title: Prolonged angina pectoris and persistent negative T waves in the precordial leads: response to atrial pacing and to methoxamine-induced hypertension.
abstract: In 18 consecutive patients without a history of myocardial infarction (MI), prolonged angina pectoris with persistent negative T waves in the precordial leads was associated with a high frequency of in-hospital spontaneous angina (14 of 18, 78%), usually accompanied by S-T segment elevation, and occasionally in-hospital MI (4 of 18, 22%). Angina and MI always involved the electrocardiographic leads with negative T waves. Coronary arteriography, performed in 16 patients, revealed greater than or equal to 90% proximal diameter reduction of the left anterior descending (LAD) coronary artery in 14 patients. No patient had severe narrowing of all 3 major coronary arteries, but the 3 who had 100% LAD occlusion lacked collateral circulation. The ejection fraction was greater than or equal to 50% in 13 patients. Atrial pacing performed in 11 patients at an average rate of 142 beats/min produced a 1.0 mm S-T segment change in only 5 patients (45%), 3 of whom had an associated lactate production. Arterial systemic hypertension induced by methoxamine in 14 patients caused reversal of negative T waves without significant S-T segment shifts or chest pain and failed to elicit lactate extraction abnormalities in each of the 5 patients in whom it was determined. Thus, prolonged angina with persistent negative T waves in the precordial leads is almost invariably associated with a critical and proximal LAD obstruction, severe narrowing of 1 or 2 coronary arteries, and poor or absent collateral vessels. The relatively preserved coronary reserve in 55% of our patients suggests that negative T waves do not represent active myocardial ischemia. The study also suggests that transient "positivization" of the negative T waves may not necessarily relate to myocardial ischemia when associated with acute systemic hypertension.
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial; D003097:Collateral Circulation; D017023:Coronary Angiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D008297:Male; D008729:Methoxamine; D008875:Middle Aged; D013318:Stroke Volume; D013667:Technetium; D016698:Technetium Tc 99m Pyrophosphate; D014003:Tin Polyphosphates
chemical_list: D014003:Tin Polyphosphates; C017742:technetium Tc 99m stannous pyrophosphate; D016698:Technetium Tc 99m Pyrophosphate; D013667:Technetium; D008729:Methoxamine