2006 - UZ Leuven

SERCA2a. In SKO mice, gene-targeted replacement of SERCA2a bySERCA2b, a pump with a higher Ca(2+) affinity, results in cardiachypertrophy and dysfunction. The stronger PLB inhibition on cardiacmorphology and performance observed in SKO was investigated herein DKO mice, which were obtained by crossing SKO with PLB(-/-)mice. The affinity for Ca(2+) of SERCA2 was found to be furtherincreased in these DKO mice. Relative to wild-type and SKO mice,DKO mice were much less spontaneously active and showed areduced life span. The DKO mice also displayed a severe cardiacphenotype characterized by a more pronounced concentrichypertrophy, diastolic dysfunction and increased ventricular stiffness.Strikingly, beta-adrenergic or forced exercise stress induced acuteheart failure and death in DKO mice. Therefore, the increased PLBinhibition represents a compensation for the imposed high Ca(2+)-affinity of SERCA2b in the SKO heart. Limiting SERCA2's affinity forCa(2+) is physiologically important for normal cardiac function. Animproved Ca(2+) transport in the sarcoplasmic reticulum may correctCa(2+) mishandling in heart failure, but a SERCA pump with a muchhigher Ca(2+) affinity may be detrimental.VLASSELAERS D., DESMET M., DESMET L., MEYNS B., DENS J.:Ventricular unloading with a miniature axial flow pump in combinationwith extracorporeal membrane oxygenation. Intensive Care Med., 2006;32(2): 329-333.Objective: ECMO for acute cardiorespiratory failure is an establishedtherapeutic option. Persistent insufficient unloading of the left ventricle(LV) can compromise recovery of ventricular function. We decided toinsert a miniature rotary blood pump (Impella) for decompression ofthe LV. In contrast to previous experience with this new device, whereit was generally used for postcardiotomy heart failure or cardiogenicshock and inserted in the operating room or the catheter laboratory,this is the first report describing the potential of this technology in theintensive care unit, in a patient on ECMO and the value ofechocardiography guidance.Patient: A 13-year-old boy with a history of congenital heart diseasewas admitted to the ICU with acute cardio-respiratory failure.Interventions: On day 2 venoarterial ECMO was instituted because ofworsening cardiorespiratory insufficiency refractory to conventionaltreatment. On day 5 a percutaneous rotary blood pump was insertedto decompress the LV.Conclusions: A percutaneous miniature rotary blood pump can be analternative to decompress a failing LV in the setting of VA-ECMO.Echocardiography can avoid the use of fluoroscopy and the transportto a catheter laboratory to insert the rotary pump.34