{'fraction_non_alphanumeric': 0.014173228346456693, 'fraction_numerical': 0.0, 'mean_word_length': 5.6947368421052635, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The isolated heart preparation.

The major advantage of the isolated heart over isolated cardiac muscle for studying the effect of anaesthetics relates to the maintenance of the anatomy and function of the heart as a pump and the use of the native coronary circulation for cardiac nutrition and oxygenation. For the latter function, perhaps the blood perfused heart-lung preparation is more physiological but less controllable, particularly for metabolic studies. However, both preparations are predominantly useful for evaluating mechanisms and comparative biochemical pharmacology, rather than being relevant for clinical management.