A hypertensive patient has heart rate of 50 beats/min and taking tablet atenolol 200 mg/day in divided doses. After anaesthesia, heart rate further fell down to 40 beats/min. What will be the appropriate treatment to improve heart rate:
**Core Concept**
The patient's heart rate is severely decreased (bradycardia) due to the combination of hypertension treatment with atenolol, a beta-1 selective beta-blocker, and anesthesia, which can further suppress the heart rate. This situation requires careful management to avoid hemodynamic instability.
**Why the Correct Answer is Right**
Atenolol acts by selectively blocking beta-1 receptors in the heart, reducing heart rate and contractility. In the setting of anesthesia, which can also depress the heart rate, the combination of atenolol and anesthesia can lead to severe bradycardia. In this scenario, administering a medication that can increase heart rate and counteract the effects of beta-blockade is necessary. Atropine, a muscarinic receptor antagonist, is the appropriate treatment as it can increase heart rate by blocking the action of acetylcholine on the sinoatrial node.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not address the underlying cause of bradycardia, which is the beta-blockade effect of atenolol. Increasing the dose of atenolol would worsen the situation.
**Option C:** This option is incorrect as it does not address the acute management of bradycardia in the peri-anesthetic period. Atropine is the preferred agent for rapid heart rate increase in this setting.
**Option D:** This option is incorrect as it does not address the specific cause of bradycardia in this patient, which is the beta-blockade effect of atenolol. Administering a medication that increases heart rate through a different mechanism may not be effective in this scenario.
**Clinical Pearl / High-Yield Fact**
In patients taking beta-blockers, such as atenolol, it is essential to be aware of the potential for severe bradycardia in the peri-anesthetic period. Atropine is the preferred agent for rapid heart rate increase in this setting.
**Correct Answer:** C. Atropine 0.5-1 mg IV bolus to be repeated as necessary.