9.6: Diseases and Disorders of the Cardiovascular System
Aneurysm
An aneurysm (AN-yŭ-rizm) is a dilation or bulging of a blood vessel caused by weakened vessel walls. Aneurysms can occur in vessels throughout the body but are more commonly found in arteries due to their increased pressure. Aneurysms can be caused by a variety of factors, including smoking, atherosclerosis (fatty plaque buildup in a vessel), and hypertension. [1] See Figure 9.9 [2] for an illustration of thoracic and abdominal aneurysms.
Aneurysms are often asymptomatic and detected incidentally during diagnostic tests that are being done for other reasons. The force of blood pumping through the vessel with an aneurysm can split the layers of the artery wall, allowing blood to leak in between them, called a dissection. An aneurysm can burst completely, called a rupture, and cause severe, life-threatening bleeding. Aneurysms are managed with antihypertensive medications or may require surgical repair. [3]
Arrhythmia
A heart rhythm that follows the regular conduction system of the heart is called normal sinus rhythm (SĪ-nŭs RITH-ŭm). For example, bradycardia and tachycardia that occurs during normal sinus rhythm have abnormally slow or fast rates but have a regular rhythm.
-
A
congenital
(kŏn-JĔN-ĭ-tăl) condition means it is present at birth. There are several types of congenital heart disorders. Some are caused by openings present in the heart that do not close as they should after birth. See Figure 9.13
[8]
for an illustration of common congenital cardiac disorders.
-
Heart failure (HART FĀL-yŭr)
(HF)
occurs when the heart loses its effectiveness in pumping blood. When the heart is not pumping effectively, symptoms of fatigue, shortness of breath, edema, or lung congestion can occur. Chronic HF is a progressive disorder that can be represented on a continuum. The continuum ranges from individuals who are at risk for HF but are asymptomatic, to individuals who have end-stage heart failure and require end-of-life care. Treatments may include medication, a low sodium diet, and fluid restrictions.
[14]
See Figure 9.16
[15]
for an illustration of common symptoms of heart failure.
Hypertension
Hypertension (hī-pĕr-TEN-shŏn) refers to elevated blood pressure greater than 120/80 mm Hg in an adult. Hypertension is very common, affecting millions of individuals worldwide. See Figure 9.17 [17] for an image of a sphygmomanometer (sfig-mō-mă-NOM-ĕt-ĕr) used to obtain blood pressure readings.
Risk factors for developing hypertension include age, ethnicity, family history, and lifestyle factors. Individuals with obesity, diets high in sodium, excessive alcohol intake, chronic stress, and limited physical activity are at higher risk for developing hypertension. Many people with hypertension do not have symptoms, so they are unaware they have the disorder until a complication like a myocardial infarction, stroke, or heart failure occurs. Treatment includes medications and healthy lifestyle changes like adopting a heart-healthy diet, exercising regularly, stopping smoking, getting good sleep, losing weight, and managing stress. [18]
Myocardial Infarction
Myocardial infarction (mī-ŏ-kar′dē-ăl in-FARK-shŏn) (MI) , commonly called a heart attack, is caused by blockage of blood flow to the heart tissue, resulting in death of the cardiac muscle cells. Acute coronary syndrome (ə-KYŪT KOR-ŏ-nā-rē SĬN-drōm) (ACS) is a general term used for medical situations in which blood supplied to the heart muscle is suddenly insufficient. An MI is commonly caused by atherosclerosis causing a blockage in a coronary artery. It can also occur when a piece of an atherosclerotic plaque breaks off and travels through the coronary arterial system until it lodges in one of the smaller vessels. See Figure 9.18 [19] for a depiction of an individual experiencing an MI and the damage occurring to the cardiac muscle as a result of the coronary artery blockage.
A classic symptom of an MI includes sudden crushing pain beneath the sternum called angina (an-JĪ-nă) that may radiate down the left arm. Individuals often describe angina as “it feels as if something is sitting on my chest.” Other common symptoms include dyspnea, diaphoresis, nausea, and light-headedness. Diaphoresis (dī-ă-fŏ-RĒ-sĭs) means profuse (excessive) sweating. However, females may not experience these symptoms and only have a feeling similar to indigestion. [20]
An MI is a medical emergency. The faster the response, the more cardiac muscle cells that can be saved, so anyone who is suspected of having an MI should call 911. An MI is diagnosed with an electrocardiogram (ē-lĕk-trō-KĂR-dē-ō-grăm) (ECG) and blood tests called cardiac enzymes. Cardiac enzymes include creatine kinase and cardiac troponin, both of which are released by damaged cardiac muscle cells. [21]
Immediate treatment typically includes administration of oxygen, aspirin (to stop the plaque from growing), and a medication called nitroglycerin (to help dilate the blood vessels to get more oxygenated blood to the cardiac muscle). Based on the results of the ECG and cardiac enzyme tests, the individual may undergo thrombolysis (thrŏm-BOL-ĭ-sĭs), a procedure that involves administering a clot-dissolving medication to restore blood flow in a coronary artery. An alternative to thrombolysis is angioplasty (AN-jee-ō-plas-tē) or coronary artery bypass graft surgery (KOR-ŏ-nā-rē AR-tĕr-ē bī-păs graft Sŭr-jĕr-ē) (CABG) . Read more about these procedures in the “Medical Specialists, Diagnostic Testing, and Procedures Related to Cardiovascular System” section of this chapter. [22]
Valvular Heart Disease
The heart has four valves that open and close at specific times during the cardiac cycle to control or regulate the blood flowing into and out of the heart. See Figure 9.19 [23] for an illustration of the heart valves including the tricuspid, pulmonary, mitral, and aortic. Three of the heart valves (tricuspid, pulmonary, and aortic valves) are composed of three leaflets or flaps that work together to open and close to allow blood to flow forward and not backwards through the opening. The mitral valve (also known as the bicuspid valve) only has two flaps that open and close.
Healthy heart valves fully open and close during the heartbeat, but patients with valvular heart disease (văl′-vyū-lăr härt dĭ-zēz′) have diseased valves that do not fully open and close. Diseased valves that become “leaky” and don’t completely close cause a condition called regurgitation (rē-gŭr′-jĭ-tā′-shŭn). When regurgitation occurs, blood flows backwards and not enough blood is pushed forward through the heart. Aortic insufficiency (ā-OR-tĭk in-sŭ-FISH-ĕn-sē) (AI) is a valvular heart disease that occurs when the aortic valve does not close properly and allows regurgitation of blood back into the left ventricle.
Another type of valve disorder occurs when the opening of the valve is narrowed and stiff, causing it to not open fully when blood is trying to pass through. This disorder is called stenosis (stĕ-NŌ-sĭs). [24]
There are several causes of valvular heart disease, including congenital heart conditions, infections, degenerative conditions (i.e., they wear out with age), and conditions linked to other types of heart disease. A murmur (MUR-mŭr), an abnormal heart sound heard on auscultation by a stethoscope, is a classic sign of a valvular heart disorder. Other symptoms include shortness of breath, chest pain, fatigue, dizziness, and palpitations. [25]
Valvular heart disease is diagnosed by echocardiography. Treatment may include medications to treat the symptoms or surgery to repair or replace the valves. [26] Read more about these procedures in the “Medical Specialists, Diagnostic Testing, and Procedures Related to the Cardiovascular System.”
Varicose Veins
Varicose veins (VAR-i-kōs VĀNZ) are a common condition caused by weak or damaged vein walls and valves. Veins have one-way valves that open and close to keep blood flowing toward the heart. Weak or damaged valves or walls in the veins can cause blood to pool and even flow backward. [27] See Figure 9.20 [28] for an image of varicose veins.
Symptoms include bulging, bluish veins, and a feeling of heaviness or discomfort in the legs and feet. Without treatment, they tend to grow worse over time. The use of compression stockings (commonly known as TED hose), as well as elevating the feet and legs whenever possible, may be helpful in alleviating the symptoms of varicose veins. However, severe cases may require resolution through medical procedures. [29]
Procedures used to treat varicose veins include the following [30] :
- Endovenous laser ablation (ĕn′-dō-vē′-nŭs lā′-zŏr ăb-lā′-shŭn) to close off a varicose vein. A health care provider uses laser or radiofrequency energy to heat the inside of the vein and close it off.
- Sclerotherapy (sklĕr-ō-THER-ă-pē) to seal off a varicose vein. The health care provider injects liquid or foam chemicals into the vein to create a plug that seals it shut.
- Phlebectomy (flĕ-BĔK-tŏ-mē) to remove small varicose veins. The health care provider makes small cuts to remove smaller veins near the skin.
- Surgery to tie off and remove large varicose veins in a procedure called vein ligation or stripping.
- Centers for Disease Control and Prevention. (2021, September 27). Aortic aneurysm . Department of Health & Human Services. www.cdc.gov/heartdisease/aortic_aneurysm.htm ↵
- “ Aortic_aneurysm.jpg ” by en:National Institutes of Health is licensed in the Public Domain. ↵
- Centers for Disease Control and Prevention. (2021, September 27). Aortic aneurysm . Department of Health & Human Services. www.cdc.gov/heartdisease/aortic_aneurysm.htm ↵
- “ Saver_One_AED.jpg ” by unknown author via Anatoliy Smaga is licensed under CC BY 4.0 ↵
- “ Blausen_0259_CoronaryArteryDisease_02.png ” by Blausen.com staff (2014). “ Medical gallery of Blausen Medical 2014. ” WikiJournal of Medicine is licensed under CC BY 3.0 ↵
- Centers for Disease Control and Prevention. (2023, February 21). Cardiomyopathy . Department of Health & Human Services. www.cdc.gov/heartdisease/cardiomyopathy.htm ↵
- “ Major_categories_of_cardiomyopathy.png ” by Npatchett is licensed under CC BY-SA 4.0 ↵
- “2009_Congenital_Heart_Defects.jpg” by OpenStax College is licensed under CC BY 3.0 ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0. Access for free at https://openstax.org/details/books/anatomy-and-physiology-2e ↵
- “2016_Occluded_Coronay_Arteries.jpg” by OpenStax College is licensed under CC BY 3.0 ↵
- Centers for Disease Control and Prevention. (2023, May 15). About heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/about.htm ↵
- This work is a derivative of StatPearls by Baker, Anjum, & dela Cruz and is licensed under CC BY 4.0 ↵
- “ Combinpedal.jpg ” by James Heilman, MD is licensed under CC BY-SA 3.0 ↵
- Centers for Disease Control and Prevention. (2023, April 14). Heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/about.htm ↵
- “Heartfailure.jpg” by National Heart, Lung, and Blood Institute, National Institutes of Health is licensed in the Public Domain. ↵
- Centers for Disease Control and Prevention. (2023, April 14). Heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/about.htm ↵
- “Grade_1_hypertension.jpg” by Steven Fruitsmaak is licensed under CC BY 3.0 ↵
- National Heart, Lung, and Blood Institute. (2022, March 24). What is high blood pressure. National Institutes of Health. https://www.nhlbi.nih.gov/health/high-blood-pressure ↵
- “ Depiction_of_a_person_suffering_from_a_heart_attack_(Myocardial_Infarction).png ” by https://www.myupchar.com/en is licensed under CC BY-SA 4.0 ↵
- American Heart Association. (n.d.). Heart attack . https://www.heart.org/en/health-topics/heart-attack ↵
- American Heart Association. (n.d.). Heart attack . https://www.heart.org/en/health-topics/heart-attack ↵
- American Heart Association. (n.d.). Heart attack . https://www.heart.org/en/health-topics/heart-attack ↵
- “ Diagram_of_the_human_heart_(cropped).svg ” by Wapcaplet is licensed under CC BY 3.0 ↵
- Centers for Disease Control and Prevention. (2019, December 9). Valvular heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/valvular_disease.htm ↵
- Centers for Disease Control and Prevention. (2019, December 9). Valvular heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/valvular_disease.htm ↵
- Centers for Disease Control and Prevention. (2019, December 9). Valvular heart disease . Department of Health & Human Services. www.cdc.gov/heartdisease/valvular_disease.htm ↵
- National Heart, Lung, and Blood Institute. (2023). Varicose veins . https://www.nhlbi.nih.gov/health/varicose-veins ↵
- “ Varicose_ASV1.jpg ” by Nini00 is licensed under CC BY-SA 3.0 ↵
- National Heart, Lung, and Blood Institute. (2023). Varicose veins . https://www.nhlbi.nih.gov/health/varicose-veins ↵
- National Heart, Lung, and Blood Institute. (2023). Varicose veins . https://www.nhlbi.nih.gov/health/varicose-veins ↵
-
Heart failure (HART FĀL-yŭr)
(HF)
occurs when the heart loses its effectiveness in pumping blood. When the heart is not pumping effectively, symptoms of fatigue, shortness of breath, edema, or lung congestion can occur. Chronic HF is a progressive disorder that can be represented on a continuum. The continuum ranges from individuals who are at risk for HF but are asymptomatic, to individuals who have end-stage heart failure and require end-of-life care. Treatments may include medication, a low sodium diet, and fluid restrictions.
[14]
See Figure 9.16
[15]
for an illustration of common symptoms of heart failure.