The Experts below are selected from a list of 486 Experts worldwide ranked by ideXlab platform
Anthony F. Dimarco - One of the best experts on this subject based on the ideXlab platform.
-
Phrenic Nerve stimulation in patients with spinal cord injury
Respiratory Physiology & Neurobiology, 2009Co-Authors: Anthony F. DimarcoAbstract:Phrenic Nerve Pacing (PNP) is a clinically useful technique to restore inspiratory muscle function in patients with respiratory failure secondary to cervical spinal cord injury. In this review, patient evaluation, equipment, methods of implementation, clinical outcomes, and the complications and side effects of PNP are discussed. Despite considerable technical development, and clinical success, however, current PNP systems have significant limitations. Even in patients with intact Phrenic Nerve function, PNP is successful in achieving full-time support in approximately 50% of patients. Inadequate inspired volume generation may arise secondary to incomplete diaphragm activation, reversed recruitment order of motor units, fiber type conversion resulting in reduced force generating capacity and lack of coincident intercostal muscle activation. A novel method of Pacing is under development which involves stimulating spinal cord tracts which synapse with the inspiratory motoneuron pools. This technique results in combined activation of the intercostal muscles and diaphragm in concert and holds promise to provide a more physiologic and effective method of PNP.
-
Phrenic Nerve stimulation in patients with spinal cord injury
Respiratory Physiology & Neurobiology, 2009Co-Authors: Anthony F. DimarcoAbstract:Phrenic Nerve Pacing (PNP) is a clinically useful technique to restore inspiratory muscle function in patients with respiratory failure secondary to cervical spinal cord injury. In this review, patient evaluation, equipment, methods of implementation, clinical outcomes, and the complications and side effects of PNP are discussed. Despite considerable technical development, and clinical success, however, current PNP systems have significant limitations. Even in patients with intact Phrenic Nerve function, PNP is successful in achieving full-time support in ∼50% of patients. Inadequate inspired volume generation may arise secondary to incomplete diaphragm activation, reversed recruitment order of motor units, fiber type conversion resulting in reduced force generating capacity and lack of coincident intercostal muscle activation. A novel method of Pacing is under development which involves stimulating spinal cord tracts which synapse with the inspiratory motoneuron pools. This technique results in combined activation of the intercostal muscles and diaphragm in concert and holds promise to provide a more physiologic and effective method of PNP.
-
respiratory dysfunction and management in spinal cord injury
Respiratory Care, 2006Co-Authors: Robert H Brown, Anthony F. Dimarco, Jeannette D Hoit, Eric GarshickAbstract:Respiratory dysfunction is a major cause of morbidity and mortality in spinal cord injury (SCI), which causes impairment of respiratory muscles, reduced vital capacity, ineffective cough, reduction in lung and chest wall compliance, and excess oxygen cost of breathing due to distortion of the respiratory system. Severely affected individuals may require assisted ventilation, which can cause problems with speech production. Appropriate candidates can sometimes be liberated from mechanical ventilation by Phrenic-Nerve Pacing and Pacing of the external intercostal muscles. Partial recovery of respiratory-muscle performance occurs spontaneously. The eventual vital capacity depends on the extent of spontaneous recovery, years since injury, smoking, a history of chest injury or surgery, and maximum inspiratory pressure. Also, respiratory-muscle training and abdominal binders improve performance of the respiratory muscles. For patients on long-term ventilation, speech production is difficult. Often, practitioners are reluctant to deflate the tracheostomy tube cuff to allow speech production. Yet cuff-deflation can be done safely. Standard ventilator settings produce poor speech quality. Recent studies demonstrated vast improvement with long inspiratory time and positive end-expiratory pressure. Abdominal binders improve speech quality in patients with Phrenic-Nerve pacers. Recent data show that the level and completeness of injury and older age at the time of injury may not be related directly to mortality in SCI, which suggests that the care of SCI has improved. The data indicate that independent predictors of all-cause mortality include diabetes mellitus, heart disease, cigarette smoking, and percent-of-predicted forced expiratory volume in the first second. An important clinical problem in SCI is weak cough, which causes retention of secretions during infections. Methods for secretion clearance include chest physical therapy, spontaneous cough, suctioning, cough assistance by forced compression of the abdomen (“quad cough”), and mechanical insufflation-exsufflation. Recently described but not yet available for general use is activation of the abdominal muscles via an epidural electrode placed at spinal cord level T9-L1.
-
Phrenic Nerve Pacing via intramuscular diaphragm electrodes in tetraplegic subjects
Chest, 2005Co-Authors: Raymond P Onders, Thomas J Mortimer, Krzysztof E Kowalski, Anthony F. Dimarco, Anthony R IgnagniAbstract:Context Diaphragm Pacing in ventilator-dependent tetraplegic subjects is usually achieved by the placement of Phrenic Nerve electrodes via thoracotomy. However, this technique may be accomplished less invasively via laparoscopic placement of IM electrodes, at a lower cost and with less risk of injury to the Phrenic Nerve. Objective To assess the feasibility of laparascopic placement of IM diaphragm electrodes to achieve long-term ventilatory support in ventilator-dependent tetraplegic subjects. Design, setting, and participants Two IM diaphragm electrodes were placed laparoscopically in each hemidiaphragm in five subjects with ventilator-dependent tetraplegia. Studies were performed either on an outpatient basis or with a single overnight hospitalization. Ventilator-dependent tetraplegic subjects were identified in whom bilateral Phrenic Nerve function was present, as determined by Phrenic Nerve conduction studies. Following electrode placement, subjects participated in a conditioning program to improve the strength and endurance of the diaphragm over a period of 15 to 25 weeks. The duration of the study was variable depending on the time necessary to determine the maximum duration that individuals could be maintained without mechanical ventilation support. Main outcome measures Magnitude of inspired volume generation and duration of ventilatory support with bilateral diaphragm Pacing alone. Results In four of the five subjects studied, initial bilateral diaphragm stimulation resulted in inspired volumes between 430 and 1,060 mL. Reconditioning of the diaphragm over several weeks resulted in substantial increases in inspired volumes to 1,100 to 1,240 mL. These subjects were comfortably maintained without mechanical ventilatory support for prolonged time periods by diaphragm Pacing, by full-time ventilatory support in three subjects, and 20 h per day, in the fourth subject. No response to stimulation was observed in one subject, most likely secondary to denervation atrophy. Conclusions Diaphragm Pacing in ventilator-dependent tetraplegic subjects can be successfully achieved via laparascopic placement of IM electrodes.
-
Phrenic Nerve Pacing in a tetraplegic patient via intramuscular diaphragm electrodes
American Journal of Respiratory and Critical Care Medicine, 2002Co-Authors: Anthony F. Dimarco, Raymond P Onders, Sandra Ferek, Michael E. Miller, Krzysztof E Kowalski, Thomas J MortimerAbstract:In patients with ventilator-dependent tetraplegia, Phrenic Nerve Pacing (PNP) provides significant clinical advantages compared with mechanical ventilation. This technique however generally requires a thoracotomy with its associated risks and in-patient hospital stay and carries some risk of Phrenic Nerve injury. We have developed a method by which the Phrenic Nerves can be activated via intramuscular diaphragm electrodes. In one patient with ventilator-dependent tetraplegia, two intramuscular diaphragm electrodes were implanted into each hemidiaphragm near the Phrenic Nerve motor points via laparoscopic surgery. The motor points were identified employing a previously devised mapping technique. Because inspired volumes were suboptimal on the right, a second laparoscopic procedure was necessary to position electrodes near the anterior and posterior branches of the right Phrenic Nerve. During bilateral stimulation, inspired volume was 580 ml. After a reconditioning program of progressively increasing diaphr...
Karlheinz Kuck - One of the best experts on this subject based on the ideXlab platform.
-
three dimensional reconstruction of the anatomic course of the right Phrenic Nerve in humans by pace mapping
Heart Rhythm, 2008Co-Authors: Boris Schmidt, Matthias Antz, Feifan Ouyang, K Julian R Chun, Andreas Metzner, Karlheinz KuckAbstract:Background Endocardial catheter ablation at the right atrial to superior vena cava junction or right pulmonary vein isolation, especially in balloon-guided procedures, is associated with risk for Phrenic Nerve palsy. Objective The purpose of this study was to obtain a three-dimensional reconstruction of the individual Phrenic Nerve course. Methods Electroanatomic reconstruction (CARTO, Biosense Webster) of the superior vena cava, right atrium, left atrium, and right superior and inferior PVs was performed. The Phrenic Nerve pace map was obtained using maximal stimulation output (10 V, 2.9 ms) and annotated on the three-dimensional map. Results Eighteen patients with paroxysmal atrial fibrillation (12 men and 6 women, mean age 61 ± 10 years) were included in the study. The Phrenic Nerve course was reconstructed over a mean craniocaudal length of 40 ± 17 mm (mediolateral 11 ± 4 mm). Median Phrenic Nerve distance to the right superior PV ostium was 12 mm (range 2–39 mm). The Phrenic Nerve could be captured in 16 of 18 patients but only in 7 of 18 patients from the right superior PV. The complete electroanatomic map was performed in 48 ± 23 minutes, including the Phrenic Nerve pace map (14 ± 6 min). Conclusion Pace mapping of the Phrenic Nerve using electroanatomic mapping can be performed within a reasonable time frame and provides important information on the true anatomic course of the Phrenic Nerve. The three-dimensional display of its position in relation to potential ablation targets may be of value in preventing Phrenic Nerve palsy, particularly when innovative ablation energies are used. However, Phrenic Nerve Pacing exclusively from the right superior PV appears insufficient to exclude a close anatomic relationship.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the antero-inferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Phrenic Nerve Palsy in AF Ablation Using Balloon. Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the anteroinferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.
Matthias Antz - One of the best experts on this subject based on the ideXlab platform.
-
three dimensional reconstruction of the anatomic course of the right Phrenic Nerve in humans by pace mapping
Heart Rhythm, 2008Co-Authors: Boris Schmidt, Matthias Antz, Feifan Ouyang, K Julian R Chun, Andreas Metzner, Karlheinz KuckAbstract:Background Endocardial catheter ablation at the right atrial to superior vena cava junction or right pulmonary vein isolation, especially in balloon-guided procedures, is associated with risk for Phrenic Nerve palsy. Objective The purpose of this study was to obtain a three-dimensional reconstruction of the individual Phrenic Nerve course. Methods Electroanatomic reconstruction (CARTO, Biosense Webster) of the superior vena cava, right atrium, left atrium, and right superior and inferior PVs was performed. The Phrenic Nerve pace map was obtained using maximal stimulation output (10 V, 2.9 ms) and annotated on the three-dimensional map. Results Eighteen patients with paroxysmal atrial fibrillation (12 men and 6 women, mean age 61 ± 10 years) were included in the study. The Phrenic Nerve course was reconstructed over a mean craniocaudal length of 40 ± 17 mm (mediolateral 11 ± 4 mm). Median Phrenic Nerve distance to the right superior PV ostium was 12 mm (range 2–39 mm). The Phrenic Nerve could be captured in 16 of 18 patients but only in 7 of 18 patients from the right superior PV. The complete electroanatomic map was performed in 48 ± 23 minutes, including the Phrenic Nerve pace map (14 ± 6 min). Conclusion Pace mapping of the Phrenic Nerve using electroanatomic mapping can be performed within a reasonable time frame and provides important information on the true anatomic course of the Phrenic Nerve. The three-dimensional display of its position in relation to potential ablation targets may be of value in preventing Phrenic Nerve palsy, particularly when innovative ablation energies are used. However, Phrenic Nerve Pacing exclusively from the right superior PV appears insufficient to exclude a close anatomic relationship.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the antero-inferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Phrenic Nerve Palsy in AF Ablation Using Balloon. Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the anteroinferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.
Seth H Sheldon - One of the best experts on this subject based on the ideXlab platform.
-
feasibility of left Phrenic Nerve Pacing during cryoballoon atrial fibrillation ablation
Journal of the American College of Cardiology, 2018Co-Authors: Tawseef Dar, Bharath Yarlagadda, Vaishnavi Veerapaneni, Donita Atkins, Seth H SheldonAbstract:Right Phrenic Nerve (PN) monitoring is the standard of care during cryoballoon ablation (CBA) for atrial fibrillation (AF). Several case reports of left Phrenic Nerve injury (PNI) have been reported. This can be a devastating complication if unrecognized and right-sided application results in
Feifan Ouyang - One of the best experts on this subject based on the ideXlab platform.
-
three dimensional reconstruction of the anatomic course of the right Phrenic Nerve in humans by pace mapping
Heart Rhythm, 2008Co-Authors: Boris Schmidt, Matthias Antz, Feifan Ouyang, K Julian R Chun, Andreas Metzner, Karlheinz KuckAbstract:Background Endocardial catheter ablation at the right atrial to superior vena cava junction or right pulmonary vein isolation, especially in balloon-guided procedures, is associated with risk for Phrenic Nerve palsy. Objective The purpose of this study was to obtain a three-dimensional reconstruction of the individual Phrenic Nerve course. Methods Electroanatomic reconstruction (CARTO, Biosense Webster) of the superior vena cava, right atrium, left atrium, and right superior and inferior PVs was performed. The Phrenic Nerve pace map was obtained using maximal stimulation output (10 V, 2.9 ms) and annotated on the three-dimensional map. Results Eighteen patients with paroxysmal atrial fibrillation (12 men and 6 women, mean age 61 ± 10 years) were included in the study. The Phrenic Nerve course was reconstructed over a mean craniocaudal length of 40 ± 17 mm (mediolateral 11 ± 4 mm). Median Phrenic Nerve distance to the right superior PV ostium was 12 mm (range 2–39 mm). The Phrenic Nerve could be captured in 16 of 18 patients but only in 7 of 18 patients from the right superior PV. The complete electroanatomic map was performed in 48 ± 23 minutes, including the Phrenic Nerve pace map (14 ± 6 min). Conclusion Pace mapping of the Phrenic Nerve using electroanatomic mapping can be performed within a reasonable time frame and provides important information on the true anatomic course of the Phrenic Nerve. The three-dimensional display of its position in relation to potential ablation targets may be of value in preventing Phrenic Nerve palsy, particularly when innovative ablation energies are used. However, Phrenic Nerve Pacing exclusively from the right superior PV appears insufficient to exclude a close anatomic relationship.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the antero-inferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.
-
ablation of atrial fibrillation in humans using a balloon based ablation system identification of the site of Phrenic Nerve damage using Pacing maneuvers and carto
Journal of Cardiovascular Electrophysiology, 2006Co-Authors: Matthias Antz, Kr Julian Chun, Feifan Ouyang, Karlheinz KuckAbstract:Phrenic Nerve Palsy in AF Ablation Using Balloon. Injury of the Phrenic Nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of Phrenic Nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous Phrenic Nerve Pacing maneuvers before and after ablation and showed that the Nerve was damaged at the level of the anteroinferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.