A pacemaker is the necessary treatment for CHB. If no escape rhythm is present, the patient will not be able to perfuse, and will subsequently arrest due to cardiac standstill.ĬHB is life-threatening, and it is typical for patients with this condition to experience severe bradycardia and hypotension. Atropine in increments of 0.2 mg IV may convert a slow junctional rhythm to sinus rhythm, particularly if secondary to a. However, when infra-Hisian (below the bundle of His) conduction disease exists as the cause, the escape focus is ventricular in origin, producing a slower, less reliable rhythm-characterized by a wide QRS complex on ECG. This is characterized by a narrow QRS complex on ECG. If the block is the result of a diseased AV node, a junctional focus (escape rhythm) emerges and produces a rate typically between 40 to 60 beats per minute. CHB caused by inferior myocardial infarctions tends to lead to junctional escape rhythms, while CHB caused by anterior myocardial infarctions causes slower ventricular escape rhythms. Systemic perfusion is maintained by an escape rhythm originating from either the junction or the ventricles.Ĭauses of CHB include myocardial infarction, AV nodal blocking drugs, or idiopathic degeneration of the conduction system.

Due to this failure, the atria and ventricles act independently of each other. Note the dissociation between the p-waves and QRS complexes.Ĭomplete heart block (CHB) is characterized by atrioventricular dissociation as atrial impulses fail to conduct to the ventricles. Stars over the QRS complexes highlight the ventricular rate. Arrows over the p-waves show the atrial rate. T-wave inversions are noted in the precordium as well as in the inferior leads. There are no ST-elevations or depressions. There is an atrial rate of approximately 100 beats per minute and a ventricular rate of 30 beats per minute. The ECG reveals a complete heart block with atrioventricular dissociation. The patient was diagnosed with a third-degree (complete) heart block.

Atropine on junctional escape rhythm