Flatliner

[…]unless my heart stops, okay? Nada — unless I'm a flatliner."

In spite of his dramatic highs and the canyon lows, Kurt was a flatliner—a patient with no heartbeat.

Though occasionally a “flatliner” can be revived with a defib, it is most commonly used to change the uncoordinated contractions of the heart (fibrillation) into a normal sinus rhythm—that is, to defibrillate the heart.