**Core Concept**
Low voltage in an electrocardiogram (ECG) refers to a reduced amplitude of the P, QRS, and T waves. This can be a significant finding, particularly in the context of cardiac disease or electrolyte imbalances.

**Why the Correct Answer is Right**
Low voltage on an ECG is often associated with conditions that affect the electrical conduction system of the heart, such as pericardial effusion, myocardial infarction, or electrolyte imbalances (e.g., hypokalemia or hyperkalemia). The reduced voltage is thought to be due to the increased electrical resistance in the myocardium, which can be caused by the accumulation of fluid or inflammatory cells in the pericardial space or the disruption of normal cellular function.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the underlying pathophysiology of low voltage in ECG.
**Option B:** This option is incorrect because it is not a direct consequence of low voltage on an ECG.
**Option C:** This option is incorrect because it is not a characteristic feature of low voltage in ECG.

**Clinical Pearl / High-Yield Fact**
In clinical practice, low voltage on an ECG can be a marker of cardiac tamponade, a life-threatening condition characterized by fluid accumulation in the pericardial space that compresses the heart and impairs its function.

**Correct Answer:** D.