The interventricular septum (IVS) diastolic thickness measures the wall separating the heart’s lower chambers during its relaxation phase, when the heart fills with blood. This measurement is a significant indicator in assessing overall heart health.
Understanding the Interventricular Septum
The interventricular septum is a muscular wall within the heart, dividing the left and right ventricles, the heart’s lower pumping chambers. It separates the pulmonary and systemic circulatory systems, preventing oxygen-poor blood from mixing with oxygen-rich blood.
The septum supports the heart and contains nerve fibers that coordinate muscle contraction. During systole, the heart’s pumping phase, the septum contracts, becoming shorter and thicker. In diastole, the heart’s resting thickness is measured.
What the Measurement Reveals
The IVS diastolic thickness is commonly assessed using an echocardiogram, a non-invasive ultrasound technique that provides real-time images of the heart. This imaging method uses high-frequency sound waves that bounce off heart structures, creating moving pictures. The measurement provides insights into the heart’s structure, particularly the left ventricle.
For adults, a normal IVS diastolic thickness typically ranges from 0.6 to 1.0 centimeters. When the IVS diastolic thickness is increased, it often indicates a thickening of the left ventricular muscle, a condition known as left ventricular hypertrophy (LVH). Mild hypertrophy is indicated by 1.1 to 1.3 cm, moderate by 1.4 to 1.6 cm, and severe by 1.7 cm or more. This thickening can alter the heart’s structure, potentially affecting its ability to function efficiently.
Common Causes of Variation
Increased interventricular septum thickness often results from conditions that cause the heart to work harder. Long-standing high blood pressure, also known as hypertension, is a common reason for the septum to thicken. The sustained elevated pressure requires the left side of the heart to exert more force to pump blood, leading to the gradual enlargement and thickening of the muscle tissue. This thickening can occur even in individuals with blood pressure values considered within the normal range, suggesting that even high-normal blood pressure may contribute to septal thickening.
Another significant cause is hypertrophic cardiomyopathy (HCM), a genetic condition where the heart muscle thickens without an obvious cause like high blood pressure. This thickening can make it more difficult for the heart to pump blood effectively. Other conditions, such as heart valve diseases like aortic stenosis, where the aortic valve narrows, can also increase the heart’s workload and contribute to septal thickening. Diabetes can also lead to heart damage and contribute to left ventricular hypertrophy.
Health Implications and Management
An increased IVS diastolic thickness can have several health implications because a thickened septum can impede the heart’s ability to fill with blood during diastole and pump efficiently. This reduced efficiency can lead to various symptoms, including shortness of breath, chest pain, and fatigue. The increased muscle mass also demands more oxygen, potentially leading to myocardial ischemia or angina.
Furthermore, a thickened septum can predispose individuals to irregular heart rhythms, known as arrhythmias, including atrial fibrillation, which may increase the risk of ischemic stroke. Management of increased IVS diastolic thickness primarily involves addressing the underlying conditions. For instance, controlling high blood pressure through lifestyle modifications, such as diet and exercise, and medical treatments, including medications like ACE inhibitors, ARBs, beta-blockers, calcium channel blockers, and diuretics, can help reduce or prevent further thickening. Regular medical consultation and ongoing monitoring are important to manage the condition and prevent complications.