This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Electrocardiography, Subject name: Medicine
Low voltage in ECG indicates? 
Select and explain. 
A. Pulmonary embolism, B. Cor pulmonale, C. Infective endocarditis, D. Pericardial effusion
D: Pericardial effusion
Answer: D: Pericardial effusion 
Explanation: ANSWER: (D) Pericardial effusionREF: Harrison 17th ed chapter 221Low voltage is indicative of conditions where the electrical signal from the heart is attenuated either because of a heart condition in itself or because of conditions outside the heart. Possible reasons Include:Pericardial effusionConstrictive pericarditisSevere Ischemic heart diseaseInfiltrative disease, e.g. amyloidosisHypothyroidismPulmonary emphysemaPleural effusionPneumothoraxGeneralized edema