TY - JOUR
T1 - Sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than LQT2 forms of congenital long QT syndrome
AU - Tanabe, Yasuko
AU - Inagaki, Masashi
AU - Kurita, Takashi
AU - Nagaya, Noritoshi
AU - Taguchi, Atsushi
AU - Suyama, Kazuhiro
AU - Aihara, Naohiko
AU - Kamakura, Shiro
AU - Sunagawa, Kenji
AU - Nakamura, Kazufumi
AU - Ohe, Tohru
AU - Towbin, Jeffrey A.
AU - Priori, Silvia G.
AU - Shimizu, Wataru
N1 - Funding Information:
Dr. Wataru Shimizu was supported in part by Japan Heart Foundaton/Pfizer Grant for Cardiovascular Disease Research, Japanese Heart Foundation/Zeria Grant, Japanese Cardiovascular Research Foundation, and a Research Grant for Cardiovascular Diseases (11C-1) from the Ministry of Health and Welfare, Japan.
PY - 2001/3/1
Y1 - 2001/3/1
N2 - OBJECTIVES: The study compared the influence of sympathetic stimulation on transmural and spatial dispersion of repolarization between LQT1 and LQT2 forms of congenital long QT syndrome (LQTS). BACKGROUND: Cardiac events are more associated with sympathetic stimulation in LQT1 than in LQT2 or LQT3 syndrome. Experimental studies have suggested that the interval between Tpeak and Tend (Tp-e) in the electrocardiogram (ECG) reflects transmural dispersion of repolarization across the ventricular wall. METHODS: We recorded 87-lead body-surface ECGs before and after epinephrine infusion (0.1 μg/kg/min) in 13 LQT1, 6 LQT2, and 7 control patients. The Q-Tend (QT-e), Q-Tpeak (QT-p), and Tp-e were measured automatically from 87-lead ECGs, corrected by Bazett's method (QTc-e, QTc-p, Tcp-e), and averaged among all 87-leads and among 24-leads, which reflect the potential from the left ventricular free wall. As an index of spatial dispersion of repolarization, the dispersion of QTc-e (QTc-eD) and QTc-p (QTc-pD) were obtained among 87-leads and among 24-leads, and were defined as the interval between the maximum and the minimum of the QTc-e and the QTc-p, respectively. RESULTS: Epinephrine significantly increased the mean QTc-e but not the mean QTc-p, resulting in a significant increase in the mean Tcp-e in both LQT1 and LQT2, but not in control patients. The epinephrine-induced increases in the mean QTc-e and Tcp-e were larger in LQT1 than in LQT2, and were more pronounced when the averaged data were obtained from 24-leads than from 87-leads. Epinephrine increased the maximum QTc-e but not the minimum QTc-e, producing a significant increase in the QTc-eD in both LQT1 and LQT2 patients, but not in control patients. The increase in the QTc-eD was larger in LQT1 than in LQT2 patients. CONCLUSIONS: Our data suggest that sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than in LQT2 syndrome, and this may explain why LQT1 patients are more sensitive to sympathetic stimulation.
AB - OBJECTIVES: The study compared the influence of sympathetic stimulation on transmural and spatial dispersion of repolarization between LQT1 and LQT2 forms of congenital long QT syndrome (LQTS). BACKGROUND: Cardiac events are more associated with sympathetic stimulation in LQT1 than in LQT2 or LQT3 syndrome. Experimental studies have suggested that the interval between Tpeak and Tend (Tp-e) in the electrocardiogram (ECG) reflects transmural dispersion of repolarization across the ventricular wall. METHODS: We recorded 87-lead body-surface ECGs before and after epinephrine infusion (0.1 μg/kg/min) in 13 LQT1, 6 LQT2, and 7 control patients. The Q-Tend (QT-e), Q-Tpeak (QT-p), and Tp-e were measured automatically from 87-lead ECGs, corrected by Bazett's method (QTc-e, QTc-p, Tcp-e), and averaged among all 87-leads and among 24-leads, which reflect the potential from the left ventricular free wall. As an index of spatial dispersion of repolarization, the dispersion of QTc-e (QTc-eD) and QTc-p (QTc-pD) were obtained among 87-leads and among 24-leads, and were defined as the interval between the maximum and the minimum of the QTc-e and the QTc-p, respectively. RESULTS: Epinephrine significantly increased the mean QTc-e but not the mean QTc-p, resulting in a significant increase in the mean Tcp-e in both LQT1 and LQT2, but not in control patients. The epinephrine-induced increases in the mean QTc-e and Tcp-e were larger in LQT1 than in LQT2, and were more pronounced when the averaged data were obtained from 24-leads than from 87-leads. Epinephrine increased the maximum QTc-e but not the minimum QTc-e, producing a significant increase in the QTc-eD in both LQT1 and LQT2 patients, but not in control patients. The increase in the QTc-eD was larger in LQT1 than in LQT2 patients. CONCLUSIONS: Our data suggest that sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than in LQT2 syndrome, and this may explain why LQT1 patients are more sensitive to sympathetic stimulation.
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U2 - 10.1016/S0735-1097(00)01200-6
DO - 10.1016/S0735-1097(00)01200-6
M3 - Article
C2 - 11693770
AN - SCOPUS:0035281517
VL - 37
SP - 911
EP - 919
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
SN - 0735-1097
IS - 3
ER -