[Effects of rejection on the contractile reserve of the graft after heart transplantation].

PURPOSE:To test the hypothesis that rejection could affect the contractility and contractile reserve of left ventricle after heart transplantation. METHODS:Echocardiographic parameters and noninvasive blood pressure end-systolic pressure (ESP), heart rate (HR), end diastolic (EDV) and end-systolic (ESV) volumes, ejection fraction (EF), end-systolic stress (ESS) and the end-systolic relation (ESS/ESV) were recorded in 68 studies in 11 patients, seven days-12 months after heart transplantation. Accordingly with the endomyocardial biopsies results were divided into two groups: group A-with no rejection (53 studies), and group B-with rejection (15 studies). RESULTS:The nitroprusside infusion changed significantly and in the same way, all the parameters except the ESS/ESV ratio (A = 5.5 +/- 1.7 x B = 4.8 +/- 1.5 g/cm2/mL, p = NS); there was a decrease in ESP (A = 107 +/- 15 and B = 109 +/- 12 mmHg, p = NS), EDV (A = 68 +/- 19 and B = 81 +/- 12 mL, p = NS), ESV (A = 12 +/- 5 and B = 18 +/- 12 mL, p = NS) and ESS (A = 59 +/- 13 and B = 82 +/- 20g/cm2, p = NS); there was an increase in HR (A = 94 +/- 9 and B = 93 +/- 16bpm, p = NS) and EF (A = 83 +/- 5 and B = 79 +/- 8%, p = NS). In the dobutamine study it was observed differences for both groups, except for ESP (A = 156 +/- 26 and B = 149 +/- 26mmHg, p = NS). The increase in HR, EF and ESS/ESV ratio was greater in group A (HR-A = 117 +/- 19 and B = 102 +/- 25bpm, p < 0.05; EF-A = 91 +/- 4 and B = 78 +/- 11%, p < 0.05; ESS/ESV-A = 13.1 +/- 6 and B = 6.1 +/- 3.1 g/cm2/mL, p < 0.05). For group A it was smaller the EDV (57 +/- 18 x 94 +/- 35 mL, p < 0.05), ESV (5 +/- 3 x 24 +/- 20 mL, p < 0.05) and ESS (57 +/- 21 x 102 +/- 40 g/cm2, p < 0.05). CONCLUSION:Rejection may not induce changes in resting left ventricular contractility, however, the contractile reserve is depressed during an episode of moderate to severe rejection.