From the Guidelines
A junctional heart rhythm is an abnormal cardiac rhythm where the electrical impulses originate from the atrioventricular (AV) junction rather than the normal sinus node, and it may occur directly post-op elective minimally invasive successful mitral valve repair due to surgical manipulation, cardioplegia, electrolyte imbalances, and other factors.
Causes of Junctional Heart Rhythm
The causes of junctional heart rhythm post-op mitral valve repair include:
- Surgical manipulation near the conduction system causing temporary inflammation or edema of the AV node 1
- Use of cardioplegia solution during surgery temporarily suppressing normal sinus node function
- Electrolyte imbalances, particularly potassium, calcium, and magnesium, disrupting normal cardiac conduction
- Catecholamine depletion and the effects of anesthetic agents
Management of Junctional Heart Rhythm
Management typically involves monitoring, correcting electrolyte abnormalities, and occasionally using temporary pacing if the patient is hemodynamically unstable. Unless the patient is symptomatic with hypotension or decreased cardiac output, specific treatment is often unnecessary as the rhythm usually converts back to normal sinus rhythm spontaneously 1.
Key Considerations
- The need for permanent pacemaker placement is common after mitral valve surgery, and patients with new onset atrioventricular block or SND should undergo permanent pacer placement before discharge for persistent symptomatic or hemodynamically significant bradycardia 1
- Placement of temporary epicardial pacing wires at the time of mitral valve surgery is routine practice, and alternative pacing strategies using pacing pulmonary artery catheters have been described for patients undergoing minimally invasive mitral valve surgery 1
From the Research
Definition of Junctional Heart Rhythm
- A junctional heart rhythm is an abnormal heart rhythm that originates from the atrioventricular (AV) junction, which is the area between the atria and ventricles 2.
- This type of rhythm can occur when the AV junction takes over as the pacemaker of the heart, often due to a disruption in the normal sinus rhythm 2.
Causes of Junctional Heart Rhythm Post-Op
- Junctional heart rhythm may occur directly post-op after elective minimally invasive successful mitral valve repair due to the surgical procedure itself [(2,3)].
- The use of cardioplegia, ischemia, or surgical trauma to the AV junction during the procedure can disrupt the normal sinus rhythm and lead to a junctional rhythm 2.
- Additionally, the maze procedure, which is often performed in conjunction with mitral valve surgery, can also increase the risk of developing a junctional rhythm 3.
Clinical Significance
- Junctional heart rhythm can lead to hemodynamic impairment due to the loss of synchronized atrial contraction 2.
- Patients with junctional heart rhythm may require inotropic support or pacemaker insertion to maintain adequate cardiac function [(2,4)].
- The incidence of junctional heart rhythm after mitral valve surgery can be significant, with one study reporting a frequency of 33% in patients undergoing valve replacement 2.