What is the desired time interval for LVAT/RWPT when pacing at low and high outputs?

The desired time interval for left ventricular activation time (LVAT) relative to right wide QRS pacing time (RWPT) when pacing at low and high outputs should be short and constant. This consistency is critical because it indicates that the pacing is effectively synchronizing with the heart's natural conduction system.

When a short and constant interval is achieved, it suggests that pacing is occurring in a manner that maintains proper ventricular function and efficiency. Efficient pacing minimizes the risk of prolonged QRS duration and helps to optimize cardiac output by ensuring appropriate and timely contraction of the ventricles. Additionally, a consistent pacing interval allows for a predictable and stable response from the myocardium, which is essential for effective cardiac performance, especially in patients with conduction system disease or heart failure.

In contexts where the interval is long and variable, it can lead to inefficient ventricular contractions and increased risks of adverse outcomes. Similarly, moderate or fluctuating intervals can denote inconsistency in the pacing effectiveness, while irregular and extended intervals generally indicate poor synchronization, potentially resulting in detrimental cardiac mechanics. Hence, establishing a short and constant LVAT/RWPT is vital for optimal pacing results.