In the context of ventricular tachycardia (VT), what is a capture beat?

• A. A beat that occurs when both atrial chambers contract
• B. A normal appearing QRS produced by a sinus node pacer
• C. A beat that is irregular with no identifiable pattern
• D. A standard heart rate with skipped beats

Answer: (B)

In the context of ventricular tachycardia (VT), a capture beat refers to a normal QRS complex that occurs when the heart's natural pacemaker (the sinus node) temporarily takes control and successfully stimulates the ventricles despite the prevailing tachycardia. This is typically seen in cases where there is a competition between the ventricular ectopic foci (causing the tachycardia) and the sinus node.

When a capture beat occurs, it generates a QRS complex that looks normal, reflecting that the electrical impulse followed the typical conduction pathway through the heart. This indicates that the sinus node is still functioning, and at that moment, the electrical activity from the sinus node overrides the abnormal rhythm of the VT.

In comparison to the other choices, those do not depict the definition of a capture beat. A capture beat specifically highlights the transient takeover by the normal sinus rhythm amidst a backdrop of VT, making it a crucial observation for telemetry monitor technicians to recognize in clinical practice.