- In junctional rhythm the electrical impulse starts in the AV node instead of the SA node.
- NB the AV node does possess autorhythmicity but is usually much slower than the SA node and so is overridden.
- In the context of severe bradycardia, this is an escape mechanism. In the context of normal/tachycardia, this is abnormal
- Results in electrical impulses travelling simultaneously to the atria and ventricles
- results in an inverted P wave seen just after or within the QRS complex. The QRS is usually narrow unless there is co-existent LBBB/RBBB
- Inappropriate slowing of sinus rhythm to 40-60bpm either due to changes in autonomic tone or disease of the sinus node
- Enhanced AV-node automaticity- usually caused by digoxin toxicity, post-op cardiac surgery, during MI or severe calcium dysregulation in the cardiac sarcoplasmic reticulum.
- The patient may present with dyspnoea and presyncope
- Depends on the underlying cause
- If digoxin toxicity- atropine and/or digitoxin immune FAb (digibind) may be given