From the Guidelines
Bisoprolol should be discontinued in a patient with Mobitz type II (second-degree) atrioventricular (AV) block due to the risk of worsening heart block and potential progression to complete heart block. Bisoprolol is a beta-blocker that slows heart rate and conduction through the atrioventricular (AV) node, which can worsen existing heart blocks and potentially lead to complete heart block, asystole, or other dangerous bradyarrhythmias 1. The medication should be discontinued immediately, and the patient should be monitored closely for worsening bradycardia or symptoms such as dizziness, syncope, or shortness of breath. Some key points to consider when discontinuing bisoprolol include:
- The risk of rebound effects in patients with underlying coronary artery disease, which can sometimes occur with abrupt cessation of beta-blockers 1
- The potential need for temporary or permanent pacemaker placement, depending on the clinical situation
- The importance of monitoring the patient closely for worsening bradycardia or symptoms such as dizziness, syncope, or shortness of breath Mobitz type II block is considered a more serious form of heart block than Mobitz type I (Wenckebach) because it often occurs below the AV node in the His-Purkinje system and has a higher risk of progressing to complete heart block. In general, beta-blockers should not be stopped suddenly unless absolutely necessary, but in the case of Mobitz type II heart block, the risk of worsening heart block generally outweighs concerns about beta-blocker withdrawal 1.
From the Research
Discontinuation of Bisoprolol in Mobitz Type II AV Block
- The decision to discontinue bisoprolol (beta blocker) in a patient with Mobitz type II (second-degree) atrioventricular (AV) block should be based on the individual patient's condition and the underlying cause of the AV block.
- According to the study 2, beta-blocker medication was initiated to prevent high sinus rates during everyday activity in a patient with tachycardia-dependent Mobitz Type II second degree AV-block, which abolished symptoms totally.
- However, in general, beta blockers like bisoprolol can affect AV node conduction and may worsen AV block in some cases.
- The study 3 suggests that Mobitz type II AV block is invariably at the level of the His-Purkinje system and is an indication for a pacemaker, but it does not provide direct guidance on the use of beta blockers in these patients.
- Other studies 4, 5, 6 provide information on the diagnosis and management of Mobitz type II AV block, but do not specifically address the use of beta blockers like bisoprolol.
Considerations for Discontinuation
- The patient's overall clinical condition, including the presence of any underlying heart disease or other medical conditions, should be taken into account when deciding whether to discontinue bisoprolol.
- The potential benefits and risks of continuing or discontinuing bisoprolol should be carefully weighed, considering the individual patient's circumstances.
- Electrophysiological studies, as described in 4 and 2, may be helpful in determining the underlying cause of the AV block and guiding management decisions.