Clinical predictors of defibrillation threshold in patients with implantable cardioverter-defibrillators
Abstract
Aim: To assess the relationship between DFT and clinical, demographic and antropometric parameters, type and progression of underlying disease as well as antiarrhyhmic therapy used in ICD recipients.
Methods: The study group consisted of 168 patients (47 females, 121 males, mean age 55±15 years, range 15-82 years) who were selected to receive an ICD. DFT was systematically tested during ICD implantation in all patients. Various clinical, demographic, antropometric and echocardiographic parameters were analysed as the function of DFT value, examining their accuracy in predicting a high (≥15 J) or a low (<15 J) DFT, using logistic regression model.
Results: Univariate analysis revealed that DFT value was significantly related to the following parameters: idiopathic VF, dilated cardiomyopathy, amiodarone therapy and the use of beta blockers. There was a significant correlation between DFT and LVEDD, height, LVEF and impedance of defibrillating system. Multivariate analysis showed that amiodarone therapy, height, impedance of defibrillating system and LVEDD were independently related to the DFT value. Parameters which predicted a high (≥15 J) DFT, consisted of amiodarone therapy (p=0.005), height (p=0.01), LVEDD (p=0.01), LVEF (p=0.03), dilated cardiomyopathy (p=0.01) and body surface area (p=0.049). Amiodarone therapy occurred to be the only parameter which independently predicted a high DFT (odds ratio 2.78; 95% confidence interval 1.19-6.5).
Conclusions: Tall stature, enhanced LVEDD, decreased LVEF and amiodarone therapy increase the risk of a high DFT in ICD recipients. Chronic amiodarone therapy increases three times the risk of elevated DFT. In patients with already implanted ICD in whom amiodarone is started, reassessment of DFT following administration of a loading dose of the drug is required.
Abstract
Aim: To assess the relationship between DFT and clinical, demographic and antropometric parameters, type and progression of underlying disease as well as antiarrhyhmic therapy used in ICD recipients.
Methods: The study group consisted of 168 patients (47 females, 121 males, mean age 55±15 years, range 15-82 years) who were selected to receive an ICD. DFT was systematically tested during ICD implantation in all patients. Various clinical, demographic, antropometric and echocardiographic parameters were analysed as the function of DFT value, examining their accuracy in predicting a high (≥15 J) or a low (<15 J) DFT, using logistic regression model.
Results: Univariate analysis revealed that DFT value was significantly related to the following parameters: idiopathic VF, dilated cardiomyopathy, amiodarone therapy and the use of beta blockers. There was a significant correlation between DFT and LVEDD, height, LVEF and impedance of defibrillating system. Multivariate analysis showed that amiodarone therapy, height, impedance of defibrillating system and LVEDD were independently related to the DFT value. Parameters which predicted a high (≥15 J) DFT, consisted of amiodarone therapy (p=0.005), height (p=0.01), LVEDD (p=0.01), LVEF (p=0.03), dilated cardiomyopathy (p=0.01) and body surface area (p=0.049). Amiodarone therapy occurred to be the only parameter which independently predicted a high DFT (odds ratio 2.78; 95% confidence interval 1.19-6.5).
Conclusions: Tall stature, enhanced LVEDD, decreased LVEF and amiodarone therapy increase the risk of a high DFT in ICD recipients. Chronic amiodarone therapy increases three times the risk of elevated DFT. In patients with already implanted ICD in whom amiodarone is started, reassessment of DFT following administration of a loading dose of the drug is required.
Keywords
implantable cardioverter-defibrillator - defibrillation threshold


Title
Clinical predictors of defibrillation threshold in patients with implantable cardioverter-defibrillators
Journal
Kardiologia Polska (Polish Heart Journal)
Issue
Pages
323-328
Published online
2005-12-12
Bibliographic record
Kardiol Pol 2005;62(4):323-328.
Keywords
implantable cardioverter-defibrillator - defibrillation threshold
Authors
Andrzej Lubiński
Ewa Lewicka-Nowak
Agnieszka Zienciuk
Tomasz Królak
Maciej Kempa
Anna Pazdyga
Grażyna Świątecka