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A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
Left ventricular sphericity index analysis for the prediction of appropriate implantable cardioverter-defibrillator
Shideh Anvari1, Mohammad Ali Akbarzadeh1,2, Fariba Bayat1
1Cardiovascular Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Background:
Implantable cardioverter-defibrillator (ICD) is the most effective therapy currently available to prevent sudden cardiac death (SCD) in patients with left ventricular (LV) dysfunction. Although LV ejection fraction (LVEF) is an excellent marker of SCD in these patients, determining other predictors might help to identify patients who will be benefit more from device implantation. The purpose of this study was to determine whether abnormal LV sphericity index (SI) in transthoracic echocardiography is associated with appropriate ICD therapy in these patients.
Methods:
A total of 140 patients with primary ICD implantation (mean age 62.59 ± 11.36 years; 98 [70%] male) were included. The patients were classified into "no ICD therapy" or "ICD therapy" group according to the information of their devices for a maximum of 2 previous years. In four-chamber view image of transthoracic echocardiography, SI was calculated by dividing the major-axis dimension to minor-axis dimension of LV in both groups.
Results:
Compared with patients with no ICD therapy, patients in ICD therapy group had lower LVEF (31.36 ± 9.58 vs 23.24 ± 6.03, P = 0.0001) and lower SI (1.79 ± 0.29 vs 1.57 ± 0.32, P = 0.0001). In multivariant logistic regression analysis, the SI of ≤1.58 was associated with fourfold increase of appropriate ICD therapy, even after adjusting for LVEF (odds ratio, 4.08; 95% confidence interval, 1.71-9.75; P = 0.02).
Conclusion:
Simple echocardiographic sphericity dimension index as a marker of cardiac remodeling may be an important predictor of appropriate ICD therapy in patients with primary prevention ICDs and may provide additive risk stratification in patients with LV systolic dysfunction.
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