Abstract
Background: We have recently demonstrated a striking impairment in cardiac uptake of 123I-metaiodobenzylguanidine (MIBG) in most patients with syndrome X. In this study we investigated the relationship between cardiac MIBG defects and cardiac autonomic activity in these patients. Methods: MIBG myocardial scintigraphy and time-domain and frequency-domain heart rate variability (HRV) were compared in 11 syndrome X patients and 10 healthy controls. Cardiac MIBG uptake was assessed by the heart/mediastinum ratio and a cardiac MIBG uptake defect score (higher values = lower uptake). Results: The heart/mediastinum ratio was lower (1.71 ± 0.6 vs 2.19 ± 0.3, p = 0.03) and MIBG uptake score higher (37.1 ± 32 vs 4.0 ± 2.5, p = 0.005) in syndrome X patients, whereas average HRV values did not differ between the two groups. However, while there were no correlations between MIBG uptake and HRV in controls, in syndrome X patients both the heart/mediastinum ratio and MIBG uptake score correlated significantly with two HRV parameters, specific for vagal activity: the square root of the mean squared differences of consecutive RR intervals (r = 0.73, p = 0.01, and r = -0.67, p = 0.02, respectively), and high frequency (r = 0.64, p = 0.03, and r = -0.74, p = 0.009, respectively). Conclusions: In patients with syndrome X, the impairment in cardiac MIBG uptake was associated with a reduction in HRV indexes mainly reflecting vagal modulation of sinus node, thus suggesting that a predominance of cardiac adrenergic activity may be present in those with abnormal cardiac MIBG scintigraphy.
| Original language | English |
|---|---|
| Pages (from-to) | 221-225 |
| Number of pages | 5 |
| Journal | Italian Heart Journal |
| Volume | 1 |
| Issue number | 3 |
| Publication status | Published - 2000 |
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Keywords
- I-metaiodo-benzylguanidine myocardial scintigraphy
- Autonomic function
- Heart rate variability
- Syndrome X
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
Cite this
Relationship between myocardial 123I-metaiodobenzylguanidine scintigraphic uptake and heart rate variability in patients with syndrome X. / Lanza, G. A.; Giordano, A.; Pristipino, C.; Calcagni, M. L.; Meduri, G.; Trani, C.; Franceschini, R.; Crea, F.; Troncone, L.
In: Italian Heart Journal, Vol. 1, No. 3, 2000, p. 221-225.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Relationship between myocardial 123I-metaiodobenzylguanidine scintigraphic uptake and heart rate variability in patients with syndrome X
AU - Lanza, G. A.
AU - Giordano, A.
AU - Pristipino, C.
AU - Calcagni, M. L.
AU - Meduri, G.
AU - Trani, C.
AU - Franceschini, R.
AU - Crea, F.
AU - Troncone, L.
PY - 2000
Y1 - 2000
N2 - Background: We have recently demonstrated a striking impairment in cardiac uptake of 123I-metaiodobenzylguanidine (MIBG) in most patients with syndrome X. In this study we investigated the relationship between cardiac MIBG defects and cardiac autonomic activity in these patients. Methods: MIBG myocardial scintigraphy and time-domain and frequency-domain heart rate variability (HRV) were compared in 11 syndrome X patients and 10 healthy controls. Cardiac MIBG uptake was assessed by the heart/mediastinum ratio and a cardiac MIBG uptake defect score (higher values = lower uptake). Results: The heart/mediastinum ratio was lower (1.71 ± 0.6 vs 2.19 ± 0.3, p = 0.03) and MIBG uptake score higher (37.1 ± 32 vs 4.0 ± 2.5, p = 0.005) in syndrome X patients, whereas average HRV values did not differ between the two groups. However, while there were no correlations between MIBG uptake and HRV in controls, in syndrome X patients both the heart/mediastinum ratio and MIBG uptake score correlated significantly with two HRV parameters, specific for vagal activity: the square root of the mean squared differences of consecutive RR intervals (r = 0.73, p = 0.01, and r = -0.67, p = 0.02, respectively), and high frequency (r = 0.64, p = 0.03, and r = -0.74, p = 0.009, respectively). Conclusions: In patients with syndrome X, the impairment in cardiac MIBG uptake was associated with a reduction in HRV indexes mainly reflecting vagal modulation of sinus node, thus suggesting that a predominance of cardiac adrenergic activity may be present in those with abnormal cardiac MIBG scintigraphy.
AB - Background: We have recently demonstrated a striking impairment in cardiac uptake of 123I-metaiodobenzylguanidine (MIBG) in most patients with syndrome X. In this study we investigated the relationship between cardiac MIBG defects and cardiac autonomic activity in these patients. Methods: MIBG myocardial scintigraphy and time-domain and frequency-domain heart rate variability (HRV) were compared in 11 syndrome X patients and 10 healthy controls. Cardiac MIBG uptake was assessed by the heart/mediastinum ratio and a cardiac MIBG uptake defect score (higher values = lower uptake). Results: The heart/mediastinum ratio was lower (1.71 ± 0.6 vs 2.19 ± 0.3, p = 0.03) and MIBG uptake score higher (37.1 ± 32 vs 4.0 ± 2.5, p = 0.005) in syndrome X patients, whereas average HRV values did not differ between the two groups. However, while there were no correlations between MIBG uptake and HRV in controls, in syndrome X patients both the heart/mediastinum ratio and MIBG uptake score correlated significantly with two HRV parameters, specific for vagal activity: the square root of the mean squared differences of consecutive RR intervals (r = 0.73, p = 0.01, and r = -0.67, p = 0.02, respectively), and high frequency (r = 0.64, p = 0.03, and r = -0.74, p = 0.009, respectively). Conclusions: In patients with syndrome X, the impairment in cardiac MIBG uptake was associated with a reduction in HRV indexes mainly reflecting vagal modulation of sinus node, thus suggesting that a predominance of cardiac adrenergic activity may be present in those with abnormal cardiac MIBG scintigraphy.
KW - I-metaiodo-benzylguanidine myocardial scintigraphy
KW - Autonomic function
KW - Heart rate variability
KW - Syndrome X
UR - http://www.scopus.com/inward/record.url?scp=0033625294&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033625294&partnerID=8YFLogxK
M3 - Article
C2 - 10806990
AN - SCOPUS:0033625294
VL - 1
SP - 221
EP - 225
JO - Italian Heart Journal
JF - Italian Heart Journal
SN - 1129-471X
IS - 3
ER -