Atrioventricular Block

Atrioventricular BlockCLINICAL SIGNS

* none.

* or slow pulse unmodified by exercise or fever for high degree block.

* or feeling weak or lipothymia.

* or syncope of Adams-Stokes .

* or signs of left or global heart failure.

* or sudden death.


* Idiopathic especially in the elderly, congenital.

* after a myocardial infarction (anterior more derogatory than inferior).

* overload or drug poisoning: digitalis, beta-blockers, Isoptin, Cordarone and other negative chronotropes.

* during Prinzmetal’s angina (trinitrine removes the two anomalies).

* Calcified aortic stenosis.


* scope, ECG:

– BAV I:

 PR> 0.20 s , asymptomatic.


 progressive extension of PR until blocking of a P wave not followed by QRS (Luciani-Wenckebach period) or unexpected blocking of the P wave not followed by the QRS wave (Mobitz 2).


 Complete atrioventricular dissociation , more P waves than the QRS without coupling with them.

 supra-hissian relay (fine QRS), hissian (fine QRS) or infra-hissian (wide QRS).

– presumption of paroxystic complete BAV:

 if BBD + HBPG or BBD + HBAG, BAV II, BBD complete isolated, …

* blood ionogram: look for hypokalemia.


* respect a well tolerated bradycardia, stop any negative chronotropic drug.

* if bad tolerance:

– hospitalization.

– venous route: G5%, oxygen therapy in the mask.

– Atropine sulphate: 0.5-1 mg IV, renewable after 5 minutes (maximum 5 mg) but not very effective for the most symptomatic large QRS BAVs.

– if failure or if QT long:

 Isuprel : 5 ampoules in 250 ml to adjust according to the frequency, to maintain above 80 / min (electric syringe in children: 0.1-1 μg / kg / min).

– set up an electrostimulation probe as soon as possible, especially if digitalis intoxication because Isuprel is contraindicated.

* treatment of the cause.