Activation mapping patterns: a focal source would be described as which of the following?

Activation mapping patterns: a focal source would be described as which of the following?

• A. A single early activation site with local spread
• B. Wide-area activation
• C. Sequential multi-site activation
• D. No clear earliest activation

Answer: (A)

Activation mapping identifies where an arrhythmia begins. A focal source is diagnosed when you can pinpoint a single earliest activation site and observe activation spreading locally from that point to surrounding tissue. This single point acts as the driver of the rhythm, with propagation stepping outward to neighboring areas. That’s why this description best fits a focal source: it captures both the isolated origin and the local spread that follows. Think of the alternatives in contrast: wide-area activation implies activation covers a broad region rather than emanating from one spot; sequential multi-site activation means several areas appear early in sequence, not a single focus; and no clear earliest activation shows up in highly disorganized rhythms where timing is scattered without a distinct starting point.

Activation mapping identifies where an arrhythmia begins. A focal source is diagnosed when you can pinpoint a single earliest activation site and observe activation spreading locally from that point to surrounding tissue. This single point acts as the driver of the rhythm, with propagation stepping outward to neighboring areas. That’s why this description best fits a focal source: it captures both the isolated origin and the local spread that follows.

Think of the alternatives in contrast: wide-area activation implies activation covers a broad region rather than emanating from one spot; sequential multi-site activation means several areas appear early in sequence, not a single focus; and no clear earliest activation shows up in highly disorganized rhythms where timing is scattered without a distinct starting point.