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Published on: February 28, 2012
Different Effects of Defibrillator Shocks on the Myocardial Damage Between Subcutaneous and Transvenous Implantable
Takahide Kadosaka1, Masaya Watanabe1, Motoki Nakao1
1Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Insights
Transvenous implantable cardioverter-defibrillator (TV-ICD) shocks cause myocardial injury, indicated by elevated troponin-I levels. Subcutaneous ICD (S-ICD) shocks did not show this association, suggesting TV-ICD shocks are more damaging.
Area of Science:
- Cardiology
- Biomedical Engineering
- Electrophysiology
Background:
- Implantable cardioverter-defibrillators (ICD) prevent sudden cardiac death but shock therapies increase mortality risk.
- The differential impact of shock therapies between Transvenous-ICD (TV-ICD) and Subcutaneous-ICD (S-ICD) on myocardial injury remains understudied.
Purpose of the Study:
- To investigate the influence of TV-ICD and S-ICD shocks on myocardial injury.
Main Methods:
- A cohort of 74 patients receiving TV-ICD or S-ICD was analyzed.
- Patients were categorized into TV-ICD with defibrillation testing (DFT), TV-ICD without DFT, and S-ICD groups.
- Serum troponin-I levels were measured pre- and post-implantation to assess myocardial injury.
Main Results:
- Delta log troponin-I significantly increased in the TV-ICD with DFT group.
- In TV-ICD patients, Delta log troponin-I correlated with total shock joules.
- Total shock joules were independently associated with troponin-I elevation in multivariable analysis.
Conclusions:
- TV-ICD shocks are linked to elevated serum troponin-I, correlating with total shock energy.
- S-ICD shocks did not show a significant association with troponin-I elevation.
- TV-ICD shocks appear to cause greater myocardial injury than S-ICD shocks, with total energy being a key factor.
Background:
Although the implantable cardioverter defibrillators (ICD) are the only established treatment to prevent sudden cardiac death, previous studies reported that those who receive shock therapies, whether appropriate or inappropriate, have a higher risk of death. However, the difference in the influence of shock therapies between via Transvenous-ICD (TV-ICD) and Subcutaneous-ICD (S-ICD) has not been adequately examined. We aimed to investigate the influence of shocks on myocardium in patients with TV-ICD and S-ICD.
Methods:
We enrolled consecutive patients who received a defibrillator or transvenous pacemaker (TV-PM) implantation between November 2020 and March 2024. A total of 74 patients were included in this study and divided into three groups: patients with TV-ICD with defibrillation testing (DFT) (TV-DFT, 27 patients), those with transvenous devices implanted without DFT (TV-no DFT, 25 patients) and those with S-ICD (22 patients).
Results:
Delta log troponin-I (the difference of serum troponin-I levels between baseline and after implantation) was significantly increased in TV-DFT group. In patients with TV-ICD (46 patients), Delta log troponin-I was significantly correlated with total shock joules. In the multivariable linear regression analysis, a value of total shock joules was independently associated with delta troponin-I.
Conclusion:
Elevation of serum troponin-I was associated with the TV-ICD shocks and correlated with the total shock energy, but not with S-ICD shocks. Our results suggest that TV-ICD shocks are associated with greater myocardial injury compared to S-ICD shocks, and that total shock energy is an important determinant of the extent of myocardial damage.
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