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document
Effect of L-carnitine on myocardial metabolism : results of a balanced , placebo-controlled , double-blind study in patients undergoing open heart surgery . The effects of L-carnitine on cardiac performance after open heart surgery were evaluated in a balanced , placebo-controlled , double-blind study in 38 patients . Preoperative haemodynamic status was good in all of them . Seventeen subjects underwent mitral valve replacement and 19 patients coronary artery bypass grafting . Five grams L-carnitine were given intravenously over 2 h , twice daily for 5 consecutive days ; moreover , 10 g L-carnitine in 1500 ml cardioplegia were administered through the aortic root after aortic cross-clamping . Surgery was always planned on treatment day 3 . The post-ischaemic functional recovery of the heart was assessed by clinical parameters , as well as by biochemical and ultrastructure evaluations on biopsy specimens . No differences were found between the control and the treatment group with respect to all clinical parameters of cardiac performance after cardiopulmonary bypass . At anaesthesia induction , serum carnitine was significantly increased in treated patients , but carnitine concentrations in the right atrial biopsy obtained just before aortic declamping were similar in the two groups . In patients with mitral valve replacement , L-carnitine therapy was associated with significantly higher concentrations of pyruvate , ATP and creatine phosphate in papillary muscle . Glycogen levels were also higher in the treated group , but the difference was not statistically significant . Myocardial ultrastructure on septal biopsies , obtained within 5 min from weaning from extracorporeal circulation , showed better preservation scores for all considered parameters ( nucleus , sarcoplasmic reticulum , mitochondria and cellular oedema ) in the treated subjects , although the difference reached statistical significance only for nuclei . When biochemical and ultrastructural data are considered , these findings suggest that L-carnitine improves myocardial metabolism . However , it can not be concluded that L-carnitine provides an advantageous support therapy for well-compensated patients requiring cardiac surgery . In contrast , the positive effects of L-carnitine on cardiac recovery after bypass might become clinically relevant in the surgical setting for haemodynamically compromised patients , in which further investigations are required .
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Intervention_Pharmacological
L-carnitine
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Intervention_Pharmacological
L-carnitine
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Intervention_Control
placebo-controlled
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Intervention_Surgical
mitral valve replacement
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Intervention_Surgical
coronary artery bypass grafting
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Intervention_Pharmacological
L-carnitine
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Intervention_Pharmacological
L-carnitine in 1500 ml cardioplegia
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Intervention_Surgical
aortic cross-clamping
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Intervention_Pharmacological
L-carnitine therapy
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Intervention_Pharmacological
L-carnitine
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Outcome_Physical
serum carnitine
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Outcome_Physical
carnitine concentrations
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Outcome_Physical
pyruvate
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Outcome_Physical
ATP
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Outcome_Physical
creatine phosphate
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Outcome_Physical
Glycogen levels
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Outcome_Physical
nucleus , sarcoplasmic reticulum , mitochondria and cellular oedema
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Outcome_Physical
myocardial metabolism
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Outcome_Other
advantageous support therapy
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Outcome_Physical
cardiac recovery
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Participant_Condition
patients undergoing open heart surgery .
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Participant_Sample-size
38
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Participant_Condition
Seventeen subjects underwent mitral valve replacement and
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Participant_Sample-size
19
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Participant_Condition
patients coronary artery bypass grafting .