Patient Care Flashcards

Stoke Volume is ________?

Answer: Related to preload

Stroke volume, the amount of blood pumped by the ventricle per beat, is directly related to preload. Preload refers to the volume of blood filling the ventricles at the end of diastole, which stretches the cardiac muscle fibers. According to the Frank-Starling mechanism, increased preload leads to a stronger contraction and thus a greater stroke volume.

A patient with chronic untreated hypertension would demonstrate?

Answer: increased afterload

Chronic untreated hypertension leads to persistently elevated systemic vascular resistance. This increased resistance against which the left ventricle must pump blood is defined as increased afterload. Over time, this forces the heart to work harder, leading to ventricular hypertrophy and potentially heart failure.

Vascular resistance/pressure is most influenced by?

Answer: Radius of the vessel

According to Poiseuille's Law, vascular resistance is inversely proportional to the fourth power of the vessel's radius (R^4). This means that even a small change in vessel radius has a dramatic effect on resistance and blood flow. While blood viscosity and vessel length also influence resistance, the radius is by far the most significant determinant.

What component of a Pulmonary Capillary Wedge pressure indicates Mitral Insufficiency?

Answer: V wave

The V wave in a Pulmonary Capillary Wedge Pressure (PCWP) tracing represents the passive filling of the left atrium during ventricular systole when the mitral valve is closed. In mitral insufficiency (regurgitation), blood flows backward from the left ventricle into the left atrium during systole, causing an abnormally large increase in left atrial pressure and thus a prominent, elevated V wave.

An elevated RVEDP is found in which pathology?

Answer: RV infarct

An elevated Right Ventricular End-Diastolic Pressure (RVEDP) indicates increased pressure within the right ventricle at the end of diastole, suggesting impaired right ventricular filling or increased resistance to outflow. A right ventricular (RV) infarct directly damages the RV muscle, leading to reduced contractility and compliance, which in turn elevates the RVEDP due to blood backing up in the right ventricle.