Anatomy & Physiology第 66 / 100 题
What is the inherent rate of the Purkinje fibers, and what does a rhythm at that rate look like?
a.60 to 100 beats per minute with narrow complexes
b.40 to 60 beats per minute with inverted P waves
c.100 to 150 beats per minute with sawtooth waves
d.20 to 40 beats per minute with wide QRS complexes and no P waves
解析
The Purkinje network is the heart's pacemaker of last resort at 20 to 40 beats per minute, and because the impulse starts below the AV junction, the QRS is wide and no P waves precede it. The 60 to 100 range belongs to the SA node and produces narrow complexes with upright P waves. The 40 to 60 range with inverted P waves describes a junctional rhythm, and sawtooth waves indicate atrial flutter.
免费刷完整 100 道题库 — 无需注册。
同考点相关题目
- What is the inherent firing rate of the sinoatrial node in a healthy adult?
- A patient's SA node fails completely. Which structure normally takes over, and at what rate?
- What is the correct order of the cardiac electrical conduction pathway?
- Why does the impulse pause briefly at the AV node, and how does that pause appear on the EKG?
- What is depolarization?
- A student asks why an EKG can look normal in a patient whose heart is not pumping effectively. What is the best explanation?