PURPOSE: We investigated whether myocardial (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy predicts impairment of myocardial functional reserve in response to dobutamine stress in patients with idiopathic dilated cardiomyopathy (DCM). METHODS: Forty DCM patients (LVEF 39 ± 12 %) underwent myocardial (123)I-MIBG scintigraphy, echocardiography, and cardiac catheterization. Myocardial (123)I-MIBG uptake was quantified as the delayed heart to mediastinum (H/M) ratio and washout rate (WR). Local denervation was evaluated on polar map images. LV dP/dt (max) and T(1/2) were determined from left ventricular pressure curves at baseline and during dobutamine infusion (15 μg/kg /min). Patients were classified into two groups as follows: group A comprised 21 patients showing a delayed H/M ratio of <1.9 (median value); group B comprised 19 patients showing a delayed H/M ratio of ≥ 1.9. RESULTS: The percentage change in heart rate (%HR), LV dP/dt (max) (%LV dP/dt (max)), and T (1/2) (%T (1/2)) from baseline to dobutamine stress were significantly more reduced in group A than in group B (39.3 ± 20.2 %, 55.2 ± 24.1 %, p < 0.01; 102.3 ± 46.3 %, 152.0 ± 72.3 %, p < 0.05; 38.7 ± 15.3 %, 46.9 ± 15.4 %, p < 0.05, respectively). No significant differences between the two groups were observed in the echocardiographic parameters or baseline cardiac catheterization parameters. Significant correlations were found between delayed H/M ratio and %HR (r = 0.35, p < 0.05), %LV dP/dt (max) (r = 0.45, p < 0.05) and %T (1/2) (r = 0.34, p < 0.05). Significant inverse correlations were also found between WR and %HR (r = -0.37, p < 0.05), %LV dP/dt (max) (r = -0.60, p < 0.0001), and %T (1/2) (r = -0.34, p < 0.05). SPECT images revealed enhanced denervation from the inferoposterior to anterior wall in accordance with the advancement of global denervation. CONCLUSION: Reduced (123)I-MIBG uptake and increased washout were related to impairment in adrenergic myocardial functional reserve in idiopathic DCM.
PURPOSE: We investigated whether myocardial (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy predicts impairment of myocardial functional reserve in response to dobutamine stress in patients with idiopathic dilated cardiomyopathy (DCM). METHODS: Forty DCMpatients (LVEF 39 ± 12 %) underwent myocardial (123)I-MIBG scintigraphy, echocardiography, and cardiac catheterization. Myocardial (123)I-MIBG uptake was quantified as the delayed heart to mediastinum (H/M) ratio and washout rate (WR). Local denervation was evaluated on polar map images. LV dP/dt (max) and T(1/2) were determined from left ventricular pressure curves at baseline and during dobutamine infusion (15 μg/kg /min). Patients were classified into two groups as follows: group A comprised 21 patients showing a delayed H/M ratio of <1.9 (median value); group B comprised 19 patients showing a delayed H/M ratio of ≥ 1.9. RESULTS: The percentage change in heart rate (%HR), LV dP/dt (max) (%LV dP/dt (max)), and T (1/2) (%T (1/2)) from baseline to dobutamine stress were significantly more reduced in group A than in group B (39.3 ± 20.2 %, 55.2 ± 24.1 %, p < 0.01; 102.3 ± 46.3 %, 152.0 ± 72.3 %, p < 0.05; 38.7 ± 15.3 %, 46.9 ± 15.4 %, p < 0.05, respectively). No significant differences between the two groups were observed in the echocardiographic parameters or baseline cardiac catheterization parameters. Significant correlations were found between delayed H/M ratio and %HR (r = 0.35, p < 0.05), %LV dP/dt (max) (r = 0.45, p < 0.05) and %T (1/2) (r = 0.34, p < 0.05). Significant inverse correlations were also found between WR and %HR (r = -0.37, p < 0.05), %LV dP/dt (max) (r = -0.60, p < 0.0001), and %T (1/2) (r = -0.34, p < 0.05). SPECT images revealed enhanced denervation from the inferoposterior to anterior wall in accordance with the advancement of global denervation. CONCLUSION: Reduced (123)I-MIBG uptake and increased washout were related to impairment in adrenergic myocardial functional reserve in idiopathic DCM.
Authors: P Merlet; C Benvenuti; D Moyse; F Pouillart; J L Dubois-Randé; A M Duval; D Loisance; A Castaigne; A Syrota Journal: J Nucl Med Date: 1999-06 Impact factor: 10.057
Authors: N B Schiller; P M Shah; M Crawford; A DeMaria; R Devereux; H Feigenbaum; H Gutgesell; N Reichek; D Sahn; I Schnittger Journal: J Am Soc Echocardiogr Date: 1989 Sep-Oct Impact factor: 5.251
Authors: M Packer; M R Bristow; J N Cohn; W S Colucci; M B Fowler; E M Gilbert; N H Shusterman Journal: N Engl J Med Date: 1996-05-23 Impact factor: 91.245