NURS 250 CHF SIM Preparation Questions

NURS 250 CHF SIM Preparation Questions

NURS 250 CHF SIM Preparation Questions

1. List the risk factors for chronic left-sided heart failure related to coronary artery disease.

• Family history of CAD – more likely to develop CAD
• Atherosclerosis – plaque buildup in the arteries that can result in a MI if an occlusion occurs; reduced blood flow and oxygen to the heart leads to decreased function and weakened heart muscle.
• Cardiotoxic drug use – injury to the heart tissue, impairing muscle function
• Diabetes – tend to develop HTN and atherosclerosis from hyperlipidemia
• Hyperlipidemia – increased risk of atherosclerosis
• HTN – “When pressure in the blood vessels is too high, the heart has to pump harder than normal to keep the blood circulating”; also increases the risk of MI in pts with atherosclerosis
• Metabolic syndrome – HTN, hyperglycemia, high cholesterol (LDL), and a large waistline; increased risk of diabetes, heart attacks, and other heart problems
• Cardiomyopathy – the heart muscle becomes abnormally enlarged, stretched, rigid, or even scarred, and is less able to pump blood through the body and maintain a normal electrical rhythm
• Obesity – heart has to work harder to pump blood throughout body
• Sedentary lifestyle – increases risk of diabetes and heart conditions
• Smoking – harm heart tissues, raises BP, and lowers BP; also damages other organs in the body. With lung disease, the heart has to work harder to get available oxygen to the rest of the body
• Valvular abnormalities – can stem from disease, infection, or birth defects; if the valves don’t open and close properly, the heart has to work harder to move the blood
• History of MI – loss of oxygen to heart muscle causes the tissue to die, leading to a decrease ability of the heart muscle to contract (American Heart Association, 2016).
• Older age – body becomes weaker in general in old age, including the heart muscle

 

(McCulloch & Osborn, 2014, p. 1026, American Heart Association, 2016, National Heart, Lung and Blood Institute, 2016)

2.  Explain the cause of the compensations for chronic heart failure.

The initial response to decreased cardiac output is activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system. Substances that are released with eventual detrimental cardiac effects include norepinephrine, angiotensin II, aldosterone, endothelin, vasopressin, and cytokines. Circulating levels play an important role in vasoconstriction, sodium retention, and toxic effects on the architecture of the heart.

In the early phases of heart failure, SNS and RAAS activation augments preload, ventricular contractility, and heart rate, thereby maintaining cardiac output. As cardiac function gets worse, these compensatory mechanisms can no longer maintain cardiac output, and ventricular function is further compromised. Increased SNS activity leads to increased norepinephrine and vasoconstriction in the pulmonary and systemic vasculature and enhances tone. This initially maintains bp and increased ventricular preload.

Norepinephrine also causes renal vasoconstriction that allows for the GFR to remain stable despite decreased perfusion of renal blood flow. Circulating norepinephrine also increases Na absorption, leading to fluid retention that initially increases intravascular volume with subsequent temporary improvements in cardiac output and blood pressure. Myocardial contractility and heart rate are stimulated and therefore increase cardiac output. Long term these effects are deleterious causing increased cardiac wall stress, hypertrophy, chamber dilation, increased myocardial oxygen consumption, worsening myocardial ischemia, and pulmonary and systemic congestion.

 

(McCullouch & Osborn, 2014, p. 1028-1029)

3.  Describe the manifestations and effects of right-sided and left-sided heart failure.

Manifestations of right-sided heart failure are congestion of peripheral tissue, liver and gastrointestinal tract. Right sided heart failure impairs the ability to move blood from the systemic venous circulation into the pulmonary circulation which leads to the development of peripheral edema in lower extremities. The impaired ability to move blood causes congestion of the viscera (ascites) and as distention progresses, blood backs up in the hepatic veins that leads to vena cava and liver engorgement. Hepatomegaly can cause pain in the right upper quadrant, decrease liver function and engorgement of the spleen. Congestion of the GI tract can interfere with digestion and absorption of nutrients, causing anorexia and abdominal distress.

Manifestations of left-sided heart failure include activity intolerance, fatigue, shortness of breath, frothy sputum, orthopnea, paroxysmal nocturnal dyspnea, cyanosis, hypoxia and respiratory crackles. Left-sided heart failure is an abnormal cardiac condition that causes a pumping inability of the left side of the heart, which eventually backs the blood up into the pulmonary circulation

 

(Porth, 2015, p. 492-494).

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