A nurse is caring for a client with a possible acute myocardial infarction (AMI). The electrocardiogram (ECG) shows no ST segment elevations or depression. The nurse is aware that an elevation of which lab result will determine if there has been cardiac injury?

Rationale:

A. This is not correct since a sinus tachycardia show have a sinus P wave unlike in the strip.

B. This is incorrect since a junctional rhythm should have a regular ventricular rhythm unlike in the above strip which is irregular.

C. A first degree heart block should have a PR interval greater than 0.20 without a disruption in the atrial to ventricular conduction.

D. This is correct since the rhythm is irregular and the P waves are absent.

A. A sinus tachycardia is characterized by a sinus P wave at a rate of more than 100 per minute followed by a narrow QRS complex unlike in the strip depicted above.

B. The above ECG strip shows a ventricular tachycardia based on the wide QRS with a rate more than 120 bpm, AV dissociation and the fusion beats.

C. A complete heart block is characterized by QRS complexes being conducted at their own rates and totally independent of the P wave.

D. An idioventricular rhythm is characterized by a slow regular ventricular rhythm with a rate less than 50 bpm unlike in the above strip. It also has a prolonged QRS interval with no P wave.