Patients with long QTs are at an increased risk of torsade de pointe, a potentially fatal ventricular arrhythmia.

长QTs患者发生尖端扭转性室性心律失常（一种潜在的致命性室性心律失常）的风险增加。

However these drugs may also cause arrhythmias, because slowly polarizations are associated with longer QT intervals and increased risk of torsades de pointes.

不过，这类药物也可能会导致心率不齐，因为极化速率减慢，会延长QT间期，增加尖端扭转型室速的风险。