TABLE 2

Kinetics of 3 Radiolabeled Catecholamines After Myocardial Infarction

Myocardial regionNormalMismatchScar
Epinephrine
 Retention index (%/min)27.2 ± 5.418.1 ± 3.1*9.9 ± 1.3*†
 Washout rate (%/min)1.1 ± 0.31.5 ± 0.4*NA‡
Hydroxyephedrine
 Retention index (%/min)17.3 ± 6.313.5 ± 4.76.2 ± 2.5*†
 Washout rate (%/min)—§—§NA‡
Phenylephrine
 Retention index (%/min)16.1 ± 2.611.5 ± 1.5*5.9 ± 0.6*†
 Washout rate (%/min)0.8 ± 0.31.2 ± 0.3*NA‡

  • ↵* P < 0.05 vs. normal.

  • ↵† P < 0.05 vs. mismatch.

  • ↵‡ Due to lack of specific uptake, washout rates in scar do not reflect catecholamine turnover.

  • ↵§ Hydroxyephedrine uptake was stable over time; washout rates were 0 or <0.