EP Characteristics in Familial WPW. Introduction: A familial form of Wolff-Parkinson-White syndro... more EP Characteristics in Familial WPW. Introduction: A familial form of Wolff-Parkinson-White syndrome (WPW) occurs in association with hypertrophic cardiomyopathy and intraventricular conduction ahnormalities. This syndrome, demonstrating autosomal dominant inheritance and segregating with a high degree of penetrance but variable expressivity, has been genetically linked to chromosome 7q3. The purpose of this study is to detail the electrophysiologic characteristics of accessory atrioventricular connections (AC) in four members of a kindred with this syndrome.Methods and Results: We clinically evaluated 32 members of a single kindred and identified 20 individuals with ventricular preexcitation, abnormal intraventricular conduction including complete AV block and/or ventricular hypertrophy, Genetic linkage analysis mapped the disease gene in this kindred to the chromosome 7q3 locus (maximum logarithm of the odds score = 6.88, θ= 0); recombination events in affected individuals reduced the genetic interval from 7 centimorgans (cM) to 5 cM. Electrophysiologic study of four individuals with preexcitation, identified seven AC (1 right sided, 3 septal, and 3 left sided). All four individuals had inducible orthodromic tachycardia; while three had multiple AC. Bidirectional conduction was demonstrated in 6 of 7 AC. Successful ablation was accomplished in 5 of 7 AC.Conclusion: The electrophysiologic characteristics and location of AC in family members having this complex cardiac phenotype are similar to those seen in individuals with isolated WPW. Identification of WPW in more than one family member should prompt clinical evaluation of relatives for additional findings of ventricular hypertrophy or conduction abnormalities.(J Cardiovasc Electrophysiol. Vol. 10, pp. 629-635, May 1999)
Objectives: The purpose of this study was to evaluate the efficacy of different therapeutic appro... more Objectives: The purpose of this study was to evaluate the efficacy of different therapeutic approaches for patients with a history of syncope and positive head-up tilt testing. Background: Head-up tilt testing has gained broad acceptance as a reliable diagnostic method for the assessment of patients with recurrent unexplained syncope. However, once the diagnosis is established, there is no consensus on the most appropriate treatment. In this respect, efficacy of drug therapy in preventing recurrence of symptoms in such patients is not entirely clear, and controversies exist regarding the need to confirm the effects of pharmacological interventions. Methods: Clinical follow-up was obtained in 303 patients with a history of syncope and positive head-up tilt testing. After the diagnostic head-up tilt, patients were assigned to different therapeutic approaches according to their preference or logistic impediments. Of 303 patients, 44 received empiric therapy, 210 were treated with medications proven effective during repeated head-up tilt testing, and 49 refused or discontinued medical therapy. The three groups were similar with regard to age, sex, and clinical presentation. The mean follow-up was 2.8 ±1.8 years. Among the patients treated according to head-up tilt guided therapy, 130 were on beta blockers, 35 on theophylline, 10 on ephedrine, 31 on disopyramide, and 4 on miscellaneous regimens. Empiric treatment consisted of beta blockers in 37 of 44 patients and other drugs in the remaining patients. Results: During the follow-up, recurrence of symptoms was experienced in 12 (6%) of the 210 patients receiving the head-up tilt guided therapy, 16 (36%) of 44 in the empiric therapy group, and 33 (67%) of 49 in the no therapy group. Recurrence of symptoms in patients on empiric or no therapy was significantly more frequent as compared to the head-up tilt guided therapy group (P<0.01). Conclusions: In patients with unexplained syncope and positive upright tilt testing, therapeutic strategies identified on the basis of response during head-up tilt have a more positive impact on the recurrence of symptoms during follow-up.
Journal of Interventional Cardiac Electrophysiology, 2004
Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complic... more Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complication, which can have a potentially catastrophic outcome. We describe a patient with random component failure, which occurred due to electrical overstress damage to the high voltage hybrid as a result of inappropriate arcing, as detected by the manufacturer. This in turn damaged other components in the device. This secondary damage caused the device to reset, emitting a constant tone. A high current state was created, thereby depleting the battery prematurely. The problem was promptly detected and rectified by ICD generator replacement.
ICD and Sedation. Implantation of implantable cardioverter defibrillators (ICDs) in the electroph... more ICD and Sedation. Implantation of implantable cardioverter defibrillators (ICDs) in the electrophysiology (EP) laboratory has been shown to be safe. However, general endotracheal anesthesia and/or administration of sedatives is mostly performed by anesthesiologists. In 53 patients undergoing ICD implantation in the EP laboratory, we prospectively assessed whether deep sedation without endotracheal intubation can be administered by nursing personnel under medical supervision. The mean patient age was 67 ± 7 years, and the mean ejection fraction was 32 ± 8%. All ICDs were placed in the abdomen requiring lead tunneling. Patients were monitored with pulse oximetry and noninvasive blood pressure recordings. The level of consciousness and vital signs were evaluated at 5-minute intervals. Deep sedation was induced with phenergan and midazolam and maintained with either meperidine or fentanyl. The mean doses given were as follows: phenergan 0.33 ± 0.15 mg/kg, midazolam 0.05 ± 0.03 mg/kg, meperidine 0.46 ± 0.10 mg/kg per hour, and fentanyl 1.94 ± 0.71 μg/kg per hour. None of the patients required intubation during or after the procedure. No death occurred and no patient had any recollection of the procedure. In three patients, O2 desaturation was easily managed by transient reversion of the effects of meperidine or fentanyl with naloxone. No patient experienced prolonged hospitalization after the implant (mean 2.4 ± 0.5 days). In conclusion: (1) adequate sedation for ICD implantation and testing can be administered safely by nursing staff in the EP lab; (2) optimum sedation protocols should include drugs easy to reverse in case of excessive respiratory depression; and (3) this may represent a more cost-effective approach to ICD implantation.
Objective: The goal of this study was to assess if tilt bears any impact on defibrillation effica... more Objective: The goal of this study was to assess if tilt bears any impact on defibrillation efficacy of biphasic shocks. Background: Although it has been shown that hiphasic waveform may increase the defibrillation efficacy, this pulsing method has not been as extensively studied in patients, and information regarding the effect of different tilts is lacking. Methods: This study consisted of two similar but distinct protocols including 33 patients undergoing transvenous defibriilator implant. In 17 patients (Part I) defibrillation threshold was obtained delivering biphasic waveforms with 50%, 65%, and 80% tilt in random fashion. Similarly, in 16 patients (Part II) testing of biphasic waveform with 40%, 50%, and 65% tilt was performed in random order. The electrode system used consisted of two transvenous leads and a subcutaneous patch in all 33 patients. Results: In Part I, tilt of 50% demonstrated a defibrillation threshold significantly lower than 65% tilt (7.5 ± 4.3 J vs 9.7 ± 5.0 J; P = 0.04) and 80% tilt (7.5 ± 4.3) vs 11.7 ± 5.9 J; P < 0.01). Similarly, 65% tilt provided a lower defibrillation threshold than 80% tilt (9.7 ± 5.0 J vs 11.7 ± 5.9 J; P = 0.02). In Part II, no significant difference was observed in terms of defibriilation threshold between 40% tilt and the two tilts of 50% and 65%. However, as in Part I, 50% tilt provided a significant reduction of the energy to defibrillate as compared to 65% tilt (6.3 ± 3.6 J vs 9.0 ± 4.8 J; P < 0.01). The 50% tilt resulted in better defibrillation efficacy than 65% tilt independent of the lead system used for testing (Medtronic Transvene and CPI Endotak-C). Conclusions: Biphasic shocks with 50% tilt required less energy for defibrillation than 40%, 65%, and 80% tilts. However, in the clinical setting a programmable tilt may be preferable to account for some patient-to-patient variability.
Several procedures performed in the electrophysiology laboratory (EP lab) require surgical manipu... more Several procedures performed in the electrophysiology laboratory (EP lab) require surgical manipulation and are lengthy. Patients undergoing such procedures usually receive general anesthesia or deep sedation administered by an anesthesiologist. In 536 consecutive procedures performed in the EP lab, we assessed the safety and efficacy of deep sedation administered under the direction of an electrophysiologist and in the absence of an anesthetist. Patients were monitored with pulse oximetry, noninvasive blood pressure recordings, and continuous ECGs. The level of consciousness and vital signs were evaluated at 5-minute intervals. Deep sedation was induced in 260 patients using midazolam, phenergan, and meperidine, then maintained with intermittent dosing of meperidine at the following mean doses: midazolam 0.031 ± 0.024 mg/kg; phenergan 0.314 ± 0.179 mg/kg; and meperidine 0.391 ± 0.167 mg/kg per hour. In the remaining 276 patients, deep sedation was induced with midazolam and fentanyl and maintained with a continuous infusion of fentanyl at a mean dose of 2.054 ± 1.43 μg/kg per hour. Fourteen patients experienced a transient reduction in oxygen saturation that was readily reversed following administration of naloxone. An additional 11 patients desaturated secondary to partial airway obstruction, which resolved after repositioning the head and neck. Fourteen patients experienced hypotension with fentanyl. All but one returned to baseline blood pressures following an infusion of normal saline. No patient required intubation and no death occurred. Only three patients had recollection of periprocedure events. No patient remembered experiencing pain with the procedure. Hospital stays were not prolonged as a result of the sedation used. In conclusion: (1) deep sedation during EP procedures can be administered safely under the guidance of the electrophysiologist without an anesthetist present; (2) the drugs used should be readily reversible in case of respiratory depression; and (3) this approach may reduce the overall cost of the procedures in the EP lab, maintaining adequate patient comfort.
WASE A., et.al.: Sensing Failure in a Tiered Therapy Implantable Cardioverter Defibrillator: Role... more WASE A., et.al.: Sensing Failure in a Tiered Therapy Implantable Cardioverter Defibrillator: Role of Auto Adjustable Gain. Implantable cardioverter defibrillators have an established role in the management of life-threatening tachyarrhythmias. These devices use sophisticated sensing circuitry to detect and promptly treat a vast majority of these arrhythmias. However, they are not foolproof. We report one case where the device failed to sense every other QRS complex during induced ventricular fibrillation due to marked electrical alterans. Thus, undersensing can be a potentially fatal problem despite the use of auto adjustable gain.
EP Characteristics in Familial WPW. Introduction: A familial form of Wolff-Parkinson-White syndro... more EP Characteristics in Familial WPW. Introduction: A familial form of Wolff-Parkinson-White syndrome (WPW) occurs in association with hypertrophic cardiomyopathy and intraventricular conduction ahnormalities. This syndrome, demonstrating autosomal dominant inheritance and segregating with a high degree of penetrance but variable expressivity, has been genetically linked to chromosome 7q3. The purpose of this study is to detail the electrophysiologic characteristics of accessory atrioventricular connections (AC) in four members of a kindred with this syndrome.Methods and Results: We clinically evaluated 32 members of a single kindred and identified 20 individuals with ventricular preexcitation, abnormal intraventricular conduction including complete AV block and/or ventricular hypertrophy, Genetic linkage analysis mapped the disease gene in this kindred to the chromosome 7q3 locus (maximum logarithm of the odds score = 6.88, θ= 0); recombination events in affected individuals reduced the genetic interval from 7 centimorgans (cM) to 5 cM. Electrophysiologic study of four individuals with preexcitation, identified seven AC (1 right sided, 3 septal, and 3 left sided). All four individuals had inducible orthodromic tachycardia; while three had multiple AC. Bidirectional conduction was demonstrated in 6 of 7 AC. Successful ablation was accomplished in 5 of 7 AC.Conclusion: The electrophysiologic characteristics and location of AC in family members having this complex cardiac phenotype are similar to those seen in individuals with isolated WPW. Identification of WPW in more than one family member should prompt clinical evaluation of relatives for additional findings of ventricular hypertrophy or conduction abnormalities.(J Cardiovasc Electrophysiol. Vol. 10, pp. 629-635, May 1999)
Objectives: The purpose of this study was to evaluate the efficacy of different therapeutic appro... more Objectives: The purpose of this study was to evaluate the efficacy of different therapeutic approaches for patients with a history of syncope and positive head-up tilt testing. Background: Head-up tilt testing has gained broad acceptance as a reliable diagnostic method for the assessment of patients with recurrent unexplained syncope. However, once the diagnosis is established, there is no consensus on the most appropriate treatment. In this respect, efficacy of drug therapy in preventing recurrence of symptoms in such patients is not entirely clear, and controversies exist regarding the need to confirm the effects of pharmacological interventions. Methods: Clinical follow-up was obtained in 303 patients with a history of syncope and positive head-up tilt testing. After the diagnostic head-up tilt, patients were assigned to different therapeutic approaches according to their preference or logistic impediments. Of 303 patients, 44 received empiric therapy, 210 were treated with medications proven effective during repeated head-up tilt testing, and 49 refused or discontinued medical therapy. The three groups were similar with regard to age, sex, and clinical presentation. The mean follow-up was 2.8 ±1.8 years. Among the patients treated according to head-up tilt guided therapy, 130 were on beta blockers, 35 on theophylline, 10 on ephedrine, 31 on disopyramide, and 4 on miscellaneous regimens. Empiric treatment consisted of beta blockers in 37 of 44 patients and other drugs in the remaining patients. Results: During the follow-up, recurrence of symptoms was experienced in 12 (6%) of the 210 patients receiving the head-up tilt guided therapy, 16 (36%) of 44 in the empiric therapy group, and 33 (67%) of 49 in the no therapy group. Recurrence of symptoms in patients on empiric or no therapy was significantly more frequent as compared to the head-up tilt guided therapy group (P<0.01). Conclusions: In patients with unexplained syncope and positive upright tilt testing, therapeutic strategies identified on the basis of response during head-up tilt have a more positive impact on the recurrence of symptoms during follow-up.
Journal of Interventional Cardiac Electrophysiology, 2004
Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complic... more Internal component failure of the Implantable Cardioverter Defibrillators (ICD) is a rare complication, which can have a potentially catastrophic outcome. We describe a patient with random component failure, which occurred due to electrical overstress damage to the high voltage hybrid as a result of inappropriate arcing, as detected by the manufacturer. This in turn damaged other components in the device. This secondary damage caused the device to reset, emitting a constant tone. A high current state was created, thereby depleting the battery prematurely. The problem was promptly detected and rectified by ICD generator replacement.
ICD and Sedation. Implantation of implantable cardioverter defibrillators (ICDs) in the electroph... more ICD and Sedation. Implantation of implantable cardioverter defibrillators (ICDs) in the electrophysiology (EP) laboratory has been shown to be safe. However, general endotracheal anesthesia and/or administration of sedatives is mostly performed by anesthesiologists. In 53 patients undergoing ICD implantation in the EP laboratory, we prospectively assessed whether deep sedation without endotracheal intubation can be administered by nursing personnel under medical supervision. The mean patient age was 67 ± 7 years, and the mean ejection fraction was 32 ± 8%. All ICDs were placed in the abdomen requiring lead tunneling. Patients were monitored with pulse oximetry and noninvasive blood pressure recordings. The level of consciousness and vital signs were evaluated at 5-minute intervals. Deep sedation was induced with phenergan and midazolam and maintained with either meperidine or fentanyl. The mean doses given were as follows: phenergan 0.33 ± 0.15 mg/kg, midazolam 0.05 ± 0.03 mg/kg, meperidine 0.46 ± 0.10 mg/kg per hour, and fentanyl 1.94 ± 0.71 μg/kg per hour. None of the patients required intubation during or after the procedure. No death occurred and no patient had any recollection of the procedure. In three patients, O2 desaturation was easily managed by transient reversion of the effects of meperidine or fentanyl with naloxone. No patient experienced prolonged hospitalization after the implant (mean 2.4 ± 0.5 days). In conclusion: (1) adequate sedation for ICD implantation and testing can be administered safely by nursing staff in the EP lab; (2) optimum sedation protocols should include drugs easy to reverse in case of excessive respiratory depression; and (3) this may represent a more cost-effective approach to ICD implantation.
Objective: The goal of this study was to assess if tilt bears any impact on defibrillation effica... more Objective: The goal of this study was to assess if tilt bears any impact on defibrillation efficacy of biphasic shocks. Background: Although it has been shown that hiphasic waveform may increase the defibrillation efficacy, this pulsing method has not been as extensively studied in patients, and information regarding the effect of different tilts is lacking. Methods: This study consisted of two similar but distinct protocols including 33 patients undergoing transvenous defibriilator implant. In 17 patients (Part I) defibrillation threshold was obtained delivering biphasic waveforms with 50%, 65%, and 80% tilt in random fashion. Similarly, in 16 patients (Part II) testing of biphasic waveform with 40%, 50%, and 65% tilt was performed in random order. The electrode system used consisted of two transvenous leads and a subcutaneous patch in all 33 patients. Results: In Part I, tilt of 50% demonstrated a defibrillation threshold significantly lower than 65% tilt (7.5 ± 4.3 J vs 9.7 ± 5.0 J; P = 0.04) and 80% tilt (7.5 ± 4.3) vs 11.7 ± 5.9 J; P < 0.01). Similarly, 65% tilt provided a lower defibrillation threshold than 80% tilt (9.7 ± 5.0 J vs 11.7 ± 5.9 J; P = 0.02). In Part II, no significant difference was observed in terms of defibriilation threshold between 40% tilt and the two tilts of 50% and 65%. However, as in Part I, 50% tilt provided a significant reduction of the energy to defibrillate as compared to 65% tilt (6.3 ± 3.6 J vs 9.0 ± 4.8 J; P < 0.01). The 50% tilt resulted in better defibrillation efficacy than 65% tilt independent of the lead system used for testing (Medtronic Transvene and CPI Endotak-C). Conclusions: Biphasic shocks with 50% tilt required less energy for defibrillation than 40%, 65%, and 80% tilts. However, in the clinical setting a programmable tilt may be preferable to account for some patient-to-patient variability.
Several procedures performed in the electrophysiology laboratory (EP lab) require surgical manipu... more Several procedures performed in the electrophysiology laboratory (EP lab) require surgical manipulation and are lengthy. Patients undergoing such procedures usually receive general anesthesia or deep sedation administered by an anesthesiologist. In 536 consecutive procedures performed in the EP lab, we assessed the safety and efficacy of deep sedation administered under the direction of an electrophysiologist and in the absence of an anesthetist. Patients were monitored with pulse oximetry, noninvasive blood pressure recordings, and continuous ECGs. The level of consciousness and vital signs were evaluated at 5-minute intervals. Deep sedation was induced in 260 patients using midazolam, phenergan, and meperidine, then maintained with intermittent dosing of meperidine at the following mean doses: midazolam 0.031 ± 0.024 mg/kg; phenergan 0.314 ± 0.179 mg/kg; and meperidine 0.391 ± 0.167 mg/kg per hour. In the remaining 276 patients, deep sedation was induced with midazolam and fentanyl and maintained with a continuous infusion of fentanyl at a mean dose of 2.054 ± 1.43 μg/kg per hour. Fourteen patients experienced a transient reduction in oxygen saturation that was readily reversed following administration of naloxone. An additional 11 patients desaturated secondary to partial airway obstruction, which resolved after repositioning the head and neck. Fourteen patients experienced hypotension with fentanyl. All but one returned to baseline blood pressures following an infusion of normal saline. No patient required intubation and no death occurred. Only three patients had recollection of periprocedure events. No patient remembered experiencing pain with the procedure. Hospital stays were not prolonged as a result of the sedation used. In conclusion: (1) deep sedation during EP procedures can be administered safely under the guidance of the electrophysiologist without an anesthetist present; (2) the drugs used should be readily reversible in case of respiratory depression; and (3) this approach may reduce the overall cost of the procedures in the EP lab, maintaining adequate patient comfort.
WASE A., et.al.: Sensing Failure in a Tiered Therapy Implantable Cardioverter Defibrillator: Role... more WASE A., et.al.: Sensing Failure in a Tiered Therapy Implantable Cardioverter Defibrillator: Role of Auto Adjustable Gain. Implantable cardioverter defibrillators have an established role in the management of life-threatening tachyarrhythmias. These devices use sophisticated sensing circuitry to detect and promptly treat a vast majority of these arrhythmias. However, they are not foolproof. We report one case where the device failed to sense every other QRS complex during induced ventricular fibrillation due to marked electrical alterans. Thus, undersensing can be a potentially fatal problem despite the use of auto adjustable gain.
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