UPDATED: 9/17/2007 - Patient Follow-Up Posted.  CLICK HERE FOR THE ANSWER

EKG Case Discussion:
EMS providers may encounter cardiac issues even in the "fit" and healthy population. Tachycardia is defined by any heart rate over 100. While this may be considered a normal physiological response to stress or exercise, a narrow complex tachycardia can be extremely harmful and can lead to death if not recognized and treated efficiently and effectively.
 
Learning Objectives:

• Basic: Recognition of narrow complex tachycardia.
• Intermediate: Identifying the range of therapies available to treat this rhythm (e.g. valsalva, drugs).
• Advanced: Awareness of possible contraindications to adenosine and the co-administration of adenosine. Being prepared for that period of "asystole" that often occurs during treatment.

Presentation:
One day, while enjoying the morning sun, you are dispatched to the workplace of a 36-year-old male with palpitations at 0935 hours. The location is not far from where you are sitting, so it takes only about 5 minutes with lights and sirens to reach the scene. You arrive at the two-story office building of a local financial services office. The receptionist leads you through the building, where you find a man seated at his desk with several of his workmates nearby looking concerned. The patient is a fit-looking male who appears to be in minimal distress.

Initial Assessment:
Beginning the assessment, your general impression of the patient is that he is a seemingly-healthy young man in minimal distress. He tells you that he has noticed his heart racing for the last 30 minutes and denies experiencing any other symptoms. You escort him to the ambulance because he insists on walking himself and he denies experiencing dizziness upon standing. You perform an initial physical assessment and find the following results:

Vital signs are:
HR 146
RR 20
BP 106/65
SpO2 97% (Room Air)
Pain 0/10

Past Medical History:
None

Allergies:
No known drug allergies (NKDA)

Meds: <generic names>
None

Initial Assessment:
You perform a quick head-to-toe assessment and find nothing abnormal to report. Your partner sets up the cardiac monitor, attaches the electrodes, and acquires a 12-lead EKG.

Initial EKG (click for larger image)

The computed interpretation is:
HR 143 bpm
PRI N/A
QRSd 84 ms
QT/QTc 274ms/423ms
Paxis N/A
QRSaxis 67
Taxis 53

It reads:
***Age and Gender Specific Analysis***
Supraventricular Tachycardia
Nonspecific ST abnormality
Abnormal EKG

What is the rhythm?

What treatments are appropriate?

What are the contraindications to drug therapy?
 
Response to Treatment:
You have a transport time of 20 minutes (Edit Update: 9/14/2007). You take a look at your partner who, without further discussion, moves into setting up two large-bore IV accesses and O2, initially via nasal cannula at 4 lpm. You ask your patient to forcefully cough and to strain. However, the rhythm remains unchanged. After not hearing any bruits over the carotids, you apply a 10-second massage to the left carotid and then to the right, but without any change. Your partner suggests contacting medical command for pharmacological intervention.

Upon speaking with medical command, your partner describes a stable, narrow-complex tachycardia that is unresponsive to valsalva maneuvers and vagus nerve stimulation. The physician on duty asks the ETA to the closest facility, which you reply to be 20 minutes. The physician then proceeds to order the administration of a fast IVP of 6 mg of adenosine.

You inform your patient that you will administer a drug that will help him restore a normal rhythm. While still monitoring the cardiac rhythm, you administer 6 mg IVP of adenosine via the right antecubital fossa, followed by a 20 mL bolus of saline and elevation of the extremity to further speed the transport of the medication. Shortly after, the heart monitor shows asystole. However, your patient does not lose consciousness and after 10 seconds, a slower sinus rhythm is restored. You obtain a second EKG for comparison.

Second EKG (click for larger image):

The computed interpretation is:
HR 102 bpm
PRI 208ms
QRSd 84 ms
QT/QTc 310ms/404ms
Paxis 76
QRSaxis 66
Taxis 59

It reads:
***Age and Gender Specific Analysis***
Sinus Tachycardia
Otherwise normal ECG
Routine EKG Interpretation

Pleased with the results, you now proceed to transport the patient to the hospital.

UPDATED: 9/17/2007 - Patient Follow-Up Posted.  CLICK HERE FOR THE ANSWER