- Email: [email protected]
Does ischemia lead to denervation? Myocardial rest MIBG uptake relates to exercise myocardial perfusion
$98
Abstracts Wednesday afternoon, April 21, 1999
48.6
52.2
RELATIONSHIP BETWEEN MENTAL STRESS INDUCED LV DYSFUNCTION AND AUTONOMIC NERVOUS SYSTEM ACTIVATION D Jain, T Josks, F Lee, R Lampert, M Burg, R Soufer, BL Zaret. Yale University, New Haven CT.
Mental Stress (MS) results in LV dysfunction (Dys) in a significant proportion of patients (pts)with coronary artery disease (CAD). The exact mechanism of MS induced LV Dys is not clear. Autonomic nervous system activation in response to MS has been postulated to be one potential mechanism. Ten pts with known CAD and exercise induced ischemia underwent a battery of MS tests [Mental Arithmetic, Anger Recall and Color Stoop test] while undergoing continuous ambulatory LV function monitoring and Holter monitoring on two separate occasions. Changes in LV function and in indices of heart rate (HR) variability (Low frequency (LF), high frequency (HI=) and LF/HF ratios ) were studied. Of a total of 58 MS tasks, 42 tasks were associated with LV Dys (_>5% fall in LV ejection fraction)(MS+). Overall there was increase in LF, HF and LF/HF with MS compared to the baseline (p
HF
LF/HF
MS+ (n--40) 2.90-+0.49 2.44_+0.54 1.21_+0.18 MS- (n=16) 2.84_+0.34 2.14_+0.54 1.31_+0.39 With MS tasks there was activation of the autonomic nervous system, but there was no difference in the magnitude of the indices of HR variability between MS tasks associated with LV Dys compared to MS tasks with no LV Dys. Therefore, differences in autonomic nervous system activation may not explain the occurrence of LV Dys with MS.
Wednesday PM, April 21, 1999 S e s s i o n s 52, 53, and 54 52.1
W E D N E S D A Y
P M A P R I L
21
Journal of Nuclear Cardiology January/February 1999, Part 2
CARDIAC NEURONAL FUNCTION AND LEFT VENTRICULAR EJECTION FRACTION IN CHILDREN WITH DILATED CARDIOMYOPATHY: A 1-123 MIBG SCINTIGRAPHIC STUDY. Ch. Maunoury, P. Acar, Th. Antonietti, S. S6bahoun, L. Barritault. HOpital Necker-Enfants Malades, Paris, France. In adults with heart failure, the 1-123 MIBG cardiac scintigraphy is a useful tool to assess cardiac adrenergic neuronal function. However, no data are available in childhood dilated cardiomyopathy. Our purpose was to assess the cardiac neuronal function in children with dilated cardiomyopathy and to compare the 1-123 MIBG cardiac uptake with the left ventricular ejection fraction (LVEF). Methods: We studied 26 consecutive patients (17 female, 9 male, aged 44+50 months, range: 2-175) with idiopathic dilated cardiomyopathy and left ventricular dysfunction. All patients underwent a planar scintigraphy performed 4 hours after IV injection of 20-75 MBq of 1-123 MIBG. The static acquisition was performed in anterior view for 10 minutes. The ROl's average size w a s 4x4 pixels (matrix size 64x64). The 1-123 MIBG cardiac uptake was calculated as heart to mediastinum count ratio. Following our standard protocol, an equilibrium radionuclide angiography was performed on the previous day. Results: The mean 1-123 MIBG cardiac uptake was 172_+34% (range: 121-255). The mean LVEF was 23+11% (range: 10-48). There was a good correlation between 1-123 MIBG cardiac uptake and LVEF (y=0.03x+1.13, r=0.80, P<0.0001). Conclusion: The cardiac neuronal dysfunction assessed by 1-123 MIBG scintigraphy w a s related to the impairment of left ventricular systolic function.
DOES ISCHEMIA LEAD TO DENERVATION ? MYOCARDIAL REST M I B G UPTAKE RELATES TO EXERCISE MYOCARDIAL PERFUSION. M.Estorch, A.Flotats, C.Mafi, J.C.Martin, Ll.Bema, R.Serra, A.Catafau, J.Narula, I.Carri6. Sant Pau. Barcelona. Spain. To assess the relationship between regional myocardial MIBG uptake at rest and regional myocardial perfusion at exercise, we studied 17 patients with CAD, by means of SPECT MIBG at rest and SPECT rest/exercise tetrofosmin (TTF). Tomograms were divided into 15 myocardial segments. Results of regional tracer uptake expressed as percentage of peak activity are shown in the following table: <35% 36-50% 51-65% 66-80% >80% MIBG 24 45 36 78 72 TTFe 15 18 57 81 84 (p<.00l, r=.784) Fourteen patients showed decreased MIBG uptake at rest and decreased exercise TTF uptake in the same segments. In 9 of them, MIBG defects were more extensive and severe than were TTF exercise defects. Patients with more severe ischemia at perfusion studies had more severe MIBG defects at rest. In conclusion, resting myocardial MIBG defects relate to myocardial perfusion defects at exercise, suggesting that repetitive episodes of ischemia can induce a permanent loss of neuronal MIBG uptake in the myocardium
52.3
SELECTIVE INFERIOR MYOCARDIAL WALL SYMPATHETIC DENERVATION IN SINUS BRADYCARDIA. M.Estorch, A.Flotats, R.Serra, C.Mari, J:C.Martin, L1.Bema, A.Catafau, J.Namla, I.Carrid. Sant Pan. Barcelona. Spain. Sinus bradycardia (SB) is an alteration of heart rhythm associated with increased vagal tone. To assess myocardial distribution of sympathetic innervation in SB, we studied 12 athletes with heart rate inferior to 60 beats/minute and 8 athletes with normal heart rate, both by means of 123I-MIBG. For each SPECT study, tomograms were divided into 15 myocardial segments. Regional tracer uptake was quantified and expressed as percentage of peak activity. Results are expressed in the following table: anterior septal lateral inferior apical bradycardia 79±10 814-17 94±4 454-14 57±14 normal rate 74±9 93+7 874-11 724-11 594-9 In SB MIBG distribution was severely reduced in the inferior myocardial region and the percentage of MIBG uptake in this region was significantly decreased (p<.01). There were no significant differences in the other myocardial re~ons. In conclusion, in SB myocardial MIBG distribution is severely reduced selectively in the inferior region, and may contribute to increased vagal tone in bradycardia.
Abstracts Wednesday afternoon, April 21, 1999
48.6
52.2
RELATIONSHIP BETWEEN MENTAL STRESS INDUCED LV DYSFUNCTION AND AUTONOMIC NERVOUS SYSTEM ACTIVATION D Jain, T Josks, F Lee, R Lampert, M Burg, R Soufer, BL Zaret. Yale University, New Haven CT.
Mental Stress (MS) results in LV dysfunction (Dys) in a significant proportion of patients (pts)with coronary artery disease (CAD). The exact mechanism of MS induced LV Dys is not clear. Autonomic nervous system activation in response to MS has been postulated to be one potential mechanism. Ten pts with known CAD and exercise induced ischemia underwent a battery of MS tests [Mental Arithmetic, Anger Recall and Color Stoop test] while undergoing continuous ambulatory LV function monitoring and Holter monitoring on two separate occasions. Changes in LV function and in indices of heart rate (HR) variability (Low frequency (LF), high frequency (HI=) and LF/HF ratios ) were studied. Of a total of 58 MS tasks, 42 tasks were associated with LV Dys (_>5% fall in LV ejection fraction)(MS+). Overall there was increase in LF, HF and LF/HF with MS compared to the baseline (p
HF
LF/HF
MS+ (n--40) 2.90-+0.49 2.44_+0.54 1.21_+0.18 MS- (n=16) 2.84_+0.34 2.14_+0.54 1.31_+0.39 With MS tasks there was activation of the autonomic nervous system, but there was no difference in the magnitude of the indices of HR variability between MS tasks associated with LV Dys compared to MS tasks with no LV Dys. Therefore, differences in autonomic nervous system activation may not explain the occurrence of LV Dys with MS.
Wednesday PM, April 21, 1999 S e s s i o n s 52, 53, and 54 52.1
W E D N E S D A Y
P M A P R I L
21
Journal of Nuclear Cardiology January/February 1999, Part 2
CARDIAC NEURONAL FUNCTION AND LEFT VENTRICULAR EJECTION FRACTION IN CHILDREN WITH DILATED CARDIOMYOPATHY: A 1-123 MIBG SCINTIGRAPHIC STUDY. Ch. Maunoury, P. Acar, Th. Antonietti, S. S6bahoun, L. Barritault. HOpital Necker-Enfants Malades, Paris, France. In adults with heart failure, the 1-123 MIBG cardiac scintigraphy is a useful tool to assess cardiac adrenergic neuronal function. However, no data are available in childhood dilated cardiomyopathy. Our purpose was to assess the cardiac neuronal function in children with dilated cardiomyopathy and to compare the 1-123 MIBG cardiac uptake with the left ventricular ejection fraction (LVEF). Methods: We studied 26 consecutive patients (17 female, 9 male, aged 44+50 months, range: 2-175) with idiopathic dilated cardiomyopathy and left ventricular dysfunction. All patients underwent a planar scintigraphy performed 4 hours after IV injection of 20-75 MBq of 1-123 MIBG. The static acquisition was performed in anterior view for 10 minutes. The ROl's average size w a s 4x4 pixels (matrix size 64x64). The 1-123 MIBG cardiac uptake was calculated as heart to mediastinum count ratio. Following our standard protocol, an equilibrium radionuclide angiography was performed on the previous day. Results: The mean 1-123 MIBG cardiac uptake was 172_+34% (range: 121-255). The mean LVEF was 23+11% (range: 10-48). There was a good correlation between 1-123 MIBG cardiac uptake and LVEF (y=0.03x+1.13, r=0.80, P<0.0001). Conclusion: The cardiac neuronal dysfunction assessed by 1-123 MIBG scintigraphy w a s related to the impairment of left ventricular systolic function.
DOES ISCHEMIA LEAD TO DENERVATION ? MYOCARDIAL REST M I B G UPTAKE RELATES TO EXERCISE MYOCARDIAL PERFUSION. M.Estorch, A.Flotats, C.Mafi, J.C.Martin, Ll.Bema, R.Serra, A.Catafau, J.Narula, I.Carri6. Sant Pau. Barcelona. Spain. To assess the relationship between regional myocardial MIBG uptake at rest and regional myocardial perfusion at exercise, we studied 17 patients with CAD, by means of SPECT MIBG at rest and SPECT rest/exercise tetrofosmin (TTF). Tomograms were divided into 15 myocardial segments. Results of regional tracer uptake expressed as percentage of peak activity are shown in the following table: <35% 36-50% 51-65% 66-80% >80% MIBG 24 45 36 78 72 TTFe 15 18 57 81 84 (p<.00l, r=.784) Fourteen patients showed decreased MIBG uptake at rest and decreased exercise TTF uptake in the same segments. In 9 of them, MIBG defects were more extensive and severe than were TTF exercise defects. Patients with more severe ischemia at perfusion studies had more severe MIBG defects at rest. In conclusion, resting myocardial MIBG defects relate to myocardial perfusion defects at exercise, suggesting that repetitive episodes of ischemia can induce a permanent loss of neuronal MIBG uptake in the myocardium
52.3
SELECTIVE INFERIOR MYOCARDIAL WALL SYMPATHETIC DENERVATION IN SINUS BRADYCARDIA. M.Estorch, A.Flotats, R.Serra, C.Mari, J:C.Martin, L1.Bema, A.Catafau, J.Namla, I.Carrid. Sant Pan. Barcelona. Spain. Sinus bradycardia (SB) is an alteration of heart rhythm associated with increased vagal tone. To assess myocardial distribution of sympathetic innervation in SB, we studied 12 athletes with heart rate inferior to 60 beats/minute and 8 athletes with normal heart rate, both by means of 123I-MIBG. For each SPECT study, tomograms were divided into 15 myocardial segments. Regional tracer uptake was quantified and expressed as percentage of peak activity. Results are expressed in the following table: anterior septal lateral inferior apical bradycardia 79±10 814-17 94±4 454-14 57±14 normal rate 74±9 93+7 874-11 724-11 594-9 In SB MIBG distribution was severely reduced in the inferior myocardial region and the percentage of MIBG uptake in this region was significantly decreased (p<.01). There were no significant differences in the other myocardial re~ons. In conclusion, in SB myocardial MIBG distribution is severely reduced selectively in the inferior region, and may contribute to increased vagal tone in bradycardia.