A 76-year-old man has documented symptomatic sinus bradycardia with intermittent pauses up to 4 seconds, alternating with paroxysmal atrial fibrillation requiring rate control. Which management strategy is correct?

• A High-dose beta blocker therapy alone will resolve both problems
• B Radiofrequency modification of the AV node is the definitive cure for the bradycardia
• C Ivabradine will restore normal sinus node function
• D Permanent pacemaker implantation is needed before aggressive pharmacologic rate control of the atrial fibrillation ✓

Explanation

Tachycardia-bradycardia syndrome reflects sick sinus syndrome with atrial fibrillation. Drugs used for ventricular rate control worsen the sinus bradycardia and pauses, so a permanent pacemaker is implanted first to permit safe use of AV nodal blocking agents. Ivabradine slows the sinus node and would aggravate the problem, and AV nodal ablation creates complete heart block rather than curing it, requiring a pacemaker anyway. Beta blocker monotherapy risks symptomatic pauses here.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.