Lesson 1, Topic 1
In Progress

Heart Diseases and Disorders

April 11, 2024

Learning Objective: Examine heart diseases and disorders, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
      Diseases and disorders of the heart affect the conduction system, the heart muscle, and the valves. The following sections describe common heart diseases and disorders.


Arrhythmias
Learning Objective: Describe arrhythmias, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
      An arrhythmia or dysrhythmia is an abnormal heart rate or rhythm. The rhythm may be irregular, or tachycardia or bradycardia may be occurring. The most common arrhythmia is atrial fibrillation, which means the rate is fast and the rhythm is irregular.
      Arrhythmias are caused by an issue with the heart’s conduction system, including an extra beat; the impulse is blocked, slowed, or takes a different pathway through the heart. Arrhythmias can be caused by diseases (e.g., heart failure), stress, substances (e.g., medications, caffeine), and electrolyte imbalances. Arrhythmias may be intermittent or constant. Signs and symptoms of arrhythmias include the following:
            • Fast or slow heart rate
            • Irregular, skipping, or uneven heartbeats
            • Lightheadedness, dizziness, shortness of breath (SOB)
            • Pallor, angina, sweating
      The provider will listen to the heart with a stethoscope. An ECG is usually the first test done. Heart monitoring devices (e.g., the Holter monitor and an event monitor) provide ECG monitoring over days to weeks. Other tests ordered may include ECHO, coronary angiography, and an electrophysiology study (EPS), an in-depth study of the heart’s electrical system. Treatment depends on the severity of the arrhythmia. Treatments may include defibrillation or cardioversion, which shocks the heart into a normal rhythm, or an implantable pacemaker to help establish a normal rate and rhythm. Antiarrhythmic medications, cardiac ablation, and an implantable cardiac defibrillator may also be used.


Cardiomyopathy
Learning Objective: Describe cardiomyopathy, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
      With cardiomyopathy, the heart muscle becomes abnormal. It may become thin and weakened, enlarged and thick, or rigid. As the disease worsens, the heart becomes less efficient at pumping blood and maintaining a normal electrical rhythm. Cardiomyopathy can lead to arrhythmias, heart failure, edema, and heart valve problems.
      There are many types of cardiomyopathies; some develop due to other diseases, and others are inherited. This disease can affect people of all ages. Here are the major risk factors for cardiomyopathy:
            • Diabetes mellitus, metabolic diseases, or severe obesity
            • Diseases that cause heart damage (e.g., heart attack, coronary heart disease)
            • A family history of cardiomyopathy
            • Long-term alcoholism
            • Long-term hypertension (high blood pressure)
      Some people may never have symptoms, whereas others do not experience symptoms during the early stages of the disease. As the condition worsens, a person may experience SOB, especially after activity, edema in the legs, feet, ankles, abdomen, distension of neck veins, and fatigue.
      The provider will obtain a history and perform a physical exam. Abnormal heart and lung sounds might be heard with a stethoscope. A heart murmur may be present. Crackling in the lungs may indicate fluid in the lungs. Swelling can also be seen, as mentioned in the previous section. A chest x-ray, an ECG, ECHO, and a stress test may be ordered. Further procedures may include cardiac catheterization, coronary angiography, or myocardial biopsy. Treatments depend on the severity of the condition. Treatments may include healthy lifestyle changes and medications, such as antiarrhythmics, anticoagulants, diuretics, and beta-blockers, which lower the heart rate. Surgery can also be done, including a septal myectomy (removal of the thickened septal muscle), a heart transplantation, and an implanted device.


Congenital Heart Defects
Learning Objective: Describe congenital heart defects, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
      There are numerous congenital heart defects. TABLE 25.5 describes common defects. Depending on the type and severity of the defect, the newborn baby may require immediate surgery.
      The cause of these congenital defects may be genetic, chromosomal, or unknown. The signs and symptoms of the defect will depend on its type and severity. For some, there are no symptoms, and the person may not realize the condition exists until adulthood. Other defects may cause the baby to have the following conditions:
            • Cyanosis, increased respiration rate, or breathing difficulties
            • Difficulty feeding, tiredness with feeding, or weight loss
            • Abnormal heart murmur
            • Sweating with feeding or crying

      Some of the defects may be identified during the pregnancy. Fetal echocardiography can be used on a baby in utero to detect cardiac abnormalities. After birth, ECHO, pulse oximetry, ECG, and chest x-rays may be performed to help diagnose the defect. Treatment for congenital heart defects depends on the type and severity of the defect. Some holes may close on their own, whereas others may require surgery to patch them. Some defects will be monitored, but no treatment will be required. Life-threatening defects will require emergency surgery after birth and follow-up throughout childhood.


Congestive Heart Failure
Learning Objective: Describe congestive heart failure, including the signs, symptoms, etiology, diagnostic procedures, and treatments.
      Congestive heart failure (CHF), also called heart failure, occurs when the heart does not efficiently pump blood. Blood backs up behind the failing pump (side of the heart). Systolic heart failure occurs when the heart muscle cannot pump the blood out of the heart. Diastolic heart failure occurs when the chamber muscle is stiff and does not completely fill up with blood. Heart failure can affect one or both sides of the heart. There are numerous types of heart failure:
            • Right-sided heart failure: Fluid may back up into the body, causing swelling in the legs, feet, and abdomen.
            • Left-sided heart failure: Fluid may back up into the lungs, causing shortness of breath and abnormal lung sounds.
            • Cor pulmonale: Right-sided heart failure caused by high blood pressure in the right ventricle and pulmonary arteries.
      Coronary artery disease (CAD) and high blood pressure are the most common causes of heart failure. Other causes include congenital problems, heart attack, faulty valves, arrhythmias, infections, and other diseases (e.g., thyroid problems). Symptoms can develop slowly or suddenly, depending on the cause. Symptoms can differ based on the side of the heart that is failing. The following are common signs and symptoms:
            • Cough and shortness of breath with reclining or activity
            • Fatigue, faintness, weakness, and loss of appetite
            • Fast or irregular pulse and palpitations
            • Pitting edema in the feet and legs
            • Swollen liver and abdomen, weight gain
      During the physical exam, the provider will listen for abnormal heart and lung sounds and check for edema (FIGURE 25.8). Echocardiography, imaging tests, and blood tests may be ordered. Treatment includes monitoring weight; limiting dietary cholesterol, salts, and fluids; and medications (e.g., diuretics, antihypertensives, and digoxin). Surgery, a pacemaker, an implantable defibrillator, or heart transplantation may also be needed.