In which situation will the QRS complex typically have a higher amplitude?

The QRS complex represents the electrical activity associated with ventricular depolarization in the heart. A higher amplitude of the QRS complex typically indicates increased voltage produced during this depolarization, which can arise from various physiological conditions.

When there is fluid in the pericardium, a condition known as pericardial effusion, the heart may have to work harder to generate sufficient force to overcome the pressure from the fluid surrounding it. This increased myocardial contraction can lead to a stronger electrical signal during depolarization, resulting in a higher amplitude QRS complex on the EKG. The increased voltage reflects the heart's efforts to effectively pump against the external pressure created by the fluid accumulation, thus leading to the observed change in the QRS complex.

In contrast, other choices do not typically produce an increase in QRS amplitude. For instance, electrolyte imbalances often disrupt the heart's electrical conductivity, leading to various abnormal EKG findings, but not necessarily an increase in amplitude by itself. Sleep generally leads to a lower heart rate and reduced myocardial demand, which can decrease QRS amplitude. Bradycardia, characterized by a slower heart rate, may also not lead to increased voltage in the active contractile phase of the heart, thus not elevating