Supraventricular tachycardia (SVT) can be triggered by which of the following?

• A. Hyperkalemia
• B. Stimulants such as cocaine, caffeine, and nicotine
• C. Hypothyroidism
• D. Asthma

Answer: (B)

SVT is commonly triggered by substances that ramp up the sympathetic nervous system. Stimulants like cocaine, caffeine, and nicotine boost catecholamine release and sympathetic tone, which increases automaticity in atrial tissue and speeds conduction through the AV node. This can facilitate a reentrant circuit and initiate a rapid, regular heart rhythm typical of SVT.

Hyperkalemia tends to disrupt conduction and cause other types of arrhythmias rather than the classic narrow-complex SVT. Hypothyroidism usually slows the heart rate rather than triggering a fast tachycardia. Asthma is a respiratory condition and does not directly provoke SVT.