Understanding Cardiac Dysrhythmias

This episode covers Chapter 79 of Rosen’s Emergency Medicine.

All those funny squigly marks on the ECG confusing you? Us too. Here is some knowledge to help you out.

1. What is the blood supply of the following parts of the conduction system: SA node, AV node
2. What are the three pathophysiologic mechanisms for dysrhythmias?
3. What causes & how does AV nodal reentry tachycardia occur?
4. List the classes of antidysrhythmics. Describe their mechanism of action and usual uses, as well as an example of each.
5. How does digoxin work as an antidysrhythmic? When is it used?
6. List underlying etiologies of sick sinus syndrome.
7. What are three ECG presentations of sick sinus syndrome?
8. Define 1° heart block.  List three causes.
9. Differentiate between the two types of  2° heart block with respect to etiology, ECG appearance and management.
10. What is ‘high grade’ heart block?  How is it managed?
11. Describe the difference between AV dissociation & 3° AV block.
12. Compare PAC’s to PVC’s.
13. Give a differential diagnosis of irregularly irregular tachycardia.
14. Define pre-excitation and list the 3 ECG features of classic WPW
15. Explain the concept of antidromic and orthodromic conduction with respect to WPW. Which pts with WPW should not receive AV node blockers?  Why?
16. List 10 causes of PVC and VT
17. How do you differentiate b/n SVT with aberrant conduction & ventricular tachycardia?
18. List 10 causes of atrial fibrillation.
19. Describe the management of AFIB, including a discussion about the CHADS2 score and long term stroke risk.
20. What is Brugada syndrome? What is the management?

WiseCracks:

1. List 8 side effects of Amiodarone.
2. Describe features that favor VT over SVT.
3. Describe the Brugada approach to the Dx of VT
4. List Causes of acquired pause-dependent QT prolongation causing Torsades & List causes of adrenergic dependent TdP
5. Describe the treatment of pause dependent TdP
6. Define PSVT and describe management
7. What’s Ashman’s phenomenon?