BACKGROUND: Chronically dysfunctional myocardium may improve after coronary revascularization. This condition was thought to be due to a chronically reduced myocardial blood flow (MBF). Recently, however, it has been shown that in patients without previous infarction but with chronic left ventricular dysfunction, baseline MBF was normal. METHODS AND RESULTS: To study the pathophysiology of chronic left ventricular dysfunction in patients with previous infarction, regional MBF (milliliter per minute per gram of water-perfusable tissue) and glucose utilization (MRG; micromoles per minute per gram) during hyperinsulinemic euglycemic clamp were measured with positron emission tomography in 30 patients before bypass. At baseline, 133 myocardial segments were normal, and 107 were dysfunctional. After revascularization, 59 of 107 segments improved, while 48 of 107 were unchanged. MBF was 0.92 +/- 0.25 mL.min-1.g-1 in normal segments, 0.87 +/- 0.31 mL.min-1.g-1 in improved segments (P = NS versus normal), and 0.82 +/- 0.40 mL.min-1.g-1 in unchanged segments (P < .05 versus normal). In 90% of the dysfunctional segments, MBF was > 0.42 mL.min-1.g-1, a cutoff value corresponding to the mean MBF minus 2 SD in normal segments. The MRG was 0.71 +/- 0.14 mumol.min-1.g-1 in 9 age-matched normal subjects, 0.45 +/- 0.19 mumol.min-1.g-1 (P < .01) in normal segments, 0.44 +/- 0.14 mumol.min-1.g-1 in improved segments (P = NS versus normal), and 0.34 +/- 0.17 mumol.min-1.g-1 in unchanged segments (P < .01 versus normal and improved). CONCLUSIONS: The results suggest that resting MBF measured with 15O-labeled water in chronically dysfunctional segments is not reduced and that the myocardium of these patients is less sensitive to insulin than that of normal subjects.
BACKGROUND: Chronically dysfunctional myocardium may improve after coronary revascularization. This condition was thought to be due to a chronically reduced myocardial blood flow (MBF). Recently, however, it has been shown that in patients without previous infarction but with chronic left ventricular dysfunction, baseline MBF was normal. METHODS AND RESULTS: To study the pathophysiology of chronic left ventricular dysfunction in patients with previous infarction, regional MBF (milliliter per minute per gram of water-perfusable tissue) and glucose utilization (MRG; micromoles per minute per gram) during hyperinsulinemic euglycemic clamp were measured with positron emission tomography in 30 patients before bypass. At baseline, 133 myocardial segments were normal, and 107 were dysfunctional. After revascularization, 59 of 107 segments improved, while 48 of 107 were unchanged. MBF was 0.92 +/- 0.25 mL.min-1.g-1 in normal segments, 0.87 +/- 0.31 mL.min-1.g-1 in improved segments (P = NS versus normal), and 0.82 +/- 0.40 mL.min-1.g-1 in unchanged segments (P < .05 versus normal). In 90% of the dysfunctional segments, MBF was > 0.42 mL.min-1.g-1, a cutoff value corresponding to the mean MBF minus 2 SD in normal segments. The MRG was 0.71 +/- 0.14 mumol.min-1.g-1 in 9 age-matched normal subjects, 0.45 +/- 0.19 mumol.min-1.g-1 (P < .01) in normal segments, 0.44 +/- 0.14 mumol.min-1.g-1 in improved segments (P = NS versus normal), and 0.34 +/- 0.17 mumol.min-1.g-1 in unchanged segments (P < .01 versus normal and improved). CONCLUSIONS: The results suggest that resting MBF measured with 15O-labeled water in chronically dysfunctional segments is not reduced and that the myocardium of these patients is less sensitive to insulin than that of normal subjects.
Authors: Roni Nielsen; Anders Jorsal; Peter Iversen; Lars Poulsen Tolbod; Kirsten Bouchelouche; Jens Sørensen; Hendrik Johannes Harms; Allan Flyvbjerg; Lise Tarnow; Caroline Kistorp; Ida Gustafsson; Hans Erik Bøtker; Henrik Wiggers Journal: J Nucl Cardiol Date: 2017-08-02 Impact factor: 5.952
Authors: Egidio Imbalzano; Marco Vatrano; Giuseppe Mandraffino; Lorenzo Ghiadoni; Sebastiano Gangemi; Rosa Maria Bruno; Vincenzo Antonio Ciconte; Nevena Paunovic; Rossella Costantino; Enrico Maria Mormina; Roberto Ceravolo; Antonino Saitta; Giuseppe Dattilo Journal: Int J Cardiovasc Imaging Date: 2015-08-04 Impact factor: 2.357
Authors: Paul Knaapen; Willem G van Dockum; Marco J W Götte; Kimiko A Broeze; Joost P A Kuijer; Jaco J M Zwanenburg; J Tim Marcus; Wouter E M Kok; Albert C van Rossum; Adriaan A Lammertsma; Frans C Visser Journal: J Nucl Cardiol Date: 2006-09 Impact factor: 5.952
Authors: F Alamanni; A Parolari; A Repossini; E Doria; F Bortone; J Campolo; M Pepi; E Sisillo; M Naliato; R Bigi; P Biglioli; O Parodi Journal: Heart Date: 2004-11 Impact factor: 5.994