Testavia Free Nursing Practice Question - QA
After experiencing uncontrolled hypertension for many years, a patient is newly diagnosed with left heart failure. What pathologic precipitant is responsible for the left heart failure?
A. increased systemic vascular resistance has weakened the heart muscle of the left ventricle.
Chronic hypertension increases systemic vascular resistance, forcing the left ventricle to pump against higher resistance. This causes hypertrophy and eventual weakening, leading to left heart failure. The increased afterload strains the myocardium, reducing contractility over time, making this the correct precipitant.
B. decreased preload has caused a pathologic reduction in the cardiac output.
Decreased preload reduces ventricular filling, potentially lowering cardiac output, but it does not typically cause left heart failure. Hypertension increases preload and afterload, straining the heart. Low preload is more associated with hypovolemia, making this choice incorrect.
C. increased pulmonary vascular resistance has weakened the heart muscle of the left ventricle.
Increased pulmonary vascular resistance affects the right ventricle, causing right heart failure, not the left. Left heart failure results from systemic hypertension or coronary disease, not pulmonary resistance, which impacts the pulmonary circulation, making this choice incorrect.
D. tricuspid valve stenosis has increased the backpressure against the left ventricle.
Tricuspid valve stenosis increases right atrial and venous pressure, affecting the right heart. It does not directly cause backpressure on the left ventricle, which is downstream. Left heart failure is driven by systemic factors, making this choice incorrect.
This question is an excerpt from Testavia's nursing testbank - Pathophisiology Exam. Take the full exam now
Full Explanation
Choice A reason: Chronic hypertension increases systemic vascular resistance, forcing the left ventricle to pump against higher resistance. This causes hypertrophy and eventual weakening, leading to left heart failure. The increased afterload strains the myocardium, reducing contractility over time, making this the correct precipitant.
Choice B reason: Decreased preload reduces ventricular filling, potentially lowering cardiac output, but it does not typically cause left heart failure. Hypertension increases preload and afterload, straining the heart. Low preload is more associated with hypovolemia, making this choice incorrect.
Choice C reason: Increased pulmonary vascular resistance affects the right ventricle, causing right heart failure, not the left. Left heart failure results from systemic hypertension or coronary disease, not pulmonary resistance, which impacts the pulmonary circulation, making this choice incorrect.
Choice D reason: Tricuspid valve stenosis increases right atrial and venous pressure, affecting the right heart. It does not directly cause backpressure on the left ventricle, which is downstream. Left heart failure is driven by systemic factors, making this choice incorrect.