technetium-tc-99m-stannous-pyrophosphate and Hypertension

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.

Topics: Adult; Aged; Angina Pectoris; Cardiac Pacing, Artificial; Collateral Circulation; Coronary Angiography; Electrocardiography; Female; Humans; Hypertension; Male; Methoxamine; Middle Aged; Stroke Volume; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates