A. Mobitz II is a type of second-degree AV block characterized by constant PR intervals and sudden dropped QRS complexes (i.e., the PR interval does not lengthen progressively). This is a more serious block because the dropped beats are unpredictable and could lead to complete block.
B. Sinus bradycardia is a slower-than-normal heart rate (usually less than 60 beats per minute) that originates from the sinus node. First-degree AV block is characterized by a prolonged PR interval, but unlike second-degree block, there are no dropped QRS complexes.
C. Mobitz I (Wenckebach) is a second-degree AV block where the PR interval gradually lengthens with each successive beat until a QRS complex is dropped. After the dropped beat, the cycle repeats. This is a relatively benign block and often resolves without intervention, though it requires monitoring.
D. Third-degree heart block (also known as complete heart block) occurs when there is no communication between the atria and ventricles. The atria and ventricles beat independently of each other. There are no relationship between the P waves and QRS complexes, and the ventricular rate is typically slower than the atrial rate.

A. Serum sodium level of 135 mEq/L (normal 135-145mEq/L) - Although important, sodium levels do not directly assess the effectiveness of furosemide in relieving fluid overload.
B. Respiratory rate of 16/minute - A decrease in respiratory rate following the administration of furosemide indicates that the client is improving, as furosemide works to reduce fluid overload and ease breathing.
C. Blood pressure reading of 120/80 - While blood pressure may be influenced by fluid status, it is not the best indicator for the effectiveness of diuretics in this case.
D. Urine output 120 mL one hour following administration - While urine output is important, a single hour’s output may not show the full effectiveness of the diuretic, and output can vary depending on the client’s hydration status.