{'fraction_non_alphanumeric': 0.009533898305084746, 'fraction_numerical': 0.0031779661016949155, 'mean_word_length': 5.5625, '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 Pulsed Doppler Coronary Artery Catheter

A new catheter which measures instantaneous changes in coronary artery blood flow velocity is described. The linear relationship between flow velocity measured with the catheter and volume flow through small arteries is documented with a correlation coefficient of r = 0.99. Coronary flow velocity has been measured from the proximal right and left coronary arteries and aortic ostia of saphenous vein bypass grafts in patients undergoing diag- unnostic coronary arteriography. The increase in coronary flow following injection of contrast media in normal coronary arteries is similar to the increase in coronary flow reported following near-maximum exercise. This increased flow response following injection of contrast media is severely limited by coronary artery stenosis and may provide a useful method for assessing hemodynamically significant stenosis in patients with coronary artery disease.