Cardiac Electrical and Structural Remodeling

Excerpt

Even with the falling rates of cardiovascular deaths, the events of deaths attributable to sudden cardiac death keep rising. A total of 350000 events of sudden cardiac death are estimated to occur in the United States every year. Coronary artery disease often leads to complex electrical and structural remodeling of the heart due to myocardial injury. This remodeling is the root cause that precipitates ventricular arrhythmias, which often lead to sudden cardiac death. Cardiac remodeling occurs in response to stress, either functional stress or structural stress. This remodeling plays a vital role in the disease process that ensues. Initially, the electrical and structural remodeling helps in compensating the cardiac performance. But over time, these compensatory mechanisms often lead to pump failure and/or fatal arrhythmias. Both atria and ventricles are affected by electrical remodeling. This process eventually leads to atrial fibrillation and fatal ventricular arrhythmias. Structural remodeling of the heart can be physiologic growth occurring in response to exercise, pregnancy, or during the postnatal period. It can also be pathologic hypertrophy in response to neurohumoral activation, injury to myocardium, or hypertension. Heart failure and malignant arrhythmia are often precipitated by pathological hypertrophy of the heart. However, they don’t occur with the physiological growth of the heart.