Super-normal 201Tl retention in hibernating myocardium: An ex-vivo study using the failing human heart

Oberdan Parodi, Renata De Maria, Roberto Testa, Ettore Vitali, Livia Ruffini, Giovanna Paleari, Edoardo Gronda, Jonica Campolo, Alessandro Pellegrini

Research output: Contribution to journalArticlepeer-review

Abstract

Objective: Although the relationship between delayed 201Tl distribution and blood flow in acutely ischemic and infarcted myocardium has been widely explored in the experimental setting, its behaviour in chronically hypoperfused dysfunctioning human myocardium has not yet been evaluated. Methods: In tissue samples of excised failing hearts taken from ischemic (IHD) patients and idiopathic dilated cardiomyopathy (IDC) controls, we evaluated the relationship between delayed 201Tl retention (4 h redistribution), blood flow (assessed by means of 99mTc-labelled human albumin microspheres injected during transplantation) and biochemically- assessed fibrosis. 201Tl activity was expressed as the percent of the activity in the region with highest flow and the least fibrosis. Results: Fibrosis and 201Tl activity were inversely related (r = -0.62, P = 0.0001). In IDC controls, low flows corresponded to uniformly preserved 201Tl retention. In IHD, 46 segments with flows ≤ 0.60 ml · min-1 · g-1 and 20 segments with flows > 0.60 ml · min-1 · g-1 showed matching delayed 201Tl retention and flow values; in the remaining 27, there was a disproportionately high tracer accumulation in comparison with flow (flow/201Tl mismatch). Despite significantly less fibrosis and lower flows, the mismatch segments showed significantly greater 201Tl activity than the segments with concordantly high tracer retention and flow values. Conversely, at equivalent flow rates, the mismatch regions had less fibrosis than the areas with concordantly depressed 201Tl activity and perfusion. Conclusions: This super-normal 201Tl retention in hibernating myocardium may indicate a mechanism of cell adaptation to chronic hypoperfusion.

Original languageEnglish
Pages (from-to)727-735
Number of pages9
JournalCardiovascular Research
Volume38
Issue number3
DOIs
Publication statusPublished - Jun 1998

Keywords

  • Coronary artery disease
  • Heart failure
  • Human
  • Perfusion
  • Radioisotopes
  • Transplantation

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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