Which of the following is NOT an appropriate indication for the use of dopamine in critical care?

B. stroke volume is the amount of blood ejected from the left ventricle with each contraction (systole) of the heart. Changes in stroke volume directly affect cardiac output. An increase in stroke volume leads to an increase in cardiac output, while a decrease in stroke volume results in a decrease in cardiac output. Factors that can affect stroke volume include preload, afterload, and contractility of the heart.

C. Heart rate refers to the number of heartbeats per minute. Heart rate directly affects cardiac output by determining how frequently the heart contracts and pumps blood. An increase in heart rate (tachycardia) leads to an increase in cardiac output, while a decrease in heart rate (bradycardia) results in a decrease in cardiac output. Factors such as sympathetic and parasympathetic nervous system activity, hormones, and medications can influence heart rate.

A. Respiratory rate does not directly affect stroke volume or heart rate but changes in respiratory rate can indirectly impact cardiac output through their effects on venous return and preload.

D. Blood pressure represents the force exerted by the blood against the walls of the arteries. While blood pressure does not directly affect cardiac output, it is influenced by cardiac output and systemic vascular resistance (SVR).

A. A heart murmur typically indicates turbulent blood flow through a heart valve. This turbulence can occur due to various reasons, such as valve stenosis (narrowing), regurgitation (leakage), or structural abnormalities of the valves. The turbulent flow produces audible sounds that can be heard with a stethoscope during cardiac auscultation.

B. A heart murmur is not caused by blood entering an inflexible chamber. Instead, it is caused by turbulent blood flow through the heart valves. The sound produced by this turbulent flow may vary depending on the underlying pathology of the valve.

C. While heart murmurs can be described based on their characteristics (such as high-pitched or low- pitched), the presence of a heart murmur does not necessarily indicate a narrow valve. Murmurs can occur due to various valve abnormalities, including stenosis (narrowing) or regurgitation (leakage). The pitch and quality of the murmur may vary depending on the underlying pathology and the location of the abnormality.

D. A heart murmur is not typically associated with inflammation around the heart. While inflammation of the heart (such as myocarditis or pericarditis) can cause symptoms and abnormal sounds, these conditions would not be described specifically as a "heart murmur."