A delay or block that occurs in one of the bundle branches ...

[joesmith1212]

A delay or block that occurs in one of the bundle branches affects ventricular depolarization.
 
  Indicate whether the statement is true or false

Question 2

In sinus arrhythmia, a gradual increasing of the heart rate is usually associated with _____.
 
  a. expiration
  b. inspiration
  c. excessive caffeine intake
  d. early signs of heart failure

[Silverbeard98]

Answer to Question 1

T
If a delay or block occurs in one of the bundle branches, the ventricles will not be depolarized at the same time. The electrical impulse travels first down the unblocked branch and stimulates that ventricle. Because of the block, the impulse must then travel from cell to cell through the myocardium, rather than through the normal conduction pathway, to stimulate the other ventricle. The ventricle with the blocked bundle branch is the last to be depolarized.

Answer to Question 2

B
Sinus arrhythmia that is associated with the phases of breathing and changes in intrathoracic pressure is called respiratory sinus arrhythmia. The rhythm is irregular; the heart rate increases gradually during inspiration (R-R intervals shorten) and decreases with expiration (R-R intervals lengthen).