Background-We hypothesized that combined assessment of factors that are associated with favorable... more Background-We hypothesized that combined assessment of factors that are associated with favorable reverse remodeling after cardiac resynchronization-defibrillator therapy (CRT-D) can be used to predict clinical response to the device. Methods and Results-The study population comprised 1761 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). Best-subset regression analysis was performed to identify factors associated with echocardiographic response (defined as percent reduction in left ventricular end-diastolic volume 1 year after CRT-D implantation) and to create a response score. Cox proportional hazards regression analysis was used to evaluate the CRT-D versus defibrillator-only reduction in the risk of heart failure or death by the response score. Seven factors were identified as associated with echocardiographic response to CRT-D and made up the response score (female sex, nonischemic origin, left bundle-branch block, QRS Ն150 milliseconds, prior hospitalization for heart failure, left ventricular end-diastolic volume Ն125 mL/m 2 , and left atrial volume Ͻ40 mL/m 2). Multivariate analysis showed a 13% (PϽ0.001) increase in the clinical benefit of CRT-D per 1-point increment in the response score (range, 0-14) and a significant direct correlation between risk reduction associated with CRT-D and response score quartiles: Patients in the first quartile did not derive a significant reduction in the risk of heart failure or death with CRT-D (hazard ratioϭ0.87; Pϭ0.52); patients in the second and third quartiles derived 33% (Pϭ0.04) and 36% (Pϭ0.03) risk reductions, respectively; and patients in the upper quartile experienced a 69% (PϽ0.001) risk reduction (P for trendϭ0.005). Conclusion-Combined assessment of factors associated with reverse remodeling can be used for improved selection of patients for cardiac resynchronization therapy.
BackgroundAblation of ventricular arrhythmias (VA) originating from the left ventricular (LV) pap... more BackgroundAblation of ventricular arrhythmias (VA) originating from the left ventricular (LV) papillary muscles (PM) has the potential to damage the mitral valve apparatus resulting in mitral regurgitation (MR). This study sought to evaluate the effect of radiofrequency (RF) ablation of a PM on MR severity.MethodsPatients with pre‐ and postablation transthoracic echocardiograms who underwent PM ablation for treatment of VA were retrospectively identified and compared to similar patients who underwent VA ablation at non‐PM sites. MR severity was evaluated pre‐ and postablation in both groups and graded as none/trace (Grade 0); mild/mild‐to‐moderate (Grade 1); moderate (Grade 2); moderate‐to‐severe/severe (Grade 3).ResultsA total of 45 and 49 patients were included in the PM and non‐PM groups, respectively. There were no significant baseline demographic differences. The PM group had longer RF ablation times (22.3 vs. 13.3 min, p < .01) compared to the non‐PM group. Most patients ha...
Computers in Cardiology 1998. Vol. 25 (Cat. No.98CH36292)
Increased amplitude variation has been associated with undersensing of ventricular Jbrillation (V... more Increased amplitude variation has been associated with undersensing of ventricular Jbrillation (VF), and may be theoretically related to dynamic VF characteristics. This study evaluates whether changes in frequency content may contribute to undersensing by implantable cardioverter deJbrillators (ICD), and more specifically the utility of using recurrence quanti$cation analysis (RQA) (a method derived from nonlinear dynamics and successjiully used in a variety of physiological signal evaluation tasks) to identifi characteristics which contribute to the undersensing. RQA can reveal subtle signal properties not easily demonstrated by power spectrum, since RQA, is not subject to stationarity nor linearity constraints.
Based on the National Inpatient Sample registry" Running head "Periprocedural Cardiac perforation... more Based on the National Inpatient Sample registry" Running head "Periprocedural Cardiac perforation in CRT-D recipients"
Key Clinical MessageAccessory pathway Wolff‐Parkinson‐white is sometimes not manifested till late... more Key Clinical MessageAccessory pathway Wolff‐Parkinson‐white is sometimes not manifested till later in life, as the conduction properties of AV node become slower, other mechanisms are also possible. Brugada pattern on EKG can be associated with various underlying clinical conditions, such as mechanical compression of RVOT by tumors. It is essential to have high index of suspicion for flecainide toxicity when encountering arrhythmias in patients taking the drug.
Journal of cardiovascular electrophysiology, Jun 24, 2016
At the time of generator replacement, after ICD implantation for primary prevention, many patient... more At the time of generator replacement, after ICD implantation for primary prevention, many patients may no longer meet implantation criteria. We investigated the occurrence of ICD therapy after generator replacement in patients initially implanted ICD for primary prevention. Patients from 3 hospitals undergoing ICD generator replacement, who were initially implanted for primary prevention, were retrospectively evaluated for occurrence of appropriate ICD therapy after generator replacement. Patients were categorized as to whether or not they had appropriate ICD therapy during their first battery life, and by their left ventricular ejection fraction (LVEF) before generator replacement. Data from 168 patients was analyzed, with average follow-up after generator replacement of 41.2±26.5 months. Seventy-six (45.2%) patients had ventricular arrhythmia episodes (> 180 beats per minutes) and 63 (37.5%) received appropriate ICD therapy during the first battery life. Among 105 patients with...
Ventricular arrhythmias are often difficult to evaluate on a quantitative basis. We present here ... more Ventricular arrhythmias are often difficult to evaluate on a quantitative basis. We present here the results of analysis with traditional Fourier transforms, and recurrence quantification analysis. The results indicate that recurrence quantification can better distinguish them, most likely due to its ability to handle nonstationary, nonlinear data.
Background: Adaptive rate sensors used in permanent pacemakers incorporate an accelerometer (XL) ... more Background: Adaptive rate sensors used in permanent pacemakers incorporate an accelerometer (XL) to increase heart rate with activity. Limited data exists regarding the relative benefit of a blended sensor (BS) (XL and minute ventilation) versus XL alone in restoring chronotropic response (CR) in chronotropically incompetent (CI) patients. Methods: One thousand five hundred thirty‐eight patients from the limiting chronotropic incompetence for pacemaker recipients (LIFE) study were implanted with a pacemaker and 1,256 patients had data collected at 1 month. Patients performed a treadmill test 1‐month postimplant while programed in nonrate responsive mode (DDD‐60) to determine CI. Only patients who completed at least three exercise stages and achieved a peak perceived exertion ≥16 were included in the analyses. The metabolic chronotropic relationship (MCR) slope was used to evaluate CR in 547 patients. Patients were randomized to XL or BS with a conservative fixed rate response factor...
Implantable cardioverter–defibrillators have an important role in the treatment of patients with ... more Implantable cardioverter–defibrillators have an important role in the treatment of patients with ventricular arrhythmias. Electromagnetic interference with permanent pacemakers and implantable defibrillators may have deleterious effects.1–11 Electronic antitheft-surveillance devices, which are widely used in stores, libraries, and other places to prevent theft, are a potential source of electromagnetic interference. Approximately 400,000 of these devices are in use worldwide. Electromagnetic interference with implantable defibrillators can generally be divided into four types. The most common type involves an overcounting of the ventricular rate. Misinterpretation of rapid rates may lead to inappropriate antitachycardia pacing or the delivery of shocks. Since the current . . .
Journal of the American College of Cardiology, 2001
OBJECTIVES Using data from the Multicenter UnSustained Tachycardia Trial (MUSTT), we examined the... more OBJECTIVES Using data from the Multicenter UnSustained Tachycardia Trial (MUSTT), we examined the factors used to select antiarrhythmic drug therapy and their impact on outcomes. BACKGROUND The MUSTT examined the use of programmed ventricular stimulation (PVS) to guide antiarrhythmic therapy in patients with coronary arteriosclerosis, left ventricular dysfunction and asymptomatic, unsustained ventricular tachycardia (VT). Trial outcomes may reflect factors used to select antiarrhythmic drug therapy. METHODS We compared subgroups of patients with inducible sustained VT randomized to PVS-guided antiarrhythmic therapy (n ϭ 351), in particular those receiving PVS-guided antiarrhythmic drug therapy (n ϭ 142) versus no antiarrhythmic therapy (controls, n ϭ 353). RESULTS "Effective" antiarrhythmic drug therapy (i.e., the term "effective" was used to denote therapy that resulted in noninducible VT or hemodynamically stable induced VT) was found for 142 of the 351 patients (43%), most often at the first or second PVS session (125/142, 88%). Mortality among the 142 patients did not differ from that among control patients. Of these 142 patients, the PVS end point was noninducibility in 91 patients and stable VT in 51 patients. Mortality did not differ between these two groups either, but arrhythmia was numerically more frequent in the PVS-induced stable VT group. Mortality was greatest in the few patients receiving propafenone (unadjusted p ϭ 0.07, adjusted p ϭ 0.14 vs. controls), but mortality with all agents did not differ from that of controls, even after adjustment. CONCLUSIONS Even when presenting the results as favorably as possible, we found no benefit with PVS-guided drug therapy in patients with clinical unsustained VT who had inducible sustained VT. These findings are unaltered by using different end points for PVS or considering the response to individual drugs.
A 47-year-old man presented with sustained monomorphic ventricular tachycardia of right ventricul... more A 47-year-old man presented with sustained monomorphic ventricular tachycardia of right ventricular origin. Surface ECG recorded during sinus rhythm showed a bizarre &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;double QRS&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; pattern. Biventricular cardiomyopathy was found with predominant right ventricular involvement, due to cardiac sarcoidosis. Electroanatomic mapping was used to characterize the right ventricular substrate abnormalities and to decipher the specific activation abnormalities responsible for the ECG findings.
Background-We hypothesized that combined assessment of factors that are associated with favorable... more Background-We hypothesized that combined assessment of factors that are associated with favorable reverse remodeling after cardiac resynchronization-defibrillator therapy (CRT-D) can be used to predict clinical response to the device. Methods and Results-The study population comprised 1761 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). Best-subset regression analysis was performed to identify factors associated with echocardiographic response (defined as percent reduction in left ventricular end-diastolic volume 1 year after CRT-D implantation) and to create a response score. Cox proportional hazards regression analysis was used to evaluate the CRT-D versus defibrillator-only reduction in the risk of heart failure or death by the response score. Seven factors were identified as associated with echocardiographic response to CRT-D and made up the response score (female sex, nonischemic origin, left bundle-branch block, QRS Ն150 milliseconds, prior hospitalization for heart failure, left ventricular end-diastolic volume Ն125 mL/m 2 , and left atrial volume Ͻ40 mL/m 2). Multivariate analysis showed a 13% (PϽ0.001) increase in the clinical benefit of CRT-D per 1-point increment in the response score (range, 0-14) and a significant direct correlation between risk reduction associated with CRT-D and response score quartiles: Patients in the first quartile did not derive a significant reduction in the risk of heart failure or death with CRT-D (hazard ratioϭ0.87; Pϭ0.52); patients in the second and third quartiles derived 33% (Pϭ0.04) and 36% (Pϭ0.03) risk reductions, respectively; and patients in the upper quartile experienced a 69% (PϽ0.001) risk reduction (P for trendϭ0.005). Conclusion-Combined assessment of factors associated with reverse remodeling can be used for improved selection of patients for cardiac resynchronization therapy.
BackgroundAblation of ventricular arrhythmias (VA) originating from the left ventricular (LV) pap... more BackgroundAblation of ventricular arrhythmias (VA) originating from the left ventricular (LV) papillary muscles (PM) has the potential to damage the mitral valve apparatus resulting in mitral regurgitation (MR). This study sought to evaluate the effect of radiofrequency (RF) ablation of a PM on MR severity.MethodsPatients with pre‐ and postablation transthoracic echocardiograms who underwent PM ablation for treatment of VA were retrospectively identified and compared to similar patients who underwent VA ablation at non‐PM sites. MR severity was evaluated pre‐ and postablation in both groups and graded as none/trace (Grade 0); mild/mild‐to‐moderate (Grade 1); moderate (Grade 2); moderate‐to‐severe/severe (Grade 3).ResultsA total of 45 and 49 patients were included in the PM and non‐PM groups, respectively. There were no significant baseline demographic differences. The PM group had longer RF ablation times (22.3 vs. 13.3 min, p < .01) compared to the non‐PM group. Most patients ha...
Computers in Cardiology 1998. Vol. 25 (Cat. No.98CH36292)
Increased amplitude variation has been associated with undersensing of ventricular Jbrillation (V... more Increased amplitude variation has been associated with undersensing of ventricular Jbrillation (VF), and may be theoretically related to dynamic VF characteristics. This study evaluates whether changes in frequency content may contribute to undersensing by implantable cardioverter deJbrillators (ICD), and more specifically the utility of using recurrence quanti$cation analysis (RQA) (a method derived from nonlinear dynamics and successjiully used in a variety of physiological signal evaluation tasks) to identifi characteristics which contribute to the undersensing. RQA can reveal subtle signal properties not easily demonstrated by power spectrum, since RQA, is not subject to stationarity nor linearity constraints.
Based on the National Inpatient Sample registry" Running head "Periprocedural Cardiac perforation... more Based on the National Inpatient Sample registry" Running head "Periprocedural Cardiac perforation in CRT-D recipients"
Key Clinical MessageAccessory pathway Wolff‐Parkinson‐white is sometimes not manifested till late... more Key Clinical MessageAccessory pathway Wolff‐Parkinson‐white is sometimes not manifested till later in life, as the conduction properties of AV node become slower, other mechanisms are also possible. Brugada pattern on EKG can be associated with various underlying clinical conditions, such as mechanical compression of RVOT by tumors. It is essential to have high index of suspicion for flecainide toxicity when encountering arrhythmias in patients taking the drug.
Journal of cardiovascular electrophysiology, Jun 24, 2016
At the time of generator replacement, after ICD implantation for primary prevention, many patient... more At the time of generator replacement, after ICD implantation for primary prevention, many patients may no longer meet implantation criteria. We investigated the occurrence of ICD therapy after generator replacement in patients initially implanted ICD for primary prevention. Patients from 3 hospitals undergoing ICD generator replacement, who were initially implanted for primary prevention, were retrospectively evaluated for occurrence of appropriate ICD therapy after generator replacement. Patients were categorized as to whether or not they had appropriate ICD therapy during their first battery life, and by their left ventricular ejection fraction (LVEF) before generator replacement. Data from 168 patients was analyzed, with average follow-up after generator replacement of 41.2±26.5 months. Seventy-six (45.2%) patients had ventricular arrhythmia episodes (> 180 beats per minutes) and 63 (37.5%) received appropriate ICD therapy during the first battery life. Among 105 patients with...
Ventricular arrhythmias are often difficult to evaluate on a quantitative basis. We present here ... more Ventricular arrhythmias are often difficult to evaluate on a quantitative basis. We present here the results of analysis with traditional Fourier transforms, and recurrence quantification analysis. The results indicate that recurrence quantification can better distinguish them, most likely due to its ability to handle nonstationary, nonlinear data.
Background: Adaptive rate sensors used in permanent pacemakers incorporate an accelerometer (XL) ... more Background: Adaptive rate sensors used in permanent pacemakers incorporate an accelerometer (XL) to increase heart rate with activity. Limited data exists regarding the relative benefit of a blended sensor (BS) (XL and minute ventilation) versus XL alone in restoring chronotropic response (CR) in chronotropically incompetent (CI) patients. Methods: One thousand five hundred thirty‐eight patients from the limiting chronotropic incompetence for pacemaker recipients (LIFE) study were implanted with a pacemaker and 1,256 patients had data collected at 1 month. Patients performed a treadmill test 1‐month postimplant while programed in nonrate responsive mode (DDD‐60) to determine CI. Only patients who completed at least three exercise stages and achieved a peak perceived exertion ≥16 were included in the analyses. The metabolic chronotropic relationship (MCR) slope was used to evaluate CR in 547 patients. Patients were randomized to XL or BS with a conservative fixed rate response factor...
Implantable cardioverter–defibrillators have an important role in the treatment of patients with ... more Implantable cardioverter–defibrillators have an important role in the treatment of patients with ventricular arrhythmias. Electromagnetic interference with permanent pacemakers and implantable defibrillators may have deleterious effects.1–11 Electronic antitheft-surveillance devices, which are widely used in stores, libraries, and other places to prevent theft, are a potential source of electromagnetic interference. Approximately 400,000 of these devices are in use worldwide. Electromagnetic interference with implantable defibrillators can generally be divided into four types. The most common type involves an overcounting of the ventricular rate. Misinterpretation of rapid rates may lead to inappropriate antitachycardia pacing or the delivery of shocks. Since the current . . .
Journal of the American College of Cardiology, 2001
OBJECTIVES Using data from the Multicenter UnSustained Tachycardia Trial (MUSTT), we examined the... more OBJECTIVES Using data from the Multicenter UnSustained Tachycardia Trial (MUSTT), we examined the factors used to select antiarrhythmic drug therapy and their impact on outcomes. BACKGROUND The MUSTT examined the use of programmed ventricular stimulation (PVS) to guide antiarrhythmic therapy in patients with coronary arteriosclerosis, left ventricular dysfunction and asymptomatic, unsustained ventricular tachycardia (VT). Trial outcomes may reflect factors used to select antiarrhythmic drug therapy. METHODS We compared subgroups of patients with inducible sustained VT randomized to PVS-guided antiarrhythmic therapy (n ϭ 351), in particular those receiving PVS-guided antiarrhythmic drug therapy (n ϭ 142) versus no antiarrhythmic therapy (controls, n ϭ 353). RESULTS "Effective" antiarrhythmic drug therapy (i.e., the term "effective" was used to denote therapy that resulted in noninducible VT or hemodynamically stable induced VT) was found for 142 of the 351 patients (43%), most often at the first or second PVS session (125/142, 88%). Mortality among the 142 patients did not differ from that among control patients. Of these 142 patients, the PVS end point was noninducibility in 91 patients and stable VT in 51 patients. Mortality did not differ between these two groups either, but arrhythmia was numerically more frequent in the PVS-induced stable VT group. Mortality was greatest in the few patients receiving propafenone (unadjusted p ϭ 0.07, adjusted p ϭ 0.14 vs. controls), but mortality with all agents did not differ from that of controls, even after adjustment. CONCLUSIONS Even when presenting the results as favorably as possible, we found no benefit with PVS-guided drug therapy in patients with clinical unsustained VT who had inducible sustained VT. These findings are unaltered by using different end points for PVS or considering the response to individual drugs.
A 47-year-old man presented with sustained monomorphic ventricular tachycardia of right ventricul... more A 47-year-old man presented with sustained monomorphic ventricular tachycardia of right ventricular origin. Surface ECG recorded during sinus rhythm showed a bizarre &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;double QRS&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; pattern. Biventricular cardiomyopathy was found with predominant right ventricular involvement, due to cardiac sarcoidosis. Electroanatomic mapping was used to characterize the right ventricular substrate abnormalities and to decipher the specific activation abnormalities responsible for the ECG findings.
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