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QT interval and QT dispersion in systemic sclerosis (scleroderma)
A Sgreccia1, S Morelli, L Ferrante
1Institute of Clinical Medicine, La Sapienza University, Rome, Italy.
Journal of Internal Medicine
|May 5, 1998
Summary
Systemic sclerosis (SSc) patients show prolonged QT intervals and increased QT dispersion, indicating potential cardiac repolarization abnormalities. Further research is needed to understand the autonomic nervous system
Area of Science:
- Cardiology
- Rheumatology
- Electrophysiology
Background:
- Systemic sclerosis (SSc) is an autoimmune disease that can affect multiple organs, including the heart.
- Cardiac involvement in SSc can manifest as myocardial fibrosis and dysfunction, potentially impacting ventricular repolarization.
- Assessing repolarization abnormalities like QT interval and dispersion is crucial for risk stratification in SSc patients.
Purpose of the Study:
- To measure QT interval and QT dispersion in patients with systemic sclerosis (SSc).
- To evaluate the relationship between QT parameters, heart rate variability (HRV), and early myocardial involvement in SSc.
- To compare these parameters between SSc patients and healthy controls.
Main Methods:
- Prospective study involving 38 SSc patients and 17 healthy controls.
- 12-lead electrocardiogram and 24-hour Holter monitoring were performed on all participants.
- Resting myocardial scintigraphy with 99mTc-sestamibi was conducted in SSc patients; Bazett's formula was used for rate-corrected QT (QTc) interval calculations.
Main Results:
- SSc patients exhibited significantly increased maximum QTc interval, QT dispersion, and QTc dispersion compared to controls.
- Sixty-one percent of SSc patients showed myocardial perfusion defects; however, QT measurements did not differ between patients with and without these defects.
- SSc patients, regardless of myocardial involvement, had significantly lower total power, low-frequency, and high-frequency HRV values than controls.
Conclusions:
- Patients with systemic sclerosis demonstrate impaired ventricular repolarization, evidenced by prolonged QTc interval and increased QT dispersion.
- The findings suggest potential alterations in autonomic nervous system function in SSc patients.
- Further investigation is warranted to elucidate the roles of the autonomic nervous system and myocardial involvement in SSc-related repolarization abnormalities.