Blood pressure describes the force of the circulating blood against the walls of the blood vessels. Two main forces create blood pressure; the pumping action of the heart that creates circulation and the force of the arteries as they resist the flow of blood, as described by the American Heart Association. Doctors classify blood pressure as high, a condition known as hypertension, when the readings increase over 140 mmHg for systolic and 90 mmHg for diastolic. If left untreated, high blood pressure contributes to many negative effects throughout the body, especially on the heart.
Coronary Artery Disease
Coronary artery disease describes a condition characterized by the buildup of plaque---a substance made of cholesterol, fat, calcium and other substances, in the arteries. The buildup of plaque, a process known as atherosclerosis, causes the arteries to narrow restricting the flow of blood. Coronary artery disease is a serious condition causing over half a million deaths every year in the United States, according to the National Heart Lung and Blood Institute.
High blood pressure contributes to the onset and progression of coronary artery disease. High blood pressure increases the pressure exerted against the artery walls. This causes damage to the walls of the arteries. Platelets, specialized blood cells, aggregate at the site of damage attracting other cells and debris, causing plaque to form. Atherosclerosis in the coronary arteries, those leading to the heart, can increase the risk for additional effects on the heart.
Heart Attack
A heart attack occurs when the heart muscle becomes damaged due to a decrease in blood flow and an inadequate amount of oxygen. High blood pressure causes atherosclerosis which causes the coronary arteries to narrow. This restricts the flow of blood to the heart. The plaque buildup can become so thick any blood fails to reach the heart, therefore resulting in a heart attack.
In addition, the buildup of plaque increases the risk of a blood clot forming. A blood clot traveling through the coronary arteries can block the flow of blood resulting in a heart attack.
Enlarged Heart
High blood pressure causes the heart to work harder in order to effectively pump blood throughout the body. When muscles work harder, they become bigger. In the case of the heart, bigger is not better. The increased workload causes the left ventricle, the chamber in the heart responsible for pumping the blood from the heart to the body, to become larger and stiffer. As the left ventricle enlarges, it limits its ability to pump therefore increasing the risk for both heart attack and heart failure, according to MayoClinic.com.
Congestive Heart Failure
Congestive heart failure, also called heart failure, occurs when the heart fails to pump enough blood to meet the demands of the body. Over time, high blood pressure causes strain on the heart that can weaken the heart muscle and interfere with its ability to contract. The weak heart continues to pump blood but the decreased rate of blood flow causes additional damage to other organs in the body including the kidneys.
