A nurse is interpreting a client's ECG strip. Which of the following components of the ECG should the nurse examine to determine the time it takes for ventricular depolarization and repolarization?

B. Muffled heart sounds, often described as distant or indistinct, are classic findings in cardiac tamponade. The accumulation of fluid in the pericardial sac dampens the transmission of sound from the heart to the chest wall, resulting in muffled heart sounds on auscultation. This finding is known as Beck's triad, which also includes hypotension and jugular venous distention.

A. Bradycardia is not a typical finding in cardiac tamponade. In fact, tachycardia is more commonly observed due to the compensatory response to decreased cardiac output and decreased stroke volume. The sympathetic nervous system is activated, leading to an increase in heart rate as a compensatory mechanism to maintain cardiac output.

C. Flattened neck veins are not consistent with cardiac tamponade. In cardiac tamponade, jugular venous distention (JVD) is typically observed due to increased venous pressure resulting from impaired right ventricular filling. The presence of JVD is an important clinical finding in cardiac tamponade and can help differentiate it from other causes of shock.

D. Sudden lethargy can occur in various medical emergencies, including cardiac tamponade, but it is not a specific or diagnostic finding for this condition. In cardiac tamponade, symptoms may include dyspnea, chest pain, hypotension, and signs of decreased cardiac output such as cool extremities and altered mental status. However, sudden lethargy alone may not be specific enough to confirm cardiac tamponade.

D. Asystole represents the absence of electrical activity in the heart and is not amenable to defibrillation. Therefore, the RRT would continue cardiopulmonary resuscitation (CPR) with chest compressions and may administer medications or other interventions as indicated. This statement provides accurate information to the family about the patient's condition and the actions being taken by the RRT.

A. Defibrillation is not indicated for asystole. Asystole represents a flatline on the cardiac monitor, indicating the absence of electrical activity in the heart. Defibrillation is only effective for certain types of cardiac rhythms, such as ventricular fibrillation or pulseless ventricular tachycardia. Therefore, the RRT would not use defibrillation for a patient in asystole.

B. It does not provide the family with information about the patient's condition or the actions being taken by the RRT. Moreover, excluding the family from the patient's care may cause additional distress and prevent them from being present to support their loved one during a critical situation.

C. Cardiopulmonary resuscitation (CPR) is performed to maintain blood flow and oxygenation to vital organs during cardiac arrest. However, it does not restore normal blood flow or circulation. The goal of CPR is to provide temporary support until advanced interventions can be initiated or until return of spontaneous circulation (ROSC) is achieved.