What is the purpose of transvenous pacing?

• A. To stimulate a contraction in patients with bradycardia or heart block.
• B. To increase heart rate in tachyarrhythmias.
• C. To reduce preload.
• D. To improve myocardial oxygen demand.

Answer: (A)

Transvenous pacing delivers electrical impulses to the heart to produce a contraction when the heart’s own rhythm is too slow or blocked. In bradycardia or high-grade heart block, the conduction system can fail to provide an adequate heart rate, leading to poor cardiac output and organ perfusion. A transvenous lead is threaded through a central vein into the heart and connected to an external pacemaker, which can be set to pace at a chosen rate (sometimes asynchronously, sometimes on demand) to maintain an effective heart rate and improve perfusion. This is typically a temporary bridge until the underlying issue resolves or a permanent pacemaker is implanted. It is not used to treat tachyarrhythmias, does not primarily reduce preload, and does not aim to improve myocardial oxygen demand.