When the heart is hypertrophied, where is the mean QRS vector displaced?

When the heart is hypertrophied, where is the mean QRS vector displaced?

• A. Away from the hypertrophied side
• B. Toward the hypertrophied side
• C. To the center of the heart
• D. There is no displacement

Answer: (B)

When the heart experiences hypertrophy, the mean QRS vector is displaced toward the hypertrophied side. This occurs because the increased muscle mass in that region generates a stronger electrical signal during depolarization. As a result, the electrical activity of the heart reflects the direction toward the hypertrophied areas.

For instance, in conditions such as left ventricular hypertrophy, the increased mass of the left ventricle leads to a more pronounced electrical vector directed towards the left side. This shift is a key component in interpreting EKGs as it helps to identify the presence of hypertrophy and can assist in the diagnosis of various cardiac conditions. Thus, the mean QRS vector provides crucial information about the structural and functional status of the heart, highlighting the correlation between hypertrophy and vector displacement.