A narrow-complex rhythm near 150
A fictional adult reports persistent palpitations but has adequate perfusion and no immediately identified instability attributable to the rhythm. The ECG is regular and narrow-complex with a ventricular rate close to 150 beats per minute. Atrial activity is difficult to see on the initial printout. A colleague declares that this rate proves AV nodal reentrant tachycardia, while another suggests examining for flutter waves and considering 2:1 atrioventricular conduction. The case does not provide a complete rhythm strip, response to maneuvers, accessory-pathway assessment or a medication order. The learning task is to distinguish the supported differential from a premature mechanism assignment and identify what the team should clarify before selecting a rhythm-specific strategy.
1. Why is the rate alone insufficient?
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Typical atrial flutter with 2:1 conduction and several other supraventricular mechanisms can produce a similar ventricular rate.
2. What should guide the next reasoning step?
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Review atrial activity, rhythm strips, hemodynamic status and relevant contraindications under the responsible clinical team rather than assume one diagnosis from the rate.