A client comes to the emergency department complaining of chest pain. An electrocardiogram (ECG) reveals myocardial ischemia and an anterior-wall myocardial infarction (MI). Which ECG characteristic indicates myocardial ischemia?
a. Prolonged PR interval
b. Absent Q wave
c. Elevated ST segment
d. Widened QRS complex
Answer C. Ischemic myocardial tissue changes cause elevation of the ST segment, a peaked or inverted T wave, and a pathological Q wave.
A prolonged PR interval occurs with first-degree heart block, the least dangerous atrioventricular heart block; this disorder may arise in healthy people but sometimes results from drug toxicity, electrolyte or metabolic disturbances, rheumatic fever, or chronic degenerative disease of the conduction system.
An absent Q wave is normal; an MI may cause a significant Q wave.
A widened QRS complex indicates a conduction delay in the His-Purkinje system.
a. Prolonged PR interval
b. Absent Q wave
c. Elevated ST segment
d. Widened QRS complex
Answer C. Ischemic myocardial tissue changes cause elevation of the ST segment, a peaked or inverted T wave, and a pathological Q wave.
A prolonged PR interval occurs with first-degree heart block, the least dangerous atrioventricular heart block; this disorder may arise in healthy people but sometimes results from drug toxicity, electrolyte or metabolic disturbances, rheumatic fever, or chronic degenerative disease of the conduction system.
An absent Q wave is normal; an MI may cause a significant Q wave.
A widened QRS complex indicates a conduction delay in the His-Purkinje system.
