The coronary arteries are narrow blood vessels that extend from the aorta and encircle the heart nourishing the heart muscle with blood. The Texas Heart Institute notes that the coronary arteries also supply the heart walls, nodes and valves with oxygenated blood. Blockages in the coronary arteries can lead to symptoms that cause discomfort and affect the function of the heart.
Angina
Angina is a squeezing pain, pressure or discomfort in the chest, caused by a lack of blood flow to certain areas of the heart due to blockages in the coronary arteries. Angina can also be experienced as pain in the arms, shoulders, neck, jaw and back. Such pain, which is caused in one area but experienced in another, is called "referred pain." Angina normally worsens with physical activity and can be triggered by stress.
Shortness of Breath
The Cleveland Clinic notes that shortness of breath occurs most often at later stages of coronary disease, as heart failure begins. This occurs because blocked coronary arteries reduce or obstruct blood flow to areas of the heart, damaging or killing the heart muscle. The heart is then weakened and not strong enough to pump blood efficiently, causing fluid to build up in the lungs. The fluid in the lung tissues causes shortness of breath and difficulty breathing that worsens as coronary artery disease progresses further, damaging the heart.
Arrhythmias
The Merck Manuals Online Medical Library explains that abnormal heart rhythms that cause rapid or irregular heartbeat can occur when the blockages in the coronary arteries affect the nodes and tissue that generate and conduct the electrical impulses in the heart and control the heart rate. The main node, which is also called the heart's pacemaker, is the sinoatrial or SA node. This node is located in the wall of the right atrium and can be affected when the coronary artery that supplies blood to it is blocked. Arrhythmias can lead to dizziness, lightheadedness and other symptoms.
