A junctional rhythm occurs when the electrical activation of the heart originates near or within the atrioventricular node, rather than from the sinoatrial node. Because the normal ventricular conduction system (His-Purkinje) is used, the QRS complex is frequently narrow.

Earthquake early warning systems like ShakeAlert® work because an alert can be transmitted almost instantaneously, whereas the shaking waves from the earthquake travel through the shallow layers of the Earth at speeds of one to a few kilometers per second (0.5 to 3 miles per second).

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You will learn about Premature Ventricular Contractions, Ventricular Tachycardia, Ventricular Fibrillation, Pulseless Electrical Activity, Agonal Rhythms, and Asystole. You will learn how to detect the warning signs of these rhythms, how to quickly interpret the rhythm, and to prioritize your nursing interventions.

If the P wave is inverted, it is most likely an ectopic atrial rhythm not originating from the sinus node. Altered P wave morphology is seen in left or right atrial enlargement. The PTa segment can be used to diagnose pericarditis or atrial infarction.

Normal sinus rhythm is defined as the rhythm of a healthy heart. It means the electrical impulse from your sinus node is being properly transmitted. In adults, normal sinus rhythm usually accompanies a heart rate of 60 to 100 beats per minute. However, normal heart rates vary from person to person.

Junctional bradycardia: rate below 40 beats per minute. Junction escape rhythm: rate 40 to 60 beats per minute. Accelerated junctional rhythm: rate of 60 to 100 beats per minute. Junctional tachycardia: rate above 100 beats per minute.

Junctional beats/rhythms are characterized by absent or inverted p-waves, absent or shorter than normal PR intervals, and normal/narrow QRS complexes.

A junctional escape beat is a delayed heartbeat originating not from the atrium but from an ectopic focus somewhere in the atrioventricular junction. It occurs when the rate of depolarization of the sinoatrial node falls below the rate of the atrioventricular node.

Symptomatic junctional rhythm is treated with atropine. Doses and alternatives are similar to management of bradycardia in general.

When everything is working smoothly, you have a normal sinus rhythm and your heart beats between 60 and 100 times per minute.

Medical Care

1. No pharmacologic therapy is needed for asymptomatic, otherwise healthy individuals with junctional rhythms that result from increased vagal tone.
2. In patients with complete AV block, high-grade AV block, or symptomatic sick sinus syndrome (ie, sinus node dysfunction), a permanent pacemaker may be needed.

A Junctional rhythm can happen either due to the sinus node slowing down or the AV node speeding up. It is generally a benign arrhythmia and in the absence of structural heart disease and symptoms, generally no treatment is required.