Third degree, or complete heart block, describes when the signal is completely blocked when moving from the atria to ventricles, every time.

三度房室传导阻滞，或称为完全阻滞，是指每个由心房向心室传导的电信号都被阻滞。

Patients with complete heart block are usually symptomatic, with symptoms ranging from syncope, confusion, dyspnea, severe chest pain, and these patients are at risk of dying.

完全传导阻滞患者通常都有症状，包括晕厥、意识障碍、呼吸困难以及严重的胸痛，甚至有死亡风险。

Second- degree type II is less common than second-degree type I but is much more dangerous as it frequently progresses to complete heart block or cardiac arrest.

相较于II级I型，II度II型比较不常见，但更危险，因为它经常进展到完全性心脏传导阻滞或心脏骤停。