What are the reasons for low QRS amplitude in ECG?

Low QRS amplitude on an ECG can result from several factors, including obesity, chronic obstructive pulmonary disease (COPD), or pericardial effusion, which can dampen the electrical signals from the heart. Additionally, conditions like myocardial infarction or cardiomyopathy may affect the heart's muscle mass and electrical conduction, contributing to reduced QRS amplitude. Electrolyte imbalances, such as hypokalemia or hypocalcemia, can also play a role in altering the amplitude of the QRS complex.