1992 Fiscal Year Final Research Report Summary
Experimental and clinical study of the ventricular late-potential
| Project/Area Number |
02454252
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Yamagata University |
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Principal Investigator |
IKEDA Kozue Yamagata Univ. Sch of Med, Assis. Prof., 医学部, 助手 (30184419)
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| Co-Investigator(Kenkyū-buntansha) |
OHTA Ikurou Yamagata Univ, Sch of Med, Assis. Prof., 医学部, 講師 (70143097)
OGUMA Masaki Yamagata Univ, Sch of Med, Assis. Prof., 医学部, 講師 (10160821)
YAMAKI Michiyasu Yamagata Univ, Sch of Med, Assis. Prof., 医学部, 助手 (40191217)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Signal-averaged ECG / Body surface mapping / Epicardial mapping / Myocardial infarction / Ventricular tachycardia / Spectral analysis |
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| Research Abstract |
To investigate the body surface distribution of high-and low frequency components within the QRS complex and ventricular tachycardia (VT), 87 signal-averaged ECGs were obtained from normal subjects (N group)and 30 patients with previous anterior myocardial infarction with VT (MI-VT(+) group, n=10) or without VT (MI-VT(-) group, n=20). Fast fourier transform analysis was performed on signal-averaged ECG. Then, inverse transform was done with five frequency ranges (0-25, 25-40, 40-80, 80-125, and 125-250 Hz). From the QRS onset to QRS offset, the time integration of the absolute value of reconstructed waveforms was calculated for each frequency range. Both MI groups had significantly smaller maximal values in the frequency ranges of 25-40 and 40-80 Hz compared with the N group. The MI-VT(+) group had significantly smaller maximal values in the frequency ranges of 40-80 and 80-150 Hz than in the MI-VT(-) group.
Spectral analysis was also performed in 8 mongrel dogs with 4-week-old myocardial infarction (MI group) and 6 sham-operated dogs (N group). Left anterior descending coronary artery was ligated under aseptic surgery. Four weeks after, 60-lead epicardial electrograms were recorded, and spectral analysis of QRS complex was performed. On the frequency ranges of 25-40, 40- 80, 80-150, and 125-250 Hz, MI group had significantly smaller values than N group in the infarcted zone. However, in the non-infarcted zone, there was no significant difference between the MI and N group.
It was demonstrated that high-frequency components were reduced in the QRS complex on the body surface ECGs and epicardial electrograms after myocardial infarction. This reduction might indicate the loss of electrical forces and abnormal conduction in the myocardial scar, and might be related to the ventricular tachycardia.
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