Harvard Heart Letter

Living with long QT syndrome

Slow recovery between heartbeats can cause problems, including sudden death.

When people talk about the heartbeat, the forceful contractions of the heart's four chambers get most of the attention. But the pause between beats is just as important. This pause that refreshes the heart is normally much quicker than the blink of an eye. In some people, though, it lasts longer than it should. The delay signals that heart muscle cells are having trouble getting ready for the next contraction. This can lead to a fast, erratic rhythm that can cause shortness of breath, fainting, and sometimes even sudden death.

Key points

  • Long QT syndrome is an inherited or acquired condition that can cause shortness of breath, fainting, and sometimes cardiac arrest.

  • Managing it involves lifestyle changes, medications, and sometimes having a defibrillator implanted. Avoiding drugs that lengthen the QT interval is also important.

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