Bonus points if you can tie the summary sentence to your question (e.g. “With all of that frustration you’ve felt with your girlfriend, have you noticed if it has affected your blood sugars?”).
This strategy requires your full attention. If your summary statement is completely inaccurate, your patient will feel vexed.
Other strategies, with increasing urgency (always done with respect):
Say the person’s name (most people will stop talking). Lean forward and express urgency on your face. Make some other sound (e.g. firmly putting your hand on a table) in addition to saying the person’s name and leaning forward.
Maria is a gem.