Carl Edwards is a 75-year-old man with congestive heart failure. Having sustaine
ID: 125296 • Letter: C
Question
Carl Edwards is a 75-year-old man with congestive heart failure. Having sustained three myocardial infarctions in the last 10 years, he has decreased left ventricular function. Mr. Edwards takes Digoxin, Capoten, Coreg, and Lasix for management of this disease. Today he presents to the emergency department with fatigue, generalized weakness, and feelings of “skipping” heartbeats. Upon arrival, he is placed on the cardiac monitor, his vital signs are assessed, and an IV is inserted. He currently denies chest pain, but is experiencing some shortness of breath, and is placed on 2 L of oxygen via nasal cannula. Mr. Edwards has noticed over the last 8 to 9 months that mild exercise causes fatigue, dizziness, palpitations, or shortness of breath and is having difficulty living independently and performing his usual ADLs.
a. Which of his medications might be contributing to his symptoms of generalized weakness and heart irregularities?
b. For what clinical manifestations should you assess to correlate to his left-sided heart failure?
c. How do his medications treat his congestive heart failure?
d. How does the hypokalemia affect the effects of Digitalis?
Explanation / Answer
Which of his medications might be contributing to his symptoms of generalized weakness and heart irregularities?
One of the major side effects of Lasix is hypokalemia. Mr. Edwards’ symptoms of fatigue, generalized weakness and cardiac irregularities are seen in the patient with hypokalemia. Hypokalemia in patients with heart failure is also problematic as it markedly weakens cardiac contractions.
What clinical manifestations should you assess for to correlate to his left-sided heart failure?
In left-sided heart failure, the left ventricle does not completely empty, eventually leading to a backup of blood into the pulmonary system. Clinical manifestations include dyspnea, cough, pulmonary crackles, low oxygen saturation, and, ultimately, decreased cardiac output.
How do his medications treat his congestive heart failure?
The Digoxin increases force of myocardial contractility and slows conduction through the atrioventricular node. This improves contractility and leads to increased left ventricular output. Capoten, an ACE-inhibitor, promotes vasodilation and diuresis by decreasing preload and afterload. The vasodilation decreases resistance to left ventricular outflow. ACE inhibitors also decrease secretion of aldosterone resulting in sodium and water excretion. Coreg is a beta-blocker administered to patients with left-sided failure to slow heart rate. Lasix is a diuretic that decreases preload.
How does the hypokalemia affect the effects of Digitalis?
Digitalis toxicity may occur secondary to hypokalemia, and increase chances of dangerous dysrhythmias.