MedCa Certification Practice EKG Q & A w/ Rationales 2026 (Complete And Verified Study material) (16pages) LEARNEXAMS

1. A patient with a history of hypertension and diabetes

presents to the emergency department with chest pain and

shortness of breath. The nurse obtains an electrocardiogram

(ECG) and observes ST segment elevation in leads V1 to

V4. What is the most likely diagnosis for this patient?

a) Anterior wall myocardial infarction*

b) Inferior wall myocardial infarction

c) Pericarditis

d) Pulmonary embolism

Rationale: ST segment elevation in leads V1 to V4

indicates an acute anterior wall myocardial infarction,

which is caused by occlusion of the left anterior descending

coronary artery. This is a medical emergency that requires

immediate revascularization.

2. A patient with a history of atrial fibrillation is on

warfarin therapy and has a target international normalized

ratio (INR) of 2.5 to 3.5. The nurse reviews the patient's

latest laboratory results and notes that the INR is 4.8. The

nurse also observes irregular R-R intervals and absent P

waves on the ECG. What is the most appropriate action for

the nurse to take?

a) Administer vitamin K as ordered by the physician

b) Hold the next dose of warfarin and notify the physician*

c) Increase the dose of warfarin to achieve therapeutic INR

d) No action is needed as the ECG findings are normal for

this patient

Rationale: An INR of 4.8 indicates that the patient is at risk

of bleeding due to over-anticoagulation. The nurse should