What medications are recommended for treating anxiety in a patient with a 1st-degree Atrioventricular (A-V) block?

Anxiety Medications in First-Degree AV Block

SSRIs and SNRIs are the preferred first-line pharmacotherapy for anxiety in patients with first-degree AV block, as they do not affect cardiac conduction and carry no risk of worsening the conduction delay. 1, 2

First-Degree AV Block: Clinical Context

First-degree AV block is characterized by a prolonged PR interval (>0.20 seconds) and is generally benign, representing delayed conduction through the AV node rather than true "block" 3, 4. The American Heart Association guidelines explicitly state that first-degree AV block does not require treatment unless it causes symptoms similar to pacemaker syndrome 3. This benign nature allows for broader medication options compared to higher-grade AV blocks.

Recommended Anxiety Medications

First-Line: SSRIs and SNRIs

Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) represent the optimal choice for anxiety treatment in patients with first-degree AV block. 1, 2

• These agents have the highest level of evidence for anxiety disorders including generalized anxiety disorder, panic disorder, and social anxiety disorder 1
• SSRIs (citalopram, fluoxetine, fluvoxamine, paroxetine, sertraline) selectively inhibit serotonin uptake without affecting cardiac conduction, neurotransmitter receptors, or enzymes 5
• They carry no risk of bradycardia or worsening AV conduction delay 5
• Treatment should continue for 6-12 months after remission 1

Second-Line Options

Buspirone and pregabalin are reasonable alternatives that do not affect cardiac conduction. 1, 2

• Buspirone (azapirone class) is effective for generalized anxiety disorder without cardiac effects 2
• Pregabalin (alpha-2-delta calcium channel modulator) demonstrates efficacy in anxiety disorders without affecting AV nodal conduction 2

Medications to AVOID

Beta-Blockers: Use with Extreme Caution

Beta-blockers should generally be avoided or used with significant caution in first-degree AV block due to their potential to worsen AV conduction delay. 3

• Beta-blockers slow AV nodal conduction and can precipitate higher-grade AV block 3
• The 2019 ACC/AHA/HRS bradycardia guidelines note that atropine is used to reverse AV block, working against cholinergic effects—beta-blockers would have the opposite effect 3
• If beta-blockers are deemed medically necessary for other indications in a patient with stable first-degree AV block, the 2019 guidelines state it is reasonable to proceed to permanent pacing rather than withhold the medication 3

Calcium Channel Blockers: Contraindicated

Verapamil and diltiazem are contraindicated for anxiety management in first-degree AV block. 3

• These non-dihydropyridine calcium channel blockers significantly slow AV nodal conduction 3
• ACC/AHA/HRS guidelines specifically warn about bradyarrhythmias and hypotension with these agents 3
• They are used therapeutically to slow AV conduction in supraventricular tachycardias, making them inappropriate when conduction is already delayed 3

Benzodiazepines: Not Recommended for Routine Use

Benzodiazepines are not recommended for routine anxiety treatment regardless of cardiac status. 1

• Current anxiety treatment guidelines explicitly state benzodiazepines should not be used routinely 1
• While they don't directly affect AV conduction, their risks (dependence, cognitive impairment, falls) outweigh benefits for chronic anxiety management 1, 2

Tricyclic Antidepressants: Avoid

Tricyclic antidepressants should be avoided due to their anticholinergic and cardiac conduction effects. 3, 1

• TCAs can prolong the PR interval and worsen conduction delays 3
• They affect multiple neurotransmitter receptors and carry significant cardiac risks 5

Clinical Algorithm

1. Confirm first-degree AV block diagnosis: PR interval >0.20 seconds on ECG, asymptomatic or minimally symptomatic 3, 4

2. Initiate SSRI or SNRI: Select based on anxiety disorder subtype, comorbidities, and side effect profile 1, 2

3. Monitor for treatment response: Remission may take several months; continue therapy 6-12 months after achieving remission 1

4. If inadequate response: Consider switching to alternative SSRI/SNRI, adding buspirone, or trying pregabalin 1, 2

5. Avoid all AV nodal blocking agents: No beta-blockers, verapamil, diltiazem, or digoxin for anxiety management 3

Critical Pitfalls

• Do not prescribe propranolol despite its historical use for performance anxiety—it will worsen AV conduction 3, 6
• Avoid combination therapy with diltiazem plus propranolol (the "pill-in-the-pocket" approach for SVT), as both agents slow AV conduction 6
• Screen for depression: Comorbid depression is common with anxiety disorders and further supports SSRI/SNRI selection 2
• Consider drug interactions: Adjust doses in elderly patients or those on multiple medications 2