Author Question: A patient with a serum potassium level of 6.8 mEq/L may exhibit electrocardiographic changes of ... (Read 108 times)

panfilo · **on:** Jun 25, 2018

A patient with a serum potassium level of 6.8 mEq/L may exhibit electrocardiographi c changes of

a. a prominent U wave.
b. tall, peaked T waves.
c. a narrowed QRS.
d. sudden ventricular dysrhythmias.

Question 2

Which classification of dysrhythmia is most common with an inferior wall infarction in the first hour after STEMI?

a. Sinus tachycardia
b. Multifocal PVCs
c. Atrial fibrillation
d. Sinus bradycardia

miss_1456@hotmail.com · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

B
Normal serum potassium levels are 3.5 to 4.5 mEq/L. Tall, narrow peaked T waves are usually, although not uniquely, associated with early hyperkalemia and are followed by prolongation of the PR interval, loss of the P wave, widening of the QRS complex, heart block, and asystole. Severely elevated serum potassium (greater than 8 mEq/L) causes a wide QRS tachycardia.

Answer to Question 2

D
Sinus bradycardia (heart rate less than 60 beats/min) occurs in 30 to 40 of patients who sustain an acute myocardial infarction (MI). It is more prevalent with an inferior wall infarction in the first hour after ST segment elevation MI. Sinus tachycardia (heart rate more than 100 beats/min) most often occurs with an anterior wall MI. Premature atrial contractions (PACs) occur frequently in patients who sustain an acute MI. Atrial fibrillation is also common and may occur spontaneously or may be preceded by PACs. Premature ventricular contractions (PVCs) are seen in almost all patients within the first few hours after an MI.