***ACUTE MI SUSPECTED*** Abnormal ECG ***Unconfirmed***

After a mind numbing session of protocol review, your partner asks you to review a 12 lead ECG. The ECG tracing was obtained from a patient who was diaphoretic, hypotensive, and semi-conscious.

What's the underlying rhythm?
What are your treatment priorities?

Rampart, prepare to receive telemetry...

12 Lead ECG:

12 Lead ECG Interpretation and Case Discussion:
Once again, kudos to the ECG interpretation software! The ECG is absolutely, without question, ***ABNORMAL***. It looks like this tracing triggered every single lifenet alert possible. The ECG reveals, simultaneously, "inferior and lateral injury patterns" coupled with "atrial fibrillation" and an "anterior injury pattern."

FIRST, the presence of a wide complex tachycardia is easily recognized. The rhythm is wide and regular which suggests ventricular tachycardia. The ventricular rate is in excess of 200 beats per minute. The combination of a wide complex tachycardia and an unstable patient should always warrants serious consideration of electrical therapy. In this particular case, a biphasic shock of 200 or 300 joules isn't likely to produce the desired result.

Now, the patient's chest hairs are signed and you're left with the same troublesome waveform. Vital signs have not improved. This tracing is classic for a specific type of ventricular tachycardia called "sinusoidal" ventricular tachycardia. This rhythm is characterized by a rapid ventricular rate a regular appearance of the QRS complex. Sinusoidal ventricular tachycardia is often called ventricular flutter. It is typically a pre-arrest rhythm that deteriorates rapidly into the more familiar ventricular fibrillation.

Though typically caused by severe hyperkalemia, ventricular flutter may be medication induced. Sodium channel blocking anti-dysrhythmics and anti-psychotics have been linked to sinusoidal VT. Treatment therefore involves:

• Rapid administration of IV calcium (stabilizes the myocardium)
• Empiric treatment for hyperkalemia (consider bicarbonate, albuterol, etc)
• Defibrillation
• Treatment of underlying cause (emergent hemodialysis)

Administration of anti-dysrhythmics such as lidocaine are not usually effective and may even precipitate deterioration of the rhythm into ventricular fibrillation.

When confronted with the dreaded sinusoidal ventricular tachycardia, consider the patient's history if at all possible. Patients with known renal disease or complex medical comorbidities may be at risk for hyperkalemia. If local protocols permit, aggressively treat hyperkalemia. Administration of calcium may render the myocardium less resistant to electrical therapy.

The patient's potassium level was measured at over 9 mEQ/L (normal 3.5-5 mEQ/L) .

Final 12 Lead ECG Interpretation:Sinusoidal ventricular tachycardia, ventricular flutter likely secondary to severe hyperkalemia