Chapter Review

  1. In sinus tachycardia, the heart rate must be above ____ BPM.

  2. The heart rate in sinus tachycardia is usually ___ and ___ BPM. It may, however, reach up to ___ BPM and in some rare circumstances up to ___BPM.

  3. Maximum heart rate is equal to ___ BPM − Age (in years).

  4. Sinus tachycardia is caused by a predominant effect of the parasympathetic nervous system. True or False.

  5. Wide QRS complexes are acceptable in sinus tachycardia. True or False.

  6. Sympathetic discharge causes faster transit times through the AV node. This leads to a shortening of the __ interval. However, the interval should still be in the normal range of between 0.12 and 0.20 seconds.

  7. Electrical alternans is electrocardiographically represented as a varying ________ of the QRS complex.

  8. Electrical alternans must be seen in every other complex in order to make the diagnosis. True or False.

  9. The following conditions may lead to electrical alternans:

A. Tachycardias

B. Myocardial infarctions

C. Pericardial effusions

D. Pericarditis

E. Both A and C are correct

F. Both B and D are correct

10. The ST segment can be depressed in tachycardias. Some possible causes include:

A. Atrial repolarization or Tp wave

B. Relative endocardial ischemia

C. Actual endocardial ischemia

D. Buried P waves

E. All the above are correct

11. Sinus tachycardia has a much shorter phase 4 of the action potential. This is electrocardiographically represented by a short ___ segment.

12. Sinus tachycardia should not be considered a pathologic rhythm but merely a physiologic response to autonomic stress. True or False.

13. The treatment of sinus tachycardia is to _________________________.

14. Tachycardias _________ the amount of passive filling time during diastole. This leads to a ________ in the stroke volume which, in turn, leads to a ________ in cardiac output.

15. The differential diagnosis of sinus tachycardia includes:

A. Exercise

B. Fevers

C. Cocaine

D. Anemia

E. Congestive heart failure

F. All of the above

16. It is common for the TP segment to be completely missing on a strip showing sinus tachycardia. True or False.

17. In an acute myocardial infarction, the tachycardia may lead to further damage because of the increased oxygen demand placed on the myocardium by the tachycardia. In this case, slowing down the heart by using beta-blocking agents, for example, is clinically appropriate (if there are no clinical contraindications or extenuating circumstances). True or False.

18. The main therapy in a sinus tachycardia that is hemodynamically stable in a patient with fever is the beta blockers. True or False.

19. Sinus tachycardias are always benign hemodynamically. True or False.

20. Treatment for sinus tachycardias includes synchronized cardioversion. True or False.