20 research outputs found
Muscle electrical stimulation improves neurovascular control and exercise tolerance in hospitalised advanced heart failure patients
Effects of electrical stimulation on muscle power and biochemical markers during hemodialysis in elderly patients: a pilot randomized clinical trial
Toward a new cold and warm nondepolarizing, normokalemic arrest paradigm for orthotopic heart transplantation
Objective: Currently, the safe human heart preservation time is limited to around 4 to 5 hours of cold ischemic storage. Longer arrest times can lead to donor heart damage, early graft dysfunction, and chronic rejection. The aim of this study was to examine a new nondepolarizing, normokalemic preservation solution with adenosine and lidocaine for as long as 6 hours of arrest at cold and warmer storage temperatures.\ud
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Methods: Isolated perfused rat hearts (n = 87) were switched from working to Langendorff (nonworking) mode and arrested at 37°C with 200-µmol/L adenosine and 500-µmol/L lidocaine in Krebs–Henseleit buffer (10-mmol/L glucose, pH 7.7, 37°C) or with Celsior (Sangstat Medical Corp, Fremont, CA). Hearts were removed and placed in static storage at 4°C for 2 and 6 hours or remained on the apparatus and were intermittently flushed at 37°C every 20 minutes for 2 minutes at 68 mm Hg (average arrest temperature 28°–30°C) for 2 and 6 hours. We further investigated the effect of the warmer adenosine–lidocaine solution supplemented with 1- or 5-mmol/L pyruvate.\ud
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Results: Adenosine–lidocaine solution arrested hearts in 16 ± 2 seconds (n = 32), whereas Celsior did so in 39 ± 4 seconds (n = 23). After 2 hours of cold static storage, there were no functional differences between the adenosine–lidocaine and Celsior groups, with approximately 70% return of cardiac output. In contrast, after 6 hours of 4°C storage, adenosine–lidocaine hearts had significantly higher functional recoveries (68% ± 5% cardiac output) than Celsior hearts (47% ± 14% cardiac output) during 60 minutes of reperfusion. In addition, Celsior hearts took 5 minutes longer to reanimate and showed early reperfusion arrhythmias. At warmer temperatures after 2 hours of arrest, adenosine–lidocaine and Celsior hearts were not significantly different, despite a 43% higher cardiac output in adenosine–lidocaine hearts (80% ± 3% vs 56% ± 12%). After 6 hours, adenosine–lidocaine hearts had recovered 55% ± 3% of prearrest cardiac output, which increased significantly to 75% ± 4% with addition of 1-mmol/L pyruvate. Adenosine–lidocaine with 1-mmol/L pyruvate hearts spontaneously recovered 106% heart rate, 93% to 105% developed pressures, 70% aortic flow, and 81% coronary flow. Coronary vascular resistance increased 1.7- to 1.9-fold during the 6-hour arrest. In contrast, Celsior hearts did not have return of aortic or coronary flow after 6 hours in these warmer conditions.\ud
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Conclusion: A new nondepolarizing, normokalemic adenosine–lidocaine arrest solution in Krebs–Henseleit buffer with 10-mmol/L glucose was versatile at both 4°C and 28°C to 30°C relative to Celsior, and the addition of 1-mmol/L pyruvate significantly improved cardiac output at warmer arrest temperatures. This new arrest paradigm may be useful in the harvest, storage, and implantation of donor hearts