如何计算Q Tc
learn.whatIsHeading
Corrected QT interval accounts for heart rate, predicting arrhythmia risk. QTc >460 ms females, >450 ms males increases torsades risk.
公式
Apply Bazett formula: QTc = QT / √RR (RR in seconds)
- QT
- QT value — Variable used in the calculation
- RR
- RR value — Variable used in the calculation
分步指南
- 1Measure QT interval from ECG
- 2Apply Bazett formula: QTc = QT / √RR (RR in seconds)
- 3Or use other formulas for extreme heart rates
例题解析
输入
QT 420 ms, HR 80 (RR 0.75 s)
结果
QTc ≈ 420/√0.75 ≈ 485 ms (prolonged)
Elevated arrhythmia risk
常见错误注意事项
- ✕Using Bazett formula at extreme heart rates (use Fridericia for HR >100)
- ✕Forgetting electrolyte abnormalities (low K, Mg, Ca) prolong QT
常见问题
Which drugs prolong QT?
Antiarrhythmics, antipsychotics, antiemetics, fluoroquinolones, and many others. Check before prescribing.
What QTc values are safe?
<450 ms males, <460 ms females normal; 450-480 borderline; >500 ms high torsades risk.
准备好计算了吗？尝试免费的 Q Tc 计算器
自己尝试一下 →