Mechanisms of dyspnea in left heart disease include all, except

Correct Answer: C

Rationale: In pediatric cardiovascular disorders, dyspnea is a common symptom of left heart disease. The correct answer, option C, states that elevated left ventricular end-diastolic pressure leads to decreased antegrade coronary blood flow. This is correct because in left heart failure, increased pressure in the left ventricle can compromise coronary artery blood flow, leading to myocardial ischemia and subsequent dyspnea. Option A, PVH and decreased lung compliance, is incorrect because pulmonary venous hypertension (PVH) and decreased lung compliance are actually mechanisms that contribute to dyspnea in left heart disease. These factors lead to pulmonary congestion and impaired gas exchange, exacerbating respiratory distress. Option B, respiratory muscle fatigue, is also incorrect. While respiratory muscle fatigue can contribute to dyspnea in some conditions, it is not a primary mechanism in left heart disease-related dyspnea. Option D, reverse 'Bernheim' effect, is a distractor and not a recognized mechanism of dyspnea in left heart disease. The Bernheim effect typically refers to a phenomenon in neurology and is not relevant to the pathophysiology of dyspnea in this context. Educationally, understanding the mechanisms of dyspnea in pediatric cardiovascular disorders is crucial for nurses caring for children with these conditions. By grasping how elevated left ventricular pressure affects coronary blood flow and contributes to dyspnea, nurses can better assess and manage respiratory distress in pediatric patients with left heart disease.

Correct Answer: B

Rationale: In the context of pediatric cardiovascular disorders nursing, understanding the factors that can impact the intensity of the first heart sound (S1) is crucial for accurate assessment and diagnosis. In this scenario, option B, Calcific mitral stenosis, is the correct answer as it can lead to an increased intensity of S1 due to the restricted opening of the mitral valve causing a louder closure sound. Option A, Mechanical ventilation, can reduce S1 intensity due to the altered mechanics of the heart during ventilation, affecting the timing and quality of the heart sounds. Option C, Short PR interval, is associated with conditions like Wolff-Parkinson-White syndrome but does not directly impact S1 intensity. Option D, LV dysfunction, can also affect S1 intensity due to changes in the closure of the mitral valve, leading to a softer S1 sound. Educationally, this question highlights the importance of recognizing how various pathophysiological conditions can influence cardiac auscultation findings in pediatric patients. It reinforces the need for nurses to have a comprehensive understanding of pediatric pharmacology, particularly in the context of cardiovascular disorders, to provide safe and effective care to young patients.

Correct Answer: B

Rationale: In pediatric cardiovascular nursing, understanding electrocardiogram (ECG) interpretation is crucial for assessing cardiac function. The correct answer, option B) (-) 45°, is determined by the QRS amplitudes in lead I and aVF being equal in magnitude but opposite in direction. This indicates an axis deviation towards lead aVF, resulting in a negative angle. Option A) (+) 15° is incorrect because the QRS amplitudes in lead I and aVF are equal but have opposite polarities, suggesting an axis deviation towards lead aVF, resulting in a negative angle, not a positive one. Option C) (-) 75° and option D) (-) 90° are incorrect as they do not account for the equal but oppositely directed QRS amplitudes seen in lead I and aVF. These angles would not align with the data provided in the question. In an educational context, understanding how to interpret ECG findings in pediatric patients is essential for assessing cardiac health and diagnosing cardiovascular disorders accurately. By comprehensively analyzing ECG data, nurses can provide appropriate care and interventions to pediatric patients with cardiovascular conditions.

Correct Answer: C

Rationale: In the context of pediatric cardiovascular disorders nursing, understanding the pharmacology of vasodilators is crucial for providing safe and effective care to pediatric patients. In this question, the correct answer is C) Prostaglandin E2. Prostaglandin E2 is a vasodilator that acts by relaxing smooth muscle in blood vessels, leading to vasodilation and decreased peripheral resistance. This mechanism of action helps to improve blood flow and reduce the workload on the heart, making it an important drug in the management of conditions such as patent ductus arteriosus in neonates. Option A) Thromboxane A2 is a vasoconstrictor that promotes platelet aggregation and vasoconstriction, leading to increased blood pressure and decreased blood flow. Option B) Endothelin is a potent vasoconstrictor that plays a role in regulating vascular tone and blood pressure. Option D) Urotensin II is a peptide vasoconstrictor involved in the regulation of vascular tone and blood pressure. Educationally, knowing the pharmacological properties of different vasoactive substances is essential for nurses caring for pediatric patients with cardiovascular disorders. Understanding the specific effects of vasodilators and vasoconstrictors helps nurses make informed decisions when administering medications and monitoring patient responses. By grasping these concepts, nurses can contribute to improved outcomes and better quality of care for pediatric patients with cardiovascular conditions.

Correct Answer: A

Rationale: The correct answer is A) Inflammation weakens blood vessels, leading to an aneurysm. Kawasaki disease is an acute febrile illness that primarily affects children. It causes inflammation in the walls of medium-sized arteries throughout the body, including the coronary arteries. This inflammation can weaken the blood vessel walls, leading to the formation of aneurysms. These aneurysms can put the child at risk for serious complications such as myocardial infarction or sudden death. Option B) Increased lipid levels lead to the development of atherosclerosis is incorrect because Kawasaki disease primarily involves inflammation of the blood vessels, not lipid abnormalities associated with atherosclerosis. Option C) Untreated disease causes mitral valve stenosis is incorrect because Kawasaki disease primarily affects the coronary arteries and does not directly cause mitral valve stenosis. Option D) Altered blood flow increases cardiac workload with resulting heart failure is incorrect because although Kawasaki disease can affect the heart, the primary concern related to the cardiovascular system in this disease is the development of coronary artery abnormalities, such as aneurysms, due to inflammation rather than altered blood flow leading to heart failure. Educationally, understanding the pathophysiology of Kawasaki disease and its effects on the cardiovascular system is crucial for nurses caring for pediatric patients. Recognizing the potential complications, such as aneurysm formation, allows nurses to provide appropriate monitoring and interventions to prevent adverse outcomes.