A 77-year-old patient with a history of coronary artery disease ...

[ahriuashd]

A 77-year-old patient with a history of coronary artery disease and heart failure has arrived in the emergency room with a rapid heart rate and feeling of impending doom.
 
  Based on pathophysiologic principles, the nurse knows the rapid heart rate could
  A)
  decrease renal perfusion and result in the development of ascites.
  B)
  be a result of catecholamines released from SNS that could increase the myocardial oxygen demand.
  C)
  desensitize the -adrenergic receptors leading to increase in norepinephrine levels.
  D)
  prolong the electrical firing from the SA node resulting in the development of a heart block.

Question 2

A 68-year-old male complains to his family physician that when he tests his blood pressure using a machine at his pharmacy, his heart rate is nearly always very low.
 
  At other times, he feels that his heart is racing, and it also seems to pause at times. The man has also had occasionally light-headedness and a recent syncopal episode. What is this client's most likely diagnosis and the phenomenon underlying it?
  A)
  Sick sinus syndrome as a result of a disease of his sinus node and atrial or junctional arrhythmias
  B)
  Ventricular arrhythmia as a result of alternating vagal and sympathetic stimulation
  C)
  Torsade de pointes as a result of disease of the bundle of His
  D)
  Premature atrial contractions that vacillate between tachycardic and bradycardic episodes as a consequence of an infectious process

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Answer to Question 1

Ans:
B

Feedback:

An increase in sympathetic activity by stimulation of the -adrenergic receptors of the heart leads to tachycardia, vasoconstriction, and arrhythmias. Acutely, tachycardia significantly increases the workload of the heart, thus increasing myocardial O2 demand and leading to cardiac ischemia, myocyte damage, and decreased contractility. Decreased renal perfusion would activate the RAA system, increasing heart rate and BP further. Ventricular arrhythmias are primarily seen at this stage of HF.

Answer to Question 2

Ans:
A

Feedback:

The client's alternating bradycardic and tachycardic episodes are indicative of sick sinus syndrome. This pattern is not characteristic of ventricular arrhythmia, premature atrial contractions, or torsade de pointes.

[ahriuashd]

Gracias!

[ricroger]

TYSM