每日一题_2022.3.7

A 54-year-old patient with no known cardiovascular disease presents to the hospital after a motor vehicle accident. Patient is doing well and planned for discharge home, however the nurse calls you and is concerned with the patient’s heart rhythm on telemetry. You review telemetry and see the above. What Is Causing the Pause in This Heart Rhythm?

A. Complete heart block with sinus pause

B. Sinus bradycardia with premature ventricular contraction and compensatory pause

C. Sinus arrest with non-compensatory pause

D. Junctional bradycardia with significant compensatory pause

答案解析：

该患者患有窦性心动过缓伴室性早搏或PVC。这一般是良性病因。PVC是心室内异位病灶引起的早搏。在早搏复合波后观察到的暂停被称为“代偿性暂停”，这是一个生理上正常的过程。术语代偿性和非代偿性是指室性早搏后的异位后暂停。
在室性早搏复合波过程中，心室细胞去极化，而心房仍能够传导。因此，窦房结不受PVC影响，并将以节律模式继续击发。在PVC期间，由于室性早搏复合波后心室不应期，来自窦房结的传导将在房室结处被阻断，因此，由窦房结驱动的一个QRS复合波将脱落，导致在该条带中观察到“代偿性间歇”。

正确答案：B