Cardio PathoPhysiology

Question 1

Which of the following is the primary reason for the early increase in cardiac output during pregnancy?

A. Increased heart rate
B. Increased end-diastolic ventricular volume
C. Decreased systemic vascular resistance
D. Increased left ventricular contractility

Answer 1

C. Decreased systemic vascular resistance
* Rationale: Systemic vascular resistance decreases by 20–30% due to the vasodilatory effects of progesterone, nitric oxide, and relaxin, allowing blood to flow more efficiently. This compensatory mechanism facilitates an increased stroke volume and cardiac output to meet maternal and fetal oxygen and nutrient demands.
* Buzzwords: Vasodilation, progesterone, nitric oxide, relaxin, stroke volume, systemic vascular resistance (-20–30%).

Question 2

At what gestational age does cardiac output typically peak during pregnancy?

A. 12 weeks
B. 20 weeks
C. 28 weeks
D. 36 weeks

Answer 2

1. B. 20 weeks
   
   • Rationale: Cardiac output increases early in pregnancy due to increased stroke volume and peaks at approximately midpregnancy (20 weeks) when vascular resistance is at its lowest. This ensures optimal placental perfusion during the critical phase of fetal growth.
   • Buzzwords: Peak CO at 20 weeks, stroke volume, placental perfusion, midpregnancy.

Question 3

What percentage increase in cardiac output occurs during pregnancy compared to the nonpregnant state?

A. ~17%
B. ~30%
C. ~40%
D. ~50%

Answer 3

1. C. ~40%
   
   • Rationale: Cardiac output increases by 40–50% during pregnancy. This is driven by a combination of increased stroke volume in early pregnancy and increased heart rate in later pregnancy. These adaptations ensure adequate oxygen delivery to maternal tissues and the developing fetus.
   • Buzzwords: +40% CO, stroke volume, heart rate, oxygen delivery.

Question 4

Which of the following is the most common cardiovascular change observed during normal pregnancy?

A. Increased systemic vascular resistance
B. Decreased pulmonary vascular resistance
C. Decreased stroke volume
D. Increased mean arterial pressure

Answer 4

1. B. Decreased pulmonary vascular resistance
   
   • Rationale: Pulmonary vascular resistance decreases by approximately 30–40%, enhancing oxygenation and facilitating increased blood flow through the lungs to meet increased oxygen demands. This change is essential for maintaining maternal and fetal oxygenation.
   • Buzzwords: Pulmonary vascular resistance (-30–40%), oxygenation, increased lung perfusion.

Question 5

A 32-year-old pregnant woman at 36 weeks gestation presents with dyspnea at rest. Which of the following is the most likely explanation?

A. Diastolic dysfunction due to hypervolemia
B. Systolic dysfunction due to increased afterload
C. Peripartum cardiomyopathy
D. Pulmonary embolism

Answer 5

1. A. Diastolic dysfunction due to hypervolemia
   
   • Rationale: Approximately 18–28% of normal pregnancies exhibit diastolic dysfunction due to increased hypervolemia and subsequent impaired myocardial relaxation. This is often transient and resolves postpartum. Dyspnea is a common symptom associated with this condition.
   • Buzzwords: Hypervolemia, diastolic dysfunction, myocardial relaxation, transient, dyspnea.

Question 6

What echocardiographic finding is commonly seen in a normal pregnancy?

A. Concentric remodeling of the left ventricle
B. Eccentric remodeling of the left ventricle
C. Decreased left ventricular mass
D. Hyperdynamic left ventricular function

Answer 6

1. B. Eccentric remodeling of the left ventricle
   
   • Rationale: The heart undergoes eccentric remodeling to accommodate increased blood volume. This involves an increase in left ventricular mass and cavity size, allowing the heart to maintain its output without increased wall stress.
   • Buzzwords: Eccentric remodeling, increased left ventricular mass, cavity size, volume accommodation.

Question 7

Which of the following changes is NOT typically seen in normal pregnancy?

A. Increased stroke volume index
B. Decreased colloid osmotic pressure
C. Decreased systemic vascular resistance
D. Hyperdynamic left ventricular contractility

Answer 7

1. D. Hyperdynamic left ventricular contractility
   
   • Rationale: While cardiac output increases due to changes in heart rate and stroke volume, intrinsic left ventricular contractility remains normal. Pregnancy adaptations focus on volume changes rather than contractility.
   • Buzzwords: Normal contractility, stroke volume, heart rate, volume-driven changes.

Question 8

Heart failure in pregnancy is most likely to occur during which period in women with pre-existing cardiac dysfunction?

A. Early pregnancy (first trimester)
B. Mid-pregnancy (20–28 weeks)
C. Late pregnancy (after 28 weeks)
D. Postpartum period

Answer 8

1. C. Late pregnancy (after 28 weeks)
   
   • Rationale: The third trimester poses the highest cardiovascular stress due to peak hypervolemia and increased cardiac output demands. These changes, coupled with labor and delivery stress, can precipitate heart failure in women with pre-existing cardiac conditions.
   • Buzzwords: Third trimester, hypervolemia, peak cardiac output, heart failure risk.

Question 9

What percentage of normal pregnancies may exhibit diastolic dysfunction or impaired myocardial relaxation?

A. 5–10%
B. 10–15%
C. 18–28%
D. 30–40%

Answer 9

1. C. 18–28%
   
   • Rationale: Up to 28% of pregnancies may show transient diastolic dysfunction due to the volume overload state of pregnancy. This generally resolves within a year postpartum.
   • Buzzwords: 18–28% diastolic dysfunction, volume overload, transient, resolves postpartum.

Question 10

A woman at term presents with acute onset heart failure. Which of the following is a likely contributing factor in the peripartum period?

A. Decreased blood volume
B. Preeclampsia
C. Hypodynamic left ventricle
D. Reduced systemic vascular resistance

Answer 10

1. B. Preeclampsia
   * Rationale: Preeclampsia is associated with increased vascular resistance and fluid retention, both of which contribute to cardiovascular decompensation and increased risk of heart failure.
   * Buzzwords: Preeclampsia, vascular resistance, fluid retention, peripartum heart failure.

Question 11

Which of the following cardiovascular parameters typically decreases during pregnancy?

A. Stroke volume index
B. Pulmonary vascular resistance
C. Mean arterial pressure
D. Cardiac output

Answer 11

1. B. Pulmonary vascular resistance
   * Rationale: Pulmonary vascular resistance decreases to enhance oxygen exchange in the lungs, facilitating the increased oxygen demands of both mother and fetus.
   * Buzzwords: Pulmonary vascular resistance (-30–40%), enhanced oxygenation, maternal-fetal demand.

Question 12

A pregnant woman undergoes cardiac MRI for an unrelated condition. Which of the following is a typical finding in late pregnancy?

A. Concentric remodeling of both ventricles
B. Increased left ventricular end-diastolic volume
C. Decreased right ventricular mass
D. Impaired left ventricular contractility

Answer 12

1. B. Increased left ventricular end-diastolic volume
   * Rationale: Hypervolemia in pregnancy leads to increased left ventricular end-diastolic volume, which accommodates the increased blood flow required to meet maternal and fetal needs. This reflects normal physiological adaptation.
   * Buzzwords: Hypervolemia, increased LV end-diastolic volume, physiological adaptation.

Question 13

What is the primary mechanism driving the increase in cardiac output during early pregnancy?

A. Increased heart rate
B. Decreased systemic vascular resistance
C. Increased end-diastolic volume
D. Hyperdynamic ventricular contractility

Answer 13

1. B. Decreased systemic vascular resistance
   
   • Rationale: Early in pregnancy, systemic vascular resistance decreases due to the vasodilatory effects of progesterone, nitric oxide, and relaxin, reducing afterload and allowing increased cardiac output to meet maternal and fetal metabolic demands.
   • Buzzwords: Systemic vascular resistance (-20–30%), progesterone, nitric oxide, relaxin, early pregnancy, afterload reduction.

Question 14

During which trimester does cardiac output typically peak in pregnancy?

A. First trimester
B. Second trimester
C. Third trimester
D. During labor

Answer 14

1. B. Second trimester
   
   • Rationale: Cardiac output increases progressively, peaking in the second trimester (~20 weeks gestation) as maternal blood volume and stroke volume reach their maximum. This ensures optimal uteroplacental perfusion during a critical phase of fetal development.
   • Buzzwords: Peak cardiac output, second trimester, uteroplacental perfusion, midpregnancy.

Question 15

Which of the following hormonal effects contributes to the reduction in systemic vascular resistance during pregnancy?

A. Increased progesterone
B. Increased oxytocin
C. Increased cortisol
D. Increased estrogen

Answer 15

1. A. Increased progesterone
   
   • Rationale: Progesterone, along with nitric oxide and relaxin, induces systemic vasodilation by relaxing vascular smooth muscles, reducing vascular resistance, and enhancing blood flow to the uterus and placenta.
   • Buzzwords: Progesterone, vasodilation, vascular smooth muscle relaxation, decreased resistance.

Question 16

Plasma volume increases by what percentage during pregnancy?

A. 10–20%
B. 20–30%
C. 30–40%
D. 40–50%

Answer 16

1. D. 40–50%
   
   • Rationale: Plasma volume expands by 40–50% to meet the increased metabolic demands of the mother and fetus, prepare for potential blood loss during delivery, and support uteroplacental perfusion.
   • Buzzwords: Plasma volume expansion, +40–50%, blood loss compensation, uteroplacental perfusion.

Question 17

What is the reason for the physiological anemia of pregnancy?

A. Reduced red cell production
B. Excessive plasma loss
C. Plasma volume expansion exceeding red cell mass increase
D. Increased oxygen demand during pregnancy

Answer 17

1. C. Plasma volume expansion exceeding red cell mass increase
   
   • Rationale: While red cell mass increases by ~20–30%, plasma volume expands more significantly (~40–50%), resulting in a dilutional decrease in hemoglobin concentration, known as physiological anemia.
   • Buzzwords: Plasma volume > red cell mass, dilutional anemia, physiological adaptation.

Question 18

What echocardiographic finding is typical in a pregnant woman due to left ventricular remodeling?

A. Decreased left ventricular end-diastolic volume
B. Spherical remodeling of the left ventricle
C. Increased right ventricular mass without left ventricular changes
D. Concentric remodeling of the left ventricle

Answer 18

1. B. Spherical remodeling of the left ventricle
   
   • Rationale: Pregnancy-induced spherical remodeling accommodates increased blood volume and reduces wall stress by making the left ventricle more rounded and efficient for handling hypervolemia.
   • Buzzwords: Spherical remodeling, hypervolemia, left ventricular efficiency, reduced wall stress.

Question 19

A pregnant woman at term experiences a 50% increase in cardiac output during labor. What is the primary cause of this increase?

A. Hypervolemia
B. Increased venous return from uterine contractions
C. Increased systemic vascular resistance
D. Increased myocardial contractility

Answer 19

B. Increased venous return from uterine contractions
• Rationale: During labor, uterine contractions increase venous return, significantly boosting cardiac output (up to 50%) to support the intense metabolic demands of labor and delivery.
• Buzzwords: Uterine contractions, venous return, labor, +50% cardiac output.

Question 20

A 30-year-old woman with a history of mitral valve stenosis presents with dyspnea at 32 weeks gestation. What is the most likely trigger for her symptoms?

A. Increased systemic vascular resistance
B. Hyperdynamic ventricular function
C. Increased cardiac output and hypervolemia
D. Decreased colloid osmotic pressure

Answer 20

1. C. Increased cardiac output and hypervolemia
   
   • Rationale: The hypervolemia and increased cardiac output during late pregnancy place additional strain on the stenotic mitral valve, leading to elevated left atrial pressure and pulmonary congestion, causing dyspnea.
   • Buzzwords: Hypervolemia, increased cardiac output, late pregnancy, pulmonary congestion, mitral stenosis.

Question 21

Which of the following changes occurs during normal pregnancy to ensure adequate placental perfusion?

A. Increased systemic vascular resistance
B. Decreased pulmonary vascular resistance
C. Increased mean arterial pressure
D. Increased stroke volume only during the first trimester

Answer 21

1. B. Decreased pulmonary vascular resistance
   
   • Rationale: Pulmonary vascular resistance decreases, facilitating enhanced blood flow through the lungs, optimizing oxygen delivery to maternal tissues and the fetus.
   • Buzzwords: Pulmonary vascular resistance (-30–40%), oxygen delivery, placental perfusion.

Question 22

Which cardiovascular adaptation in pregnancy is most likely to predispose a woman with pre-existing cardiomyopathy to heart failure?

A. Increased systemic vascular resistance
B. Increased heart rate and hypervolemia
C. Decreased colloid osmotic pressure
D. Decreased pulmonary vascular resistance

Answer 22

1. B. Increased heart rate and hypervolemia
   
   • Rationale: Increased heart rate and hypervolemia during pregnancy heighten cardiac workload, potentially leading to heart failure in women with limited cardiac reserve due to pre-existing conditions.
   • Buzzwords: Hypervolemia, increased heart rate, cardiac workload, limited reserve, cardiomyopathy.

Question 23

Which of the following explains why a pregnant woman with severe mitral stenosis may develop pulmonary edema in late pregnancy?

A. Increased colloid osmotic pressure
B. Increased pulmonary vascular resistance
C. Increased left atrial pressure due to hypervolemia
D. Decreased systemic vascular resistance

Answer 23

1. C. Increased left atrial pressure due to hypervolemia
   
   • Rationale: Hypervolemia in late pregnancy increases left atrial pressure in the presence of mitral stenosis, leading to backflow of blood into the lungs and subsequent pulmonary edema.
   • Buzzwords: Hypervolemia, left atrial pressure, pulmonary edema, mitral stenosis.

Question 24

In a healthy pregnancy, which of the following cardiovascular parameters typically decreases?

A. Stroke volume
B. Pulmonary vascular resistance
C. Mean arterial pressure
D. Cardiac output

Answer 24

1. B. Pulmonary vascular resistance
   
   • Rationale: Pulmonary vascular resistance decreases by 30–40%, facilitating improved oxygen exchange in the lungs and meeting the increased oxygen demands of pregnancy.
   • Buzzwords: Pulmonary vascular resistance (-30–40%), oxygen exchange, maternal-fetal demand.

Question 25

During the postpartum period, when do cardiovascular parameters return to prepregnancy levels? A. Immediately after delivery B. 2 weeks postpartum C. 6–8 weeks postpartum D. 3 months postpartum

Answer 25

1. C. 6–8 weeks postpartum * Rationale: Cardiovascular changes such as cardiac output, plasma volume, and heart rate gradually normalize within 6–8 weeks postpartum, as the maternal body returns to its prepregnancy state. * Buzzwords: Postpartum normalization, 6–8 weeks, cardiovascular reset.

Question 26

Which of the following cardiovascular parameters is most likely to increase further during labor? A. Mean arterial pressure B. Pulmonary vascular resistance C. Cardiac output D. Stroke volume

Answer 26

1. C. Cardiac output * Rationale: During labor, cardiac output surges due to increased venous return and sympathetic activation caused by uterine contractions and pain. * Buzzwords: Labor, cardiac output surge, venous return, sympathetic activation.

Question 27

A pregnant woman with a history of congenital heart disease presents at 30 weeks gestation with fatigue and dyspnea. Which physiological adaptation of pregnancy is most likely to unmask her underlying condition? A. Increased plasma volume B. Increased systemic vascular resistance C. Decreased heart rate D. Increased colloid osmotic pressure

Answer 27

1. A. Increased plasma volume * Rationale: The hypervolemia of pregnancy significantly increases the workload on the heart, potentially unmasking underlying cardiac conditions in women with limited cardiac reserve. * Buzzwords: Hypervolemia, cardiac workload, unmasking, congenital heart disease.

Question 28

During pregnancy, cardiac output increases significantly. Which of the following factors contributes to this increase? A. Increased systemic vascular resistance B. Increased heart rate and stroke volume C. Decreased end-diastolic ventricular volume D. Increased pulmonary vascular resistance

Answer 28

1. B. Increased heart rate and stroke volume * Rationale: Cardiac output rises due to a combination of increased heart rate (~15–20%) and stroke volume (~30%), which is driven by expanded blood volume and reduced systemic vascular resistance. These changes accommodate the increased metabolic demands of the mother and fetus. * Buzzwords: Cardiac output, stroke volume, heart rate, hypervolemia, maternal-fetal demand.

Question 29

What is the primary reason for the decrease in systemic vascular resistance during pregnancy? A. Increased colloid osmotic pressure B. Hormone-induced vasodilation C. Increased plasma volume D. Eccentric remodeling of the left ventricle

Answer 29

1. B. Hormone-induced vasodilation (e.g., progesterone, nitric oxide) * Rationale: Progesterone, nitric oxide, and relaxin lead to smooth muscle relaxation and vasodilation, significantly lowering systemic vascular resistance. This adaptation ensures optimal perfusion to the placenta and maternal organs. * Buzzwords: Progesterone, nitric oxide, relaxin, vasodilation, reduced resistance.

Question 30

Which cardiovascular adaptation prevents pulmonary edema despite the significant increase in blood volume during pregnancy? A. Increased mean arterial pressure B. Decreased pulmonary vascular resistance C. Increased heart rate D. Spherical remodeling of the heart

Answer 30

1. B. Decreased pulmonary vascular resistance * Rationale: A reduction in pulmonary vascular resistance (~30–40%) helps maintain adequate blood flow through the lungs without causing pressure overload, preventing pulmonary edema despite the increased plasma volume. * Buzzwords: Pulmonary vascular resistance, oxygen exchange, blood flow, edema prevention.

Question 31

Physiological anemia of pregnancy is caused by which of the following mechanisms? A. Reduced red blood cell production B. Plasma volume expansion exceeding red cell mass increase C. Decreased cardiac output D. Increased systemic vascular resistance

Answer 31

1. B. Plasma volume expansion exceeding red cell mass increase * Rationale: Plasma volume increases by 40–50%, while red cell mass increases by only ~20–30%, leading to hemodilution and a drop in hemoglobin concentration. This is a normal physiological adaptation and not indicative of pathology. * Buzzwords: Hemodilution, plasma volume > red cell mass, physiological anemia.

Question 32

In pregnancy, mean arterial pressure (MAP) typically: A. Increases by 20% due to hypervolemia B. Decreases significantly due to reduced vascular resistance C. Slightly increases due to increased cardiac output D. Remains unchanged

Answer 32

1. C. Slightly increases due to increased cardiac output * Rationale: Although systemic vascular resistance decreases, the increase in cardiac output slightly elevates MAP during pregnancy, returning to baseline levels later in gestation. * Buzzwords: MAP, cardiac output, vascular resistance, baseline normalization.

Question 33

Which structural cardiac adaptation is characteristic of pregnancy? A. Concentric remodeling of the left ventricle B. Longitudinal remodeling of the heart C. Spherical remodeling of the heart D. Decreased left ventricular mass

Answer 33

1. C. Spherical remodeling of the heart * Rationale: During pregnancy, the left ventricle undergoes spherical remodeling, increasing in size and becoming more rounded. This enhances its capacity to handle the increased blood volume. * Buzzwords: Spherical remodeling, left ventricle, hypervolemia.

Question 34

A pregnant woman presents with dyspnea and pulmonary edema at 36 weeks gestation. Which of the following hemodynamic changes is most likely contributing to her symptoms? A. Increased pulmonary vascular resistance B. Increased stroke volume and cardiac output C. Decreased plasma volume D. Reduced heart rate

Answer 34

1. B. Increased stroke volume and cardiac output * Rationale: The increased stroke volume and cardiac output in late pregnancy place additional strain on the heart, particularly in women with limited cardiac reserve, potentially leading to pulmonary congestion and edema. * Buzzwords: Stroke volume, cardiac output, pulmonary congestion, late pregnancy.

Question 35

What is the primary hemodynamic stress during the peripartum period? A. Increased systemic vascular resistance B. Decreased mean arterial pressure C. Maximum cardiac output demand due to labor and delivery D. Reduced pulmonary vascular resistance

Answer 35

1. C. Maximum cardiac output demand due to labor and delivery * Rationale: Labor increases cardiac output by 50% due to pain, uterine contractions, and increased venous return. These changes pose significant stress, particularly in women with pre-existing cardiac conditions. * Buzzwords: Peripartum, +50% cardiac output, labor stress, venous return.

Question 36

What cardiovascular adaptation ensures adequate blood supply to both the fetus and maternal tissues during pregnancy? A. Decreased plasma volume B. Increased hypervolemia and stroke volume C. Decreased heart rate D. Increased systemic vascular resistance

Answer 36

1. B. Increased hypervolemia and stroke volume * Rationale: The hypervolemia of pregnancy increases stroke volume, ensuring adequate perfusion to the placenta and maternal organs. This adaptation is critical for fetal development. * Buzzwords: Hypervolemia, stroke volume, perfusion, fetal development.

Question 37

Cardiogenic shock during pregnancy is most likely to occur in women with: A. Physiological anemia B. Pre-existing severe cardiac dysfunction C. Increased systemic vascular resistance D. Decreased stroke volume

Answer 37

1. B. Pre-existing severe cardiac dysfunction * Rationale: Women with underlying cardiac conditions, such as cardiomyopathy or valvular disease, may not tolerate the increased cardiac output and volume load of pregnancy, leading to cardiogenic shock in severe cases. * Buzzwords: Cardiogenic shock, cardiac dysfunction, volume load, cardiac output.

Question 38

What is the key difference between eccentric and spherical remodeling during pregnancy? A. Eccentric remodeling decreases heart wall thickness, while spherical remodeling thickens the walls. B. Eccentric remodeling occurs during pregnancy, while spherical remodeling is postpartum. C. Eccentric remodeling is typical of nonpregnant individuals, while spherical remodeling is specific to pregnancy. D. Eccentric remodeling reduces cardiac output, while spherical remodeling increases it.

Answer 38

1. C. Eccentric remodeling is typical of nonpregnant individuals, while spherical remodeling is specific to pregnancy. * Rationale: In nonpregnant states, the heart enlarges longitudinally (eccentric remodeling), whereas pregnancy induces spherical remodeling to handle increased volume without increasing wall stress. * Buzzwords: Eccentric remodeling, spherical remodeling, longitudinal vs. rounded changes.

Question 39

Which of the following is a protective cardiovascular adaptation during pregnancy? A. Increased systemic vascular resistance B. Decreased colloid osmotic pressure C. Decreased pulmonary vascular resistance D. Concentric left ventricular remodeling

Answer 39

1. C. Decreased pulmonary vascular resistance * Rationale: A reduction in pulmonary vascular resistance ensures efficient blood flow through the lungs, preventing pulmonary hypertension and facilitating maternal-fetal oxygen exchange. * Buzzwords: Pulmonary vascular resistance, protection, oxygen exchange.

Question 40

A pregnant woman with pre-existing cardiomyopathy is at highest risk of developing heart failure during which period? A. First trimester B. Midpregnancy C. Late pregnancy and peripartum D. Postpartum only

Answer 40

1. C. Late pregnancy and peripartum * Rationale: The late pregnancy and peripartum period are marked by peak hypervolemia and cardiac output demands, significantly increasing the risk of decompensation in women with pre-existing cardiomyopathy. * Buzzwords: Late pregnancy, peripartum, hypervolemia, heart failure risk.

Question 41

What is the primary contributor to the increased heart rate observed in pregnancy? A. Increased systemic vascular resistance B. Hypervolemia and increased metabolic demands C. Decreased stroke volume D. Reduced oxygen demand of maternal tissues

Answer 41

1. B. Hypervolemia and increased metabolic demands * Rationale: The increased metabolic demands of the mother and fetus, combined with hypervolemia, stimulate an increase in heart rate to maintain adequate perfusion. * Buzzwords: Increased metabolic demands, hypervolemia, heart rate, perfusion.

Question 42

Pulmonary edema in pregnancy is most commonly caused by which of the following mechanisms? A. Increased systemic vascular resistance B. Increased pulmonary vascular resistance C. Left ventricular failure secondary to hypervolemia D. Decreased stroke volume

Answer 42

1. C. Left ventricular failure secondary to hypervolemia * Rationale: The significant hypervolemia of pregnancy can lead to left ventricular failure in women with pre-existing heart disease, resulting in pulmonary congestion and edema. * Buzzwords: Pulmonary edema, hypervolemia, left ventricular failure, congestion.

Question 43

What percentage increase in cardiac output is observed during pregnancy, and when does it peak? A. +20%, early first trimester B. +30%, late third trimester C. +40%, midpregnancy D. +50%, postpartum

Answer 43

1. C. +40%, midpregnancy * Rationale: Cardiac output (CO) increases by ~40% during pregnancy to meet the increased metabolic demands of the mother and fetus. This rise is initially driven by increased stroke volume in early pregnancy, peaking by 20 weeks gestation (midpregnancy), with a subsequent contribution from increased heart rate. * Buzzwords: +40% cardiac output, midpregnancy, stroke volume, metabolic demands.

Question 44

Which of the following factors contributes to the reduction in systemic vascular resistance during pregnancy? A. Increased pulmonary vascular resistance B. Hormonal effects of progesterone, nitric oxide, and relaxin C. Increased cardiac output D. Eccentric remodeling of the ventricles

Answer 44

1. B. Hormonal effects of progesterone, nitric oxide, and relaxin * Rationale: Progesterone, nitric oxide, and relaxin relax vascular smooth muscle, resulting in systemic vasodilation and reduced vascular resistance. This adaptation enhances blood flow to the uterus and placenta. * Buzzwords: Progesterone, nitric oxide, relaxin, vasodilation, reduced resistance.

Question 45

What is the main cause of physiological anemia during pregnancy? A. Increased destruction of red blood cells B. Decreased production of hemoglobin C. Plasma volume expansion exceeding red cell mass increase D. Loss of blood through uterine circulation

Answer 45

1. C. Plasma volume expansion exceeding red cell mass increase * Rationale: Plasma volume expands by 40–50%, while red cell mass increases by only ~20–30%, causing a dilutional decrease in hemoglobin concentration. This is a normal physiological response to meet increased perfusion demands. * Buzzwords: Physiological anemia, plasma volume > red cell mass, dilutional hemoglobin decrease.

Question 46

During labor, cardiac output increases by approximately what percentage? A. 10% B. 25% C. 50% D. 75%

Answer 46

1. C. 50% * Rationale: Cardiac output surges by 50% during labor due to increased venous return from uterine contractions and sympathetic activation from pain and stress. This can strain the maternal cardiovascular system, especially in those with pre-existing heart disease. * Buzzwords: +50% cardiac output, venous return, labor, sympathetic activation.

Question 47

Which of the following is a characteristic adaptation of the heart during pregnancy? A. Concentric remodeling B. Eccentric remodeling with ventricular enlargement C. Decreased stroke volume D. Increased systemic vascular resistance

Answer 47

1. B. Eccentric remodeling with ventricular enlargement * Rationale: The heart undergoes eccentric remodeling, where the left ventricular mass and cavity size increase to accommodate the expanded blood volume, while maintaining normal wall thickness. * Buzzwords: Eccentric remodeling, ventricular enlargement, volume accommodation.

Question 48

A 35-year-old woman with multifetal pregnancy is more likely to experience which of the following cardiovascular changes? A. Decreased cardiac output B. Exaggerated hypervolemia C. Increased systemic vascular resistance D. Decreased pulmonary vascular resistance

Answer 48

1. B. Exaggerated hypervolemia * Rationale: Multifetal pregnancies place a greater hemodynamic burden on the cardiovascular system due to significantly increased plasma volume, leading to exaggerated hypervolemia and a higher risk of complications such as heart failure. * Buzzwords: Multifetal pregnancy, exaggerated hypervolemia, hemodynamic burden.

Question 49

Which of the following physiological changes is most likely to prevent pulmonary edema in pregnancy? A. Increased plasma volume B. Decreased pulmonary vascular resistance C. Increased mean arterial pressure D. Decreased heart rate

Answer 49

1. B. Decreased pulmonary vascular resistance * Rationale: The reduction in pulmonary vascular resistance (~30–40%) facilitates increased blood flow through the lungs without causing pulmonary congestion, thereby reducing the risk of edema despite hypervolemia. * Buzzwords: Pulmonary vascular resistance (-30–40%), blood flow, edema prevention.

Question 50

A pregnant woman at 36 weeks presents with dyspnea and fluid retention. Which condition is most likely contributing to her symptoms? A. Preeclampsia B. Physiological anemia C. Heart failure due to volume overload D. Diastolic dysfunction

Answer 50

1. C. Heart failure due to volume overload * Rationale: Hypervolemia and increased cardiac output in late pregnancy can overload the heart, especially if there is underlying cardiac dysfunction, leading to heart failure with symptoms like dyspnea and fluid retention. * Buzzwords: Volume overload, heart failure, hypervolemia, dyspnea.

Question 51

What cardiovascular adaptation explains the increased oxygen delivery to maternal tissues and the fetus during pregnancy? A. Increased systemic vascular resistance B. Decreased mean arterial pressure C. Increased stroke volume and heart rate D. Decreased plasma volume

Answer 51

1. C. Increased stroke volume and heart rate * Rationale: Stroke volume and heart rate increase during pregnancy, resulting in greater cardiac output, which ensures adequate oxygen and nutrient delivery to both maternal tissues and the fetus. * Buzzwords: Stroke volume, heart rate, cardiac output, oxygen delivery.

Question 52

Which of the following is true regarding mean arterial pressure (MAP) during pregnancy? A. MAP significantly increases throughout pregnancy B. MAP decreases and never returns to baseline C. MAP slightly increases and returns to baseline later in pregnancy D. MAP remains unchanged during pregnancy

Answer 52

1. C. MAP slightly increases and returns to baseline later in pregnancy * Rationale: Although systemic vascular resistance decreases, the increase in cardiac output causes a slight rise in mean arterial pressure, which returns to baseline as pregnancy progresses. * Buzzwords: MAP, cardiac output, baseline normalization.

Question 53

What is the most common cause of pulmonary edema during pregnancy? A. Reduced cardiac output B. Hypervolemia and left ventricular dysfunction C. Decreased pulmonary vascular resistance D. Physiological anemia

Answer 53

1. B. Hypervolemia and left ventricular dysfunction * Rationale: Hypervolemia increases preload, which can overwhelm the heart's capacity, particularly in women with left ventricular dysfunction, resulting in pulmonary congestion and edema. * Buzzwords: Pulmonary edema, hypervolemia, left ventricular dysfunction, congestion.

Question 54

In which period is the risk of cardiogenic shock highest in women with pre-existing cardiac disease? A. First trimester B. Midpregnancy C. Peripartum period D. Postpartum period

Answer 54

1. C. Peripartum period * Rationale: The peripartum period involves peak cardiovascular stress due to labor, delivery, and immediate postpartum volume shifts, placing women with pre-existing cardiac disease at the greatest risk of cardiogenic shock. * Buzzwords: Peripartum period, cardiogenic shock, volume shifts, labor stress.

Question 55

Diastolic dysfunction, observed in 18–28% of pregnancies, is most likely to: A. Be permanent and cause postpartum complications B. Be transient and resolve within 1 year postpartum C. Lead to systolic heart failure in most cases D. Occur due to increased systemic vascular resistance

Answer 55

1. B. Be transient and resolve within 1 year postpartum * Rationale: Diastolic dysfunction is caused by hypervolemia and increased workload during pregnancy. In most cases, it is transient and resolves within 1 year after delivery. * Buzzwords: Diastolic dysfunction, transient, resolves postpartum, hypervolemia.

Question 56

A pregnant woman with preeclampsia is at increased risk for which of the following cardiovascular complications? A. Increased systemic vascular resistance and pulmonary edema B. Decreased cardiac output and systemic vascular resistance C. Decreased pulmonary vascular resistance and diastolic dysfunction D. Eccentric remodeling of the left ventricle

Answer 56

1. A. Increased systemic vascular resistance and pulmonary edema * Rationale: Preeclampsia is characterized by increased vascular resistance, leading to hypertension and fluid overload, which can cause pulmonary edema and other complications. * Buzzwords: Preeclampsia, vascular resistance, pulmonary edema, hypertension.

Question 57

Which cardiovascular adaptation is specific to pregnancy and involves a more rounded ventricular shape? A. Concentric remodeling B. Spherical remodeling C. Longitudinal remodeling D. Eccentric remodeling

Answer 57

1. B. Spherical remodeling * Rationale: Spherical remodeling occurs during pregnancy, where the left ventricle becomes more rounded to accommodate increased blood volume and maintain efficient pumping. * Buzzwords: Spherical remodeling, rounded left ventricle, volume adaptation.

Question 58

Which condition can exacerbate heart failure in pregnant women with underlying cardiac disease? A. Decreased systemic vascular resistance B. Increased cardiac output during labor C. Decreased plasma volume D. Reduced stroke volume

Answer 58

1. B. Increased cardiac output during labor * Rationale: During labor, the surge in cardiac output can overwhelm a compromised heart, exacerbating symptoms of heart failure in women with pre-existing cardiac conditions. * Buzzwords: Labor, cardiac output, heart failure, pre-existing cardiac disease.

Question 59

A 32-year-old pregnant woman develops severe hypertension and pulmonary edema. Which diagnosis is most likely? A. Physiological anemia B. Preeclampsia C. Diastolic dysfunction D. Multifetal pregnancy

Answer 59

1. B. Preeclampsia * Rationale: Preeclampsia is associated with severe hypertension, fluid overload, and increased vascular resistance, which can lead to pulmonary edema and other complications. * Buzzwords: Preeclampsia, severe hypertension, pulmonary edema, fluid overload.

Question 60

What is the main cardiovascular adaptation during pregnancy to ensure uteroplacental perfusion? A. Decreased systemic vascular resistance B. Increased mean arterial pressure C. Decreased cardiac output D. Increased pulmonary vascular resistance

Answer 60

1. A. Decreased systemic vascular resistance * Rationale: The reduction in systemic vascular resistance facilitates enhanced uteroplacental perfusion, ensuring adequate oxygen and nutrient delivery to the fetus. * Buzzwords: Systemic vascular resistance (-20–30%), uteroplacental perfusion, oxygen delivery.