Question

Which of the following heart block dysrhythmias is identified by a repetitious prolonging PR interval pattern after each blocked QRS complex
a) first degree heart block
b) second degree heart block type I
c) second degree heart block type II
d) third degree heart block

Answer 1

Answer: Option A.

first degree heart block

Explanation:

First degree atrioventricular block is a condition that is associated with electrical condition system of the heart in which the electrical impulses is conducted from the cardiac atria to the ventricles via atrioventricular node in a slow manner compare to the normal transmission.

It is first degree great block because it is characterized by prolong PR interval on an electrocardiogram (ECG) to more than 200 msec and atrial impulse is transfered to the ventricles, which lead to regular ventricular rate.

The PR interval of the surface ECG is measured from the start of atrial depolarization (P wave) to the commensement of ventricular depolarization or QRS complex.