Chapter 19 - Section 19.6 - Study Guide - Assess Your Learning Outcomes - Page 741: 15

**Conditions that Increase Afterload:** Afterload refers to the pressure that the heart has to overcome to eject blood from the ventricles into the arterial system. Any condition that increases the resistance that the heart has to work against during systole can increase afterload. Some conditions that can increase afterload include: 1. **Hypertension:** High blood pressure increases the pressure that the heart has to generate to overcome the resistance in the arterial system. 2. **Aortic Stenosis:** Narrowing of the aortic valve restricts blood flow from the left ventricle into the aorta, increasing the resistance the heart has to overcome. 3. **Pulmonary Hypertension:** Elevated blood pressure in the pulmonary arteries increases the resistance that the right ventricle has to overcome to pump blood into the lungs. **Effect of Afterload on Cardiac Output:** Afterload has a direct impact on cardiac output—the volume of blood pumped by the heart in a minute. Increased afterload decreases stroke volume (the amount of blood pumped with each heartbeat) and, consequently, cardiac output. This is because the heart has to work harder to overcome the increased resistance, which can lead to a decrease in the amount of blood ejected during each contraction. **Cor Pulmonale and Lung Diseases:** Cor pulmonale is a condition in which the right side of the heart becomes enlarged due to lung-related problems that increase the afterload of the right ventricle. Certain lung diseases lead to cor pulmonale because they cause increased pulmonary resistance, which puts strain on the right ventricle. The most common lung diseases associated with cor pulmonale are chronic obstructive pulmonary disease (COPD) and pulmonary hypertension. Here's how certain lung diseases lead to cor pulmonale: 1. **Chronic Obstructive Pulmonary Disease (COPD):** COPD, which includes conditions like chronic bronchitis and emphysema, leads to narrowed airways and reduced lung function. The narrowed airways increase airway resistance, leading to decreased airflow and retention of carbon dioxide. This can cause pulmonary hypertension, which increases the resistance that the right ventricle has to overcome to pump blood to the lungs. Over time, the right ventricle may become hypertrophied (enlarged) due to the increased workload, leading to cor pulmonale. 2. **Pulmonary Hypertension:** Primary or secondary pulmonary hypertension can be caused by various factors, including chronic lung diseases, blood clots, or certain heart conditions. In pulmonary hypertension, the blood vessels in the lungs become narrowed and stiff, increasing the afterload of the right ventricle. The right ventricle has to pump against this elevated resistance, which can eventually lead to its enlargement and cor pulmonale. In summary, conditions that increase afterload, such as hypertension, aortic stenosis, and pulmonary hypertension, can impact cardiac output. Certain lung diseases, particularly COPD and pulmonary hypertension, can lead to cor pulmonale by increasing the resistance that the right ventricle has to overcome, resulting in right ventricular enlargement and dysfunction.

**Conditions that Increase Afterload:** Afterload refers to the pressure that the heart has to overcome to eject blood from the ventricles into the arterial system. Any condition that increases the resistance that the heart has to work against during systole can increase afterload. Some conditions that can increase afterload include: 1. **Hypertension:** High blood pressure increases the pressure that the heart has to generate to overcome the resistance in the arterial system. 2. **Aortic Stenosis:** Narrowing of the aortic valve restricts blood flow from the left ventricle into the aorta, increasing the resistance the heart has to overcome. 3. **Pulmonary Hypertension:** Elevated blood pressure in the pulmonary arteries increases the resistance that the right ventricle has to overcome to pump blood into the lungs. **Effect of Afterload on Cardiac Output:** Afterload has a direct impact on cardiac output—the volume of blood pumped by the heart in a minute. Increased afterload decreases stroke volume (the amount of blood pumped with each heartbeat) and, consequently, cardiac output. This is because the heart has to work harder to overcome the increased resistance, which can lead to a decrease in the amount of blood ejected during each contraction. **Cor Pulmonale and Lung Diseases:** Cor pulmonale is a condition in which the right side of the heart becomes enlarged due to lung-related problems that increase the afterload of the right ventricle. Certain lung diseases lead to cor pulmonale because they cause increased pulmonary resistance, which puts strain on the right ventricle. The most common lung diseases associated with cor pulmonale are chronic obstructive pulmonary disease (COPD) and pulmonary hypertension. Here's how certain lung diseases lead to cor pulmonale: 1. **Chronic Obstructive Pulmonary Disease (COPD):** COPD, which includes conditions like chronic bronchitis and emphysema, leads to narrowed airways and reduced lung function. The narrowed airways increase airway resistance, leading to decreased airflow and retention of carbon dioxide. This can cause pulmonary hypertension, which increases the resistance that the right ventricle has to overcome to pump blood to the lungs. Over time, the right ventricle may become hypertrophied (enlarged) due to the increased workload, leading to cor pulmonale. 2. **Pulmonary Hypertension:** Primary or secondary pulmonary hypertension can be caused by various factors, including chronic lung diseases, blood clots, or certain heart conditions. In pulmonary hypertension, the blood vessels in the lungs become narrowed and stiff, increasing the afterload of the right ventricle. The right ventricle has to pump against this elevated resistance, which can eventually lead to its enlargement and cor pulmonale. In summary, conditions that increase afterload, such as hypertension, aortic stenosis, and pulmonary hypertension, can impact cardiac output. Certain lung diseases, particularly COPD and pulmonary hypertension, can lead to cor pulmonale by increasing the resistance that the right ventricle has to overcome, resulting in right ventricular enlargement and dysfunction.