Question: causes of reverse splitting of second heart sound
[{'answer': 'Aortic stenosis', 'provenance': [{'wikipedia_id': '21026957', 'title': 'Split S2', 'start_paragraph_id': 19, 'start_character': 76, 'end_paragraph_id': 19, 'end_character': 91, 'bleu_score': 1.0, 'section': 'Section::::Pathological split.\n'}]}, {'answer': 'hypertrophic cardiomyopathy', 'provenance': [{'wikipedia_id': '21026957', 'title': 'Split S2', 'start_paragraph_id': 19, 'start_character': 93, 'end_paragraph_id': 19, 'end_character': 120, 'bleu_score': 1.0, 'section': 'Section::::Pathological split.\n'}]}, {'answer': 'ventricular pacemaker', 'provenance': [{'wikipedia_id': '21026957', 'title': 'Split S2', 'start_paragraph_id': 19, 'start_character': 161, 'end_paragraph_id': 19, 'end_character': 182, 'bleu_score': 1.0, 'section': 'Section::::Pathological split.\n'}]}, {'answer': 'left bundle branch block ( LBBB )'}, {'provenance': [{'wikipedia_id': '21026957', 'title': 'Split S2', 'start_paragraph_id': 19, 'start_character': 0, 'end_paragraph_id': 19, 'end_character': 244, 'bleu_score': 0.9364250605898111, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4999848669257523845}, 'section': 'Section::::Pathological split.\n'}]}]