Non-Q wave versus Q wave myocardial infarction: regional myocardial metabolism and blood flow assessed by positron emission tomography.
This study compared regional myocardial blood flow at rest and during supine exercise as well as regional myocardial glucose utilization in the fasting condition in 22 patients, 11 with antecedent non-Q wave and 11 with antecedent Q wave infarction. With use of N-13 (nitrogen-13) ammonia and F-18 (fluorine-18) deoxyglucose as tracers of blood flow and exogenous glucose utilization and positron emission tomography, hypoperfused areas were noted at rest and during exercise in all 11 patients (100%) with Q wave infarction. Among the 11 patients with non-Q wave infarction such areas were noted in only 5 (45%) at rest and in 8 (73%) during exercise. Furthermore, segmentally enhanced F-18 deoxyglucose uptake corresponding to the infarcted areas (identified electrocardiographically) was seen in 10 (91%) of the 11 patients with non-Q wave infarction but in only 4 (36%) of the 11 patients with Q wave infarction (p less than 0.01). In conclusion, segmental F-18 deoxyglucose uptake as a possible sign of myocardial viability was seen more frequently in non-Q wave than in Q wave infarction and, importantly, regionally enhanced F-18 deoxyglucose uptake occurred even in the absence of segmental rest or exercise blood flow abnormalities, or both, in 5 (45%) of 11 patients with non-Q wave infarction.