The heart is a four-chambered muscular organ that beats from 60 to 100 times per minute in the average adult. The heart responds to the body's need for more oxygen by increasing the heart rate or slowing down when the body is at rest. Many diseases outside the heart affect the functionality of the heart and can lead to heart diseases such as rhythm irregularities, heart failure and stroke.
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease, or COPD, is a common lung disease that manifests as chronic bronchitis, emphysema or a combination of both, according to Medline Plus. As COPD progresses, the tiny air sacs in the lungs are destroyed, causing pulmonary hypertension. When pulmonary hypertension occurs, the right side of the heart struggles to produce enough oxygen-rich blood for the body. Cor pulmonale is a heart disease that develops when the right ventricle is no longer able to pump efficiently against the effects of the pulmonary hypertension. Cor pulmonale is a serious condition that can lead to death.
Diabetes
People with diabetes are at a high risk for developing heart disease. The American Diabetes Association reports that two of three diabetics will die from a stroke or heart disease. Diabetes is a disease in which the body cannot process insulin properly or does not produce enough insulin to manage the glucose in the blood. In diabetes, the blood sugar level rises instead of absorbing into the cells. High levels of blood sugar lead to damaged blood vessels, including those within the heart. Keeping blood sugar levels under control will help reduce the risk for heart disease related to diabetes.
Lyme Disease
Borrelia burgdorferi, the tick-borne bacterium that causes Lyme disease, is easily treatable in the early stages, with full recovery likely, according to the Mayo Clinic. Oral antibiotics such as doxycycline, amoxicillin or cefuroxime are the usual choices. If left untreated, complications such as facial palsy, impaired memory, chronic joint inflammation and heart rhythm irregularities may occur.
Lupus
Lupus, a chronic autoimmune disease, can cause damage to any organ or part of the body. In lupus, the immune system attacks and destroys healthy cells. Women's Health states that nine of every 10 people with lupus are women between the ages of 15 and 45. Lupus increases the risk for women developing coronary artery disease, with the chances of chest pain or heart attack 50 times higher than for women without the disease. Symptoms of lupus include fatigue, joint pain, muscle aches, skin rashes and trouble concentrating. Treatments include nonsteroidal anti-inflammatory drugs, corticosteroids, anti-malarial drugs and chemotherapy.


