An old anteroseptal infarct refers to a past heart attack that damaged the front wall of the heart and the muscular wall dividing its lower chambers. This diagnosis indicates a historical event, not an ongoing, acute situation.
Understanding Myocardial Infarction
A myocardial infarction, commonly known as a heart attack, occurs when blood flow to a part of the heart muscle is severely reduced or completely cut off. This lack of blood supply, called ischemia, deprives the heart tissue of essential oxygen and nutrients. Without adequate oxygen, the affected heart muscle cells begin to die, leading to tissue damage and potentially permanent impairment of heart function.
The heart receives its blood supply through a network of specialized vessels known as coronary arteries. These arteries wrap around the heart’s surface and branch into smaller vessels that penetrate the heart muscle. When one of these coronary arteries becomes blocked, the portion of the heart muscle it supplies can no longer function properly.
Most heart attacks happen due to coronary artery disease, a condition where fatty, cholesterol-containing deposits, called plaque, build up inside the arteries. This process, known as atherosclerosis, narrows the arteries over time. If a plaque ruptures, a blood clot can form at the site, which can completely obstruct blood flow and trigger a heart attack.
Pinpointing the Location Anteroseptal Region
The term “anteroseptal” describes the location of the heart muscle affected by the infarct. “Antero” refers to the anterior, or front, wall of the heart’s left ventricle, which pumps oxygenated blood to the body.
“Septal” points to the interventricular septum, the muscular wall dividing the heart’s lower chambers. This septum plays a role in the heart’s pumping action by contracting and thickening during systole. It also forms part of the heart’s electrical conduction system.
An anteroseptal infarct means tissue death has occurred in the front wall of the left ventricle and a portion of the interventricular septum. This damage can compromise the heart’s ability to efficiently pump blood.
The Meaning of “Old” in a Heart Infarct
The descriptor “old” signifies a past myocardial infarction, not a recent or ongoing event. It indicates the heart attack occurred in the past. This distinction is important because the immediate medical response to an acute heart attack differs significantly from the management of past heart damage.
When heart muscle tissue dies during an infarction, the body initiates a healing process. Over several weeks, the dead muscle cells are gradually replaced by scar tissue, a process known as myocardial fibrosis or replacement fibrosis. This scar tissue is composed primarily of proteins like collagen and lacks the ability to contract and pump blood like healthy heart muscle.
The presence of scar tissue is a permanent change to the heart muscle. An “old” infarct therefore refers to the presence of this healed scar, which serves as a lasting marker of a previous heart attack. While an acute heart attack is a medical emergency requiring immediate intervention, an old infarct represents the long-term aftermath of such an event.
Causes and Consequences of an Old Anteroseptal Infarct
An anteroseptal infarct is caused by a blockage in the left anterior descending (LAD) artery, often called the “widowmaker” artery. This major branch of the left main coronary artery supplies blood to the left ventricle’s anterior wall and interventricular septum.
The blockage in the LAD artery results from coronary artery disease, where plaque buildup narrows or obstructs the vessel. When blood supply is interrupted, the anteroseptal heart muscle is deprived of oxygen, causing tissue damage.
The long-term consequences of an old anteroseptal infarct result from the non-contractile scar tissue. This scarring can reduce the heart’s pumping efficiency, potentially leading to heart failure, where the heart cannot pump enough blood to meet the body’s needs. Scarred tissue can also disrupt the heart’s electrical pathways, increasing the risk of abnormal heart rhythms (arrhythmias).