictive factor for ectopic atrial or junctional rhythm, with the extended trans-septal approach being associated with a higher incidence of junctional rhythm 3
- Atrial fibrillation, which can occur after mitral valve surgery, can also lead to junctional rhythm, especially after the maze procedure 4
Fixing Junctional Rhythm Post-Mitral Valve Repair
- Transesophageal echocardiography (TEE) can be useful in identifying the etiology of unstable hemodynamics after cardiac surgery, including junctional rhythm, and guiding treatment 2
- Atrial pacing can be used to restore atrioventricular synchrony and improve hemodynamics in patients with junctional rhythm, as it can decrease left atrial pressure and increase cardiac output 5
- In some cases, permanent pacemaker insertion may be necessary to manage junctional rhythm, especially in patients who have undergone the maze procedure 4