Treatment of AV nodal blocks
First Degree AV Block
Generally, people with first degree AV block do not require any treatment. However, if the patient has severe bradycardia, or if there is a risk that the disease may progress into a high-degree AV block, then medications such as atropine or isoproterenol should be used before a cardiac pacemaker is implanted.
Any underlying conditions, such as digitalis intoxications, myocardial infarction, etc., should be treated accordingly. If the patient has severe electrolyte abnormalities, they should be corrected.
If the patient is taking medications that may worsen the AV block, these medications should be discontinued if it is possible.
Second Degree AV Block
If second degree AV block is asymptomatic then there is no need for specific therapy. However, if the patient is symptomatic, then standard guidelines for bradycardia should be implemented (this includes the use of atropine and transcutaneous pacing).
If there is a suspicion that the patient might have myocardial ischemia, then appropriate anti-ischemic regimen should be implemented.
Second degree AV block can also be the result of digoxin, beta-blockers, and calcium channel blockers overdose. If that is the case, then decreasing the dosage or even discontinuinguse may be indicated.
Permanent cardiac pacemaker is installed if the condition is gradually growing worse. This operation is also used for patients with Mobitz II AV block, since it can present serious risks for the patient’s health.
Third Degree AV Block
Complete heart block is a medical emergency, the treatment of which is based on the level of the block. If the patient with myocardial infarction of the inferior wall is asymptomatic and has a stable heart rate of 35 beats per minute, then they are in no immediate risk. On the other hand, a patient with anterior wall myocardial infarction with a distal high-grade block may be in serious danger of asystole (complete stopping of the heart). Thus, a pacemaker should be prepared which can be implanted temporarily or permanently.
One of the most important steps for treating an AV block is of course the withdrawal of any agents which may cause an AV block. Among other drugs mentioned previously, calcium channel blockers are among the few drugs that can cause a complete heart block.
Prognosis depends on the degree of the block and the underlying condition. Generally, the prognosis is good, unless there is a risk of a transition between Mobitz II second degree AV block and third degree AV block, which can lead to asystole.