Megacode: Unstable Ventricular Tachycardia Part 2

Oxygen at 2L/min is placed on the patient and an IV is quickly established.   Blood work for lab studies are obtained for a CBC, comprehensive metabolic panel, CK, CKF, and TNI.   The patient’s medical history is obtained and he states that he had “the worst case of indigestion this morning that I ever had.”   He took an antacid and sat down on the job site and began feeling a little better.  He is currently taking a blood pressure pill every morning, has frequent indigestion, and was told by his family doctor that his cholesterol was high.  He stopped taking his cholesterol medication because it made him “ache all over.”  When the MD returns, he stated that he has spoken with a consulting cardiologist and that he recommended immediate cardioversion based upon the patient’s symptoms.  IV fluids are started on the patient and preparations are made for immediate synchronized cardioversion.  Appropriate sedation and analgesics are administered to the patient.

6.  What is your assessment of the rhythm?

a.  The monitor had failed to capture and the mAs should be increased

b.  The monitor has correctly synchronized with the R waves of the rhythm

c.  The monitor is ready for immediate defibrillation

d.  The monitor has failed to sense the patient’s underlying rhythm

7.  Synchronized cardioversion may be used on all of the following rhythms EXCEPT:

a.  Atrial flutter

b.  Monomorphic ventricular tachycardia

c.  Polymorphic ventricular tachycardia

d.  New onset atrial fibrillation with rapid ventricular response

8.  Define synchronized cardioversion.

Synchronized cardioversion:

9.  What is the pathophysiology of the hemodynamic instability in a patient with unstable tachycardia?

10.  What is the recommended initial joule setting when performing synchronized cardioversion on a patient with unstable monomorphic ventricular tachycardia?

1.  200 joules monophasic

2.  120-200 joules biphasic

3.  50-100 joules monophasic

4.  100 joules biphasic

Answers

6.  What is your assessment of the rhythm?

b.  The monitor has correctly synchronized with the R waves of the rhythm

7. Synchronized cardioversion may be used on all of the following rhythms EXCEPT:

c.  Polymorphic ventricular tachycardia

8. Define synchronized cardioversion.

Synchronized cardioversion: is shock delivery that is timed (synchronized) with the QRS complex. This synchronization avoids shock delivery during the relative refractory period of the cardiac cycle when a shock could produce VF.

9.  What is the pathophysiology of the hemodynamic instability in a patient with unstable tachycardia?

The heart is beating so fast that the ventricular filling time is reduced which causes a lower stroke volume and lower cardiac output.

The heart is beating ineffectively so that coordination between the atrium and the ventricles or the ventricles themselves causes a reduction in the cardiac output

10.  What is the recommended initial joule setting when performing synchronized cardioversion on a patient with unstable monomorphic ventricular tachycardia?

4.  100 joules biphasic