A nurse is providing care for a 70-year-old male client in the intensive care unit.

Exhibits

For each assessment finding, click to specify if the finding is expected or unexpected for a client post-tricuspid valve replacement surgery.

Choice A rationale

Pericardiocentesis is a procedure used to remove fluid from the pericardial sac surrounding the heart. This is indicated for pericardial effusion causing cardiac tamponade, not for atrial fibrillation. Cardiac tamponade presents with symptoms like jugular venous distension, muffled heart sounds, and hypotension.

Choice B rationale

Synchronized electrical cardioversion is the delivery of a controlled electrical shock timed with the R wave of the QRS complex on the electrocardiogram. This procedure is used to convert atrial fibrillation, an irregular and rapid atrial rhythm, back to a normal sinus rhythm, especially in symptomatic clients experiencing palpitations, lightheadedness, and shortness of breath.

Choice C rationale

A pericardial window is a surgical procedure that creates an opening in the pericardium to allow fluid to drain into the chest cavity. This is typically performed for recurrent pericardial effusions or constrictive pericarditis, not for the management of atrial fibrillation.

Choice D rationale

Septal myectomy is a surgical procedure involving the removal of a portion of the thickened interventricular septum. This is primarily used to treat hypertrophic obstructive cardiomyopathy (HOCM) and is not indicated for atrial fibrillation.

Choice A rationale

Troponin T is a cardiac-specific protein that is released into the bloodstream when myocardial damage occurs. It is highly sensitive and specific for cardiac injury, becoming elevated within 3 to 12 hours after the onset of myocardial infarction, peaking at 12 to 48 hours, and remaining elevated for 5 to 14 days. Normal values for Troponin T are typically less than 0.1 ng/mL, although reference ranges can vary slightly between laboratories. Its early elevation makes it a key indicator of recent cardiac muscle injury.

Choice B rationale

Creatine kinase (CK) is an enzyme found in various tissues, including the heart, skeletal muscle, and brain. While CK levels rise with myocardial infarction, they are less specific than troponin because elevations can also occur due to skeletal muscle injury. CK levels typically begin to rise 3 to 12 hours after the onset of chest pain, peak at 24 hours, and return to normal within 2 to 3 days. Normal total CK ranges from 55 to 170 U/L for men and 30 to 135 U/L for women.

Choice C rationale

Brain natriuretic peptide (BNP) is a hormone released primarily from the ventricles in response to increased ventricular volume and pressure. While BNP is a useful marker for heart failure and can be elevated after a myocardial infarction due to ventricular remodeling, it is not a primary indicator of early cardiac muscle injury. Normal BNP levels are generally less than 100 pg/mL, but values increase with age.

Choice D rationale

Creatine kinase-myocardial band (CK-MB) is an isoenzyme of CK that is more specific to cardiac muscle than total CK. CK-MB levels rise within 3 to 12 hours after myocardial infarction, peak at 18 to 24 hours, and return to normal within 2 to 3 days. While more specific to the heart than total CK, troponin is considered a more sensitive and specific marker for early myocardial injury. Normal CK-MB levels are typically less than 3-5% of total CK or less than 25 U/L.