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Sample records for radiofrequency cardiac catheter

  1. Radiation exposure to operator and patients during cardiac electrophysiology study, radiofrequency catheter ablation and cardiac device implantation procedures

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Cho, J. H.; Park, S. J.; Kim, J. S.; On, Y. K.; Huh, J.

    2015-10-01

    The purpose of this study was to measure the radiation exposure to operator and patient during cardiac electrophysiology study, radiofrequency catheter ablation and cardiac device implantation procedures and to calculate the allowable number of cases per year. We carried out 9 electrophysiology studies, 40 radiofrequency catheter ablation and 11 cardiac device implantation procedures. To measure occupational radiation dose and dose-area product (DAP), 13 photoluminescence glass dosimeters were placed at eyes (inside and outside lead glass), thyroids (inside and outside thyroid collar), chest (inside and outside lead apron), wrists, genital of the operator (inside lead apron), and 6 of photoluminescence glass dosimeters were placed at eyes, thyroids, chest and genital of the patient. Exposure time and DAP values were 11.7 ± 11.8 min and 23.2 ± 26.2 Gy cm2 for electrophysiology study; 36.5 ± 42.1 min and 822.4 ± 125.5 Gy cm2 for radiofrequency catheter ablation; 16.2 ± 9.3 min and 27.8 ± 16.5 Gy cm2 for cardiac device implantation procedure, prospectively. 4591 electrophysiology studies can be conducted within the occupational exposure limit for the eyes (150 mSv), and 658-electrophysiology studies with radiofrequency catheter ablation can be carried out within the occupational exposure limit for the hands (500 mSv). 1654 cardiac device implantation procedure can be conducted within the occupational exposure limit for the eyes (150 mSv). The amounts of the operator and patient's radiation exposure were comparatively small. So, electrophysiology study, radio frequency catheter ablation and cardiac device implantation procedures are safe when performed with modern equipment and optimized protective radiation protect equipment.

  2. An in vivo comparison of radiofrequency cardiac lesions formed by standard and magnetically steered 4 mm tip catheters

    PubMed Central

    Thornton, A.S.; De Castro, C.A. Brito; van Deel, E.; van Beusekom, H.M.M.; Jordaens, L.

    2010-01-01

    Background. In vivo comparison of cardiac radiofrequency ablation lesions between standard and magnetically steered 4 mm tip catheters has never been reported. Methods. High and low right atrium (RA) free wall, isthmus, right ventricle (RV) free wall and outflow tract lesions were studied macroscopically and microscopically five days after lesion formation in seven pigs. Shape, size, thrombus formation, and ablation parameters were compared. The effect of minimal, medium and high wall contact was assessed by a contact measurement utility for magnetic catheters. Results. All 14 RA free wall lesions were transmural with a similar epicardial and endocardial surface area. In the RV, the epicardial area usually appeared to be smaller than the endocardial area with standard catheters. Isthmus lesions were difficult to assess transmurality. There was no difference in endocardial area: standard 39 mm2 (range 16 to 82 mm2) vs. magnetic 36 mm2 (range 23 to 111 mm2). If the catheter tip was perpendicular to the tissue, magnetic lesions were more often round or oval, while standard lesions were more often elongated (p<0.05). When the catheter tip was parallel to tissue, lesions always tended to be elongated. Microscopic characteristics were similar. The contact utility was not useful. Average impedance (p<0.0001) and energy delivered (p<0.05) were less with magnetic catheters. Conclusion. Lesions from magnetically steered catheters are transmural of similar size, but with less variability than standard catheter lesions when the tip is perpendicular to the tissue. Magnetic lesions are associated with lower impedance and energy delivery. This suggests a more stable tip-to-tissue contact. (Neth Heart J 2010;18:66–71.) PMID:20200611

  3. Incidence and Factors Predicting Skin Burns at the Site of Indifferent Electrode during Radiofrequency Catheter Ablation of Cardiac Arrhythmias

    PubMed Central

    Ibrahim, Hussain; Finta, Bohuslav; Rind, Jubran

    2016-01-01

    Radiofrequency catheter ablation (RFA) has become a mainstay for treatment of cardiac arrhythmias. Skin burns at the site of an indifferent electrode patch have been a rare, serious, and likely an underreported complication of RFA. The purpose of this study was to determine the incidence of skin burns in cardiac RFA procedures performed at one institution. Also, we wanted to determine the factors predicting skin burns after cardiac RFA procedures at the indifferent electrode skin pad site. Methods. A retrospective case control study was performed to compare the characteristics in patients who developed skin burns in a 2-year period. Results. Incidence of significant skin burns after RFA was 0.28% (6/2167). Four of the six patients were female and all were Caucasians. Four controls for every case were age and sex matched. Burn patients had significantly higher BMI, procedure time, and postprocedure pain, relative to control subjects (p < 0.05, one-tailed testing). No one in either group had evidence of dispersive pad malattachment. Conclusions. Our results indicate that burn patients had higher BMI and longer procedure times compared to control subjects. These findings warrant further larger studies on this topic. PMID:27213077

  4. Contact Geometry Affects Lesion Formation in Radio-Frequency Cardiac Catheter Ablation

    PubMed Central

    Gallagher, Neal; Fear, Elise C.; Byrd, Israel A.; Vigmond, Edward J.

    2013-01-01

    One factor which may be important for determining proper lesion creation during atrial ablation is catheter-endocardial contact. Little information is available that relates geometric contact, depth and angle, to ablation lesion formation. We present an electrothermal computer model of ablation that calculated lesion volume and temperature development over time. The Pennes bioheat equation was coupled to a quasistatic electrical problem to investigate the effect of catheter penetration depth, as well as incident catheter angle as may occur in practice. Biological experiments were performed to verify the modelling of electrical phenomena. Results show that for deeply penetrating tips, acute catheter angles reduced the rate of temperature buildup, allowing larger lesions to form before temperatures elevated excessively. It was also found that greater penetration did not lead to greater transmurality of lesions. We conclude that catheter contact angle plays a significant role in lesion formation, and the time course must be considered. This is clinically relevant because proper identification and prediction of geometric contact variables could improve ablation efficacy. PMID:24086275

  5. Pulmonary Vein Stenosis Complicating Radiofrequency Catheter Ablation

    PubMed Central

    Lu, Hai-Wen; Wei, Ping; Jiang, Sen; Gu, Shu-yi; Fan, Li-Chao; liang, Shuo; Ji, Xiaobin; Rajbanshi, Bhavana; Xu, Jin-Fu

    2015-01-01

    Abstract The aim of this study is to characterize the clinical manifestations and features of pulmonary vein stenosis (PVS) by retrospectively analyzing clinical data of patients in addition to reviewing the literature simultaneously to improve the understanding of PVS complicating radiofrequency catheter ablation and to provide evidence for early diagnosis and timely treatment. Clinical, imaging, and follow-up data of 5 patients with PVS-complicating radiofrequency catheter ablation were retrospectively analyzed between January 2012 and December 2014 in Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. Relevant studies previously reported were also reviewed. Three out of 5 patients received pulmonary angiography. The initial symptoms were not specific, presenting chest pain in 3 cases, hemoptysis in 2 cases. The average duration between radiofrequency ablation to the onset of symptoms was 5.8 months. The chest image results were consolidation and pleural effusion mainly. Veins distributed in the left lungs were mostly influenced in 4 patients, and the inferior veins in 3 patients. Cardiac ultrasound examinations showed pulmonary arterial hypertension in 2 patients. Two patients received selective bronchial artery embolization after bronchial artery radiography because of hemoptysis. One patient underwent video-assisted thoracoscopic biopsy because of the suspicion of tumor. PVS is a condition mostly undetected because of its silent manifestations and inconsistent follow-up. The accurate clinical diagnosis is very difficult. A careful review of medical history and follow-up observation may be useful for all the patients who received the radiofrequency catheter ablation to recognize PVS in the early stage. PMID:26313772

  6. The use of radiofrequency catheter ablation to cure dilated cardiomyopathy.

    PubMed

    Schmidt, S B; Lobban, J H; Reddy, S; Hoelper, M; Palmer, D L

    1997-01-01

    Incessant supraventricular tachycardia can cause a dilated cardiomyopathy. This article discusses the case of a 55-year-old woman whose cardiomyopathy was reversed when she underwent successful radiofrequency catheter ablation of a unifocal atrial tachycardia. PMID:9197188

  7. A novel four-wire-driven robotic catheter for radio-frequency ablation treatment

    PubMed Central

    Kato, Takahisa; Song, Sang-Eun; Hata, Nobuhiko

    2014-01-01

    Purpose Robotic catheters have been proposed to increase the efficacy and safety of the radio-frequency ablation treatment. The robotized motion of current robotic catheters mimics the motion of manual ones—namely, deflection in one direction and rotation around the catheter. With the expectation that the higher dexterity may achieve further efficacy and safety of the robotically driven treatment, we prototyped a four-wire-driven robotic catheter with the ability to deflect in two- degree-of-freedom motions in addition to rotation. Methods A novel quad-directional structure with two wires was designed and developed to attain yaw and pitch motion in the robotic catheter. We performed a mechanical evaluation of the bendability and maneuverability of the robotic catheter and compared it with current manual catheters. Results We found that the four-wire-driven robotic catheter can achieve a pitching angle of 184.7° at a pulling distance of wire for 11mm, while the yawing angle was 170.4° at 11mm. The robotic catheter could attain the simultaneous two- degree-of-freedom motions in a simulated cardiac chamber. Conclusion The results indicate that the four-wire-driven robotic catheter may offer physicians the opportunity to intuitively control a catheter and smoothly approach the focus position that they aim to ablate. PMID:24510205

  8. Radiofrequency catheter ablation in pediatric patients with supraventricular arrhythmias.

    PubMed

    Rhodes, L A; Lobban, J H; Schmidt, S B

    1995-01-01

    Radiofrequency (RF) ablation of foci leading to abnormal cardiac rhythms is rapidly becoming the procedure of choice in the management of arrhythmias in adults. This report reviews our initial experience with RF ablation in the pediatric population. PMID:8533398

  9. Transcatheter radiofrequency ablation of atrial tissue using a suction catheter.

    PubMed

    Lavergne, T; Prunier, L; Cuize, L; Bruneval, P; Von Euw, D; Le Heuzey, J Y; Peronneau, P

    1989-01-01

    Closed chest ablative technique that avoid barotrauma would be attractive for ablation at thin walled cardiac structures, such as the atrial free wall or coronary sinus. Transcatheter radiofrequency (RF) currents produce tissue necrosis the size of which is dependent on the contact between the tissue and the electrode. In order to assess the effects of transvenous RF ablation of atrial free wall using a suction electrode catheter, we delivered in ten dogs, one single unmodulated RF pulse 1.2 MHz, in a unipolar mode, through the distal electrode of a lumen catheter (USCI 8F) (USCI, Billerica, MA USA) located in the right appendage. During the pulse an 80 KPa vacuum depression was applied to the lumen of the catheter. Each pulse had a 10 seconds duration and the mean delivered power was 4.3 +/- 1.4 W. Aortic pressure and electrocardiogram were monitored during the procedure. A right atrial electrophysiological study was performed at the ablated site, at control, after suction application and after RF pulse delivery. The animals were sacrificed after 14 or 21 days. Atrial pacing threshold values decreased after suction application in comparison to control values after the pulse (0.42 +/- 0.06 vs 0.60 +/- 0.23 mA, P less than O.05) but increased after the pulse delivery (2.60 +/- 1.85 mA, P less than 0.01). In contrast, the atrial effective refractory period did not significantly change after suction, nor after RF pulse delivery. Aortic pressure remained unchanged throughout the procedure. Complex arrhythmias were not observed during or after RF pulse delivery. One dog died suddenly at the first day after ablation, but this death was most probably unrelated to RF ablation. Anatomic lesions had a length of 8.8 +/- 3.3 mm, a width of 4.6 +/- 2.5 mm and a depth of 3.6 +/- 1.1 mm. They were transmural in nine of the ten dogs but without atrial wall perforation in any case. Lesions suggesting tissue volatilization were present in four dogs. These results demonstrate that

  10. Novel catheter enabling simultaneous radiofrequency ablation and optical coherence reflectometry

    PubMed Central

    Herranz, D.; Lloret, Juan; Jiménez-Valero, Santiago; Rubio-Guivernau, J. L.; Margallo-Balbás, Eduardo

    2015-01-01

    A novel radiofrequency ablation catheter has been developed with integrated custom designed optics, enabling real-time monitoring of radiofrequency ablation procedures through polarization-sensitive optical coherence reflectometry. The optics allow for proper tissue illumination through a view-port machined in the catheter tip, thus providing lesion depth control over the RF ablation treatment. The system was verified in an in-vitro model of swine myocardium. Optical performance and thermal stability was confirmed after more than 25 procedures, without any damage to the optical assembly induced by thermal stress or material degradation. The use of this catheter in RF ablation treatments may make possible to assess lesion depth during therapy, thus translating into a reduction of potential complications on the procedure. PMID:26417499

  11. Compensation for Unconstrained Catheter Shaft Motion in Cardiac Catheters

    PubMed Central

    Degirmenci, Alperen; Loschak, Paul M.; Tschabrunn, Cory M.; Anter, Elad; Howe, Robert D.

    2016-01-01

    Cardiac catheterization with ultrasound (US) imaging catheters provides real time US imaging from within the heart, but manually navigating a four degree of freedom (DOF) imaging catheter is difficult and requires extensive training. Existing work has demonstrated robotic catheter steering in constrained bench top environments. Closed-loop control in an unconstrained setting, such as patient vasculature, remains a significant challenge due to friction, backlash, and physiological disturbances. In this paper we present a new method for closed-loop control of the catheter tip that can accurately and robustly steer 4-DOF cardiac catheters and other flexible manipulators despite these effects. The performance of the system is demonstrated in a vasculature phantom and an in vivo porcine animal model. During bench top studies the robotic system converged to the desired US imager pose with sub-millimeter and sub-degree-level accuracy. During animal trials the system achieved 2.0 mm and 0.65° accuracy. Accurate and robust robotic navigation of flexible manipulators will enable enhanced visualization and treatment during procedures. PMID:27525170

  12. Ultraminiature manometer-tipped cardiac catheter

    NASA Technical Reports Server (NTRS)

    Coon, G. W.

    1967-01-01

    Miniature diaphragm-type capacitance transducer capable of being mounted on the end of a cardiac catheter has been developed for measurement of intravascular pressures. The transducer can be inserted in small ducts /arteries and veins/ without disturbing the flow characteristics. It is very useful for making measurements in babies.

  13. Teflon-buttressed sutures plus pericardium patch repair left ventricular rupture caused by radiofrequency catheter ablation

    PubMed Central

    Cao, Hao; Zhang, Qi; He, Yanzhong; Feng, Xiaodong; Liu, Zhongmin

    2016-01-01

    Abstract Background: Cardiac rupture often occurs after myocardial infarction or chest trauma with a high mortality rate. However, left ventricular rupture caused by radiofrequency catheter ablation (RFCA) is extremely rare. Methods: We describe a case of a 61-year-old male who survived from left ventricular rupture caused by a RFCA procedure for frequent ventricular premature contractions. Surgical exploration with cardiopulmonary bypass (CPB) was performed when the signs of cardiac tamponade developed 7 hours after the ablation surgery. Results: Teflon-buttressed sutures of the tear in the left ventricular posterolateral wall and pericardium patch applied to the contusion region on the wall repaired the rupture safely and effectively. Conclusion: Timely surgical intervention under CPB facilitated the survival of the patient. Teflon-buttressed sutures plus pericardium patch achieved the successful repair of the rupture. PMID:27661047

  14. Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in children

    PubMed Central

    Emmel, M.; Sreeram, N.

    2005-01-01

    Background The definitive therapeutic options for symptomatic obstructive cardiomyopathy in childhood are restricted. At present, extensive surgical myectomy is the only procedure that is of proven benefit. Patients and Methods Three patients, aged 5, 11 and 17 years, respectively, with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms were considered for radiofrequency catheter septal ablation. The peak Doppler gradient recorded on several occasions ranged between 50 to 90mmHg. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions were placed in the hypertrophied septum, taking care to stay away from the His bundle. A total of 17, 50 and 45 lesions were applied in the three patients. In one case, the procedure was complicated by two episodes of ventricular fibrillation requiring DC cardioversion but without any neurological sequelae. Results The preablation peak-to-peak gradient between left ventricle and aorta was 50 mmHg, 60 mmHg and 60 mmHg, respectively, and remained unchanged immediately after the procedure. All patients were discharged from hospital 48 hours later. Serial measurement of serum troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography both at seven days and at six weeks postablation confirmed a beneficial haemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms. Conclusion In young children, in whom alcohol-induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:25696442

  15. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    NASA Astrophysics Data System (ADS)

    Evtushenko, A. V.; Evtushenko, V. V.; Saushkina, Yu. V.; Lishmanov, Yu. B.; Pokushalov, E. A.; Sergeevichev, D. S.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Anfinogenova, Ya. D.; Smyshlyaev, K. A.; Lotkov, A. I.; Kurlov, I. O.

    2015-11-01

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using 123I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  16. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    SciTech Connect

    Evtushenko, A. V. Evtushenko, V. V.; Saushkina, Yu. V.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Smyshlyaev, K. A.; Kurlov, I. O.; Lishmanov, Yu. B.; Anfinogenova, Ya. D.; Sergeevichev, D. S.; Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V.; Lotkov, A. I.; Pokushalov, E. A.

    2015-11-17

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  17. Radiofrequency catheter ablation of Type 1 atrial flutter using a large-tip electrode catheter and high-power radiofrequency energy generator.

    PubMed

    Feld, Gregory K

    2004-11-01

    Recent studies have demonstrated a high degree of efficacy of 8 mm electrode-tipped or saline-irrigated-tip catheters for ablation of atrial flutter (AFL). These catheters have a theoretical advantage as they produce a large ablation lesion. However, large-tip ablation catheters have a larger surface area and require a higher power radiofrequency (RF) generator with up to 100 W capacity to produce adequate ablation temperatures (50-60 degrees C). The potential advantages of a large-tip ablation catheter and high-power RF generator include the need for fewer energy applications, shorter procedure and fluoroscopy times, and greater efficacy. Therefore, the safety and efficacy of AFL ablation using 8 or 10 mm electrode catheters and a 100-W RF generator was studied using the Boston Scientific, Inc., EPT-1000 XP cardiac ablation system. There were 169 patients, aged 61 +/- 12 years involved. Acute end points were bidirectional isthmus block and no inducible AFL. Following ablation, patients were seen at 1, 3 and 6 months, with event monitoring performed weekly and for any symptoms. Three quality of life surveys were completed during follow-up. Acute success was achieved in 158 patients (93%), with 12 +/- 11 RF energy applications. The efficacy of 8 and 10 mm electrodes did not differ significantly. The number of RF energy applications (10 +/- 8 vs. 14 +/- 8) and ablation time (0.5 +/- 0.4 vs. 0.8 +/- 0.6 h) were less with 10 mm compared with 8 mm electrodes (p < 0.01). Of 158 patients with acute success, 42 were not evaluated at 6 months due to study exclusions. Of the 116 patients evaluated at 6 months, 112 (97%) had no AFL recurrence. Of those without AFL recurrence at 6 months, 95 and 93% were free of symptoms at 12 and 24 months, respectively. Ablation of AFL improved quality of life scores (p < 0.05) and reduced anti-arrhythmic and rate control drug use (p < 0.05). Complications occurred in six out of 169 patients (3.6%) but there were no deaths. It was concluded

  18. Ultrasound catheters for circumferential cardiac ablation

    NASA Astrophysics Data System (ADS)

    Diederich, Chris J.; Nau, William H.; Taylor, Kevin; Maguire, Mark T.; Picazo, Guillermo; Gangu, Madhuri; Lesh, Michael D.

    1999-05-01

    The purpose of this study was to investigate performance characteristics of a catheter-based ultrasound applicator intended for circumferential ablation of cardiac tissue. The catheter design integrates a cylindrical ultrasound transducer within a distendable water filled balloon in order to produce circumferential lesions at sites in the atria (i.e., pulmonary vein ostia), intended for treatment of certain atrial arrhythmias. Biothermal simulations were used to investigate thermal lesion depths corresponding to variations in applied power, duration, balloon diameter, and acoustic efficiency. Prototype applicators of varying frequency (7 - 12 MHz) and balloon diameter were constructed and characterized using measurements of acoustic efficiency and rotational beam plots. In vitro studies were performed in freshly excised beef hearts to characterize the radial penetration, axial length, and angular uniformity of thermal lesions produced by these applicators. Selected applicators were tested in vivo within pulmonary veins, coronary sinus, and atrial appendage of canine and porcine hearts. These preliminary efforts have indicated that circumferential ablation of cardiac tissue using ultrasound balloon catheters is feasible, and devices between 7 - 12 MHz with balloon diameters of 1.5 - 2.0 cm are capable of producing uniform lesions between 1 - 5 mm depth or greater for treatment durations of 120 seconds or less.

  19. Catheter microwave ablation therapy for cardiac arrhythmias.

    PubMed

    Lin, J C

    1999-01-01

    This article describes three microwave catheter antennas for percutaneous cardiac ablation. A particular design feature of these antennas is that there is no reflected microwave current from the antenna flowing up the transmission line. Thus, it minimizes heating of the coaxial cable. The power reflection coefficients are very low (4% or less) in phantom equivalent materials. These antennas can also serve as bipolar electrodes for sensing endocardiac electrograms. Our studies in dogs, during both cardiopulmonary bypass and closed-chest operations via the femoral vein, have shown microwave energy greater than 200 joules (J) delivered to the heart through a split-tip dipole catheter antenna can produce irreversible block of the heart rhythms. This energy was achieved either by increasing the delivered power from 20 to 40 watts or by increasing the treatment duration from 7 to 11 s (210 to 330 J per application). It produced an endocardium temperature of about 65 degrees C. We found that the percutaneous, transcatheter microwave system is capable of inducing AV blocks consistently in dogs using the flexible, curved tip, split-tip catheter antenna. In addition, our studies have shown that the width and height of SAR distributions for cap-choke and split-tip catheter antennas are similar for the same antenna length. The cap-slot design had a much longer SAR distribution compared to the others. Moreover, a longer (4 mm) split-tip antenna can also induce larger lesions. These results suggest that it could be possible to ablate a ventricular tachycardia focus using the 4 mm split-tip as well as the cap-slot microwave catheter antennas. PMID:10334721

  20. Chronic incomplete atrioventricular block induced by radiofrequency catheter ablation

    SciTech Connect

    Huang, S.K.; Bharati, S.; Graham, A.R.; Gorman, G.; Lev, M. )

    1989-10-01

    To determine if catheter ablation of the atrioventricular (AV) junction with radiofrequency energy can induce chronic incomplete (first- and second-degree) AV block to avoid the need for a permanent pacemaker, 20 closed-chest dogs were studied. Group 1 (10 dogs) received radiofrequency energy (750 kHz) with a fixed power setting (5 or 10 W) while increasing the pulse duration from 10 to 50 seconds for each application. Group 2 (10 dogs) received energy with a fixed pulse duration (20 or 30 seconds) while increasing the power setting from 5 to 10 W or from 10 to 20 W during each energy delivery. Radiofrequency energy was delivered between a chest-patch electrode and the distal electrode of a regular 7F tripolar His bundle catheter. For each application, the energy delivery was interrupted when (1) the PR interval prolonged (greater than 50%) or (2) second-degree or complete AV block occurred and persisted up to 5 seconds. The ablation procedure ended when there was (1) persistent PR prolongation (greater than 50%) or persistent second-degree AV block (lasting greater than 30 minutes) after ablation, (2) occurrence of two consecutive transient (less than 1 minute) complete AV blocks after each energy delivery, or (3) complete AV block (lasting greater than 2 minutes) after ablation. Of seven dogs in group 1 and five dogs in group 2 in which incomplete AV block was achieved 1 hour after the procedure, six in group 1 and five in group 2 remained in incomplete AV block 2-3 months after ablation. One dog in group 1 progressed into complete AV block. Of the remaining three dogs in group 1 and five dogs in group 2 in which complete AV block was initially achieved 1 hour after ablation, two in group 1 and four in group 2 continued to have complete AV block, whereas one in each group had AV conduction returned to incomplete at 1-2 months of follow-up.

  1. Reversal of ventricular premature beat induced cardiomyopathy by radiofrequency catheter ablation.

    PubMed

    Blaauw, Y; Pison, L; van Opstal, J M; Dennert, R M; Heesen, W F; Crijns, H J G M

    2010-10-01

    Frequent monomorphic ventricular premature beats (VPBs) may lead to left ventricular dysfunction. We describe two patients with frequent monomorphic VPBs and dilated cardiomyopathy in whom left ventricular function normalised after elimination of the VPBs by radiofrequency catheter ablation. The recent literature on this topic is summarised and potential candidates for catheter ablation are discussed. (Neth Heart J 2010;18:493-8.).

  2. Integrated RFA/OCT catheter for real-time guidance of cardiac RFA therapy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Fu, Xiaoyong; Blumenthal, Colin; Dosluoglu, Deniz; Wang, Yves T.; Jenkins, Michael W.; Souza, Rakesh; Snyder, Christopher; Arruda, Mauricio; Rollins, Andrew M.

    2016-03-01

    Currently, cardiac radiofrequency ablation is guided by indirect signals. We demonstrate an integrated radiofrequency ablation (RFA) and optical coherence tomography (OCT) probe for directly monitoring of the RFA procedure with OCT images in real time. The integrated RFA/OCT probe is modified from a standard commercial RFA catheter, and a newly designed and fabricated miniature forward-viewing cone-scanning OCT probe is integrated into the modified probe. The OCT system is verified with the human finger images, and the results show the integrated RFA/OCT probe can acquire high quality OCT images. The radiofrequency energy delivering function of the integrated probe is verified by comparing the RFA lesion sizes with standard commercial RFA probe. For the standard commercial probe, the average width and depth of the 10 lesions were 3.5 mm and 1.8 mm respectively. For the integrated RFA/OCT probe, the average width and depth of the 10 lesions were 3.6 mm and 1.7 mm respectively. The lesions created by the two probes are indistinguishable in size. This demonstrates that our glass window in the integrated probe has little effect on the RF energy delivery. And the integrated probe is used to monitoring the cardiac RFA procedure in real time. The results show that the RFA lesion formation can be confirmed by the loss of birefringence in the heart tissue. The system can potentially in vivo image of the cardiac wall to aid RFA therapy for cardiac arrhythmias.

  3. Successful radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia in a patient with dextrocardia due to unilateral pulmonary agenesis: a case report

    PubMed Central

    Aksu, Tolga; Guler, Tumer Erdem; Golcuk, Ebru; Erden, Ismail; Ozcan, Kazım Serhan

    2015-01-01

    Radiofrequency catheter ablation of the slow pathway is considered to be the treatment of choice for patients with atrioventricular nodal reentrant tachycardia. We report a 34-year-old female with mirror image dextrocardia due to unilateral pulmonary agenesis who underwent successful slow pathway ablation for typical atrioventricular nodal reentrant tachycardia. Using contrast injection, cardiac anatomy was identified in a short time and successfully ablated. PMID:25674017

  4. Successful control of life-threatening polymorphic ventricular tachycardia by radiofrequency catheter ablation in an infant.

    PubMed

    Abe, Yuriko; Sumitomo, Naokata; Okuma, Hiromi; Nakamura, Takahiro; Fukuhara, Junji; Ichikawa, Rie; Matsumura, Masaharu; Miyashita, Michio; Kamiyama, Hiroshi; Ayusawa, Mamoru; Watanabe, Mamie; Joo, Kunitaka; Makita, Naomasa; Horie, Minoru

    2014-05-01

    We present a case of a 9-month-old girl in whom malignant polymorphic ventricular tachycardia (VT) was successfully controlled by radiofrequency catheter ablation under guidance with a three-dimensional mapping system. The VTs originated from the left ventricular lateral wall, left ventricular anterior wall, and left ventricular apex. At least six types of VTs were documented during the electrophysiology study. All VTs were successfully controlled after two sessions of radiofrequency catheter ablation, and she was discharged from our hospital on propranolol, mexiletine, flecainide, and aprindine. PMID:23836069

  5. Automated Pointing of Cardiac Imaging Catheters

    PubMed Central

    Loschak, Paul M.; Brattain, Laura J.; Howe, Robert D.

    2013-01-01

    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control. PMID:24683501

  6. Automated Pointing of Cardiac Imaging Catheters.

    PubMed

    Loschak, Paul M; Brattain, Laura J; Howe, Robert D

    2013-12-31

    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control.

  7. Pulmonary artery catheter entrapment in cardiac surgery: a simple percutaneous solution.

    PubMed

    Divakaran, Vijay; Caldera, Angel; Stephens, Jack; Gonzalez, Rafael

    2015-10-01

    Pulmonary artery catheter entrapment is a reported complication after cardiac surgery from inadvertent suturing of the catheter to the vena-caval wall during surgery. This article reports a simple percutaneous technique to retrieve the trapped catheter.

  8. Reversal of premature ventricular complex-induced cardiomyopathy following successful radiofrequency catheter ablation.

    PubMed

    Efremidis, Michalis; Letsas, Konstantinos P; Sideris, Antonios; Kardaras, Fotios

    2008-06-01

    Premature ventricular complex (PVC)-induced cardiomyopathy is an underappreciated cause of left-ventricular (LV) dysfunction. The present report describes the case of an elderly man with a very high burden of monomorphic PVCs and LV dysfunction. Elimination of the left ventricular focus following radiofrequency catheter ablation resulted in reversal of cardiomyopathy.

  9. Pulmonary vein stenosis complicating radiofrequency catheter ablation for atrial fibrillation: A literature review.

    PubMed

    Edriss, Hawa; Denega, Tatiana; Test, Victor; Nugent, Kenneth

    2016-08-01

    Radiofrequency catheter ablation has become a widely used intervention in the treatment of atrial fibrillation. Pulmonary vein stenosis (PVS) is one of the most serious complications associated with this procedure; the degree of stenosis ranges from mild (<50%) to complete venous occlusion. The natural history of PVS and the risk of progression of existing PVS are uncertain. Symptomatic and/or severe PVS is a serious medical problem and can be easily misdiagnosed since it is an uncommon and relatively new medical problem, often has low clinical suspicion among clinicians, and has a non-specific presentation that mimics other more common respiratory or cardiac diseases. The estimated incidence varies in literature reports from 0% to 42% of ablation procedures, depending on technical aspects of the procedure and operator skill. Most patients with significant PVS remain asymptomatic or have few symptoms. Symptomatic patients usually present with dyspnea, chest pain, or hemoptysis and are usually treated with balloon angioplasty and/or stent placement. Little is known about the long term effect of PV stenosis/occlusion on the pulmonary circulation and the development of pulmonary hypertension. Evolving technology may reduce the frequency of this complication, but long term studies are needed to understand the effect of therapeutic atrial injury and adverse outcomes. This review summarizes the current literature and outlines an approach to the evaluation and management of these patients. PMID:27492534

  10. Value of Implantable Loop Recorders in Monitoring Efficacy of Radiofrequency Catheter Ablation in Atrial Fibrillation

    PubMed Central

    Yang, Ping; Pu, Lijin; Yang, Liuqing; Li, Fang; Luo, Zhiling; Guo, Tao; Hua, Baotong; Li, Shumin

    2016-01-01

    Background The aim of this study was to evaluate the value of the implantable loop recorder (ILR) in diagnosing atrial fibrillation (AF) and assessing the postoperative efficacy of radiofrequency catheter ablation (RFCA). Material/Methods A total of 32 patients who successfully underwent RFCA were selected. These patients discontinued antiarrhythmic medication with no AF recurrence for more than 3 months after RFCA, and underwent ILR placement by a conventional method. The clinical manifestations and information on arrhythmias recorded by the ILR were followed up to assess the efficacy of AF RFCA. Results The mean follow-up period was 24.7±12.5 months. Of 32 patients with ILR information, 27 had successful RFCA and 5 had recurrent AF. The follow-up results obtained by traditional methods showed 29 patients with successful RFCA and 3 with recurrent AF (P<0.05). Among the 18 patients with clinical symptoms, 13 had recorded cardiac arrhythmic events (72.2%) and 5 showed sinus rhythm (27.8%). The ILRs recorded 18 patients with arrhythmic events (56.3%), including 12 cases of atrial arrhythmias, among whom 5 recurred at 9, 12, 16, 17, and 32 months after AF RFCA; there were also 2 patients with ventricular tachycardia (VT) and 4 with bradycardia. Conclusions The value of ILR in assessing the efficacy of AF RFCA was superior to that of traditional methods. ILR can promptly detect asymptomatic AF, and can monitor electrocardiogram features after RFCA, thus providing objective evidence of efficacy. PMID:27518153

  11. Color Doppler Imaging of Cardiac Catheters Using Vibrating Motors

    PubMed Central

    Reddy, Kalyan E.; Light, Edward D.; Rivera, Danny J.; Kisslo, Joseph A.; Smith, Stephen W.

    2010-01-01

    We attached a miniature motor rotating at 11,000 rpm onto the proximal end of cardiac electrophysiological (EP) catheters in order to produce vibrations at the tip which were then visualized by color Doppler on ultrasound scanners. We imaged the catheter tip within a vascular graft submerged in a water tank using the Volumetrics Medical Imaging 3D scanner, the Siemens Sonoline Antares 2D scanner, and the Philips ie33 3D ultrasound scanner with TEE probe. The vibrating catheter tip was visualized in each case though results varied with the color Doppler properties of the individual scanner. PMID:19514134

  12. [Cardiac tamponade after withdrawal of a peripheral access central catheter].

    PubMed

    García-Galiana, E; Sanchis-Gil, V; Martínez-Navarrete, M Á

    2015-03-01

    Central venous catheterization is a very common technique, although its complications can be multiple and sometimes fatal. A case is presented of cardiac tamponade by parenteral nutrition a few hours after moving a central venous catheter peripherally inserted a few days before. The diagnosis was made by echocardiography, and an emergency pericardiocentesis was performed, achieving complete recovery of the patient. Peripherally inserted central venous catheters are more likely to change their position secondary to the movements of the patient's arm, thus it is important to use soft catheters, make sure the tip lies above the carina to avoid perforation of the pericardial reflexion, and fix it well to the skin. Diagnosis must be made as soon as possible, given the high mortality rate of this complication, and the essential diagnostic tool is echocardiography. Elective treatment consists of early catheter withdrawal and emergency pericardiocentesis.

  13. Cardiac ablation catheter guidance by means of a single equivalent moving dipole inverse algorithm

    PubMed Central

    Lee, Kichang; Lv, Wener; Ter-Ovanesyan, Evgeny; Barley, Maya E.; Voysey, Graham E.; Galea, Anna; Hirschman, Gordon; LeRoy, Kristen; Marini, Robert P.; Barrett, Conor; Armoundas, Antonis A.; Cohen, Richard J.

    2015-01-01

    We developed and evaluated a novel system for guiding radio-frequency catheter ablation therapy of ventricular tachycardia. This guidance system employs an Inverse Solution Guidance Algorithm (ISGA) utilizing a single equivalent moving dipole (SEMD) localization method. The method and system were evaluated in both a saline-tank phantom model and in-vivo animal (swine) experiments. A catheter with two platinum electrodes spaced 3 mm apart was used as the dipole source in the phantom study. A 40 Hz sinusoidal signal was applied to the electrode pair. In the animal study, four to eight electrodes were sutured onto the right ventricle. These electrodes were connected to a stimulus generator delivering one millisecond duration pacing pulses. Signals were recorded from 64 electrodes, located either on the inner surface of the saline-tank or the body surface of the pig, and then processed by the ISGA to localize the physical or bioelectrical SEMD. In the phantom studies, the guidance algorithm was used to advance a catheter tip to the location of the source dipole. The distance from the final position of the catheter tip to the position of the target dipole was 2.22 ± 0.78 mm in real space and 1.38± 0.78 mm in image space (computational space). The ISGA successfully tracked the locations of electrodes sutured on the ventricular myocardium and the movement of an endocardial catheter placed in the animal’s right ventricle. In conclusion, we successfully demonstrated the feasibility of using a SEMD inverse algorithm to guide a cardiac ablation catheter. PMID:23448231

  14. New-onset ventricular arrhythmias post radiofrequency catheter ablation for atrial fibrillation

    PubMed Central

    Wu, Lingmin; Lu, Yanlai; Yao, Yan; Zheng, Lihui; Chen, Gang; Ding, Ligang; Hou, Bingbo; Qiao, Yu; Sun, Wei; Zhang, Shu

    2016-01-01

    Abstract As a new complication, new-onset ventricular arrhythmias (VAs) post atrial fibrillation (AF) ablation have not been well defined. This prospective study aimed to describe the details of new-onset VAs post AF ablation in a large study cohort. One thousand fifty-three consecutive patients who underwent the first radiofrequency catheter ablation for AF were enrolled. All patients had no evidence of pre-ablation VAs. New-onset VAs were defined as new-onset ventricular tachycardia (VT) or premature ventricular contractions (PVC) ≥1000/24 h within 1 month post ablation. There were 46 patients (4.4%) who had 62 different new-onset VAs, among whom 42 were PVC alone, and 4 were PVC coexisting with nonsustained VT. Multivariate analysis showed that increased serum leukocyte counts ≥50% post ablation were independently associated with new-onset VAs (OR: 1.9; 95% CI: 1.0–3.5; P = 0.043). The median number of PVC was 3161 (1001–27,407) times/24 h. Outflow tract VAs were recorded in 35 (76.1%) patients. No significant differences were found in origin of VAs (P = 0.187). VAs disappeared without any treatment in 6 patients (13.0%). No VAs-related adverse cardiac event occurred. The study revealed a noticeable prevalence but relatively benign prognosis of new-onset VAs post AF ablation. Increased serum leukocyte counts ≥50% post ablation appeared to be associated with new-onset VAs, implying that inflammatory response caused by ablation might be the mechanism. PMID:27603357

  15. New-onset ventricular arrhythmias post radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Wu, Lingmin; Lu, Yanlai; Yao, Yan; Zheng, Lihui; Chen, Gang; Ding, Ligang; Hou, Bingbo; Qiao, Yu; Sun, Wei; Zhang, Shu

    2016-09-01

    As a new complication, new-onset ventricular arrhythmias (VAs) post atrial fibrillation (AF) ablation have not been well defined. This prospective study aimed to describe the details of new-onset VAs post AF ablation in a large study cohort.One thousand fifty-three consecutive patients who underwent the first radiofrequency catheter ablation for AF were enrolled. All patients had no evidence of pre-ablation VAs. New-onset VAs were defined as new-onset ventricular tachycardia (VT) or premature ventricular contractions (PVC) ≥1000/24 h within 1 month post ablation.There were 46 patients (4.4%) who had 62 different new-onset VAs, among whom 42 were PVC alone, and 4 were PVC coexisting with nonsustained VT. Multivariate analysis showed that increased serum leukocyte counts ≥50% post ablation were independently associated with new-onset VAs (OR: 1.9; 95% CI: 1.0-3.5; P = 0.043). The median number of PVC was 3161 (1001-27,407) times/24 h. Outflow tract VAs were recorded in 35 (76.1%) patients. No significant differences were found in origin of VAs (P = 0.187). VAs disappeared without any treatment in 6 patients (13.0%). No VAs-related adverse cardiac event occurred.The study revealed a noticeable prevalence but relatively benign prognosis of new-onset VAs post AF ablation. Increased serum leukocyte counts ≥50% post ablation appeared to be associated with new-onset VAs, implying that inflammatory response caused by ablation might be the mechanism. PMID:27603357

  16. Toward guidance of epicardial cardiac radiofrequency ablation therapy using optical coherence tomography

    PubMed Central

    Fleming, Christine P.; Quan, Kara J.; Rollins, Andrew M.

    2010-01-01

    Radiofrequency ablation (RFA) is the standard of care to cure many cardiac arrhythmias. Epicardial ablation for the treatment of ventricular tachycardia has limited success rates due in part to the presence of epicardial fat, which prevents proper rf energy delivery, inadequate contact of ablation catheter with tissue, and increased likelihood of complications with energy delivery in close proximity to coronary vessels. A method to directly visualize the epicardial surface during RFA could potentially provide feedback to reduce complications and titrate rf energy dose by detecting critical structures, assessing probe contact, and confirming energy delivery by visualizing lesion formation. Currently, there is no technology available for direct visualization of the heart surface during epicardial RFA therapy. We demonstrate that optical coherence tomography (OCT) imaging has the potential to fill this unmet need. Spectral domain OCT at 1310 nm is employed to image the epicardial surface of freshly excised swine hearts using a microscope integrated bench-top scanner and a forward imaging catheter probe. OCT image features are observed that clearly distinguish untreated myocardium, ablation lesions, epicardial fat, and coronary vessels, and assess tissue contact with catheter-based imaging. These results support the potential for real-time guidance of epicardial RFA therapy using OCT imaging. PMID:20799788

  17. Toward guidance of epicardial cardiac radiofrequency ablation therapy using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Fleming, Christine P.; Quan, Kara J.; Rollins, Andrew M.

    2010-07-01

    Radiofrequency ablation (RFA) is the standard of care to cure many cardiac arrhythmias. Epicardial ablation for the treatment of ventricular tachycardia has limited success rates due in part to the presence of epicardial fat, which prevents proper rf energy delivery, inadequate contact of ablation catheter with tissue, and increased likelihood of complications with energy delivery in close proximity to coronary vessels. A method to directly visualize the epicardial surface during RFA could potentially provide feedback to reduce complications and titrate rf energy dose by detecting critical structures, assessing probe contact, and confirming energy delivery by visualizing lesion formation. Currently, there is no technology available for direct visualization of the heart surface during epicardial RFA therapy. We demonstrate that optical coherence tomography (OCT) imaging has the potential to fill this unmet need. Spectral domain OCT at 1310 nm is employed to image the epicardial surface of freshly excised swine hearts using a microscope integrated bench-top scanner and a forward imaging catheter probe. OCT image features are observed that clearly distinguish untreated myocardium, ablation lesions, epicardial fat, and coronary vessels, and assess tissue contact with catheter-based imaging. These results support the potential for real-time guidance of epicardial RFA therapy using OCT imaging.

  18. Optoacoustic monitoring of real-time lesion formation during radiofrequency catheter ablation

    NASA Astrophysics Data System (ADS)

    Pang, Genny A.; Bay, Erwin; Deán-Ben, Xosé L.; Razansky, Daniel

    2015-03-01

    Current radiofrequency cardiac ablation procedures lack real-time lesion monitoring guidance, limiting the reliability and efficacy of the treatment. The objective of this work is to demonstrate that optoacoustic imaging can be applied to develop a diagnostic technique applicable to radiofrequency ablation for cardiac arrhythmia treatment with the capabilities of real-time monitoring of ablated lesion size and geometry. We demonstrate an optoacoustic imaging method using a 256-detector optoacoustic imaging probe and pulsed-laser illumination in the infrared wavelength range that is applied during radiofrequency ablation in excised porcine myocardial tissue samples. This technique results in images with high contrast between the lesion volume and unablated tissue, and is also capable of capturing time-resolved image sequences that provide information on the lesion development process. The size and geometry of the imaged lesion were shown to be in excellent agreement with the histological examinations. This study demonstrates the first deep-lesion real-time monitoring for radiofrequency ablation generated lesions, and the technique presented here has the potential for providing critical feedback that can significantly impact the outcome of clinical radiofrequency ablation procedures.

  19. In vitro assessment of a combined radiofrequency ablation and cryo-anchoring catheter for treatment of mitral valve prolapse.

    PubMed

    Boronyak, Steven M; Merryman, W David

    2014-03-21

    Percutaneous approaches to mitral valve repair are an attractive alternative to surgical repair or replacement. Radiofrequency ablation has the potential to approximate surgical leaflet resection by using resistive heating to reduce leaflet size, and cryogenic temperatures on a percutaneous catheter can potentially be used to reversibly adhere to moving mitral valve leaflets for reliable application of radiofrequency energy. We tested a combined cryo-anchoring and radiofrequency ablation catheter using excised porcine mitral valves placed in a left heart flow loop capable of reproducing physiologic pressure and flow waveforms. Transmitral flow and pressure were monitored during the cryo-anchoring procedure and compared to baseline flow conditions, and the extent of radiofrequency energy delivery to the mitral valve was assessed post-treatment. Long term durability of radiofrequency ablation treatment was assessed using statically treated leaflets placed in a stretch bioreactor for four weeks. Transmitral flow and pressure waveforms were largely unaltered during cryo-anchoring. Parameter fitting to mechanical data from leaflets treated with radiofrequency ablation and cryo-anchoring revealed significant mechanical differences from untreated leaflets, demonstrating successful ablation of mitral valves in a hemodynamic environment. Picrosirius red staining showed clear differences in morphology and collagen birefringence between treated and untreated leaflets. The durability study indicated that statically treated leaflets did not significantly change size or mechanics over four weeks. A cryo-anchoring and radiofrequency ablation catheter can adhere to and ablate mitral valve leaflets in a physiologic hemodynamic environment, providing a possible percutaneous alternative to surgical leaflet resection of mitral valve tissue.

  20. Cardiac tissue ablation with catheter-based microwave heating.

    PubMed

    Rappaport, C

    2004-11-01

    The common condition of atrial fibrillation is often treated by cutting diseased cardiac tissue to disrupt abnormal electrical conduction pathways. Heating abnormal tissue with electromagnetic power provides a minimally invasive surgical alternative to treat these cardiac arrhythmias. Radio frequency ablation has become the method of choice of many physicians. Recently, microwave power has also been shown to have great therapeutic benefit in medical treatment requiring precise heating of biological tissue. Since microwave power tends to be deposited throughout the volume of biological media, microwave heating offers advantages over other heating modalities that tend to heat primarily the contacting surface. It is also possible to heat a deeper volume of tissue with more precise control using microwaves than with purely thermal conduction or RF electrode heating. Microwave Cardiac Ablation (MCA) is used to treat heart tissue that allows abnormal electrical conduction by heating it to the point of inactivation. Microwave antennas that fit within catheter systems can be positioned close to diseased tissue. Specialized antenna designs that unfurl from the catheter within the heart can then radiate specifically shaped fields, which overcome problems such as excessive surface heating at the contact point. The state of the art in MCA is reviewed in this paper and a novel catheter-based unfurling wide aperture antenna is described. This antenna consists of the centre conductor of a coaxial line, shaped into a spiral and insulated from blood and tissue by a non-conductive fluid filled balloon. Initially stretched straight inside a catheter for transluminal guiding, once in place at the cardiac target, the coiled spiral antenna is advanced into the inflated balloon. Power is applied in the range of 50-150 W at the reserved industrial, scientific and medical (ISM) frequency of 915 MHz for 30-90 s to create an irreversible lesion. The antenna is then retracted back into the

  1. [Infectious mitral endocarditis after radiofrequency catheter ablation of a left lateral accessory pathway].

    PubMed

    Benito Bartolomé, F; Sánchez Fernández-Bernal, C

    2001-08-01

    A 2-years-old child with Wolff-Parkinson-White syndrome associated with life-threatening symptoms underwent radiofrequency ablation of a left lateral accessory pathway. A deflectable 5F bipolar electrode catheter positioned above the atrioventricular groove by transeptal approach was used for ablation. The catheters were repeatedly used after ethylene oxide sterilisation. Although immediate post-ablation echocardiography demonstrated no complications, the patient was readmitted two days later with fever and a new mitral murmur. Penicillin-susceptible Staphylococcus aureus was isolated and intravenous antibiotics were administered. In the following weeks, the patient developed constrictive pericarditis requiring surgical treatment and acute hemiplegia caused by brain embolism arising from valvular vegetation. At 5 years of follow-up the patient presents residual hemiparesia and grade II/IV mitral insufficiency. PMID:11481116

  2. PATH OPTIMIZATION AND CONTROL OF A SHAPE MEMORY ALLOY ACTUATED CATHETER FOR ENDOCARDIAL RADIOFREQUENCY ABLATION

    PubMed Central

    Wiest, Jennifer H.; Buckner, Gregory D.

    2014-01-01

    This paper introduces a real-time path optimization and control strategy for shape memory alloy (SMA) actuated cardiac ablation catheters, potentially enabling the creation of more precise lesions with reduced procedure times and improved patient outcomes. Catheter tip locations and orientations are optimized using parallel genetic algorithms to produce continuous ablation paths with near normal tissue contact through physician-specified points. A nonlinear multivariable control strategy is presented to compensate for SMA hysteresis, bandwidth limitations, and coupling between system inputs. Simulated and experimental results demonstrate efficient generation of ablation paths and optimal reference trajectories. Closed-loop control of the SMA-actuated catheter along optimized ablation paths is validated experimentally. PMID:25684857

  3. Initial outcome following invasive cardiac electrophysiologic studies and radiofrequency ablation of atrial fibrillation

    PubMed Central

    Uwanuruochi, Kelechukwu; Saravanan, Sabari; Ganasekar, Anita; Solomon, Benjamin S; Murugesan, Ravikumar; Shah, Ruchit A; Krishnamoorthy, Jaishankar; Pandurangi, Ulhas M

    2016-01-01

    Background: Cardiac electrophysiologic study and radiofrequency ablation (RFA) have become an established mode of treatment for patients with refractory arrhythmias. These procedures are carried out regularly at the cardiac catheterization laboratory of Madras Medical Mission India. Objective: The purpose of this study was to evaluate our experience with cardiac electrophysiologic studies (EPS) and RFA catheter of atrial fibrillation (AF). Materials and Methods: This was a retrospective study carried out in the Cardiac Electrophysiology Department of the Institute of Cardiovascular Diseases, Madras Medical Mission, India. All cases diagnosed to have AF following cardiac EPS between January 2010 and April 2014 was selected for the study. The records, which were obtained from the Cardiac Electrophysiology Clinical Research Office of Madras Medical Mission, were reviewed. Forty-nine cases were chosen for analysis, using SPSS statistical software version 15. Results: There were 49 patients, 23 males and 26 females. The mean age was 57.53 years. Commonly associated diseases were diabetes mellitus 8 (16.3%), hypertension 18 (36.7%), and coronary heart disease 14 (28.5%). The ventricular rate was rapid most cases (91.2%). AF was diagnosed as being paroxysmal in 40 (81.6%), persistent in 5 (10.2%), chronic in 3 (6.1%), and lone in 1 (2.0%). Ablation was carried out in 28 (57.1%), the success rate being 90% for pulmonary vein isolation, and 90.9% for atrioventricular node ablation. Complication rate was 2.04%. Conclusions: Treatment of AF by RFA is highly effective and safe. PMID:27127736

  4. Permanent catheter drainage system for palliation of diuretic‐resistant cardiac ascites

    PubMed Central

    Penn, Lee‐Anne; Mitchell, Andrew R. J.

    2016-01-01

    Abstract We report the case of a 69‐year‐old man with dilated cardiomyopathy treated with a permanent catheter drainage system for diuretic resistant cardiac ascites. At 1 year follow‐up, the patient had no heart failure related hospitalisations, displayed improved quality of life measures and had incurred no complications related to the catheter. Permanent tunnelled catheters are widely used to treat malignant ascites but may also be considered for palliation of cardiac ascites.

  5. Computational Modeling of Open-Irrigated Electrodes for Radiofrequency Cardiac Ablation Including Blood Motion-Saline Flow Interaction.

    PubMed

    González-Suárez, Ana; Berjano, Enrique; Guerra, Jose M; Gerardo-Giorda, Luca

    2016-01-01

    Radiofrequency catheter ablation (RFCA) is a routine treatment for cardiac arrhythmias. During RFCA, the electrode-tissue interface temperature should be kept below 80 °C to avoid thrombus formation. Open-irrigated electrodes facilitate power delivery while keeping low temperatures around the catheter. No computational model of an open-irrigated electrode in endocardial RFCA accounting for both the saline irrigation flow and the blood motion in the cardiac chamber has been proposed yet. We present the first computational model including both effects at once. The model has been validated against existing experimental results. Computational results showed that the surface lesion width and blood temperature are affected by both the electrode design and the irrigation flow rate. Smaller surface lesion widths and blood temperatures are obtained with higher irrigation flow rate, while the lesion depth is not affected by changing the irrigation flow rate. Larger lesions are obtained with increasing power and the electrode-tissue contact. Also, larger lesions are obtained when electrode is placed horizontally. Overall, the computational findings are in close agreement with previous experimental results providing an excellent tool for future catheter research.

  6. Computational Modeling of Open-Irrigated Electrodes for Radiofrequency Cardiac Ablation Including Blood Motion-Saline Flow Interaction

    PubMed Central

    González-Suárez, Ana; Berjano, Enrique; Guerra, Jose M.; Gerardo-Giorda, Luca

    2016-01-01

    Radiofrequency catheter ablation (RFCA) is a routine treatment for cardiac arrhythmias. During RFCA, the electrode-tissue interface temperature should be kept below 80°C to avoid thrombus formation. Open-irrigated electrodes facilitate power delivery while keeping low temperatures around the catheter. No computational model of an open-irrigated electrode in endocardial RFCA accounting for both the saline irrigation flow and the blood motion in the cardiac chamber has been proposed yet. We present the first computational model including both effects at once. The model has been validated against existing experimental results. Computational results showed that the surface lesion width and blood temperature are affected by both the electrode design and the irrigation flow rate. Smaller surface lesion widths and blood temperatures are obtained with higher irrigation flow rate, while the lesion depth is not affected by changing the irrigation flow rate. Larger lesions are obtained with increasing power and the electrode-tissue contact. Also, larger lesions are obtained when electrode is placed horizontally. Overall, the computational findings are in close agreement with previous experimental results providing an excellent tool for future catheter research. PMID:26938638

  7. Computational Modeling of Open-Irrigated Electrodes for Radiofrequency Cardiac Ablation Including Blood Motion-Saline Flow Interaction.

    PubMed

    González-Suárez, Ana; Berjano, Enrique; Guerra, Jose M; Gerardo-Giorda, Luca

    2016-01-01

    Radiofrequency catheter ablation (RFCA) is a routine treatment for cardiac arrhythmias. During RFCA, the electrode-tissue interface temperature should be kept below 80 °C to avoid thrombus formation. Open-irrigated electrodes facilitate power delivery while keeping low temperatures around the catheter. No computational model of an open-irrigated electrode in endocardial RFCA accounting for both the saline irrigation flow and the blood motion in the cardiac chamber has been proposed yet. We present the first computational model including both effects at once. The model has been validated against existing experimental results. Computational results showed that the surface lesion width and blood temperature are affected by both the electrode design and the irrigation flow rate. Smaller surface lesion widths and blood temperatures are obtained with higher irrigation flow rate, while the lesion depth is not affected by changing the irrigation flow rate. Larger lesions are obtained with increasing power and the electrode-tissue contact. Also, larger lesions are obtained when electrode is placed horizontally. Overall, the computational findings are in close agreement with previous experimental results providing an excellent tool for future catheter research. PMID:26938638

  8. Novel use of epidural catheter: Air injection for neuroprotection during radiofrequency ablation of spinal osteoid osteoma

    PubMed Central

    Doctor, JR; Solanki, SL; Patil, VP; Divatia, JV

    2016-01-01

    Osteoid osteoma (OO) is a benign bone tumor, with a male-female ratio of approximately 2:1 and mainly affecting long bones. Ten percent of the lesions occur in the spine, mostly within the posterior elements. Treatment options for OO include surgical excision and percutaneous imaging-guided radiofrequency ablation (RFA). Lesions within the spine have an inherent risk of thermal damage to the vital structure because of proximity to the neural elements. We report a novel use of the epidural catheter for air injection for the neuroprotection of nerves close to the OO of the spine. A 12-year-old and 30 kg male child with an OO of the L3 vertebra was taken up for RFA. His preoperative examinations were within normal limits. The OO was very close to the L3 nerve root. Under general anesthesia, lumbar epidural catheter was placed in the L3-L4 space under imaging guidance. Ten ml of aliquots of air was injected under imaging guidance to avoid injury to the neural structures due to RFA. The air created a gap between neural elements and the tumor and served as an insulating material thereby protecting the neural elements from damage due to the RFA. Postoperatively, the patient did not develop any neurological deficit. PMID:27375396

  9. Radiofrequency catheter ablation of intractable ventricular tachycardia in an infant following arterial switch operation.

    PubMed

    Costello, John P; He, Dingchao; Greene, Elizabeth A; Berul, Charles I; Moak, Jeffrey P; Nath, Dilip S

    2014-01-01

    A full-term male neonate presented with cyanosis upon delivery and was subsequently diagnosed with d-transposition of the great arteries, ventricular septal defect, and restrictive atrial septal defect. Following initiation of intravenous prostaglandins and balloon atrial septostomy, an arterial switch operation was performed on day 3 of life. The postoperative course was complicated by intractable ventricular tachycardia that was refractory to lidocaine, amiodarone, esmolol, fosphenytoin, and mexiletine drug therapy. Ventricular tachycardia was suppressed with overdrive atrial pacing but recurred upon discontinuation. Seven weeks postoperatively, radiofrequency catheter ablation was performed due to hemodynamically compromising persistent ventricular tachycardia refractory to medical therapy. The ventricular tachycardia was localized to the inferior-lateral right ventricular outlet septum. The procedure was successful without complications or recurrence. Antiarrhythmics were discontinued after the ablation procedure. Seven days after the ablation, a different, slower fascicular rhythm was noted to compete with the infant's sinus rhythm. This was consistent with the preablation amiodarone having reached subtherapeutic levels given its very long half-life. The patient was restarted on oral beta blockers and amiodarone. The patient was subsequently discharged home in predominantly sinus rhythm with intermittent fascicular rhythm. PMID:23647934

  10. Improvements in determination of cardiac output with a Swan-Ganz catheter.

    PubMed

    Sakagami, M; Kuwana, K; Nakanishi, H; Sakai, K

    1990-01-01

    The time constant for heat transfer may affect exact determination of cardiac output with Swan-Ganz catheters. Commercially available Swan-Ganz catheters are provided with thermistors with varying time constants. Current monitoring of cardiac output is not corrected for these time constants, so the conventional method of determining cardiac output using the equation of Stewart-Hamilton produces marked errors. The authors propose a new method of determining cardiac output with Swan-Ganz catheters with varying time constants from thermal dilution curve data based on Newton's cooling law. Values for blood flow rate determined by the new method using a completely stirred tank of original design, mimicking the natural heart and using bovine blood, are almost the same as values observed at varying saline infusion volumes, saline temperatures, and saline infusion times.

  11. Radiofrequency catheter ablation: different cooled and noncooled electrode systems induce specific lesion geometries and adverse effects profiles.

    PubMed

    Dorwarth, Uwe; Fiek, Michael; Remp, Thomas; Reithmann, Cristopher; Dugas, Martin; Steinbeck, Gerhard; Hoffmann, Ellen

    2003-07-01

    The success and safety of standard catheter radiofrequency ablation may be limited for ablation of atrial fibrillation and ventricular tachycardia. The aim of this study was to characterize and compare different cooled and noncooled catheter systems in terms of their specific lesion geometry, incidence of impedance rise, and crater and coagulum formation to facilitate appropriate catheter selection for special indications. The study investigated myocardial lesion generation of three cooled catheter systems (7 Fr, 4-mm tip): two saline irrigation catheters with a showerhead-type electrode tip (sprinkler) and a porous metal tip and an internally cooled catheter. Noncooled catheters (7 Fr) had a large tip electrode (8 mm) and a standard tip electrode (4 mm). RF energy was delivered on isolated porcine myocardium superfused with heparinized pig blood (37 degrees C) at power settings of 10-40 W. Both irrigated systems were characterized by a large lesion depth (8.1 +/- 1.6 mm) and a large lesion diameter (13.8 +/- 1.6 mm). In comparison, internally cooled lesions showed a similar lesion depth (8.0 +/- 1.0 mm), but a significantly smaller lesion diameter (12.3 +/- 1.2 mm,P = 0.04). Large tip lesions had a similar lesion diameter (14.5 +/- 1.6 mm), but a significantly smaller lesion depth (6.3 +/- 1.0 mm,P = 0.002) compared to irrigated lesions. However, lesion volume was not significantly different between the three cooled and the large tip catheter. To induce maximum lesion size, power requirements were three times higher for the irrigation systems and two times higher for the internally cooled and the large tip catheter compared to the standard catheter. Impedance rise was rarest with irrigated and large tip ablation. In case of impedance rise crater formation was a frequent observation (61-93%). Irrigated catheters prevented coagulum formation most effectively. Irrigated rather than internally cooled ablation appears to be most adequate for the induction of deep and

  12. Atrial conduction delay predicts atrial fibrillation in paroxysmal supraventricular tachycardia patients after radiofrequency catheter ablation.

    PubMed

    Xu, Zhen-Xing; Zhong, Jing-Quan; Zhang, Wei; Yue, Xin; Rong, Bing; Zhu, Qing; Zheng, Zhaotong; Zhang, Yun

    2014-06-01

    This study aimed to assess whether intra- and inter-atrial conduction delay could predict atrial fibrillation (AF) for paroxysmal supraventricular tachycardia (PSVT) patients after successful treatment by radiofrequency catheter ablation (RFCA). Echocardiography examination was performed on 524 consecutive PSVT patients (15 patients were excluded). Left atrial dimension, right atrial diameter and intra- and inter-atrial conduction delay were measured before ablation. Patients were divided into group A (n = 32): occurrence of AF after the ablation and group B (n = 477): remained in sinus rhythm during follow-up. Receiver operating characteristic (ROC) curve analysis was performed to estimate the predictive value of intra- and inter-atrial conduction delay. Both intra- and inter-atrial conduction delay were higher in group A than in group B (4.79 ± 0.30 msec vs. 4.56 ± 0.32 msec; 21.98 ± 1.32 msec vs. 20.01 ± 1.33; p < 0.05). Binary logistic regression analysis showed that intra- and inter-atrial conduction were significant influential factors for the occurrence of AF (odds ratio [OR] = 13.577, 95% confidence interval [CI], 3.469-48.914; OR = 2.569, 95% CI, 1.909-3.459, p < 0.05). The ROC cure analysis revealed that intra-atrial conduction delay ≥ 4.45 msec and inter-atrial conduction delay ≥ 20.65 were the most optimal cut-off value for predicting AF in PSVT patients after RFCA. In conclusion, this is the first study to show that the intra- and inter-atrial conduction delay could effectively predict AF in post-ablation PSVT patients.

  13. Pediatric Tachyarrhythmia and Radiofrequency Catheter Ablation: Results From 1993 to 2011

    PubMed Central

    Park, Hyoung-Seob; Hyun, Myung Chul; Kim, Yoon-Nyun

    2012-01-01

    Background and Objectives We performed a retrospective study to elucidate the frequency of tachycardia mechanisms and the characteristics of accessory pathways (APs), confirmed by radiofrequency catheter ablation (RFCA) in pediatric tachycardia. In addition, we analyzed the efficacy and safety of pediatric RFCA. Subjects and Methods The authors retrospectively reviewed the records of a total of 260 patients (aged 2 to 18 years) who had undergone RFCA between August 1993 and July 2011 at two medical centers in Daegu. Results Two hundred and sixty patients underwent 272 RFCAs at less than 18 years of age. Of these 260 patients, 9 patients (3%) were younger than 6 years, and 175 patients (67%) were older than 12 years. The tachycardia mechanisms observed were atrioventricular reentry tachycardia (AVRT) in 175 patients (65%), atrioventricular nodal reentry tachycardia (AVNRT) in 83 patients (30%), ventricular tachycardia in 12 patients (4%), and atrial tachycardia in 2 patients (0.7%). Among the patients with AVRT, there were 94 concealed APs and 81 manifest APs. Left-side APs were more common in concealed APs than in manifest APs (72/94, 77% vs. 33/81, 41%, p<0.001). Sixty-six percent (55/83) of AVNRT cases were located at the M1 and/or M2 sites. Four patients had multiple tachycardia mechanisms (AVNRT+AVRT) and 9 patients had multiple APs. The recurrence rate was 5% (13/272). Of these recurrent cases, 12 patients had AVRT. The overall success rate was 95%. Conclusion Pediatric RFCA provides a good success rate and an acceptable recurrence. In addition, we suggest that the APs location may be associated with concealed or manifest property of APs. PMID:23236324

  14. Patient Characteristics and the Incidence of Radiation-induced Dermatitis Following Radiofrequency Catheter Ablation

    PubMed Central

    Cha, Myung-Jin; Jo, Seong Jin; Cho, Youngjin; Choi, Eue-Keun

    2016-01-01

    Background and Objectives Radiofrequency catheter ablation (RFCA) exposes patients to fixed angle radiation for extended periods of time. We investigated the incidence and characteristics of radiation-induced dermatitis (RID) associated with RFCA. Subjects and Methods We screened 1347 consecutive patients from 2000 to 2011 who underwent RFCA for any indication and reviewed patients with dermatologic issues at the 1-month follow-up. Skin lesions were classified into three groups: most likely RID, probable RID, and possible RID. Results Of the 1347 enrolled patients, 12 (0.89%) experienced dermatologic issues within 1 month after RFCA, including six patients (0.45%) clinically classified as 'most likely RID' and four patients (0.30%) with 'probable RID'. Ten patients, including most likely RID or probable RID patients, developed skin lesions on the right back and upper arm. Skin lesions did not improve without meticulous treatment, and three cases required surgical intervention. We compared the RID group to the remaining 1335 patients (normal group). The mean body mass indices (BMIs) of the RID and normal groups were 29.3 and 23.9 kg/m2, respectively (p<0.001). Radiation exposure times were longer in the RID group (180±31.0 vs. 47±49.9 minutes, p<0.001). We further analyzed 44 patients (6 RID cases and 38 normal patients) that had BMIs >26 kg/m2 and exposure times >115 minutes based on receiver operator characteristic curve analyses. Among the 35 patients without RID, 29 patients (82.9%) did not use biplane fluoroscopy. Conclusions Patients with high BMIs have a higher risk of developing severe RID with increasing fluoroscopy times using biplane fluoroscopy. PMID:27721855

  15. Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure

    PubMed Central

    See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi Keong

    2016-01-01

    INTRODUCTION The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. METHODS We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSite™ NavX™ or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. RESULTS A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. CONCLUSION The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. PMID:26805664

  16. The use of Foley balloon catheters in cardiac surgery.

    PubMed

    Black, J J; Allan, A; Williams, B T

    1993-01-01

    Situations may arise during elective and emergency surgery when vascular control is required but conventional vascular clamps cannot be used. We have found the Foley catheter useful for the control of inadvertent perforation of the heart especially in "redo" operations. We describe the use of the Foley catheter for the control of the difficult aorta and illustrate its potential versatility in a variety of uncommon situations. As Foley catheters are present in every operating theatre we hope that our experience will be of benefit to other surgeons who encounter similar problems.

  17. Acute Safety of an Open-Irrigated Ablation Catheter with 56-Hole Porous Tip for Radiofrequency Ablation of Paroxysmal Atrial Fibrillation: Analysis from 2 Observational Registry Studies

    PubMed Central

    OZA, SAUMIL R; HUNTER, TINA D; BIVIANO, ANGELO B; DANDAMUDI, GOPI; HERWEG, BENGT; PATEL, ANSHUL M; POLLAK, SCOTT J; WANG, HUIJIAN; FISHEL, ROBERT S

    2014-01-01

    Acute Safety from 2 AF Ablation Registries Introduction This report presents safety data on the use of a new open-irrigation radiofrequency ablation (RFA) catheter with a 56-hole porous tip in 742 patients enrolled in 2 US prospective, multicenter observational registry studies representing real-world use of the catheter. Methods This analysis is comprised of patients who underwent RFA of drug-refractory recurrent symptomatic paroxysmal atrial fibrillation (AF). Acute adverse events (AEs) were collected and categorized by seriousness, timing, and relatedness, with 7 days of follow-up data in one study and at least 120 days of data from a 1-year follow-up in the other. Acute serious adverse events (SAEs) that were identified as potentially related to the device and/or procedure were adjudicated by an independent safety committee. Results A total of 30 patients (4.0%) in the combined studies experienced an acute SAE related to the device and/or procedure, which was similar in the subset of patients age 65 and over (4.2%). These SAEs included 1.2% cardiac tamponade/perforation, 0.7% pericarditis, 0.5% pulmonary events, and 0.8% vascular access complications. No myocardial infarction, stroke, transient ischemic attack, or atrioesophageal fistulas within 7 days postprocedure were reported. In the study with extended follow-up, 1 pulmonary vein stenosis and 1 esophageal injury were seen beyond 7 days postprocedure (0.2% each). There were no device or procedure related deaths. Conclusion Results from 2 large observational studies demonstrated that a new porous tip RFA catheter was safe for the treatment of drug refractory, recurrent, symptomatic paroxysmal AF, including treatment of older patients (≥65 years). PMID:24602038

  18. Case 222: Pericardioesophageal Fistula after Cardiac Radiofrequency Ablation.

    PubMed

    Miller, Joseph M; Sukov, Richard J

    2015-10-01

    History A 56-year-old woman presented to the emergency department after a cross-country flight. While in flight, she experienced sudden onset of epigastric and midsternal chest pain with shortness of breath. Her symptoms improved markedly after she received oxygen on board, and she finished the flight without further incident. Once home later that night, the pain recurred, and she was taken to the hospital. Her history included chronic pain syndrome, hypertension, and refractory paroxysmal atrial fibrillation, for which she had undergone radiofrequency ablation on two occasions. Her most recent ablation was 1 month prior. Upon arrival in the emergency department, her vital signs were within normal limits, and an electrocardiogram was unchanged from baseline. A chest radiograph obtained at the time of physical examination was unchanged from baseline. Given her recent travel history, there was suspicion for a pulmonary embolism. Ventilation-perfusion imaging and lower extremity Doppler ultrasonography were performed (images not shown) and revealed no evidence of pulmonary embolism or lower extremity thrombus. Because of the patient's clinical stability and because her symptoms had improved, she declined admission for observation and returned home against medical advice. The patient returned to the emergency department 2 days later in severe distress, with unstable vital signs, a jaundiced appearance, and substantial pain in her chest and abdomen. Her creatinine level was 4.4 mg/dL (388.9 μmol/L) (increased from 0.9 mg/dL [79.6 μmol/L] 2 days prior). Frontal and lateral radiographs of the chest were obtained and indicated increasing pericardial effusion. Bedside echocardiography enabled confirmation of these radiographic findings, and pericardiocentesis was performed. The patient's condition immediately improved, and she was admitted to the cardiac intensive care unit. Her symptoms recurred 3 days later, and a pericardial drain was placed. Fluid cultures were

  19. Catheter-Malposition-Induced Cardiac Tamponade via Contrast Media Leakage During Computed Tomography Study

    SciTech Connect

    Liang, C.-D. Ko, S.-F.; Huang, C.-F.; Chien, S.J.; Tiao, M.M.

    2005-12-15

    We present a rare case of a central venous catheter-malposition-induced life-threatening cardiac tamponade as a result of computed tomography (CT) with contrast enhancement in an infant with a ventricular septal defect and pulmonary atresia after a modified Blalock-Taussig shunt. The diagnosis was confirmed by chest radiographs and CT study with catheter perforation through the right atrial wall and extravasation of the contrast medium into the pericardium, leading to cardiac tamponade and subsequent circulatory collapse. Two hours after successful cardiopulmonary resuscitation, the patient gradually resumed normal hemodynamic status.

  20. Catheter ablation for cardiac arrhythmias: A 14-year experience with 5330 consecutive patients at the Quebec Heart Institute, Laval Hospital

    PubMed Central

    O’Hara, Gilles E; Philippon, François; Champagne, Jean; Blier, Louis; Molin, Franck; Côté, Jean-Marc; Nault, Isabelle; Sarrazin, Jean-François; Gilbert, Marcel

    2007-01-01

    radiofrequency ablation is safe and effective, supporting ablation therapy as a first-line therapy for the majority of patients with cardiac arrhythmias. PMID:17932590

  1. Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.

    PubMed

    Matsuda, Hisao; Parwani, Abdul Shokor; Attanasio, Philipp; Huemer, Martin; Wutzler, Alexander; Blaschke, Florian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2016-09-01

    Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV.

  2. Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.

    PubMed

    Matsuda, Hisao; Parwani, Abdul Shokor; Attanasio, Philipp; Huemer, Martin; Wutzler, Alexander; Blaschke, Florian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2016-09-01

    Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV. PMID:26498938

  3. Combined Therapeutic and Monitoring Ultrasonic Catheter for Cardiac Ablation Therapies.

    PubMed

    Carias, Mathew; Hynynen, Kullervo

    2016-01-01

    This study evaluated the feasibility of a combined therapeutic and diagnostic ultrasonic catheter for cardiac ablation therapies. Ultrasound can be used to determine when diseased cardiac tissues have become fully coagulated through a method known as local harmonic motion imaging (LHMI). LHMI is an imaging modality for treatment monitoring that uses acoustic radiation force, displacement tracking and the different mechanical properties of viable and ablated tissues. In this study, we developed catheters that are capable of LHMI measurements. Experiments were conducted in phantoms, ex vivo cardiac samples and the in vivo beating hearts of healthy porcine subjects. In vivo experiments revealed that four of four epicardial sonications revealed a decrease in measured displacements from LHMI experiments and that when lower power was used, no lesions formed and there was no corresponding decrease in measured displacement amplitudes. In addition, two of three endocardial lesions were confirmed and corresponded to a decrease in the measured displacement amplitude. PMID:26431798

  4. Three-dimensional tracking of cardiac catheters using an inverse geometry x-ray fluoroscopy system

    SciTech Connect

    Speidel, Michael A.; Tomkowiak, Michael T.; Raval, Amish N.; Van Lysel, Michael S.

    2010-12-15

    Purpose: Scanning beam digital x-ray (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis at multiple planes. This study describes a tomosynthesis-based method for 3D tracking of high-contrast objects and present the first experimental investigation of cardiac catheter tracking using a prototype SBDX system. Methods: The 3D tracking algorithm utilizes the stack of regularly spaced tomosynthetic planes that are generated by SBDX after each frame period (15 frames/s). Gradient-filtered versions of the image planes are generated, the filtered images are segmented into object regions, and then a 3D coordinate is calculated for each object region. Two phantom studies of tracking performance were conducted. In the first study, an ablation catheter in a chest phantom was imaged as it was pulled along a 3D trajectory defined by a catheter sheath (10, 25, and 50 mm/s pullback speeds). SBDX tip tracking coordinates were compared to the 3D trajectory of the sheath as determined from a CT scan of the phantom after the registration of the SBDX and CT coordinate systems. In the second study, frame-to-frame tracking precision was measured for six different catheter configurations as a function of image noise level (662-7625 photons/mm{sup 2} mean detected x-ray fluence at isocenter). Results: During catheter pullbacks, the 3D distance between the tracked catheter tip and the sheath centerline was 1.0{+-}0.8 mm (mean {+-}one standard deviation). The electrode to centerline distances were comparable to the diameter of the catheter tip (2.3 mm), the confining sheath (4 mm outside diameter), and the estimated SBDX-to-CT registration error ({+-}0.7 mm). The tip position was localized for all 332 image frames analyzed and 83% of tracked positions were inside the 3D sheath volume derived from CT. The pullback speeds derived from the catheter trajectories were within 5% of the programed pullback speeds

  5. Radiofrequency ablation with a vibrating catheter: A new method for electrode cooling.

    PubMed

    Yu, Kaihong; Yamashita, Tetsui; Shingyochi, Shigeaki; Matsumoto, Kazuo; Ohta, Makoto

    2016-05-01

    A new electrode cooling system using a vibrating catheter is described for conditions of low blood flow when saline irrigation cannot be used. Vibrations of the catheter are hypothesized to disturb blood flow around the electrode, leading to increased convective cooling of the electrode. The aim of this study is to confirm the cooling effect of vibration and investigate the associated mechanisms. As methods, an in vitro system with polyvinyl alcohol-hydrogel (PVA-H) as ablated tissue and saline flow in an open channel was used to measure changes in electrode and tissue temperatures under vibration of 0-63 Hz and flow velocity of 0-0.1 m/s. Flow around the catheter was observed using particle image velocimetry (PIV). Results show that under conditions of no flow, electrode temperatures decreased with increasing vibration frequency, and in the absence of vibrations, electrode temperatures decreased with increasing flow velocity. In the presence of vibrations, electrode temperatures decreased under conditions of low flow velocity, but not under those of high flow velocity. PIV analyses showed disturbed flow around the vibrating catheter, and flow velocity around the catheter increased with higher-frequency vibrations. In conclusion, catheter vibration facilitated electrode cooling by increasing flow around the catheter, and cooling was proportional to vibration frequency.

  6. Surface evaluation of cardiac angiographic catheters after simulated use and reprocessing

    NASA Astrophysics Data System (ADS)

    Lucas, Thabata Coaglio; Oréfice, Rodrigo Lambert; Pinotti, Marcos; Huebner, Rudolf

    2009-12-01

    Reprocessing of single-use intravascular catheters is a common practice in public health services and hospitals. The determination of safe number of reprocessing cycles before the catheter integrity becomes compromised has been a priority issue. The present paper addresses the evaluating molecular and micro-structural integrity of reprocessed cardiac angiographic catheters. The Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy were carried out to elucidate morphological changes. The tensile test was performed on catheters to examine changes in bulk characteristics. In this work, samples of catheters were reprocessed until nine times and sterilized by hydrogen peroxide plasma. It was observed that the number of hydrogen-bonded carbonyls groups increased in 0.05 u.a. ( p < 0.001) after each reprocessing cycle. The spectra indicated degradation products included acids, esters, alcohols, and small amounts of other products containing a carbonyl functional group. The micrographs revealed that only after the fourth reprocessing cycle the effect increased in the surface roughness was more pronounced. On the other hand, after each reprocessing cycle and as consequence of extensive aging of polyamide/polyurethane blends of the catheters surface, it was observed that the micro-fissures, micro-scratches and micro-pores increased in quantity and length. The mechanical test proved that the Young modulus increased in average 3.26 MPa ( p = 0.0003) at increasing number of reprocessing cycles, also suggestive of crosslinking in this material.

  7. Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice

    PubMed Central

    Abraham, Dennis; Mao, Lan

    2016-01-01

    Cardiac pressure-volume loop analysis is the “gold-standard” in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice. PMID:26436838

  8. Intracardiac echocardiography to guide transseptal catheterization for radiofrequency catheter ablation of left-sided accessory pathways: two case reports.

    PubMed

    Citro, Rodolfo; Ducceschi, Valentino; Salustri, Alessandro; Santoro, Michele; Salierno, Michele; Gregorio, Giovanni

    2004-10-08

    Intracardiac echocardiography (ICE) is a useful tool for guiding transseptal puncture during electrophysiological mapping and ablation procedures. Left-sided accessory pathways (LSAP) can be ablated by using two different modalities: retrograde approach through the aortic valve and transseptal approach with puncture of the fossa ovalis. We shall report two cases of LSAP where transcatheter radiofrequency ablation (TCRFA) was firstly attempted via transaortic approach with ineffective results. Subsequently, a transseptal approach under ICE guidance has been performed. During atrial septal puncture ICE was able to locate the needle tip position precisely and provided a clear visualization of the "tenting effect" on the fossa ovalis. ICE allowed a better mapping of the mitral ring and a more effective catheter ablation manipulation and tip contact which resulted in a persistent and complete ablation of the accessory pathway with a shorter time of fluoroscopic exposure. ICE-guided transseptal approach might be a promising modality for TCRFA of LSAP.

  9. 3D X-ray imaging methods in support catheter ablations of cardiac arrhythmias.

    PubMed

    Stárek, Zdeněk; Lehar, František; Jež, Jiří; Wolf, Jiří; Novák, Miroslav

    2014-10-01

    Cardiac arrhythmias are a very frequent illness. Pharmacotherapy is not very effective in persistent arrhythmias and brings along a number of risks. Catheter ablation has became an effective and curative treatment method over the past 20 years. To support complex arrhythmia ablations, the 3D X-ray cardiac cavities imaging is used, most frequently the 3D reconstruction of CT images. The 3D cardiac rotational angiography (3DRA) represents a modern method enabling to create CT like 3D images on a standard X-ray machine equipped with special software. Its advantage lies in the possibility to obtain images during the procedure, decreased radiation dose and reduction of amount of the contrast agent. The left atrium model is the one most frequently used for complex atrial arrhythmia ablations, particularly for atrial fibrillation. CT data allow for creation and segmentation of 3D models of all cardiac cavities. Recently, a research has been made proving the use of 3DRA to create 3D models of other cardiac (right ventricle, left ventricle, aorta) and non-cardiac structures (oesophagus). They can be used during catheter ablation of complex arrhythmias to improve orientation during the construction of 3D electroanatomic maps, directly fused with 3D electroanatomic systems and/or fused with fluoroscopy. An intensive development in the 3D model creation and use has taken place over the past years and they became routinely used during catheter ablations of arrhythmias, mainly atrial fibrillation ablation procedures. Further development may be anticipated in the future in both the creation and use of these models.

  10. A case of premature ventricular contractions, ventricular tachycardia, and arrhythmic storm induced by right ventricular pacing during cardiac resynchronization therapy: Electrophysiological mechanism and catheter ablation

    PubMed Central

    Pedretti, Stefano; Vargiu, Sara; Paolucci, Marco; Lunati, Maurizio

    2015-01-01

    A 77-year-old man with ischemic cardiomyopathy and a cardiac resynchronization therapy-defibrillator (CRT-D) device came to our attention due to incessant ventricular tachycardia and multiple implantable cardioverter defibrillator (ICD) shocks. An electrocardiogram showed non-sustained monomorphic ventricular tachycardias (NSVTs) constantly occurring after each biventricular stimulation. During an electrophysiological study, NSVTs reproducibly recurred only after right ventricular (RV) pacing; LV pacing did not induce any NSVTs. The activation map was consistent with a localized reentry at the interventricular septum, and a double exit; at the LV exit site, a single radiofrequency energy application immediately interrupted the occurrence of the NSVTs. Current evidence supports LV pacing to be pro-arrhythmogenic in few CRT patients. This unusual case shows that RV pacing during CRT could produce frequent ventricular arrhythmias and arrhythmic storm. Catheter ablation can be considered an effective therapeutic option, especially when CRT maintenance is highly advisable. PMID:26702324

  11. Real-time x-ray fluoroscopy-based catheter detection and tracking for cardiac electrophysiology interventions

    SciTech Connect

    Ma Yingliang; Housden, R. James; Razavi, Reza; Rhode, Kawal S.; Gogin, Nicolas; Cathier, Pascal; Gijsbers, Geert; Cooklin, Michael; O'Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo

    2013-07-15

    Purpose: X-ray fluoroscopically guided cardiac electrophysiology (EP) procedures are commonly carried out to treat patients with arrhythmias. X-ray images have poor soft tissue contrast and, for this reason, overlay of a three-dimensional (3D) roadmap derived from preprocedural volumetric images can be used to add anatomical information. It is useful to know the position of the catheter electrodes relative to the cardiac anatomy, for example, to record ablation therapy locations during atrial fibrillation therapy. Also, the electrode positions of the coronary sinus (CS) catheter or lasso catheter can be used for road map motion correction.Methods: In this paper, the authors present a novel unified computational framework for image-based catheter detection and tracking without any user interaction. The proposed framework includes fast blob detection, shape-constrained searching and model-based detection. In addition, catheter tracking methods were designed based on the customized catheter models input from the detection method. Three real-time detection and tracking methods are derived from the computational framework to detect or track the three most common types of catheters in EP procedures: the ablation catheter, the CS catheter, and the lasso catheter. Since the proposed methods use the same blob detection method to extract key information from x-ray images, the ablation, CS, and lasso catheters can be detected and tracked simultaneously in real-time.Results: The catheter detection methods were tested on 105 different clinical fluoroscopy sequences taken from 31 clinical procedures. Two-dimensional (2D) detection errors of 0.50 {+-} 0.29, 0.92 {+-} 0.61, and 0.63 {+-} 0.45 mm as well as success rates of 99.4%, 97.2%, and 88.9% were achieved for the CS catheter, ablation catheter, and lasso catheter, respectively. With the tracking method, accuracies were increased to 0.45 {+-} 0.28, 0.64 {+-} 0.37, and 0.53 {+-} 0.38 mm and success rates increased to 100%, 99

  12. Low Cardiac Output Secondary to a Malpositioned Umbilical Venous Catheter: Value of Targeted Neonatal Echocardiography

    PubMed Central

    Weisz, Dany E.; Poon, Wei Bing; James, Andrew; McNamara, Patrick J.

    2014-01-01

    Systemic hypotension is common in very low birthweight preterm infants but the nature of the precipitating cause may be unclear. Targeted neonatal echocardiography (TnEcho) is being increasingly used to support hemodynamic decisions in the neonatal intensive care unit (NICU), including identifying impairments in the transitional circulation of preterm infants, providing timely re-evaluation after institution of therapies and evaluating the placement of indwelling catheters. We present a case of a preterm infant with systemic hypotension and low cardiac output secondary to a large transatrial shunt induced by a malpositioned umbilical venous catheter. Repositioning of the line led to resolution of the hemodynamic disturbance and clinical instability, highlighting the utility of TnEcho in the NICU. PMID:25032055

  13. Periprocedural anticoagulation of patients undergoing pericardiocentesis for cardiac tamponade complicating catheter ablation of atrial fibrillation.

    PubMed

    Lin, Tao; Bai, Rong; Chen, Ying-wei; Yu, Rong-hui; Tang, Ri-bo; Sang, Cai-hua; Li, Song-nan; Ma, Chang-sheng; Dong, Jian-zeng

    2015-01-01

    Anticoagulation of patients with cardiac tamponade (CT) complicating catheter ablation of atrial fibrillation (AF) is an ongoing problem. The aim of this study was to survey the clinical practice of periprocedural anticoagulation in such patients. This study analyzed the periprocedural anticoagulation of 17 patients with CT complicating AF ablation. Emergent pericardiocentesis was performed once CT was confirmed. The mean drained volume was 410.0 ± 194.1 mL. Protamine sulfate was administered to neutralize heparin (1 mg neutralizes 100 units heparin) in 11 patients with persistent pericardial bleeding and vitamin K1 (10 mg) was given to reverse warfarin in 3 patients with supratherapeutic INR (INR > 2.1). Drainage catheters were removed 12 hours after echocardiography confirmed absence of intrapericardial bleeding and anticoagulation therapy was restored 12 hours after removing the catheter. Fifteen patients took oral warfarin and 10 of them were given subcutaneous injection of LMWH (1 mg/kg, twice daily) as a bridge to resumption of systemic anticoagulation with warfarin. Two patients with a small amount of persistent pericardial effusion were given LMWH on days 5 and 13, and warfarin on days 6 and 24. The dosage of warfarin was adjusted to keep the INR within 2-3 in all patients. After 12 months of follow-up, all patients had no neurological events and no occurrence of delayed CT. The results showed that it was effective and safe to resume anticoagulation therapy 12 hours after removal of the drainage catheter. This may help to prevent thromboembolic events following catheter ablation of AF.

  14. Prevention and Treatment of Lower Limb Deep Vein Thrombosis after Radiofrequency Catheter Ablation: Results of a Prospective active controlled Study

    PubMed Central

    Li, Lan; Zhang, Bao-jian; Zhang, Bao-ku; Ma, Jun; Liu, Xu-zheng; Jiang, Shu-bin

    2016-01-01

    We conducted a prospective, single-center, active controlled study from July 2013 to January 2015, in Chinese patients with rapid ventricular arrhythmia who had received radiofrequency catheter ablation (RFCA) treatment to determine formation of lower extremity deep vein thrombosis (LDVT) post RFCA procedure, and evaluated the effect of rivaroxaban on LDVT. Patients with asymptomatic pulmonary thromboembolism who had not received any other anticoagulant and had received no more than 36 hours of treatment with unfractionated heparin were included. Post RFCA procedure, patients received either rivaroxaban (10 mg/d for 14 days beginning 2–3 hours post-operation; n = 86) or aspirin (100 mg/d for 3 months beginning 2–3 hours post-operation; n = 90). The primary outcome was a composite of LDVT occurrence, change in diameter of femoral veins, and safety outcomes that were analyzed based on major or minor bleeding events. In addition, blood flow velocity was determined. No complete occlusive thrombus or bleeding events were reported with either of the group. The lower incidence rate of non-occluded thrombus in rivaroxaban (5.8%) compared to the aspirin group (16.7%) indicates rivaroxaban may be administered post-RFCA to prevent and treat femoral venous thrombosis in a secure and effective way with a faster inset of action than standard aspirin therapy. PMID:27329582

  15. Materials for Multifunctional Balloon Catheters With Capabilities in Cardiac Electrophysiological Mapping and Ablation Therapy

    PubMed Central

    Kim, Dae-Hyeong; Lu, Nanshu; Ghaffari, Roozbeh; Kim, Yun-Soung; Lee, Stephen P.; Xu, Lizhi; Wu, Jian; Kim, Rak-Hwan; Song, Jizhou; Liu, Zhuangjian; Viventi, Jonathan; de Graff, Bassel; Elolampi, Brian; Mansour, Moussa; Slepian, Marvin J.; Hwang, Sukwon; Moss, Joshua D.; Won, Sang-Min; Huang, Younggang; Litt, Brian; Rogers, John A.

    2011-01-01

    Development of advanced surgical tools for minimally invasive procedures represents an activity of central importance to improvements in human health. A key materials challenge is in the realization of bio-compatible interfaces between the classes of semiconductor and sensor technologies that might be most useful in this context and the soft, curvilinear surfaces of the body. This paper describes a solution based on biocompatible materials and devices that integrate directly with the thin elastic membranes of otherwise conventional balloon catheters, to provide multimodal functionality suitable for clinical use. We present sensors for measuring temperature, flow, tactile, optical and electrophysiological data, together with radio frequency (RF) electrodes for controlled, local ablation of tissue. These components connect together in arrayed layouts designed to decouple their operation from large strain deformations associated with deployment and repeated inflation/deflation. Use of such ‘instrumented’ balloon catheter devices in live animal models and in vitro tests illustrates their operation in cardiac ablation therapy. These concepts have the potential for application in surgical systems of the future, not only those based on catheters but also on other platforms, such as surgical gloves. PMID:21378969

  16. Catheter-Based Radiofrequency Renal Denervation: Location Effects on Renal Norepinephrine

    PubMed Central

    Zhang, Yongxing; Hata, Cary; Narciso, Irvin; Hall, Michael E.; Hall, John E.

    2015-01-01

    BACKGROUND Clinical studies indicate that blood pressure (BP)-lowering effects of radiofrequency (RF) renal denervation (RD) are sustained for up to 2 years, although a recent clinical trial failed to find a major effect compared to sham treatment. In most previous studies, the efficacy of RD has not been assessed. The current study determined whether RD in different regions of the renal artery causes different degrees of RD as assessed with renal norepinephrine (NE) levels. METHODS AND RESULTS Unilateral RD was performed on 14 pigs divided into 3 groups: RD near the ostium, in the main renal artery near the bifurcation, and in extrarenal branches of the renal artery. After 2 weeks post-RD, the pigs were euthanized, renal cortex tissue was collected for NE measurement, and renal arteries were prepared for histological analysis. Renal NE decreased by 12% with RD at the ostium, 45% with RD near the bifurcation in the main renal artery, and 74% when RD was performed in extrarenal artery branches. The number of renal nerves was greatest in extrarenal branches and in the main artery compared to the ostium and the average distance from the lumen was greatest for nerves at the ostium and least at the branches. CONCLUSIONS RF RD lowers renal NE more significantly when performed in branches of the renal artery closer to the kidney. Increased efficacy of RF RD in extrarenal arterial branches may be due to the greater number of nerves in close proximity to the artery lumen in the branches. PMID:25576624

  17. Acute success and short-term follow-up of catheter ablation of isthmus-dependent atrial flutter; a comparison of 8 mm tip radiofrequency and cryothermy catheters

    PubMed Central

    Janse, P.; Alings, M.; Scholten, M. F.; Mekel, J. M.; Miltenburg, M.; Jessurun, E.; Jordaens, L.

    2008-01-01

    Objectives To compare the acute success and short-term follow-up of ablation of atrial flutter using 8 mm tip radiofrequency (RF) and cryocatheters. Methods Sixty-two patients with atrial flutter were randomized to RF or cryocatheter (cryo) ablation. Right atrial angiography was performed to assess the isthmus. End point was bidirectional isthmus block on multiple criteria. A pain score was used and the analgesics were recorded. Patients were followed for at least 3 months. Results The acute success rate for RF was 83% vs 69% for cryo (NS). Procedure times were similar (mean 144 ± 48 min for RF, vs 158 ± 49 min for cryo). More applications were given with RF than with cryo (26 ± 17 vs. 18 ± 10, p < 0.05). Fluoroscopy time was longer with RF (29 ± 15 vs. 19 ± 12 min, p < 0.02). Peak CK, CK-MB and CK-MB mass were higher, also after 24 h in the cryo group. Troponin T did not differ. Repeated transient block during application (usually with cryoablation) seemed to predict failure. Cryothermy required significantly less analgesia (p < 0.01), and no use of long sheaths (p < 0.005). The isthmus tended to be longer in the failed procedures (p = 0.117). This was similar for both groups, as was the distribution of anatomic variations. Recurrences and complaints in the successful patients were similar for both groups, with a very low recurrence of atrial flutter after initial success. Conclusions In this randomized study there was no statistical difference but a trend to less favorable outcome with 8 mm tip cryocatheters compared to RF catheters for atrial flutter ablation. Cryoablation was associated with less discomfort, fewer applications, shorter fluoroscopy times and similar procedure times. The recurrence rate was very low. Cryotherapy can be considered for atrial flutter ablation under certain circumstances especially when it has been used previously in the same patient, such as in an AF ablation. PMID:18363087

  18. Radiofrequency catheter ablation for idiopathic right ventricular tachycardia with special reference to morphological variation and long-term outcome.

    PubMed Central

    Chinushi, M.; Aizawa, Y.; Takahashi, K.; Kitazawa, H.; Shibata, A.

    1997-01-01

    OBJECTIVE: To assess the long term outcome of radiofrequency (RF) catheter ablation for idiopathic ventricular tachycardia (VT) originating from the outflow tract of the right ventricle, with special reference to the morphological variation in the VT-QRS complexes. PATIENTS: 13 patients whose ventricular tachycardia was treated with RF ablation were followed up more than 18 months after RF ablation. RESULTS: Endocardial mapping revealed the various extensions of ventricular tachycardia origin (from 0.5 x 0.5 cm to 2.0 x 2.0 cm) in which the earliest local electrogram was recorded during ventricular tachycardia. In all five tachycardias from a relatively wider origin (more than 0.5 x 0.5 cm) and in four of eight from a narrow origin (< 0.5 x 0.5 cm), subtle morphological variation in the VT-QRS complexes was observed. In tachycardias with morphological variation, the local electrogram at the tachycardia origin also showed concomitant variation in morphology and activation sequence. Ventricular tachycardia from a narrow site was eliminated by RF ablation to the confined site, but a larger number of RF applications was required in tachycardias from a wider origin. All 13 tachycardias were successfully ablated by RF current, and during the follow up period of 28.2 (SD 7.2) months, recurrence was observed in only one patient who had a wider origin. CONCLUSIONS: Long term efficacy of RF ablation was excellent in idiopathic ventricular tachycardia originating from the outflow tract of the right ventricle. Subtle morphological variations were frequently observed in this type of ventricular tachycardia, and about half of them represented a relatively wider arrhythmogenic area. PMID:9391287

  19. Catheter-Based Educational Experiences: A Canadian Survey of Current Residents and Recent Graduates in Cardiac Surgery.

    PubMed

    Juanda, Nadzir; Chan, Vincent; Chan, Ryan; Rubens, Fraser D

    2016-03-01

    The past decade has witnessed significant developments in the use of catheter-based therapies in cardiovascular medicine. We sought to assess the educational opportunities for cardiac surgery trainees to determine their readiness for participation in these strategies. A web-based survey was distributed to current residents, recent graduates, and program directors in Canadian cardiac surgery residency programs from 2008-2013. The survey was distributed to 110 residents and graduates. Forty-five percent completed the survey. Thirty-five percent expressed that they experienced resistance organizing their rotations because they had to compete with non-cardiac surgery colleagues, and 6 were denied local cardiac catheterization rotations. By the end of the rotation, 56% were comfortable performing a diagnostic cardiac catheterization independently. Exposure to being the operator performing diagnostic catheterization was significantly associated with the positive perception of being able to perform a diagnostic catheterization independently (odds ratio [OR], 5.14; 95% confidence interval [CI], 1.33-19.81; P = 0.017). Eighty-eight percent of respondents expressed the need for more exposure in catheter-based rotations. Seven of 11 program directors completed the survey. All believed such rotations should be mandatory and foresaw a bigger role for hybrid catheter-based/cardiac surgery procedures in the future. Trainees and program directors perceive that increased exposure to catheter-based therapies is important to career development as a cardiac surgeon. This survey will contribute to the development of a cardiac surgery training curriculum as we foresee more hybrid and team procedures.

  20. Real-time optical monitoring of permanent lesion progression in radiofrequency ablated cardiac tissue (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Singh-Moon, Rajinder P.; Hendon, Christine P.

    2016-02-01

    Despite considerable advances in guidance of radiofrequency ablation (RFA) therapies for atrial fibrillation, success rates have been hampered by an inability to intraoperatively characterize the extent of permanent injury. Insufficient lesions can elusively create transient conduction blockages that eventually reconduct. Prior studies suggest significantly greater met-myoglobin (Mmb) concentrations in the lesion core than those in the healthy myocardium and may serve as a marker for irreversible tissue damage. In this work, we present real-time monitoring of permanent injury through spectroscopic assessment of Mmb concentrations at the catheter tip. Atrial wedges (n=6) were excised from four fresh swine hearts and submerged under pulsatile flow of warm (37oC) phosphate buffered saline. A commercial RFA catheter inserted into a fiber optic sheath allowed for simultaneous measurement of tissue diffuse reflectance (DR) spectra (500-650nm) during application of RF energy. Optical measurements were continuously acquired before, during, and post-ablation, in addition to healthy neighboring tissue. Met-myoglobin, oxy-myoglobin, and deoxy-myoglobin concentrations were extracted from each spectrum using an inverse Monte Carlo method. Tissue injury was validated with Masson's trichrome and hematoxylin and eosin staining. Time courses revealed a rapid increase in tissue Mmb concentrations at the onset of RFA treatment and a gradual plateauing thereafter. Extracted Mmb concentrations were significantly greater post-ablation (p<0.0001) as compared to healthy tissue and correlated well with histological assessment of severe thermal tissue destruction. On going studies are aimed at integrating these findings with prior work on near infrared spectroscopic lesion depth assessment. These results support the use of spectroscopy-facilitated guidance of RFA therapies for real-time permanent injury estimation.

  1. Draining Fluids through a Peritoneal Catheter in Newborns after Cardiac Surgery Helps to Control Fluid Balance.

    PubMed

    Ruano Cea, Elisa; Jouvet, Philippe; Vobecky, Suzanne; Merouani, Aicha

    2010-01-01

    Dialysis can be used in severe cases, but may not be well tolerated. In such patients, peritoneal drainage could be an alternative option for fluid removal. We report the case of a newborn with a truncus arteriosus who developed postoperatively a complicated clinical course with right ventricular dysfunction, prerenal condition as well as fluid overload despite diuretic therapy. Dialysis was indicated for fluid removal. Peritoneal dialysis was started using a surgically placed Tenckhoff catheter and stopped due to inefficacy and leaks and no other modalities of dialysis were used. However, the catheter was left in place over a period of two months for fluid drainage and removed because of unexplained fever. In order to determine the effect of peritoneal drainage, we selected a period of one week before and one week after the removal of the drain to compare daily clinical data, urine electrolytes and renal function and found a positive effect on fluid balance control. We conclude that the fluid removal by continuous peritoneal drainage is a simple and safe alternative that can be used to control fluid balance in infants after cardiac surgery. PMID:20379389

  2. The analgesic efficacy of continuous presternal bupivacaine infusion through a single catheter after cardiac surgery

    PubMed Central

    Nasr, Dalia Abdelhamid; Abdelhamid, Hadeel Magdy; Mohsen, Mai; Aly, Ahmad Helmy

    2015-01-01

    Background: Median sternotomy, sternal spreading, and sternal wiring are the main causes of pain during the early recovery phase following cardiac surgery. Aim: This study was designed to evaluate the analgesic efficacy of continuous presternal bupivacaine infusion through a single catheter after parasternal block following cardiac surgery. Materials and Methods: The total of 40 patients (American Society of Anesthesiologist status II, III), 45–60 years old, undergoing coronary – artery bypass grafting were enrolled in this prospective, randomized, double-blind study. A presternal catheter was inserted with continuous infusion of 5 mL/h bupivacaine 0.25% (Group B) or normal saline (Group C) during the first 48 postoperative hrs. Primary outcomes were postoperative morphine requirements and pain scores, secondary outcomes were extubation time, postoperative respiratory parameters, incidence of wound infection, Intensive Care Unit (ICU) and hospital stay duration, and bupivacaine level in blood. Statistical Methods: Student's t-test was used to analyze the parametric data and Chi-square test for categorical variables. Results: During the postoperative 48 h, there was marked reduction in morphine requirements in Group B compared to Group C, (8.6 ± 0.94 mg vs. 18.83 ± 3.4 mg respectively, P = 0.2), lower postoperative pain scores, shorter extubation time (117 ± 10 min vs. 195 ± 19 min, respectively, P = 0.03), better respiratory parameters (PaO2/FiO2, PaCO2 and pH), with no incidence of wound infection, no differences in ICU or hospital stay duration. The plasma concentration of bupivacaine remained below the toxic threshold (at T24, 1.2 ug/ml ± 0.3 and T48 h 1.7 ± 0.3 ug/ml). Conclusion: Continuous presternal bupivacaine infusion has resulted in better postoperative analgesia, reduction in morphine requirements, shorter time to extubation, and better postoperative respiratory parameters than the control group. PMID:25566704

  3. Cardiac lymphoscintigraphy following closed-chest catheter injection of radiolabeled colloid into the myocardium of dogs: concise communication

    SciTech Connect

    Osbakken, M.D.; Kopiwoda, S.Y.; Swan, A.; Castronovo, F.P.; Strauss, H.W.

    1982-10-01

    A catheter technique for injection of radiolabeled colloids into the myocardium was developed and tested in a series of 15 dogs. A multipurpose angiographic catheter was modified to permit an inner core of PE-50 polyethylene tubing, tipped with a 23-gage needle, to pass through the lumen for intra-myocardial injection of radiocolloids. For injection of the left ventricle, the catheter is introduced through the femoral artery: for the right ventricle, the femoral vein. The catheter advanced under fluoroscopy until the desired surface for injection is reached. The inner core is then extended to lodge the needle in the endocardium. A mixture of Renografin (to confirm the endocardial injection site) and radiolabeled colloid was injected in 13 animals. Ten minutes after injection, scintigraphy was begun and continued for up to 6 hr. In three dogs the procedure was repeated 3 or 4 times. From two to five nodes were visible in all animals, irrespective of whether the right or left ventricular myocardium was injected. In two animals the injection was given intravenously, and no nodes were seen. These data suggest that cardiac lymphatic drainage can be studied with a catheter injection method.

  4. Successful radiofrequency ablation of atrial tachycardias in surgically repaired Ebstein's anomaly using the Carto XP system and the QwikStar catheter.

    PubMed

    Drago, Fabrizio; Brancaccio, Gianluca; Grutter, Giorgia; De Santis, Antonella; Fazio, Giovanni; Silvetti, Massimo Stefano

    2007-06-01

    We describe the case of a child with three different atrial tachyarrhythmias originating from the right atrium, in whom a limited modified maze procedure was performed during surgical repair of an Ebstein's anomaly. Successful radiofrequency transcatheter ablation of all atrial tachyarrhythmias, one re-entrant and two focal, was obtained using the Carto XP EP three-dimensional navigation and ablation system, the new QwikMap software technology and the new mapping/ablation QwikStar multipolar catheter. No conventional mapping was used in addition to the three-dimensional system. Total procedural time was about 3 h and fluoroscopy time was 40 min. There were neither recurrences of the tachycardias nor complications during the follow-up (15 months).

  5. [Catheter ablation of atrial fibrillation: Health Technology Assessment Report from the Italian Association of Arrhythmology and Cardiac Pacing (AIAC)].

    PubMed

    Themistoclakis, Sakis; Tritto, Massimo; Bertaglia, Emanuele; Berto, Patrizia; Bongiorni, Maria Grazia; Catanzariti, Domenico; De Fabrizio, Giuseppe; De Ponti, Roberto; Grimaldi, Massimo; Pandozi, Claudio; Tondo, Claudio; Gulizia, Michele

    2011-11-01

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and significantly impact patients' quality of life, morbidity and mortality. The number of affected patients is expected to increase as well as the costs associated with AF management, mainly driven by hospitalizations. Over the last decade, catheter ablation techniques targeting pulmonary vein isolation have demonstrated to be effective in treating AF and preventing AF recurrence. This Health Technology Assessment report of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) aims to define the current role of catheter ablation of AF in terms of effectiveness, efficiency and appropriateness. On the basis of an extensive review of the available literature, this report provides (i) an overview of the epidemiology, clinical impact and socio-economic burden of AF; (ii) an evaluation of therapeutic options other than catheter ablation of AF; and (iii) a detailed presentation of clinical outcomes and cost-benefit ratio associated with catheter ablation. The costs of catheter ablation of AF in Italy were obtained using a bottom-up analysis of a resource utilization survey of 52 hospitals that were considered a representative sample, including 4 Centers that contributed with additional unit cost information in a separate questionnaire. An analysis of budget impact was also performed to evaluate the impact of ablation on the management costs of AF. Results of this analysis show that (1) catheter ablation is effective, safe and superior to antiarrhythmic drug therapy in maintaining sinus rhythm; (2) the cost of an ablation procedure in Italy typically ranges from €8868 to €9455, though current reimbursement remains insufficient, covering only about 60% of the costs; (3) the costs of follow-up are modest (about 8% of total costs); (4) assuming an adjustment of reimbursement to the real cost of an ablation procedure and a 5-10% increase in the annual rate of ablation procedures, after

  6. Initial feasibility testing of limited field of view magnetic resonance thermometry using a local cardiac radiofrequency coil.

    PubMed

    Volland, Nelly A; Kholmovski, Eugene G; Parker, Dennis L; Hadley, J Rock

    2013-10-01

    The visualization of lesion formation in real time is one potential benefit of carrying out radiofrequency ablation under magnetic resonance (MR) guidance in the treatment of atrial fibrillation. MR thermometry has the potential to detect such lesions. However, performing MR thermometry during cardiac radiofrequency ablation requires high temporal and spatial resolution and a high signal-to-noise ratio. In this study, a local MR coil (2-cm diameter) was developed to investigate the feasibility of performing limited field of view MR thermometry with high accuracy and speed. The local MR coil allowed high-resolution (1 × 1 × 3 mm(3)) image acquisitions in 76.3 ms with a field of view 64 × 32 mm(2) during an open-chest animal experiment. This represents a 4-fold image acquisition acceleration and an 18-fold field of view reduction compared to that achieved using external MR coils. The signal sensitivity achieved using the local coil was over 20 times greater than that achievable using external coils with the same scan parameters. The local coil configuration provided fewer artifacts and sharper and more stable images. These results demonstrate that MR thermometry can be performed in the heart wall and that lesion formation can be observed during radiofrequency ablation procedures in a canine model.

  7. Minimal Use of Fluoroscopy to Reduce Fetal Radiation Exposure during Radiofrequency Catheter Ablation of Maternal Supraventricular Tachycardia

    PubMed Central

    Raman, Ajay Sundara; Hariharan, Ramesh

    2015-01-01

    Electrophysiologic procedures in the young engender concern about the potential long-term effects of radiation exposure. This concern is manifold if such procedures are contemplated during pregnancy. Catheter ablations in pregnancy are indicated only in the presence of an unstable tachycardia that cannot be controlled by antiarrhythmic agents. This report describes the case of an 18-year-old pregnant woman and our stratagem to minimize irradiation of the mother and the fetus. PMID:25873828

  8. Minimal use of fluoroscopy to reduce fetal radiation exposure during radiofrequency catheter ablation of maternal supraventricular tachycardia.

    PubMed

    Raman, Ajay Sundara; Sharma, Saumya; Hariharan, Ramesh

    2015-04-01

    Electrophysiologic procedures in the young engender concern about the potential long-term effects of radiation exposure. This concern is manifold if such procedures are contemplated during pregnancy. Catheter ablations in pregnancy are indicated only in the presence of an unstable tachycardia that cannot be controlled by antiarrhythmic agents. This report describes the case of an 18-year-old pregnant woman and our stratagem to minimize irradiation of the mother and the fetus. PMID:25873828

  9. Successful radiofrequency catheter ablation of a right posterolateral bypass tract in a patient with Wolff-Parkinson-White syndrome after a previous failed ablative procedure: taking the high road.

    PubMed

    Cohen, T J

    2000-07-01

    A 16-year-old high school basketball player with symptomatic Wolff-Parkinson-White syndrome underwent an unsuccessful radiofrequency catheter ablative procedure from the femoral venous approach. During this procedure, the patient received 30 applications of radiofrequency energy without injury to the accessory pathway. The patient was treated with flecinide 100 mg orally twice daily and rescheduled for a second ablative procedure via the right internal jugular venous approach. At the second session, prior to any right internal jugular venous applications, 3 additional applications were delivered via the right femoral venous approach using a different catheter, without success. A single radiofrequency energy application from the right internal jugular venous approach eliminated the bypass tract in approximately 2 seconds. The superior approach achieved a more stable catheter position thereby eliminating the bypass tract. In conclusion, an alternative plan of attack should be considered after multiple failures from a given approach. In other words, take the high road if you can't take the low road.

  10. A randomized prospective mechanistic cardiac magnetic resonance study correlating catheter stability, late gadolinium enhancement and 3 year clinical outcomes in robotically assisted vs. standard catheter ablation

    PubMed Central

    Arujuna, Aruna; Karim, Rashed; Zarinabad, Niloufar; Gill, Jaspal; Rhode, Kawal; Schaeffter, Tobias; Wright, Matthew; Rinaldi, C. Aldo; Cooklin, Michael; Razavi, Reza; O'Neill, Mark D.; Gill, Jaswinder S.

    2015-01-01

    Aims To prospectively compare cardiac magnetic resonance late gadolinium enhancement (LGE) findings created by standard vs. robotically assisted catheter ablation lesions and correlate these with clinical outcomes. Methods and results Forty paroxysmal atrial fibrillation patients (mean age 54 ± 13.8 years) undergoing first left atrial ablation were randomized to either robotic-assisted navigation (Hansen Sensei® X) or standard navigation. Pre-procedural, acute (24 h post-procedure) and late (beyond 3 months) scans were performed with LGE and T2W imaging sequences and percentage circumferential enhancement around the pulmonary vein (PV) antra were quantified. Baseline pre-procedural enhancements were similar in both groups. On acute imaging, mean % encirclements by LGE and T2W signal were 72% and 80% in the robotic group vs. 60% (P = 0.002) and 76%(P = 0.45) for standard ablation. On late imaging, the T2W signal resolved to baseline in both groups. Late gadolinium enhancement remained the predominant signal with 56% encirclement in the robotic group vs. 45% in the standard group (P = 0.04). At 6 months follow-up, arrhythmia-free patients had an almost similar mean LGE encirclement (robotic 64%, standard 60%, P = 0.45) but in recurrences, LGE was higher in the robotic group (43% vs. 30%, P = 0.001). At mean 3 years follow-up, 1.3 procedures were performed in the robotic group compared with 1.9 (P < 0.001) in the standard to achieve a success rate of 80% vs. 75%. Conclusion Robotically assisted ablation results in greater LGE around the PV antrum. Effective lesions created through improved catheter stability and contact force during initial treatment may have a role in reducing subsequent re-do procedures. PMID:25687748

  11. Adenosine-induced atrioventricular block: a rapid and reliable method to assess surgical and radiofrequency catheter ablation of accessory atrioventricular pathways.

    PubMed

    Keim, S; Curtis, A B; Belardinelli, L; Epstein, M L; Staples, E D; Lerman, B B

    1992-04-01

    Adenosine has been shown to inhibit anterograde and retrograde conduction through the atrioventricular (AV) node while having little or no effect on accessory pathway conduction. Its rapid onset of action and short half-life make it particularly suitable for repetitive measurements. In this study, the utility of adenosine was tested in assessing completeness of accessory pathway ablation. Sixteen patients with an accessory pathway were studied (eight surgical ablations, eight catheter ablations with radiofrequency energy). Before ablation, no accessory pathway was sensitive to adenosine. Twelve patients with pre-excitation showed high grade AV node block with maximal pre-excitation on the administration of adenosine during atrial pacing. Four patients with a concealed accessory pathway demonstrated high grade AV block without evidence of latent anterograde accessory pathway conduction. Preablation ventriculoatrial (VA) block was not observed in any of the 16 patients in response to adenosine during ventricular pacing. Immediately after accessory pathway ablation, all patients developed AV and VA block with the administration of adenosine during atrial and ventricular pacing, respectively. These findings were confirmed during follow-up study 1 week later. Atrioventricular block during atrial and ventricular pacing with adenosine affords a reliable and immediate assessment of successful pathway ablation. PMID:1552087

  12. Urinary catheters

    MedlinePlus

    Catheter - urine; Foley catheter; Indwelling catheter; Suprapubic catheters ... many sizes, materials (latex, silicone, Teflon™), and types (Foley, straight, coude tip). A Foley catheter, for example, ...

  13. Use of a Simply Modified Drainage Catheter for Peritoneal Dialysis Treatment of Acute Renal Failure Associated With Cardiac Surgery in Infants

    PubMed Central

    Chen, Qiang; Cao, Hua; Hu, Yun-Nan; Chen, Liang-Wan; He, Jia-jun

    2014-01-01

    Abstract Acute renal failure (ARF) is a common complication in infants who undergo cardiac surgery in the intensive care unit. We report on a modified drainage catheter used in peritoneal dialysis (PD) for the treatment of ARF associated with cardiac surgery in infants. Thirty-nine infants with congenital heart disease undergoing cardiac surgery who developed ARF at our center between January 2009 and January 2012 were assessed. A modified drainage catheter for PD was used in these infants. Their demographic, clinical, and surgical data were analyzed. Thirty infants with ARF were cured by PD, and the other 9 died in the first 48 hours because of the severity of the acute cardiac dysfunction. All these infants were dependent upon mechanical ventilation during the postoperative period and used vasoactive drugs. In the survival group, the interval between the procedure and initiation of PD was 13.6 ± 6.5 (range, 6–30) hours. PD duration was 3.9 ± 0.9 (3–6) days. Minor complications were encountered in some patients (asymptomatic hypokalemia, hyperglycemia, and thrombocytopenia). These complications were readily treated by drugs or resolved spontaneously. Hemodynamics, cardiac function, and renal function improved significantly during PD. These data suggest that PD using a modified drainage catheter for ARF after cardiac surgery in infants is safe, feasible, inexpensive, and yields good results. PMID:25255020

  14. Prediction of Primary Slow-Pathway Ablation Success Rate according to the Characteristics of Junctional Rhythm Developed during the Radiofrequency Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia

    PubMed Central

    Bagherzadeh, Ataallah; Rezaee, Mohammad Esmaeel; Farahani, Maryam Moshkani

    2011-01-01

    Background Nowadays, developed junctional rhythm (JR) that occurs during slow-pathway radiofrequency (RF) catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) has been focused upon as a highly sensitive surrogate end point for successful radiofrequency ablation. This study was conducted to assess the relationship between the presence and pattern of developed JR during the RF ablation of AVNRT and a successful outcome. Methods Seventy-five patients aged between 14 and 88 who underwent slow-pathway RF ablation due to symptomatic AVNRT were enrolled into the study and received a total of 162 RF energy applications. Combined anatomic and electrogram mapping approach was used for slow-pathway RF ablation. The ablation procedure consisted of 60-second, 60 °C temperature-controlled energy delivery. After each ablation pulse, successful ablation was assessed according to the loss of AVNRT inducibility via isoproterenol infusion. Four different patterns were considered for the developed JR, namely sparse, intermittent, continuous, and transient block. Success ablation rate was assessed with respect to the position, pattern, and number of junctional beats. Results Successful RF ablation with a loss of AVNRT inducibility was achieved in 43 (57.3%) patients using 119 RF energy applications (73.5%). JR developed in 133 of the 162 (82.1%) applications with a given sensitivity of 90.8% and low specificity of 41.9% as an end point of successful RF ablation, with a negative predictive value of 62.1%. The mean number of the developed junctional beats was significantly higher in the successful ablations (p value < 0.001), and the ROC analysis revealed that the best cut-off point of the cumulative junctional beats for identifying accurate AVNRT ablation therapy is 14 beats with 90.76 % sensitivity and 90.70% specificity. There were no significant differences in terms of successful ablation rates according to the four different patterns of JR and its positions (p

  15. Continuous cardiac output measurement by un-calibrated pulse wave analysis and pulmonary artery catheter in patients with septic shock.

    PubMed

    Ganter, Michael T; Alhashemi, Jamal A; Al-Shabasy, Adel M; Schmid, Ursina M; Schott, Peter; Shalabi, Sanaa A; Badri, Ahmed M; Hartnack, Sonja; Hofer, Christoph K

    2016-02-01

    Septic shock is a serious medical condition. With increased concerns about invasive techniques, a number of non-invasive and semi-invasive devices measuring cardiac output (CO) have become commercially available. The aim of the present study was to determine the accuracy, precision and trending abilities of the FloTrac and the continuous pulmonary artery catheter thermodilution technique determining CO in septic shock patients. Consecutive septic shock patients were included in two centres and CO was measured every 4 h up to 48 h by FloTrac (APCO) and by pulmonary artery catheter (PAC) using the continuous (CCO) and intermittent (ICO) technique. Forty-seven septic shock patients with 326 matched sets of APCO, CCO and ICO data were available for analysis. Bland and Altman analysis revealed a mean bias ±2 SD of 0.0 ± 2.14 L min(-1) for APCO-ICO (%error = 34.5 %) and 0.23 ± 2.55 L min(-1) for CCO-ICO (%error = 40.4 %). Trend analysis showed a concordance of 85 and 81 % for APCO and CCO, respectively. In contrast to CCO, APCO was influenced by systemic vascular resistance and by mean arterial pressure. In septic shock patients, APCO measurements assessed by FloTrac but also the established CCO measurements using the PAC did not meet the currently accepted statistical criteria indicating acceptable clinical performance.

  16. Safety and efficacy of multipolar pulmonary vein ablation catheter vs. irrigated radiofrequency ablation for paroxysmal atrial fibrillation: a randomized multicentre trial

    PubMed Central

    McCready, J.; Chow, A. W.; Lowe, M. D.; Segal, O. R.; Ahsan, S.; de Bono, J.; Dhaliwal, M.; Mfuko, C.; Ng, A.; Rowland, E. R.; Bradley, R. J. W.; Paisey, J.; Roberts, P.; Morgan, J. M.; Sandilands, A.; Yue, A.; Lambiase, P. D.

    2014-01-01

    Aims The current challenge in atrial fibrillation (AF) treatment is to develop effective, efficient, and safe ablation strategies. This randomized controlled trial assesses the medium-term efficacy of duty-cycled radiofrequency ablation via the circular pulmonary vein ablation catheter (PVAC) vs. conventional electro-anatomically guided wide-area circumferential ablation (WACA). Methods and results One hundred and eighty-eight patients (mean age 62 ± 12 years, 116 M : 72 F) with paroxysmal AF were prospectively randomized to PVAC or WACA strategies and sequentially followed for 12 months. The primary endpoint was freedom from symptomatic or documented >30 s AF off medications for 7 days at 12 months post-procedure. One hundred and eighty-three patients completed 12 m follow-up. Ninety-four patients underwent PVAC PV isolation with 372 of 376 pulmonary veins (PVs) successfully isolated and all PVs isolated in 92 WACA patients. Three WACA and no PVAC patients developed tamponade. Fifty-six percent of WACA and 60% of PVAC patients were free of AF at 12 months post-procedure (P = ns) with a significant attrition rate from 77 to 78%, respectively, at 6 months. The mean procedure (140 ± 43 vs. 167 ± 42 min, P<0.0001), fluoroscopy (35 ± 16 vs. 42 ± 20 min, P<0.05) times were significantly shorter for PVAC than for WACA. Two patients developed strokes within 72 h of the procedure in the PVAC group, one possibly related directly to PVAC ablation in a high-risk patient and none in the WACA group (P = ns). Two of the 47 patients in the PVAC group who underwent repeat ablation had sub-clinical mild PV stenoses of 25–50% and 1 WACA patient developed delayed severe PV stenosis requiring venoplasty. Conclusion The pulmonary vein ablation catheter is equivalent in efficacy to WACA with reduced procedural and fluoroscopy times. However, there is a risk of thrombo-embolic and pulmonary stenosis complications which needs to be addressed and prospectively monitored. Clinical

  17. Radiofrequency Catheter Ablation Improves the Quality of Life Measured with a Short Form-36 Questionnaire in Atrial Fibrillation Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Choi, Jong-Il; Kim, Young-Hoon

    2016-01-01

    Background The main purpose of performing radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) patients is to improve the quality of life (QoL) and alleviate AF-related symptoms. We aimed to determine the qualitative and quantitative effects of RFCA on the QoL in AF patients. Methods We performed a systemic review and meta-analysis using a random effects model. We searched for the studies that reported the physical component summary score (PCS) and mental component summary score (MCS) of the short form-36, a validated system to assess and quantify the QoL, before and after RFCA in AF patients. PCS and MCS are T-scores with a mean of 50 and standard deviation of 10. Results Of the 470 studies identified through systematic search, we included 13 studies for pre-RFCA vs. the post-RFCA analysis and 5 studies for treatment success vs. AF recurrence analyses. In the pre-RFCA vs. post-RFCA analysis, RFCA was associated with a significant increase in both the PCS (weighted mean difference [WMD] = 6.33 [4.81–7.84]; p < 0.001) and MCS (WMD = 7.80 [6.15–9.44]; p < 0.001). The ΔPCS (post-RFCA PCS–pre-RFCA PCS) and ΔMCS values were used for the treatment success vs. AF recurrence analysis. Patients with successful ablation had a higher ΔPCS (WMD = 7.46 [4.44–10.49]; p < 0.001) and ΔMCS (WMD = 7.59 [4.94–10.24]; p < 0.001). Conclusions RFCA is associated with a significant increase in the PCS and MCS in AF patients. Patients without AF recurrence after RFCA had a better improvement in the PCS and MCS than patients who had AF recurrence. PMID:27681507

  18. Development of an Electrophysiology (EP)-Enabled Intracardiac Ultrasound Catheter Integrated With NavX 3-Dimensional Electrofield Mapping for Guiding Cardiac EP Interventions

    PubMed Central

    Li, Xiao Kui; Pemberton, James; Thomenius, Kai; Dentinger, Aaron; Lowe, Robert I.; Ashraf, Muhammad; Shung, K. Kirk; Chia, Raymond; Stephens, Douglas N.; O'Donnell, Matthew; Mahajan, Aman; Balaji, Seshadri; Shivkumar, Kalyanam; Sahn, David J.

    2015-01-01

    Objective We have developed an integrated high-resolution intracardiac echocardiography (ICE) catheter for electrophysiology (EP) testing, which can be coregistered in 3-dimensional space with EP testing and ablation catheters using electrofield sensing. Methods Twelve open-chest pigs (34–55 kg) and 3 closed-chest pigs were studied. After introduction from the jugular or femoral venous locations, the 9F side-looking, highly steerable (0°–180°), 64-element array catheters could be manipulated easily throughout the right side of the heart. Multisite cardiac pacing was performed for assessing left ventricular (LV) synchrony using tissue Doppler methods. Also, in the open-chest pigs, right atrial (RA) and right ventricular (RV) ablations were performed with a separate radio frequency catheter under fluoroscopic guidance and visualized with ICE to characterize the changes. In the 3 closed-chest pigs, electrofield NavX 3-dimensional coregistration (St Jude Medical Corp, Minneapolis, MN) allowed us to test whether this additional feature could shorten the time necessary to perform 4 targeted ablations in each animal while imaging the ablation catheter and the adjacent region by ICE. Results Intracardiac anatomy, tricuspid, aortic, pulmonary, and mitral valve function, and pulmonary vein flow were all imaged reproducibly from scanning locations in the RA or RV in all animals, along with assessment of cardiac motion and the effects of multisite pacing. Three-dimensional electrofield displays detailed the spatial relationship between the ICE catheter and ablation catheters such that the time to visualize and ablate 4 sites in each of the 3 closed-chest animals was reduced. Conclusions This new technology is a first step in the integration of ICE with EP procedures. PMID:17957051

  19. The Effects That Cardiac Motion has on Coronary Hemodynamics and Catheter Trackability Forces for the Treatment of Coronary Artery Disease: An In Vitro Assessment.

    PubMed

    Morris, Liam; Fahy, Paul; Stefanov, Florian; Finn, Ronan

    2015-12-01

    The coronary arterial tree experiences large displacements due to the contraction and expansion of the cardiac muscle and may influence coronary haemodynamics and stent placement. The accurate measurement of catheter trackability forces within physiological relevant test systems is required for optimum catheter design. The effects of cardiac motion on coronary flowrates, pressure drops, and stent delivery has not been previously experimentally assessed. A cardiac simulator was designed and manufactured which replicates physiological coronary flowrates and cardiac motion within a patient-specific geometry. A motorized delivery system delivered a commercially available coronary stent system and monitored the trackability forces along three phantom patient-specific thin walled compliant coronary vessels supported by a dynamic cardiac phantom model. Pressure drop variation is more sensitive to cardiac motion than outlet flowrates. Maximum pressure drops varied from 7 to 49 mmHg for a stenosis % area reduction of 56 to 90%. There was a strong positive linear correlation of cumulative trackability force with the cumulative curvature. The maximum trackability forces and curvature ranged from 0.24 to 0.87 N and 0.06 to 0.22 mm(-1) respectively for all three vessels. There were maximum and average percentage differences in trackability forces of (23-49%) and (1.9-5.2%) respectively when comparing a static pressure case with the inclusion of pulsatile flow and cardiac motion. Cardiac motion with pulsatile flow significantly altered (p value <0.001) the trackability forces along the delivery pathways with high local percentage variations and pressure drop measurements.

  20. Catheter-based Intramyocardial Injection of FGF1 or NRG1-loaded MPs Improves Cardiac Function in a Preclinical Model of Ischemia-Reperfusion

    PubMed Central

    Garbayo, Elisa; Gavira, Juan José; de Yebenes, Manuel Garcia; Pelacho, Beatriz; Abizanda, Gloria; Lana, Hugo; Blanco-Prieto, María José; Prosper, Felipe

    2016-01-01

    Cardiovascular protein therapeutics such as neuregulin (NRG1) and acidic-fibroblast growth factor (FGF1) requires new formulation strategies that allow for sustained bioavailability of the drug in the infarcted myocardium. However, there is no FDA-approved injectable protein delivery platform due to translational concerns about biomaterial administration through cardiac catheters. We therefore sought to evaluate the efficacy of percutaneous intramyocardial injection of poly(lactic-co-glycolic acid) microparticles (MPs) loaded with NRG1 and FGF1 using the NOGA MYOSTAR injection catheter in a porcine model of ischemia-reperfusion. NRG1- and FGF1-loaded MPs were prepared using a multiple emulsion solvent-evaporation technique. Infarcted pigs were treated one week after ischemia-reperfusion with MPs containing NRG1, FGF1 or non-loaded MPs delivered via clinically-translatable percutaneous transendocardial-injection. Three months post-treatment, echocardiography indicated a significant improvement in systolic and diastolic cardiac function. Moreover, improvement in bipolar voltage and decrease in transmural infarct progression was demonstrated by electromechanical NOGA-mapping. Functional benefit was associated with an increase in myocardial vascularization and remodeling. These findings in a large animal model of ischemia-reperfusion demonstrate the feasibility and efficacy of using MPs as a delivery system for growth factors and provide strong evidence to move forward with clinical studies using therapeutic proteins combined with catheter-compatible biomaterials. PMID:27184924

  1. Measurement of cardiac function using pressure–volume conductance catheter technique in mice and rats

    PubMed Central

    Pacher, Pál; Nagayama, Takahiro; Mukhopadhyay, Partha; Bátkai, Sándor; Kass, David A

    2008-01-01

    Ventricular pressure–volume relationships have become well established as the most rigorous and comprehensive ways to assess intact heart function. Thanks to advances in miniature sensor technology, this approach has been successfully translated to small rodents, allowing for detailed characterization of cardiovascular function in genetically engineered mice, testing effects of pharmacotherapies and studying disease conditions. This method is unique for providing measures of left ventricular (LV) performance that are more specific to the heart and less affected by vascular loading conditions. Here we present descriptions and movies for procedures employing this method (anesthesia, intubation and surgical techniques, calibrations). We also provide examples of hemodynamics measurements obtained from normal mice/rats, and from animals with cardiac hypertrophy/heart failure, and describe values for various useful load-dependent and load-independent indexes of LV function obtained using different types of anesthesia. The completion of the protocol takes 1–4 h (depending on the experimental design/end points). PMID:18772869

  2. Preparation of liposomal amiodarone and investigation of its cardiomyocyte-targeting ability in cardiac radiofrequency ablation rat model.

    PubMed

    Zhuge, Ying; Zheng, Zhi-Feng; Xie, Mu-Qing; Li, Lin; Wang, Fang; Gao, Feng

    2016-01-01

    The objective of this study was to develop an amiodarone hydrochloride (ADHC)-loaded liposome (ADHC-L) formulation and investigate its potential for cardiomyocyte targeting after cardiac radiofrequency ablation (CA) in vivo. The ADHC-L was prepared by thin-film method combined with ultrasonication and extrusion. The preparation process was optimized by Box-Behnken design with encapsulation efficiency as the main evaluation index. The optimum formulation was quantitatively obtained with a diameter of 99.9±0.4 nm, a zeta potential of 35.1±10.9 mV, and an encapsulation efficiency of 99.5%±13.3%. Transmission electron microscopy showed that the liposomes were spherical particles with integrated bilayers and well dispersed with high colloidal stability. Pharmacokinetic studies were investigated in rats after intravenous administration, which revealed that compared with free ADHC treatment, ADHC-L treatment showed a 5.1-fold increase in the area under the plasma drug concentration-time curve over a period of 24 hours (AUC0-24 h) and an 8.5-fold increase in mean residence time, suggesting that ADHC-L could facilitate drug release in a more stable and sustained manner while increasing the circulation time of ADHC, especially in the blood. Biodistribution studies of ADHC-L demonstrated that ADHC concentration in the heart was 4.1 times higher after ADHC-L treatment in CA rat model compared with ADHC-L sham-operated treatment at 20 minutes postinjection. Fluorescence imaging studies further proved that the heart-targeting ability of ADHC-L was mainly due to the CA in rats. These results strongly support that ADHC-L could be exploited as a potential heart-targeting drug delivery system with enhanced bioavailability and reduced side effects for arrhythmia treatment after CA. PMID:27313453

  3. Preparation of liposomal amiodarone and investigation of its cardiomyocyte-targeting ability in cardiac radiofrequency ablation rat model

    PubMed Central

    Zhuge, Ying; Zheng, Zhi-Feng; Xie, Mu-Qing; Li, Lin; Wang, Fang; Gao, Feng

    2016-01-01

    The objective of this study was to develop an amiodarone hydrochloride (ADHC)-loaded liposome (ADHC-L) formulation and investigate its potential for cardiomyocyte targeting after cardiac radiofrequency ablation (CA) in vivo. The ADHC-L was prepared by thin-film method combined with ultrasonication and extrusion. The preparation process was optimized by Box–Behnken design with encapsulation efficiency as the main evaluation index. The optimum formulation was quantitatively obtained with a diameter of 99.9±0.4 nm, a zeta potential of 35.1±10.9 mV, and an encapsulation efficiency of 99.5%±13.3%. Transmission electron microscopy showed that the liposomes were spherical particles with integrated bilayers and well dispersed with high colloidal stability. Pharmacokinetic studies were investigated in rats after intravenous administration, which revealed that compared with free ADHC treatment, ADHC-L treatment showed a 5.1-fold increase in the area under the plasma drug concentration–time curve over a period of 24 hours (AUC0–24 h) and an 8.5-fold increase in mean residence time, suggesting that ADHC-L could facilitate drug release in a more stable and sustained manner while increasing the circulation time of ADHC, especially in the blood. Biodistribution studies of ADHC-L demonstrated that ADHC concentration in the heart was 4.1 times higher after ADHC-L treatment in CA rat model compared with ADHC-L sham-operated treatment at 20 minutes postinjection. Fluorescence imaging studies further proved that the heart-targeting ability of ADHC-L was mainly due to the CA in rats. These results strongly support that ADHC-L could be exploited as a potential heart-targeting drug delivery system with enhanced bioavailability and reduced side effects for arrhythmia treatment after CA. PMID:27313453

  4. Role of Cardiac Magnetic Resonance Imaging in the Management and Treatment of Ventricular Tachycardia in Patients With Structural Heart Disease.

    PubMed

    Mehrotra, Amit K; Callans, David

    2015-01-01

    Treatment for ventricular tachycardia (VT) generally includes 1 or more of the following options: antiarrhythmic therapy, an implantable cardioverter-defibrillator and/or catheter ablation. Catheter ablation is performed with an electroanatomic mapping system to define the heart's 3D anatomy, as well as regions of scar. Radiofrequency energy is then applied to areas of abnormal substrate within which are located channels critical to the VT circuit. Cardiac magnetic resonance (CMR) imaging is a non-invasive modality that provides high-resolution images of cardiac structure and function. CMR has become a very useful tool for sudden cardiac death risk stratification and to facilitate successful radiofrequency ablation of VT in patients with abnormal cardiac substrate. The role of CMR in the management and treatment of VT in patients with structural heart disease is reviewed.

  5. Image-based view-angle independent cardiorespiratory motion gating and coronary sinus catheter tracking for x-ray-guided cardiac electrophysiology procedures

    NASA Astrophysics Data System (ADS)

    Panayiotou, Maria; Rhode, Kawal S.; King, Andrew P.; Ma, Yingliang; Cooklin, Michael; O'Neill, Mark; Gill, Jaswinder; Rinaldi, C. A.; Housden, R. James

    2015-10-01

    Determination of the cardiorespiratory phase of the heart has numerous applications during cardiac imaging. In this article we propose a novel view-angle independent near-real time cardiorespiratory motion gating and coronary sinus (CS) catheter tracking technique for x-ray fluoroscopy images that are used to guide cardiac electrophysiology procedures. The method is based on learning CS catheter motion using principal component analysis and then applying the derived motion model to unseen images taken at arbitrary projections, using the epipolar constraint. This method is also able to track the CS catheter throughout the x-ray images in any arbitrary subsequent view. We also demonstrate the clinical application of our model on rotational angiography sequences. We validated our technique in normal and very low dose phantom and clinical datasets. For the normal dose clinical images we established average systole, end-expiration and end-inspiration gating success rates of 100%, 85.7%, and 92.3%, respectively. For very low dose applications, the technique was able to track the CS catheter with median errors not exceeding 1 mm for all tracked electrodes. Average gating success rates of 80.3%, 71.4%, and 69.2% were established for the application of the technique on clinical datasets, even with a dose reduction of more than 10 times. In rotational sequences at normal dose, CS tracking median errors were within 1.2 mm for all electrodes, and the gating success rate was 100%, for view angles from RAO 90° to LAO 90°. This view-angle independent technique can extract clinically useful cardiorespiratory motion information using x-ray doses significantly lower than those currently used in clinical practice.

  6. Transient sinus node dysfunction following sinus node artery occlusion due to radiofrequency catheter ablation of the septal superior vena cava-right atrium junction.

    PubMed

    Kitamura, Takeshi; Fukamizu, Seiji; Arai, Ken; Hojo, Rintaro; Aoyama, Yuya; Komiyama, Kota; Sakurada, Harumizu; Hiraoka, Masayasu

    2016-01-01

    We performed catheter ablation to septal superior vena cava (SVC)-right atrium (RA) junction rapid firing in a 57-year-old man with paroxysmal atrial fibrillation. He later experienced transient sinus node dysfunction resulting from injury to the sinus node artery (SNA), which branched only from the proximal region of the left circumflex artery. The direction of the SNA should be considered during catheter ablation at the septal SVC-RA junction, especially if the sinus node is supplied by only one SNA from the right coronary artery or the left circumflex artery.

  7. Development of a Novel Shock Wave Catheter Ablation System

    NASA Astrophysics Data System (ADS)

    Yamamoto, H.; Hasebe, Yuhi; Kondo, Masateru; Fukuda, Koji; Takayama, Kazuyoshi; Shimokawa, Hiroaki

    Although radio-frequency catheter ablation (RFCA) is quite effective for the treatment tachyarrhythmias, it possesses two fundamental limitations, including limited efficacy for the treatment of ventricular tachyarrhythmias of epicardial origin and the risk of thromboembolism. Consequently, new method is required, which can eradicate arrhythmia source in deep part of cardiac muscle without heating. On the other hand, for a medical application of shock waves, extracorporeal shock wave lithotripter (ESWL) has been established [1]. It was demonstrated that the underwater shock focusing is one of most efficient method to generate a controlled high pressure in a small region [2]. In order to overcome limitations of existing methods, we aimed to develop a new catheter ablation system with underwater shock waves that can treat myocardium at arbitrary depth without causing heat.

  8. Inducing valvular regurgitation in mice via thermal ablation of cardiac valves.

    PubMed

    Mulchrone, Ashley M; Brace, Christopher L; Hacker, Timothy A; Chesler, Naomi C

    2014-01-01

    This study presents early data in the development of a novel mouse model of heart failure utilizing thermal ablation on cardiac valves to induce valvular regurgitation. Thermal ablation of the valve was achieved through the application of radiofrequency (RF) electrical current. The objective was to apply enough energy to induce valve stiffening and retraction, which was hypothesized to produce valve insufficiency and blood regurgitation in vivo. Preliminary studies were performed to develop a workable energy delivery catheter that could be inserted through the carotid artery to the aortic valve. Catheter position between the aortic valve leaflets was verified by echocardiography. Valve function was evaluated before and after the thermal insult using Doppler measurements near the valve inflow and outflow, and early results demonstrate that the energy delivery catheter could successfully induce acute valve insufficiency. Further study is needed to refine the catheter to provide greater control over the degree of thermal damage and resulting changes in cardiac physiology.

  9. Transcatheter desiccation of the canine left ventricle using radiofrequency energy: a pilot study

    SciTech Connect

    Huang, S.K.; Graham, A.R.; Hoyt, R.H.; Odell, R.C.

    1987-07-01

    Catheter ablation of cardiac tissue by means of direct-current electrical energy is associated with several complications. We assessed the efficacy and safety of closed-chest catheter desiccation of the left ventricular myocardium with microbipolar radiofrequency (RF) energy (750 kHz) in five dogs. The unipolar configuration was used with RF energy delivered between the tip electrode of a standard No. 7F tripolar catheter in the left ventricle and an external patch electrode on the left lateral chest wall. A single application with different RF energy settings (100 J, 200 J, and 300 J) was delivered to three individual endocardial sites of the left ventricle. Ventricular tachycardia or fibrillation was not observed during energy application and 24 hours after ablation, as assessed by a Holter recording. There was no damage to the electrode catheter. Dogs were killed on the fifth day. Pathology showed well-delineated ovoid or round-shaped coagulation necrosis at the ablation sites. Microscopic findings consisted of circumscribed areas of necrosis surrounded by a zone of fibroblastic and mononuclear proliferation. In conclusion, catheter ablation of the ventricular myocardium with RF energy is an apparently safe procedure and can effectively produce discrete areas of injury without destruction of surrounding uninvolved myocardium. This method offers potential clinical utility for catheter ablation of refractory sustained ventricular tachycardia.

  10. In vivo intracardiac OCT imaging through percutaneous access: towards image guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2012-01-01

    BACKGROUND Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. We aim to develop optical coherence tomography (OCT) as an imaging guidance for RFA. OBJECTIVES The purpose of this study is to evaluate the feasibility of using OCT catheter to image endocardia wall in active beating hearts through percutaneous access. This is a critical step toward image guided RFA in a clinic setting. METHODS A cone-scanning forward-viewing OCT catheter was advanced into active beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardia wall. The images were then acquired at 10 frames per second at an axial resolution and lateral resolution of 15 μm. RESULTS We report the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. We are able to acquire high quality OCT images in active beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium and readily evaluate catheter-tissue contact. CONCLUSIONS It is feasible to acquire OCT images in beating hearts through percutaneous access. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  11. Catheter ablation of a monofocal premature ventricular complex triggering idiopathic ventricular fibrillation.

    PubMed

    Takatsuki, S; Mitamura, H; Ogawa, S

    2001-07-01

    A 62 year old man was admitted for evaluation of recurrent episodes of syncope. A surface ECG showed frequent repetitive premature ventricular complexes of right ventricular outflow tract origin. Ventricular fibrillation was inducible by programmed electrical stimulation but otherwise cardiac evaluation was unremarkable. A diagnosis of idiopathic ventricular fibrillation was made and an implantable cardioverter-defibrillator (ICD) was installed. However, spontaneous ventricular fibrillation recurred, requiring repeated ICD discharges. The ventricular fibrillation was reproducibly triggered by a single premature ventricular complex with a specific QRS morphology. Radiofrequency catheter ablation was carried out to eradicate this complex. No ventricular fibrillation has developed after this procedure, and the patient does not require drug treatment.

  12. Catheter ablation of a polymorphic ventricular tachycardia inducing monofocal premature ventricular complex.

    PubMed

    Uemura, Takashi; Yamabe, Hiroshige; Tanaka, Yasuaki; Morihisa, Kenji; Kawano, Hiroaki; Kaikita, Koichi; Sumida, Hitoshi; Sugiyama, Seigo; Ogawa, Hisao

    2008-01-01

    Ventricular tachycardia originating from the right ventricular outflow tract (RVOT) is considered benign, but sometimes it causes polymorphic ventricular tachycardia and ventricular fibrillation, resulting in sudden cardiac death. A 58-year-old woman without structural heart disease was admitted for evaluation of recurrent episodes of syncope. Surface ECG showed frequent repetitive premature ventricular contraction (PVC) of RVOT origin. Polymorphic ventricular tachycardia triggered by the same PVC was documented by Holter ECG during an episode of syncope. Radiofrequency catheter ablation was performed to eradicate this PVC. No polymorphic ventricular tachycardia has developed after the procedure, and the patient has had no recurrence of syncope.

  13. Precision test apparatus for evaluating the heating pattern of radiofrequency ablation devices.

    PubMed

    Chang, I; Beard, B

    2002-11-01

    Radiofrequency has established itself as a useful technique for managing cardiac arrhythmias and treating soft tissue tumors. However, despite its pervasive use, many of the biophysical principals needed to fully understand and optimize the radiofrequency ablation technique have not been explored. We have designed a test rig that is useful for studying the heat transfer mechanisms that affect the outcome of radiofrequency ablation devices. Using both solid and liquid phantom materials, which simulate body tissues and blood, the test rig is designed for systematic testing of the effects of predictable flow patterns on the temperature profiles generated within the solid phantom. The test rig consists of a custom built thermistor array, a linear test chamber, and a radiofrequency generator. We calibrate the flow of a liquid phantom material to demonstrate that predictable laminar flow profiles are generated. To demonstrate the performance of the ablation system, we present preliminary data attained using a commercially available cardiac ablation catheter. The advantages of this test system are its flexibility, its reproducibility, its precision, and its low cost. Thus, it is ideally suited for studying a variety of complex ablation problems involving multiple tissues types and complex blood flow geometries.

  14. Catheter Ablation of Multiple Accessory Pathways in Duchenne Muscular Dystrophy

    PubMed Central

    Stöllberger, Claudia; Steger, Christine; Gatterer, Edmund

    2013-01-01

    A 23-year-old male with Duchenne muscular dystrophy (DMD) experienced self-limiting palpitations at age 19 years for the first time. Palpitations recurred not earlier than at age 23 years, and were attributed to narrow complex tachycardia, which could be terminated with adenosine. Since electrocardiography showed a delta-wave, Wolff-Parkinson-White (WPW) syndrome was diagnosed, ajmaline prescribed and radio-frequency catheter ablation of three accessory pathways carried out one week later. One day after ablation, however, a relapse of the supraventricular tachycardia occurred and was terminated with ajmaline. Re-entry tachycardia occurred a second time six days after ablation, and as before, it was stopped only with ajmaline. Despite administration of verapamil to prevent tachycardia, it occurred a third time four months after ablation. This case shows that cardiac involvement in DMD may manifest also as WPW-syndrome. In these patients, repeated radio-frequency catheter ablation of accessory pathways may be necessary to completely block the re-entry mechanism. PMID:23508228

  15. Real-time circumferential mapping catheter tracking for motion compensation in atrial fibrillation ablation procedures

    NASA Astrophysics Data System (ADS)

    Brost, Alexander; Bourier, Felix; Wimmer, Andreas; Koch, Martin; Kiraly, Atilla; Liao, Rui; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2012-02-01

    Atrial fibrillation (AFib) has been identified as a major cause of stroke. Radiofrequency catheter ablation has become an increasingly important treatment option, especially when drug therapy fails. Navigation under X-ray can be enhanced by using augmented fluoroscopy. It renders overlay images from pre-operative 3-D data sets which are then fused with X-ray images to provide more details about the underlying soft-tissue anatomy. Unfortunately, these fluoroscopic overlay images are compromised by respiratory and cardiac motion. Various methods to deal with motion have been proposed. To meet clinical demands, they have to be fast. Methods providing a processing frame rate of 3 frames-per-second (fps) are considered suitable for interventional electrophysiology catheter procedures if an acquisition frame rate of 2 fps is used. Unfortunately, when working at a processing rate of 3 fps, the delay until the actual motion compensated image can be displayed is about 300 ms. More recent algorithms can achieve frame rates of up to 20 fps, which reduces the lag to 50 ms. By using a novel approach involving a 3-D catheter model, catheter segmentation and a distance transform, we can speed up motion compensation to 25 fps which results in a display delay of only 40 ms on a standard workstation for medical applications. Our method uses a constrained 2-D/3-D registration to perform catheter tracking, and it obtained a 2-D tracking error of 0.61 mm.

  16. Cardiac tissue characterization using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh Moon, Rajinder; Hendon, Christine P.

    2014-03-01

    Cardiac tissue from swine and canine hearts were assessed using diffuse reflectance near-infrared spectroscopy (NIRS) ex vivo. Slope measured between 800-880 nm reflectance was found to reveal differences between epicardial fat and normal myocardium tissue. This parameter was observed to increase monotonically from measurements obtained from the onset of radiofrequency ablation (RFA). A sheathe-style fiber optic catheter was then developed to allow real-time sampling of the zone of resistive heating during RFA treatment. A model was developed and used to extract changes in tissue absorption and reduced scattering based on the steady-state diffusion approximation. It was found that key changes in tissue optical properties occur during application of RF energy and can be monitored using NIRS. These results encourage the development of NIRS integrated catheters for real-time guidance of the cardiac ablation treatment.

  17. In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2011-11-01

    Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  18. Evaluation of catheter ablation of periatrial ganglionic plexi in patients with atrial fibrillation.

    PubMed

    Danik, Stephan; Neuzil, Petr; d'Avila, Andre; Malchano, Zachary J; Kralovec, Stepan; Ruskin, Jeremy N; Reddy, Vivek Y

    2008-09-01

    Recent data suggests that the cardiac autonomic nervous system has an important role in the initiation and maintenance of atrial fibrillation (AF). This study investigated (1) the feasibility of identifying and targeting these autonomic ganglia using endocardial radiofrequency stimulation and ablation, respectively; (2) the efficacy of endocardial ablation to completely eliminate the vagal response elicited from epicardial stimulation; and (3) the effect of autonomic ablation on the acute inducibility of AF. The study included 18 patients referred for catheter ablation of suspected vagal-mediated AF. The endocardial left atrial surface was stimulated at high frequency (20 to 50 Hz) to elicit a vagal response. In selected patients (n = 5), pericardial access was obtained using a subxyphoid puncture to permit epicardial stimulation. Catheter ablation of the putative autonomic ganglionic sites was performed from the left atrial endocardium using irrigated radiofrequency energy. After ablation of all identifiable autonomic ganglia, high-frequency pacing was repeated to induce AF. In all patients, stimulation at certain endocardial sites elicited a vagal response. Endocardial ablation abrogated this vagal responsiveness. Furthermore, for sites accessible from the pericardium, the vagal response elicited using epicardial stimulation was also eliminated. Despite successful ablation of these ganglia, AF was still inducible in 17 of 18 patients. In conclusion, successful ablation of autonomic ganglia from an endocardial approach can be reliably achieved using an irrigated catheter. In addition, ablation of these structures in patients with vagal-mediated AF is insufficient to prevent its acute reinduction with high-frequency atrial stimulation. PMID:18721515

  19. Radiofrequency Ablation of Cancer

    SciTech Connect

    Friedman, Marc; Mikityansky, Igor; Kam, Anthony; Libutti, Steven K.; Walther, McClellan M.; Neeman, Ziv; Locklin, Julia K.; Wood, Bradford J.

    2004-09-15

    Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.

  20. Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures

    PubMed Central

    2012-01-01

    Background One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating. Methods A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip. Results A maximum temperature rise of 22.4°C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2°C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8°C. Conclusion Up to a maximum of 22.4°C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip

  1. Dilemma with the route of venous access for hemodialysis catheter insertion in a patient with dilated ischemic cardiomyopathy treated by cardiac resynchronization therapy

    PubMed Central

    Ashokananda, Devanahalli; Chakravarthy, Murali; Gowda, Mohan; Maddirala, Pavani; Sripar, Sanjay

    2016-01-01

    A 68 year old patient requiring urgent dialysis due to raising potassium was referred to our center. He had 3 indwelling catheters in his heart via right subclavian vein. His left subclavian and interngal jugular veins were thrombosed possibly due to earlier indwelling catheters. The dilemma was if right internal jugular venous route could be used for insertion of dialysis catheter. Under fluoroscopic guidance, right internal jugular vein was cannulated with the dialysis catheter without problems. This case is being presented to highlight the need for imaging both by ultrasound and radiography during the procedure. PMID:27397439

  2. Urinary catheter - infants

    MedlinePlus

    Bladder catheter - infants; Foley catheter - infants; Urinary catheter - neonatal ... A urinary catheter is a small, soft tube placed in the bladder. This article addresses urinary catheters in babies. WHY IS ...

  3. Architecture of the pulmonary veins: relevance to radiofrequency ablation

    PubMed Central

    Ho, S; Cabrera, J; Tran, V; Farre, J; Anderson, R; Sanchez-Quintana, D

    2001-01-01

    BACKGROUND—Radiofrequency ablation of tissues in pulmonary veins can eliminate paroxysmal atrial fibrillation.
OBJECTIVE—To explore the characteristics of normal pulmonary veins so as to provide more information relevant to radiofrequency ablation.
METHODS—20 structurally normal heart specimens were examined grossly. Histological sections were made from 65 pulmonary veins.
RESULTS—The longest myocardial sleeves were found in the superior veins. The sleeves were thickest at the venoatrial junction in the left superior pulmonary veins. For the superior veins, the sleeves were thickest along the inferior walls and thinnest superiorly. The sleeves were composed mainly of circularly or spirally oriented bundles of myocytes with additional bundles that were longitudinally or obliquely oriented, sometimes forming mesh-like arrangements. Fibrotic changes estimated at between 5% and 70% across three transverse sections were seen in 17 veins that were from individuals aged 30 to 72 years.
CONCLUSIONS—The myocardial architecture in normal pulmonary veins is highly variable. The complex arrangement, stretch, and increase in fibrosis may produce greater non-uniform anisotropic properties.


Keywords: arrhythmias; catheter ablation; fibrillation; cardiac veins PMID:11514476

  4. Is Single-View Fluoroscopy Sufficient in Guiding Cardiac Ablation Procedures?

    PubMed Central

    Fallavollita, Pascal

    2010-01-01

    The CARTO XP ablation system provides real-time data on 3D, color-coded maps of the electrical activity of the heart; however, it is expensive and can only use a dedicated costly magnetic catheter per patient intervention. The purpose of our study is to shorten the duration of the radiofrequency ablation procedure and increase its efficacy by developing an affordable prototype catheter navigation system that simulates the CARTO system. To obtain 3D geometrical data from catheter locations inside the heart chamber, we acquired only single-view images using an Integris Allura fluoroscope and estimated the depth of the mapping electrode using pattern recognition techniques. Validation was performed in ideal and clinical conditions. For phantom experiment, when using a 7-French catheter, the average recovered depth error was 2.05 ± 1.46 mm using a single image. However, when using the 8-French catheter, the average recovered depth error was 1.54 ± 1.29 mm. In clinical experimentation, the standard error of estimate for the estimated depth was about 13.1 mm and 10.1 mm, respectively, for the posterior and lateral views. In conclusion, this paper describes our achievements and shortfalls in developing an affordable fluoroscopic navigation system to guide RF catheter ablation of cardiac arrhythmias. PMID:20368770

  5. The transponder system: a new method of precise catheter placement in the right atrium under echocardiographic guidance.

    PubMed

    Landzberg, J S; Franklin, J O; Langberg, J J; Herre, J M; Scheinman, M M; Schiller, N B

    1988-09-01

    The ability to localize catheters within the heart has gained importance with the use of percutaneous catheter ablation and the transseptal approach for valvuloplasty. A prototype interactive transponder catheter system, specifically designed to mark the catheter tip for echocardiographic visualization, was used to place catheters at the tricuspid anulus and the fossa ovalis in anesthetized dogs. Catheter tip location was marked by lesions produced by radiofrequency energy delivered at the distal catheter electrode. At autopsy, the center of the radiofrequency-induced lesion was located 2.8 +/- 0.7 mm from the edge of the lateral tricuspid anulus and 3.5 +/- 3.1 mm from the center of the fossa ovalis. The transponder catheter system offers the ability to precisely position catheters in the right atrium under echocardiographic guidance.

  6. Esophageal papilloma: Flexible endoscopic ablation by radiofrequency

    PubMed Central

    del Genio, Gianmattia; del Genio, Federica; Schettino, Pietro; Limongelli, Paolo; Tolone, Salvatore; Brusciano, Luigi; Avellino, Manuela; Vitiello, Chiara; Docimo, Giovanni; Pezzullo, Angelo; Docimo, Ludovico

    2015-01-01

    Squamous papilloma of the esophagus is a rare benign lesion of the esophagus. Radiofrequency ablation is an established endoscopic technique for the eradication of Barrett esophagus. No cases of endoscopic ablation of esophageal papilloma by radiofrequency ablation (RFA) have been reported. We report a case of esophageal papilloma successfully treated with a single session of radiofrequency ablation. Endoscopic ablation of the lesion was achieved by radiofrequency using a new catheter inserted through the working channel of endoscope. The esophageal ablated tissue was removed by a specifically designed cup. Complete ablation was confirmed at 3 mo by endoscopy with biopsies. This case supports feasibility and safety of as a new potential indication for BarrxTM RFA in patients with esophageal papilloma. PMID:25789102

  7. Primary Cardiac Sarcoidosis with Syncope and Refractory Atrial Arrhythmia: A Case Report and Review of the Literature

    PubMed Central

    Thangam, Manoj; Nathan, Sriram; Kar, Biswajit; Petrovic, Marija; Patel, Manish; Loyalka, Pranav; Buja, L. Maximilian

    2016-01-01

    We discuss the case of a 38-year-old black man who presented at our hospital with his first episode of syncope, recently developed atrial arrhythmias refractory to pharmacologic therapy, and a left atrial thrombus. He was diagnosed with primary cardiac sarcoidosis characterized by predominant involvement of the epicardium that caused atrial fibrillation and atrial flutter. Histologic analysis of his epicardial lesions yielded a diagnosis of sarcoidosis. This patient's atrial arrhythmia was successfully treated with a hybrid operation that involved resection of his atrial appendage, an Epicor maze procedure, and radiofrequency ablation during a catheter-based electrophysiologic study. The cardiac sarcoidosis was successfully managed with corticosteroid therapy. Our case report shows that sarcoidosis can initially manifest itself as syncope with new-onset atrial arrhythmia. Sarcoidosis is important in the differential diagnosis because of its progressive nature and its potential for treatment with pharmacologic, surgical, and catheter-based interventions. PMID:27303240

  8. Ethanol for the treatment of cardiac arrhythmias

    PubMed Central

    Schurmann, Paul; Peñalver, Jorge; Valderrábano, Miguel

    2015-01-01

    Introduction Ethanol infusion was an early mode of ablative treatment for cardiac arrhythmias. Its initial descriptions involved coronary intra-arterial delivery, targeting arrhythmogenic substrates in drug-refractory ventricular tachycardia or the atrioventricular node. Largely superseded by radiofrequency ablation (RFA) and other contact-based technologies as a routine ablation strategy, intracoronary arterial ethanol infusion remains as an alternative option in the treatment of ventricular tachycardia when conventional ablation fails. Arrhythmic foci that are deep-seated in the myocardium may not be amenable to catheter ablation from either the endocardium or the epicardium by RFA, but they can be targeted by an ethanol infusion. Recent findings Recently, we have explored ethanol injection through cardiac venous systems, in order to avoid the risks of complications and limitations of coronary arterial instrumentation. Vein of Marshall ethanol infusion is being studied as an adjunctive procedure in ablation of atrial fibrillation, and coronary venous ethanol infusion for ventricular tachycardia. Conclusion Ethanol ablation remains useful as a bail-out technique for refractory cases to RFA, or as an adjunctive therapy that may improve the efficacy of catheter ablation procedures. PMID:26049378

  9. The past, the present, and the future of cardiac arrhythmia ablation.

    PubMed

    Andrade, Jason G; Rivard, Léna; Macle, Laurent

    2014-12-01

    The development and evolution of percutaneous catheter ablation for the treatment of cardiac arrhythmias has advanced significantly since the early days of direct current shock ablation, and in parallel with an increasing understanding about arrhythmia mechanisms. Because of the ever-changing landscape that is cardiac electrophysiology, the purpose of this review is to discuss the future of invasive arrhythmia management within the context of the history and contemporary practice of this cardiac subspecialty. Topics of discussion include: (1) the evolution of ablation technologies from direct current shock and radiofrequency to alternative energy sources such as cryothermal ablation; (2) the use and development of nonfluoroscopic navigation systems; (3) the progression of ablation toolsets and modalities; and (4) the advancement of ablation strategies and techniques, including ablation of complex atrial and ventricular dysrhythmias tailored to the individual patient.

  10. Conservative Management of Left Atrial Intramural Hematoma after Catheter Ablation

    PubMed Central

    Oraii, Saeed; Roshanali, Farideh; Ghorbanisharif, Alireza; Mikaeili, Javad; Tahraei, Mahmood

    2016-01-01

    Left atrial intramural hematoma is a very rare complication of radiofrequency ablation procedures. A patient with tachyarrhythmia underwent radiofrequency catheter ablation. Echocardiography performed the following morning showed a large mass in the left atrium, suggestive of intramural hematoma formation. The patient was in a stable condition; therefore, it was decided that follow-up should be conservative and her anticoagulation therapy was continued. The size of the hematoma decreased significantly over the following 50 days. This case highlights a rare complication of a complex catheter ablation procedure in the left atrium that was managed via a noninvasive approach, with which all interventionists should be familiar. PMID:27482270

  11. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty.

    PubMed

    Lee, B I; Becker, G J; Waller, B F; Barry, K J; Connolly, R J; Kaplan, J; Shapiro, A R; Nardella, P C

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal "hot-tip" catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal "molding" of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty

    SciTech Connect

    Lee, B.I.; Becker, G.J.; Waller, B.F.; Barry, K.J.; Connolly, R.J.; Kaplan, J.; Shapiro, A.R.; Nardella, P.C.

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal hot-tip catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal molding of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.

  13. [Radiofrequency transcatheter ablation in atrial tachycardia].

    PubMed

    Velázquez Rodríguez, E; Morales Hernández, J A

    2000-01-01

    Incessant atrial tachycardia is an infrequent arrhythmia. Specially difficult to treat medically. Radiofrequency catheter ablation has been used successfully to cure a variety of supraventricular tachycardias. The purpose of this work is to report our initial experience in the treatment of atrial tachycardia. Ten patients, mean age 28.7 +/- 15 year with conventional drug-resistant symptomatic atrial tachycardia were treated with selective ablation of the focus using radiofrequency energy. It was found an abnormal automaticity in 10 tachycardias and in only one patient intra-atrial reentrant was supported. Radiofrequency energy was successful in 10 of 11 tachycardias with a mean of 9.3 +/- 6.8 applications using the technique of local atrial electrogram activation time with a mean value of -54 +/- -31 milliseconds at the successful ablation sites. No complications were observed and one patient had an early clinical recurrence. All patients with successful ablation are symptom-free, in sinus rhythm and without antiarrhythmic medications after 1 to 28 months of follow-up. Our initial experience support that radiofrequency catheter ablation is a safe and effective therapeutic option for incessant atrial tachycardia. PMID:10855411

  14. Balloon catheter coronary angioplasty

    SciTech Connect

    Angelini, P.

    1987-01-01

    The author has produced a reference and teaching book on balloon angioplasty. Because it borders in surgery and is performed on an awake patient without circulatory assistance, it is a complex and demanding procedure that requires thorough knowledge before it is attempted. The text is divided into seven sections. The first section describes coronary anatomy and pathophysiology, defines the objectives and mechanisms of the procedure and lists four possible physiologic results. The next section describes equipment in the catheterization laboratory, catheters, guidewires and required personnel. The following section is on the procedure itself and includes a discussion of examination, testing, technique and follow-up. The fourth section details possible complications that can occur during the procedure, such as coronary spasms, occlusion, thrombosis, perforations and ruptures, and also discusses cardiac surgery after failed angioplasty. The fifth section details complex or unusual cases that can occur. The sixth and seventh sections discuss radiation, alternative procedures and the future of angioplasty.

  15. Patient-specific left atrial wall-thickness measurement and visualization for radiofrequency ablation

    NASA Astrophysics Data System (ADS)

    Inoue, Jiro; Skanes, Allan C.; White, James A.; Rajchl, Martin; Drangova, Maria

    2014-03-01

    INTRODUCTION: For radiofrequency (RF) catheter ablation of the left atrium, safe and effective dosing of RF energy requires transmural left atrium ablation without injury to extra-cardiac structures. The thickness of the left atrial wall may be a key parameter in determining the appropriate amount of energy to deliver. While left atrial wall-thickness is known to exhibit inter- and intra-patient variation, this is not taken into account in the current clinical workflow. Our goal is to develop a tool for presenting patient-specific left atrial thickness information to the clinician in order to assist in the determination of the proper RF energy dose. METHODS: We use an interactive segmentation method with manual correction to segment the left atrial blood pool and heart wall from contrast-enhanced cardiac CT images. We then create a mesh from the segmented blood pool and determine the wall thickness, on a per-vertex basis, orthogonal to the mesh surface. The thickness measurement is visualized by assigning colors to the vertices of the blood pool mesh. We applied our method to 5 contrast-enhanced cardiac CT images. RESULTS: Left atrial wall-thickness measurements were generally consistent with published thickness ranges. Variations were found to exist between patients, and between regions within each patient. CONCLUSION: It is possible to visually determine areas of thick vs. thin heart wall with high resolution in a patient-specific manner.

  16. Catheter-Associated Infections

    PubMed Central

    Trautner, Barbara W.; Darouiche, Rabih O.

    2010-01-01

    Intravascular catheters and urinary catheters are the 2 most commonly inserted medical devices in the United States, and they are likewise the two most common causes of nosocomially acquired bloodstream infection. Biofilm formation on the surfaces of indwelling catheters is central to the pathogenesis of infection of both types of catheters. The cornerstone to any preventive strategy of intravascular catheter infections is strict attention to infection control practices. Antimicrobial-impregnated intravascular catheters are a useful adjunction to infection control measures. Prevention of urinary catheter–associated infection is hindered by the numbers and types of organisms present in the periurethral area as well as by the typically longer duration of catheter placement. Antimicrobial agents in general have not been effective in preventing catheter-associated urinary tract infection in persons with long-term, indwelling urethral catheters. Preventive strategies that avoid the use of antimicrobial agents may be necessary in this population. PMID:15111369

  17. Catheter-based endomyocardial delivery of mesenchymal precursor cells using 3D echo guidance improves cardiac function in a chronic myocardial injury ovine model.

    PubMed

    Cheng, Yanping; Yi, Genghua; Conditt, Gerard B; Sheehy, Alexander; Kolodgie, Frank D; Tellez, Armando; Polyakov, Igor; Gu, Anguo; Aboodi, Michael S; Wallace-Bradley, David; Schuster, Michael; Martens, Timothy; Itescu, Silviu; Kaluza, Greg L; Basu, Shubhayu; Virmani, Renu; Granada, Juan F; Sherman, Warren

    2013-01-01

    The administration of bone marrow-derived stem cells may provide a new treatment option for patients with heart failure. Transcatheter cell injection may require multi-imaging modalities to optimize delivery. This study sought to evaluate whether endomyocardial injection of mesenchymal precursor cells (MPCs) could be guided by real-time 3D echocardiography (RT3DE) in treating chronic, postinfarction (MI) left ventricular (LV) dysfunction in sheep. Four weeks after induction of an anterior wall myocardial infarction in 39 sheep, allogeneic MPCs in doses of either 25 × 10(6) (n = 10), 75 × 10(6) (n = 9), or 225 × 10(6) (n = 10) cells or nonconditioned control media (n = 10) were administered intramyocardially into infarct and border zone areas using a catheter designed for combined fluoroscopic and RT3DE-guided injections. LV function was assessed before and after injection. Infarct dimension and vascular density were evaluated histologically. RT3DE-guided injection procedures were safe. Compared to controls, the highest dose MPC treatment led to increments in ejection fraction (3 ventricula 3% in 225M MPCs vs. -5 ± 4% in the control group, p < 0.01) and wall thickening in both infarct (4 ± 4% in 225M MPCs vs. -3 ± 6% in the control group, p = 0.02) and border zones (4 ± 6% in 225M MPCs vs. -8 ± 9% in the control group, p = 0.01). Histology analysis demonstrated significantly higher arteriole density in the infarct and border zones in the highest dose MPC-treated animals compared to the lower dose or control groups. Endomyocardial implantation of MPCs under RT3DE guidance was safe and without observed logistical obstacles. Significant increases in LV performance (ejection fraction and wall thickening) and neovascularization resulted from this technique, and so this technique has important implications for treating patients with postischemic LV dysfunction.

  18. Presternal peritoneal catheter.

    PubMed

    Twardowski, Zbylut J

    2002-04-01

    The swan neck presternal catheter is composed of 2 flexible (silicon rubber) tubes joined by a titanium connector at the time of implantation. The exit site is located in the parasternal area. The catheter located on the chest was designed to reduce the incidence of exit site infections compared to peritoneal dialysis catheters with abdominal exits. From August 1991 to September 30, 2001, 974 swan neck presternal catheters were implanted worldwide. At the university of Missouri, 150 of these catheters were implanted and followed for over 130 patient years. Presternal catheters tended to perform better than swan neck abdominal catheters regarding exit and tunnel infections, even though they were implanted in several patients in whom regular catheters with the exit on the abdomen would be difficult or impossible to implant. Two-year survival probability of presternal catheters was 0.95. Recurrent/refractory peritonitis was the only reason for catheter failure. The catheter is particularly useful in obese patients (body mass index >35), patients with ostomies, children with diapers and fecal incontinence, and patients who want to take baths without the risk of exit contamination. Many patients prefer presternal catheter because of better body image. Disadvantages of the presternal catheter are minimal. Compared with abdominal catheters, dialysis-solution flow is slightly slower because of the increased catheter length; however, slower flow is insignificant clinically. There is a possibility of catheter disconnection in the tunnel, but this complication is extremely rare in adults and easily corrected. Finally, the implantation technique is more challenging compared with that of single-piece, abdominal catheters. PMID:12085389

  19. Idiopathic ventricular tachycardia: feasibility and efficacy of catheter ablation.

    PubMed

    Velazquez Rodriguez, E; Frank, R; Fontaine, G; Tonet, J; Lascault, G; Rosas, F; Eslami, M; Nakazato, Y

    1995-01-01

    Idiopathic ventricular tachycardia is a well described syndrome of both left and right ventricular origin. This study reports the feasibility and efficacy of catheter ablation in this entity. Fourteen patients (mean age 30 +/- 10 years of age) and six patients (mean age 51 +/- 9 years of age) underwent endocardial catheter ablation with either direct-current shocks and radiofrequency energy, respectively. Earliest right and left ventricular activation and endocardial mapping during tachycardia were made to localize the site of ventricular tachycardia origin. The overall clinical efficacy was 93% for direct-current method with a mean number of shocks of 3.3 +/- 0.9/patient after a mean follow-up of 38 +/- 25 months. Radiofrequency ablation achieved an overall clinical efficacy of 83.6% with a mean of 3.2 pulses/patient during a follow-up of 10.5 +/- 4 months. The isoenzyme MB fraction of peak creatine kinase after ablation was less than 5%. There were no complications in any patient who underwent radiofrequency energy. Endocardial catheter ablation is feasible in patients with idiopathic ventricular tachycardia. Both methods are highly effective but radiofrequency energy is most desirable because of its lack of barotrauma, and may be considered as early therapy. PMID:7620280

  20. A statistical model of catheter motion from interventional x-ray images: application to image-based gating

    NASA Astrophysics Data System (ADS)

    Panayiotou, M.; King, A. P.; Ma, Y.; Housden, R. J.; Rinaldi, C. A.; Gill, J.; Cooklin, M.; O'Neill, M.; Rhode, K. S.

    2013-11-01

    The motion and deformation of catheters that lie inside cardiac structures can provide valuable information about the motion of the heart. In this paper we describe the formation of a novel statistical model of the motion of a coronary sinus (CS) catheter based on principal component analysis of tracked electrode locations from standard mono-plane x-ray fluoroscopy images. We demonstrate the application of our model for the purposes of retrospective cardiac and respiratory gating of x-ray fluoroscopy images in normal dose x-ray fluoroscopy images, and demonstrate how a modification of the technique allows application to very low dose scenarios. We validated our method on ten mono-plane imaging sequences comprising a total of 610 frames from ten different patients undergoing radiofrequency ablation for the treatment of atrial fibrillation. For normal dose images we established systole, end-inspiration and end-expiration gating with success rates of 100%, 92.1% and 86.9%, respectively. For very low dose applications, the method was tested on the same ten mono-plane x-ray fluoroscopy sequences without noise and with added noise at signal to noise ratio (SNR) values of √50, √10, √8, √6, √5, √2 and √1 to simulate the image quality of increasingly lower dose x-ray images. The method was able to detect the CS catheter even in the lowest SNR images with median errors not exceeding 2.6 mm per electrode. Furthermore, gating success rates of 100%, 71.4% and 85.7% were achieved at the low SNR value of √2, representing a dose reduction of more than 25 times. Thus, the technique has the potential to extract useful information whilst substantially reducing the radiation exposure.

  1. Biopsy catheter (image)

    MedlinePlus

    ... examination, a heart biopsy can be performed. A catheter is carefully threaded into an artery or vein to gain access into the heart. A bioptome (catheter with jaws in its tip) is then introduced. ...

  2. Central venous catheters - ports

    MedlinePlus

    Central venous catheter - subcutaneous; Port-a-Cath; InfusaPort; PasPort; Subclavian port; Medi - port; Central venous line - port ... Catheters are used when you need medical treatment over a long period of time. For example, you ...

  3. Ultrasound Current Source Density Imaging in live rabbit hearts using clinical intracardiac catheter

    NASA Astrophysics Data System (ADS)

    Li, Qian

    Ultrasound Current Source Density Imaging (UCSDI) is a noninvasive modality for mapping electrical activities in the body (brain and heart) in 4-dimensions (space + time). Conventional cardiac mapping technologies for guiding the radiofrequency ablation procedure for treatment of cardiac arrhythmias have certain limitations. UCSDI can potentially overcome these limitations and enhance the electrophysiology mapping of the heart. UCSDI exploits the acoustoelectric (AE) effect, an interaction between ultrasound pressure and electrical resistivity. When an ultrasound beam intersects a current path in a material, the local resistivity of the material is modulated by the ultrasonic pressure, and a change in voltage signal can be detected based on Ohm's Law. The degree of modulation is determined by the AE interaction constant K. K is a fundamental property of any type of material, and directly affects the amplitude of the AE signal detected in UCSDI. UCSDI requires detecting a small AE signal associated with electrocardiogram. So sensitivity becomes a major challenge for transferring UCSDI to the clinic. This dissertation will determine the limits of sensitivity and resolution for UCSDI, balancing the tradeoff between them by finding the optimal parameters for electrical cardiac mapping, and finally test the optimized system in a realistic setting. This work begins by describing a technique for measuring K, the AE interaction constant, in ionic solution and biological tissue, and reporting the value of K in excised rabbit cardiac tissue for the first time. K was found to be strongly dependent on concentration for the divalent salt CuSO4, but not for the monovalent salt NaCl, consistent with their different chemical properties. In the rabbit heart tissue, K was determined to be 0.041 +/- 0.012 %/MPa, similar to the measurement of K in physiologic saline: 0.034 +/- 0.003 %/MPa. Next, this dissertation investigates the sensitivity limit of UCSDI by quantifying the relation

  4. Radiofrequency Ablation of Liver Tumors

    MedlinePlus

    ... Other equipment such as needle electrodes, an electrical generator and grounding pads may also be used. Radiofrequency ... retractable electrodes that extend when needed. The radiofrequency generator produces electrical currents in the range of radiofrequency ...

  5. The successful withdrawal of a migrated central venous catheter

    PubMed Central

    Zamani, Hassan; Babazadeh, Kazem; Ghaffari, Rahman; Karami, Hossein; Fattahi, Saeid; Mokhtari Esbuie, Farzad

    2012-01-01

    Background: Central venous catheters (CVCs) have been used widely in clinics. These catheters are also recommended for children and infants receiving chemotherapy and total parenteral nutrition (TPN) and etc. In this paper, we present migrated fractured control line of the heart of a girl. Case Presentation: A 2.5 year old girl with migrated of the fractured central line into the heart. In the catheterization laboratory, first we placed a long sheath (8 F) into the inferior vena cava via femoral vein and then trapped the foreign body by pigtail catheter and wire 0.035 inch and pulled it down to make its proximal free. After that, we snared the catheter by snare-catheter and pulled it into the femoral vein, and then the cardiac surgeon bridged it out by cut-down successfully. Conclusion: A rare complication in the use of central catheters is fraction and cardiac embolization. We offer gentle bringing out of the catheter lines under fluoroscopy guide in all of the cases, if this is technically possible and safe. PMID:24009933

  6. Problems of indwelling Foley catheters.

    PubMed

    Ndirangu, K; Ngugi, M

    1994-02-01

    One hundred patients undergoing urinary bladder catheterization for various reasons were studied. 42 patients received Sewoon catheters of various sizes. 38 received Eschmann catheters of various sizes and 20 received Bard catheters of various sizes. The duration of catheterization ranged from a few hours to 21 days. Various problems associated with catheterization were recorded whenever encountered. Stuck catheter was found to occur in 15 of the 40 patients who received Sewoon catheters. There were no stuck catheters recorded for Eschmann or Bard catheters. Infections occurred in 9 out of 100 patients, 7 of whom had Sewoon catheters. Leakage was recorded in 12 of the 100 patients, 9 of whom had Sewoon catheters. Blockage of balloon occurred in 5 patients, 3 of whom had Sewoon catheters. Painful spasms occurred in 8 patients, 4 with Bard, 4 with Sewoon catheters. It is concluded that Sewoon type of Foley catheters was associated with more problems than the other types studied.

  7. Cryo-balloon catheter localization in fluoroscopic images

    NASA Astrophysics Data System (ADS)

    Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

  8. [Suprapubic catheter insertion].

    PubMed

    Neumann, Eva; Schwentner, Christian

    2016-01-01

    The suprapubic catheter enables a percutaneous drainage of urine. The insertion is made superior of the pubic bone through the abdominal wall into the bladder. It allows a permanent drainage of urine bypassing the urethra. The insertion of a suprapubic catheter requires knowledge and expertise. This paper summarizes the basic background and allows to follow the practical application step by step.

  9. [Suprapubic catheter insertion].

    PubMed

    Neumann, Eva; Schwentner, Christian

    2016-01-01

    The suprapubic catheter enables a percutaneous drainage of urine. The insertion is made superior of the pubic bone through the abdominal wall into the bladder. It allows a permanent drainage of urine bypassing the urethra. The insertion of a suprapubic catheter requires knowledge and expertise. This paper summarizes the basic background and allows to follow the practical application step by step. PMID:26800072

  10. The echo-transponder electrode catheter: a new method for mapping the left ventricle.

    PubMed

    Langberg, J J; Franklin, J O; Landzberg, J S; Herre, J M; Kee, L; Chin, M C; Bharati, S; Lev, M; Himelman, R B; Schiller, N B

    1988-07-01

    The ability to locate catheter position in the left ventricle with respect to endocardial landmarks might enhance the accuracy of ventricular tachycardia mapping. An echo-transponder system (Telectronics, Inc.) was compared with biplane fluoroscopy for left ventricular endocardial mapping. A 6F electrode catheter was modified with the addition of a piezoelectric crystal 5 mm from the tip. This crystal was connected to a transponder that received and transmitted ultrasound, resulting in a discrete artifact on the two-dimensional echocardiographic image corresponding to the position of the catheter tip. Catheters were introduced percutaneously into the left ventricle of nine anesthetized dogs. Two-dimensional echo-transponder and biplane fluoroscopic images were recorded on videotape with the catheter at multiple endocardial sites. Catheter location was marked by delivering radiofrequency current to the distal electrode, creating a small endocardial lesion. Catheter location by echo-transponder and by fluoroscopy were compared with lesion location without knowledge of other data. Location by echo-transponder was 8.7 +/- 5.1 mm from the center of the radiofrequency lesion versus 14 + 7.8 mm by fluoroscopy (n = 15, p = 0.023). Echo-transponder localization is more precise than is biplane fluoroscopy and may enhance the accuracy of left ventricular electrophysiologic mapping.

  11. Percutaneous Retrieval of a Pulmonary Artery Catheter Knot in Pacing Electrodes

    SciTech Connect

    Valenzuela-Garcia, Luis Felipe Almendro-Delia, Manuel; Gonzalez-Valdayo, Miguel; Munoz-Campos, Juan; Dorado-Garcia, Jose C.; Gomez-Rosa, Francisco; Vazquez-Garcia, Rafael; Calderon-Leal, Jose M.

    2007-09-15

    To illustrate a successful approach to resolving a pulmonary artery catheter knot in the pacing leads of a cardiac resynchronization device. When planning invasive monitoring for patients having right chamber electrodes, fluoroscopic-guided catheter insertion and extraction is advisable. In the event of coiling or knotting, an interventional radiologist should be contacted as soon as possible to avoid serious complications.

  12. [Cardiac Rehabilitation 2015].

    PubMed

    Hoffmann, Andreas

    2015-11-25

    The goals of cardiac rehabilitation are (re-)conditioning and secondary prevention in patients with heart disease or an elevated cardiovascular risk profile. Rehabilitation is based on motivation through education, on adapted physical activity, instruction of relaxation techniques, psychological support and optimized medication. It is performed preferably in groups either in outpatient or inpatient settings. The Swiss working group on cardiac rehabilitation provides a network of institutions with regular quality auditing. Positive effects of rehabilitation programs on mortality and morbidity have been established by numerous studies. Although a majority of patients after cardiac surgery are being referred to rehabilitation, these services are notoriously underused after catheter procedures. PMID:26602848

  13. Suprapubic catheter removal: the cuffing effect of deflated catheter balloons.

    PubMed

    Robinson, John

    2003-05-01

    Supra-pubic catheterization plays an important role in patient care and management when this method of indwelling catheterization is required. However, one area of concern often experienced by nurses is the problem removing supra-pubic catheters or not being able to remove it. Catheter balloons, when deflated, incur crease or ridge formation. Removing supra-pubic catheters, a 'cuffing' effect occurs as the catheter is being removed. This seems to affect 100% silicone catheters more than non-silicone catheters. This article looks at the changes 100% silicone catheter balloons undergo following deflation and removal.

  14. Radiofrequency coblation tonsillectomy.

    PubMed

    Grobler, Alethea; Carney, A Simon

    2006-06-01

    Radiofrequency coblation is a new technology that is finding favour as a method for performing tonsillectomy. Its benefits include reduced pain and postoperative morbidity but there is controversy regarding possible increased postoperative haemorrhage rates.

  15. Nanoscale memristive radiofrequency switches

    NASA Astrophysics Data System (ADS)

    Pi, Shuang; Ghadiri-Sadrabadi, Mohammad; Bardin, Joseph C.; Xia, Qiangfei

    2015-06-01

    Radiofrequency switches are critical components in wireless communication systems and consumer electronics. Emerging devices include switches based on microelectromechanical systems and phase-change materials. However, these devices suffer from disadvantages such as large physical dimensions and high actuation voltages. Here we propose and demonstrate a nanoscale radiofrequency switch based on a memristive device. The device can be programmed with a voltage as low as 0.4 V and has an ON/OFF conductance ratio up to 1012 with long state retention. We measure the radiofrequency performance of the switch up to 110 GHz and demonstrate low insertion loss (0.3 dB at 40 GHz), high isolation (30 dB at 40 GHz), an average cutoff frequency of 35 THz and competitive linearity and power-handling capability. Our results suggest that, in addition to their application in memory and computing, memristive devices are also a leading contender for radiofrequency switch applications.

  16. [Radiofrequency ablation in ventricular tachycardia: initial experience and evaluation of its limitations].

    PubMed

    Velázquez, E; Rosas, F; Frank, R; Tonet, J; Fontaine, G; Lascault, G; Gallais, Y

    1994-01-01

    The purpose of this paper is to report our initial experience with radiofrequency catheter ablation in 21 patients with ventricular tachycardia of different etiologies and to evaluate the causes which play a role in its limitation. The results show a low rate of effectiveness: total clinical success of 43%. Nevertheless there was a high success rate in a specific subsets of patients. The results depends on several factors: the electrophysiologic mechanisms and substrates of the tachycardia, the criteria to localize the critical area perpetuating the arrhythmia and the biophysical aspects of radiofrequency energy. Its usefulness is manifested in ventricular tachycardia with structurally normal heart and it has a limited success in cases with organic heart disease. Improvement of technical aspects and better understanding of the mechanisms of the tachycardia and characteristics of the target site will enhance the results of radiofrequency catheter ablation in ventricular tachycardia. PMID:7979818

  17. Cardiac catheterization

    MedlinePlus

    Catheterization - cardiac; Heart catheterization; Angina - cardiac catheterization; CAD - cardiac catheterization; Coronary artery disease - cardiac catheterization; Heart valve - cardiac catheterization; Heart failure - ...

  18. Comparison of Standard Catheters Versus Radial Artery-Specific Catheter in Patients Who Underwent Coronary Angiography Through Transradial Access.

    PubMed

    Chen, On; Goel, Sunny; Acholonu, Michael; Kulbak, Guy; Verma, Shivani; Travlos, Efstratios; Casazza, Richard; Borgen, Elliot; Malik, Bilal; Friedman, Michael; Moskovits, Norbert; Frankel, Robert; Shani, Jacob; Ayzenberg, Sergey

    2016-08-01

    In this prospective, randomized controlled study, we aim to compare the performance outcomes of standard catheters with the radial artery-specific catheter. Over the past decade, transradial cardiac catheterization has gained widespread popularity because of its low complication rates compared with transfemoral access. Operators have the choice of using either standard catheters (used for both transfemoral and transradial approach, with need for separate catheter use for either right or left coronary artery engagement) or a dedicated radial artery catheter, which is specifically designed to engage both coronary arteries through radial artery access. A total of 110 consecutive patients who underwent coronary angiography at our institution from March 2015 to April 2015 were prospectively randomized to either radial artery-specific Tiger catheter (5Fr; Terumo Interventional Systems, Somerset, New Jersey) versus standard Judkins left and right catheters (5Fr R4, L4; Cordis Corporation, Miami, Florida). The end points of the study included fluoroscopy time, dose-area product, contrast volume used, and total procedure time for the coronary angiography. A total of 57 patients (52%) were randomized to radial artery-specific catheter and 53 (48%) to the standard catheter. Tiger catheter was associated with significantly lower fluoroscopy time (184 ± 91 vs 238 ± 131 seconds, p = 0.015), which was statistically significant. Other outcome measures such as dose-area product (2,882.4 ± 1,471.2 vs 3,524.6 ± 2,111.7 Gy·cm(2), p = 0.07), total contrast volume (48.1 ± 16.1 vs 53.4 ± 18.5 ml, p = 0.114), and total procedure time (337 ± 382 vs 434 ± 137 seconds, p = 0.085) were also lower in single-catheter group, but it did not reach statistical significance. A total of 8 patients (14%) were crossed over from radial-specific catheter arm to standard catheter arm because of substandard image quality and difficulty in coronary engagement. Six patients had to be

  19. Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

    SciTech Connect

    Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun; Feng Xi; Shen Qiang; Chen Minshan; Lau, Wan Yee; Nicholls, Joanna; Jiao Long; Habib, Nagy

    2013-02-15

    We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

  20. Sinuplasty (Balloon Catheter Dilation)

    MedlinePlus

    ... development of the balloon dilating catheter and its adaptation to sinus surgery. In the 1980s, the field ... used in endoscopic sinus surgery. It is the adaptation or application of minimally-invasive balloon technology to ...

  1. Central venous catheter - flushing

    MedlinePlus

    ... To flush your catheter, you will need: Clean paper towels Saline syringes (clear), and maybe heparin syringes ( ... your fingers before washing. Dry with a clean paper towel. Set up your supplies on a clean ...

  2. Indwelling catheter care

    MedlinePlus

    ... Common reasons to have an indwelling catheter are urinary incontinence (leakage), urinary retention (not being able to urinate), ... gov/pubmed/22094023 . Read More Radical prostatectomy Stress urinary incontinence Transurethral resection of the prostate Urge incontinence Urinary ...

  3. Suprapubic catheter care

    MedlinePlus

    ... You may need a catheter because you have urinary incontinence (leakage), urinary retention (not being able to urinate), ... vaginal wall repair Inflatable artificial sphincter Radical prostatectomy Urinary incontinence - injectable implant Urinary incontinence - retropubic suspension Urinary incontinence - ...

  4. [Urinary catheter biofilm infections].

    PubMed

    Holá, V; Růzicka, F

    2008-04-01

    Urinary tract infections, most of which are biofilm infections in catheterized patients, account for more than 40% of hospital infections. Bacterial colonization of the urinary tract and catheters causes not only infection but also other complications such as catheter blockage by bacterial encrustation, urolithiasis and pyelonephritis. About 50% of long-term catheterized patients face urinary flow obstruction due to catheter encrustation, but no measure is currently available to prevent it. Encrustation has been known either to result from metabolic dysfunction or to be of microbial origin, with urease positive bacterial species implicated most often. Infectious calculi account for about 15-20% of all cases of urolithiasis and are often associated with biofilm colonization of a long-term indwelling urinary catheter or urethral stent. The use of closed catheter systems is helpful in reducing such problems; nevertheless, such a system only delays the inevitable, with infections emerging a little later. Various coatings intended to prevent the bacterial adhesion to the surface of catheters and implants and thus also the emergence of biofilm infections, unfortunately, do not inhibit the microbial adhesion completely and permanently and the only reliable method for biofilm eradication remains the removal of the foreign body from the patient.

  5. A rare instructive complication of balloon catheter fracture during percutaneous coronary intervention.

    PubMed

    Nomura, Tetsuya; Higuchi, Yusuke; Kato, Taku; Keira, Natsuya; Tatsumi, Tetsuya

    2016-01-01

    The entrapment, fracture, and dislodgement of catheterization devices during percutaneous coronary intervention (PCI) are rare complications, for which cardiac surgery is sometimes required. Here, we encountered a rare but instructive case of balloon catheter fracture during PCI. Although there have been some reports of guidewire fracture in PCI, reports on balloon catheter fracture are very rare to our knowledge. A simulation test to examine the mechanism of balloon catheter fracture revealed that overuse of the balloon catheter, both for kissing balloon inflation and balloon anchor, was highly likely to have been the cause of the fracture. PMID:25708708

  6. Repeated radiofrequency ablation of atrial tachycardia in restrictive cardiomyopathy secondary to myofibrillar myopathy.

    PubMed

    Stöllberger, Claudia; Gatterer, Edmund; Finsterer, Josef; Kuck, Karl-Heinz; Tilz, Roland Richard

    2014-08-01

    Myofibrillar myopathy is characterized by nonhyaline and hyaline lesions due to mutations in nuclear genes encoding for extra-myofibrillar or myofibrillar proteins. Cardiac involvement in myofibrillar myopathy may be phenotypically expressed as dilated, hypertrophic, or restrictive cardiomyopathy. Radiofrequency ablation of atrial fibrillation and flutter has so far not been reported in myofibrillar myopathy. We report the case of a young female with myofibrillar myopathy and deteriorating heart failure due to restrictive cardiomyopathy and recurrent atrial fibrillation and atrial tachycardias intolerant to pharmacotherapy. Cardiac arrhythmias were successfully treated with repeat radiofrequency ablations and resulted in regression of heart failure, thus postponing the necessity for cardiac transplantation.

  7. Radiofrequency ablation for benign thyroid nodules.

    PubMed

    Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

    2016-09-01

    Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

  8. Radiofrequency Ablation of Lung Tumors

    MedlinePlus

    ... computed tomography (CT) imaging, needle electrodes , an electrical generator and grounding pads are used. There are two ... retractable electrodes that extend when needed. The radiofrequency generator produces electrical currents in the range of radiofrequency ...

  9. Cryo-balloon catheter position planning using AFiT

    NASA Astrophysics Data System (ADS)

    Kleinoeder, Andreas; Brost, Alexander; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2012-02-01

    Atrial fibrillation (AFib) is the most common heart arrhythmia. In certain situations, it can result in life-threatening complications such as stroke and heart failure. For paroxsysmal AFib, pulmonary vein isolation (PVI) by catheter ablation is the recommended choice of treatment if drug therapy fails. During minimally invasive procedures, electrically active tissue around the pulmonary veins is destroyed by either applying heat or cryothermal energy to the tissue. The procedure is usually performed in electrophysiology labs under fluoroscopic guidance. Besides radio-frequency catheter ablation devices, so-called single-shot devices, e.g., the cryothermal balloon catheters, are receiving more and more interest in the electrophysiology (EP) community. Single-shot devices may be advantageous for certain cases, since they can simplify the creation of contiguous (gapless) lesion sets around the pulmonary vein which is needed to achieve PVI. In many cases, a 3-D (CT, MRI, or C-arm CT) image of a patient's left atrium is available. This data can then be used for planning purposes and for supporting catheter navigation during the procedure. Cryo-thermal balloon catheters are commercially available in two different sizes. We propose the Atrial Fibrillation Planning Tool (AFiT), which visualizes the segmented left atrium as well as multiple cryo-balloon catheters within a virtual reality, to find out how well cryo-balloons fit to the anatomy of a patient's left atrium. First evaluations have shown that AFiT helps physicians in two ways. First, they can better assess whether cryoballoon ablation or RF ablation is the treatment of choice at all. Second, they can select the proper-size cryo-balloon catheter with more confidence.

  10. The effect of elastic modulus on ablation catheter contact area

    NASA Astrophysics Data System (ADS)

    Camp, Jon J.; Linte, Cristian A.; Rettmann, Maryam E.; Sun, Deyu; Packer, Douglas L.; Robb, Richard A.; Holmes, David R.

    2015-03-01

    Cardiac ablation consists of navigating a catheter into the heart and delivering RF energy to electrically isolate tissue regions that generate or propagate arrhythmia. Besides the challenges of accurate and precise targeting of the arrhythmic sites within the beating heart, limited information is currently available to the cardiologist regarding intricate electrodetissue contact, which directly impacts the quality of produced lesions. Recent advances in ablation catheter design provide intra-procedural estimates of tissue-catheter contact force, but the most direct indicator of lesion quality for any particular energy level and duration is the tissue-catheter contact area, and that is a function of not only force, but catheter pose and material elasticity as well. In this experiment, we have employed real-time ultrasound (US) imaging to determine the complete interaction between the ablation electrode and tissue to accurately estimate contact, which will help to better understand the effect of catheter pose and position relative to the tissue. By simultaneously recording tracked position, force reading and US image of the ablation catheter, the differing material properties of polyvinyl alcohol cryogel[1] phantoms are shown to produce varying amounts of tissue depression and contact area (implying varying lesion quality) for equivalent force readings. We have shown that the elastic modulus significantly affects the surface-contact area between the catheter and tissue at any level of contact force. Thus we provide evidence that a prescribed level of catheter force may not always provide sufficient contact area to produce an effective ablation lesion in the prescribed ablation time.

  11. Balloon Catheter Prevents Contamination

    NASA Technical Reports Server (NTRS)

    Higginson, Gregory A.; Bouffard, Marc R.; Hoehicke, Beth S.; King, Bradley D.; Peterson, Sandra L.

    1994-01-01

    Balloon catheter similar to that used in such medical procedures as angioplasty and heart surgery protects small orifices against contamination and blockage by chips generated in machining operations. Includes small, inflatable balloon at end of thin, flexible tube. Contains additional features adapting it to anticontamination service: balloon larger to fit wider channel it must block; made of polyurethane (rather than latex), which does not fragment if bursts; material made thicker to resist abrasion better; and kink-resistant axial wire helps catheter negotiate tight bends.

  12. Nanoscale memristive radiofrequency switches.

    PubMed

    Pi, Shuang; Ghadiri-Sadrabadi, Mohammad; Bardin, Joseph C; Xia, Qiangfei

    2015-01-01

    Radiofrequency switches are critical components in wireless communication systems and consumer electronics. Emerging devices include switches based on microelectromechanical systems and phase-change materials. However, these devices suffer from disadvantages such as large physical dimensions and high actuation voltages. Here we propose and demonstrate a nanoscale radiofrequency switch based on a memristive device. The device can be programmed with a voltage as low as 0.4 V and has an ON/OFF conductance ratio up to 10(12) with long state retention. We measure the radiofrequency performance of the switch up to 110 GHz and demonstrate low insertion loss (0.3 dB at 40 GHz), high isolation (30 dB at 40 GHz), an average cutoff frequency of 35 THz and competitive linearity and power-handling capability. Our results suggest that, in addition to their application in memory and computing, memristive devices are also a leading contender for radiofrequency switch applications. PMID:26108890

  13. A simple and fast technique for radiofrequency-assisted perforation of the atrial septum in congenital heart disease

    PubMed Central

    Sandoval, Juan Pablo; Chaturvedi, Rajiv R

    2016-01-01

    Radiofrequency (RF) assisted perforation of the atrial septum was performed successfully in three infants using a 0.035” RF wire deployed through a Williams right posterior catheter. Balloon atrial septoplasty was performed over the 0.035” RF wire in two of them, shortening the procedural time. PMID:27011690

  14. Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias

    PubMed Central

    Yücel, Meryem A.; Steele, Sarah C.; Alexander, Mark E.; Boas, David A.; Borsook, David; Becerra, Lino

    2016-01-01

    The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia. PMID:27415436

  15. Thermistor guided radiofrequency ablation of atrial insertion sites in patients with accessory pathways.

    PubMed

    Tracy, C M; Moore, H J; Solomon, A J; Rodak, D J; Fletcher, R D

    1995-11-01

    Radiofrequency ablation has gained acceptance in the treatment of patients with symptomatic Wolff-Parkinson-White syndrome. The purpose of this study was to characterize the relation between temperature and other electroconductive parameters in patients undergoing atrial insertion accessory pathway ablation utilizing a thermistor equipped catheter. The mean temperature and power at sites of atrial insertion ablation are lower than has been previously associated with creation of radiofrequency lesions in the ventricle. While high cavitary blood flow in the atrium may result in cooling, the thinner atrial tissue may require less energy to achieve adequate heating than ventricular myocardium.

  16. 3D ablation catheter localisation using individual C-arm x-ray projections

    NASA Astrophysics Data System (ADS)

    Haase, C.; Schäfer, D.; Dössel, O.; Grass, M.

    2014-11-01

    Cardiac ablation procedures during electrophysiology interventions are performed under x-ray guidance with a C-arm imaging system. Some procedures require catheter navigation in complex anatomies like the left atrium. Navigation aids like 3D road maps and external tracking systems may be used to facilitate catheter navigation. As an alternative to external tracking a fully automatic method is presented here that enables the calculation of the 3D location of the ablation catheter from individual 2D x-ray projections. The method registers a high resolution, deformable 3D attenuation model of the catheter to a 2D x-ray projection. The 3D localization is based on the divergent beam projection of the catheter. On an individual projection, the catheter tip is detected in 2D by image filtering and a template matching method. The deformable 3D catheter model is adapted using the projection geometry provided by the C-arm system and 2D similarity measures for an accurate 2D/3D registration. Prior to the tracking and registration procedure, the deformable 3D attenuation model is automatically extracted from a separate 3D cone beam CT reconstruction of the device. The method can hence be applied to various cardiac ablation catheters. In a simulation study of a virtual ablation procedure with realistic background, noise, scatter and motion blur an average 3D registration accuracy of 3.8 mm is reached for the catheter tip. In this study four different types of ablation catheters were used. Experiments using measured C-arm fluoroscopy projections of a catheter in a RSD phantom deliver an average 3D accuracy of 4.5 mm.

  17. 3D ablation catheter localisation using individual C-arm x-ray projections.

    PubMed

    Haase, C; Schäfer, D; Dössel, O; Grass, M

    2014-11-21

    Cardiac ablation procedures during electrophysiology interventions are performed under x-ray guidance with a C-arm imaging system. Some procedures require catheter navigation in complex anatomies like the left atrium. Navigation aids like 3D road maps and external tracking systems may be used to facilitate catheter navigation. As an alternative to external tracking a fully automatic method is presented here that enables the calculation of the 3D location of the ablation catheter from individual 2D x-ray projections. The method registers a high resolution, deformable 3D attenuation model of the catheter to a 2D x-ray projection. The 3D localization is based on the divergent beam projection of the catheter. On an individual projection, the catheter tip is detected in 2D by image filtering and a template matching method. The deformable 3D catheter model is adapted using the projection geometry provided by the C-arm system and 2D similarity measures for an accurate 2D/3D registration. Prior to the tracking and registration procedure, the deformable 3D attenuation model is automatically extracted from a separate 3D cone beam CT reconstruction of the device. The method can hence be applied to various cardiac ablation catheters. In a simulation study of a virtual ablation procedure with realistic background, noise, scatter and motion blur an average 3D registration accuracy of 3.8 mm is reached for the catheter tip. In this study four different types of ablation catheters were used. Experiments using measured C-arm fluoroscopy projections of a catheter in a RSD phantom deliver an average 3D accuracy of 4.5 mm.

  18. Radiofrequency Guide Wire Recanalization of Venous Occlusions in Patients with Malignant Superior Vena Cava Syndrome

    SciTech Connect

    Davis, Robert M.; David, Elizabeth; Pugash, Robyn A.; Annamalai, Ganesan

    2012-06-15

    Fibrotic central venous occlusions in patients with thoracic malignancy and prior radiotherapy can be impassable with standard catheters and wires, including the trailing or stiff end of a hydrophilic wire. We report two patients with superior vena cava syndrome in whom we successfully utilized a radiofrequency guide wire (PowerWire, Baylis Medical, Montreal, Quebec, Canada) to perforate through the occlusion and recanalize the occluded segment to alleviate symptoms.

  19. Robotic navigation for catheter ablation: benefits and challenges.

    PubMed

    Aagaard, Philip; Natale, Andrea; Di Biase, Luigi

    2015-07-01

    Manual radio frequency (RF) ablation to restore a normal cardiac rhythm requires significant skill, manual dexterity and experience. In response to this, ablation methods and technologies have evolved rapidly in the past decade, including the development of remote navigation technologies. Today, two principal methods of remote navigation are available. One utilizes magnetic field vectors to navigate proprietary catheters, the other maneuvers standard catheters robotically. The main advantages of remote navigation include improved catheter stability, reduced fluoroscopy times and decreased total radiation exposure to both the patient and the operator. The main limitations include cost and longer procedure times. Remote magnetic navigation appears to have the best safety profile; however, its efficacy in creating lesions may be lower, which has been attributed to the soft-tip catheter used. Remote robotic navigation on the other hand, which uses regular catheter tips, is associated with a slightly higher overall complication rate, but higher efficacy. This article reviews the pros and cons of remote navigation for ablation of both atrial and ventricular substrates. Finally, it attempts to predict the direction of this field in the coming years.

  20. A 4-DOF Robot for Positioning Ultrasound Imaging Catheters

    PubMed Central

    Loschak, Paul M.; Degirmenci, Alperen; Tenzer, Yaroslav; Howe, Robert D.

    2015-01-01

    In this paper we present the design, fabrication, and testing of a robot for automatically positioning ultrasound imaging catheters. Our system will point ultrasound (US) catheters to provide real-time imaging of anatomical structures and working instruments during minimally invasive surgeries. Manually navigating US catheters is difficult and requires extensive training in order to aim the US imager at desired targets. Therefore, a four DOF robotic system was developed to automatically navigate US imaging catheters for enhanced imaging. A rotational transmission enables three DOF for pitch, yaw, and roll of the imager. This transmission is translated by the fourth DOF. An accuracy analysis was conducted to calculate the maximum allowable joint motion error. Rotational joints must be accurate to within 1.5° and the translational joint must be accurate within 1.4 mm. Motion tests were then conducted to validate the accuracy of the robot. The average resulting errors in positioning of the rotational joints were measured to be 0.28°-0.38° with average measured backlash error 0.44°. Average translational positioning and backlash errors were measured to be significantly lower than the reported accuracy of the position sensor. The resulting joint motion errors were well within the required specifications for accurate robot motion. Such effective navigation of US imaging catheters will enable better visualization in various procedures ranging from cardiac arrhythmia treatment to tumor removal in urological cases. PMID:26925468

  1. Cardiac Arrhythmias: Diagnosis, Symptoms, and Treatments.

    PubMed

    Fu, Du-Guan

    2015-11-01

    The cardiac arrhythmia is characterized by irregular rhythm of heartbeat which could be either too slow (<60 beats/min) or too fast (>100 beats/min) and can happen at any age. The use of pacemaker and defibrillators devices has been suggested for heart arrhythmias patients. The antiarrhythmic medications have been reported for the treatment of cardiac arrhythmias or irregular heartbeats. The diagnosis, symptoms, and treatments of cardiac arrhythmias as well as the radiofrequency ablation, tachycardia, Brugada syndrome, arterial fibrillation, and recent research on the genetics of cardiac arrhythmias have been described here.

  2. FBG Sensor for Contact Level Monitoring and Prediction of Perforation in Cardiac Ablation

    PubMed Central

    Ho, Siu Chun Michael; Razavi, Mehdi; Nazeri, Alireza; Song, Gangbing

    2012-01-01

    Atrial fibrillation (AF) is the most common type of arrhythmia, and is characterized by a disordered contractile activity of the atria (top chambers of the heart). A popular treatment for AF is radiofrequency (RF) ablation. In about 2.4% of cardiac RF ablation procedures, the catheter is accidently pushed through the heart wall due to the application of excessive force. Despite the various capabilities of currently available technology, there has yet to be any data establishing how cardiac perforation can be reliably predicted. Thus, two new FBG based sensor prototypes were developed to monitor contact levels and predict perforation. Two live sheep were utilized during the study. It was observed during operation that peaks appeared in rhythm with the heart rate whenever firm contact was made between the sensor and the endocardial wall. The magnitude of these peaks varied with pressure applied by the operator. Lastly, transmural perforation of the left atrial wall was characterized by a visible loading phase and a rapid signal drop-off correlating to perforation. A possible pre-perforation signal was observed for the epoxy-based sensor in the form of a slight signal reversal (12–26% of loading phase magnitude) prior to perforation (occurring over 8 s). PMID:22368507

  3. In Vivo Evaluations of a Phased Ultrasound Array for Transesophageal Cardiac Ablation

    NASA Astrophysics Data System (ADS)

    Jaiswal, Devina; Werner, Jacob; Park, Eun-Joo; Francischelli, David; Smith, Nadine Barrie

    2010-03-01

    Atrial fibrillation is one of the most common arrhythmias that affects over 2.2 million Americans each year. Catheter ablation, one of the effective treatments, has shown high rate of success in treating paroxysmal atrial fibrillation. Currently, radiofrequency which is being used for catheter ablation is an invasive procedure. Measurable morbidity and significant costs and time are associated with this modality of treatment of permanent or persistent atrial fibrillation. In order to address these issues, a transesophageal ultrasound applicator for noninvasive cardiac ablation was designed, developed and evaluated. The ultrasound energy delivered by the phased array was used to create a lesion in the myocardial tissue. Various factors, simulation results of transducer arrays, current transesophageal medical devices, and throat anatomy, were considered while designing a phased ultrasound transducer that can be inserted into the esophagus. For this research, a two-dimensional sparse phased array with flat tapered elements was fabricated and evaluated in in vivo experiments. Five pigs were anesthetized; the array was passed transesophagealy and positioned over the heart. An operating frequency of 1.6 MHz and 8˜15 minutes of array operation resulted in both single and multiple lesions on atrial and ventricular myocardium. The average size of lesions was 5.1±2.1 mm in diameter and 7.8±2.5 mm in length. Experimental results indicate that the array delivered sufficient power to produce ablation at the focal point while not grossly damaging the tissue surrounding the area of interest. These results demonstrate a potential application of the ultrasound applicator for noninvasive transesophageal cardiac surgery in atrial fibrillation treatment.

  4. [Clinical study of Silver Lubricath Foley catheter].

    PubMed

    Nakada, J; Kawahara, M; Onodera, S; Oishi, Y

    1996-06-01

    We evaluated the Silver Lubricath Foley Catheter (silver catheter) coated with silver and hydrogel developed to prevent urinary infection, in comparison with the silicone-coated catheter (silicone catheter). Twelve patients ranging from 71 to 95 years of age (median age, 82 years) were catheterized and the 16 of 18F catheter was replaced every 2 weeks. They answered a questionnaire which included inquiry about the treatment with urinary catheter. Because of less leakage and discomfort to the urethra, the silver catheter had advantages over the silicone catheter. The risk of bacteriuria after 14 days of catheterization was not significantly different between the two types of catheter. Scanning electron microscopic analysis revealed that bacterial biofilm developed on the inner surface of both catheters after 14 days of catheterization. On the other hand, the amount of bacterial biofilm on the outer surface of a silver catheter was less than that on the outer surface of a silicone catheter.

  5. 5-F catheter in cerebral angiography

    SciTech Connect

    O'Reilly, G.V.; Naheedy, M.H.; Colucci, V.M.; Hammerschlag, S.B.

    1981-11-01

    Although the 5-F catheter is reputed to cause less vascular trauma than larger catheters, subintimal injections of contrast material have occurred following intimal damage by the catheter tip. Microscopic studies of the tips of two widely used 5-F polyethylene catheters have revealed a difference in configuration resulting in one of the catheters becoming markedly damaged during angiography. The authors make recommendations for finishing and protecting the catheter tip.

  6. Cardiac Rehabilitation

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Cardiac Rehabilitation? Cardiac rehabilitation (rehab) is a medically supervised program ... be designed to meet your needs. The Cardiac Rehabilitation Team Cardiac rehab involves a long-term commitment ...

  7. Temperature-controlled cooled-tip radiofrequency ablation in left ventricular myocardium.

    PubMed

    Watanabe, Ichiro; Nuo, Min; Okumura, Yasuo; Ohkubo, Kimie; Ashino, Sonoko; Kofune, Masayoshi; Kofune, Tatsuya; Nakai, Toshiko; Kasamaki, Yuji; Hirayama, Atsushi

    2010-05-01

    Steam pop and intramural charring have been reported during cooled-tip radiofrequency catheter ablation (RFCA). We studied the feasibility of temperature-controlled cooled-tip RFCA in the canine heart.An internally cooled ablation catheter was inserted into the left ventricle. A custom-made radiofrequency (RF) generator capable of controlling the tip-temperature at the preset level by slow increases in the power was used. Temperature-controlled cooled-tip RF applications were performed at a target temperature of 40 degrees C for 90 seconds. Acute study: Intramyocardial temperature was measured at the ablation site in 10 dogs by inserting a fluoroptic probe. Chronic study: Lesion depth and volume were measured in 5 dogs after 3 weeks of survival. In the acute study, no pop or abrupt impedance rise was observed. Maximum intramyocardial temperature was 72.4 + or - 14.4 degrees C at 2-4 mm above the endocardium. No coagulum formation, craters, or intramural charring were observed. Maximum lesion depth was 6.7 + or - 1.5 mm, and lesion volume was 404 + or - 219 mm3. In the chronic study, maximum lesion depth was 5.9 + or - 1.1 mm, and lesion volume was 281 + or - 210 mm(3).Temperature controlled RFCA is feasible with a cooled-tip catheter and an RF generator that slowly increases the RF power until the preset catheter-tip temperature is reached. PMID:20558910

  8. Cultures of Needleless Connectors Are Useful for Ruling Out Central Venous Catheter Colonization

    PubMed Central

    Pérez-Granda, María Jesús; Cruces, Raquel; Martín-Rabadán, Pablo; Bouza, Emilio

    2015-01-01

    Semiquantitative cultures of skin surrounding intravascular catheter entry sites and catheter hubs have high negative predictive values for catheter tip colonization. However, culturing samples from the inner side of the hub requires the catheter to be manipulated, thus increasing the risk of migration of microorganisms into the bloodstream. Today, hubs are closed using needleless connectors (NCs). Cultures of NCs could predict catheter colonization. Our objective was to compare the yield of NC sonicate cultures for prediction of catheter colonization with that of hub cultures. For 6 months, we prospectively collected all short-term central lines and systems removed from patients admitted to the cardiac surgery postoperative care unit, irrespective of the reason for withdrawal. Hub cultures were obtained immediately before withdrawal and were cultured using a semiquantitative method. Catheter tips were cultured using the roll-plate technique and sonication, and NCs were cultured using a semiquantitative technique after sonication. We considered NCs to be colonized when ≥1 culture was positive. We collected a total of 75 central systems. The catheter colonization rate was 10.7%. The rates for hub and NC colonization were 6.7% and 12.0%, respectively. The validity values for hubs and NCs for prediction of catheter colonization were as follows: sensitivity, 25.0% and 87.5%; specificity, 95.5% and 97.0%; positive predictive value, 40.0% and 77.8%; negative predictive value, 91.4% and 98.5%; validity index, 88.0% and 96.0%, respectively. Cultures of closed NCs can be used to rule out catheter tip colonization and are superior to hub cultures in ruling out short-term central venous catheter colonization. PMID:25878353

  9. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  10. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  11. Radiofrequency attenuator and method

    SciTech Connect

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  12. Radiofrequency attenuator and method

    DOEpatents

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-11-10

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3 C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  13. The Hunter Pulmonary Angiography Catheter for a Brachiocephalic Vein Approach

    SciTech Connect

    Rosen, Galia Kowalik, Karen J.; Ganguli, Suverano; Hunter, David W.

    2006-12-15

    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a 'C-shaped' curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk.

  14. A statistical method for retrospective cardiac and respiratory motion gating of interventional cardiac x-ray images

    SciTech Connect

    Panayiotou, Maria King, Andrew P.; Housden, R. James; Ma, YingLiang; Rhode, Kawal S.; Cooklin, Michael; O'Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo

    2014-07-15

    Purpose: Image-guided cardiac interventions involve the use of fluoroscopic images to guide the insertion and movement of interventional devices. Cardiorespiratory gating can be useful for 3D reconstruction from multiple x-ray views and for reducing misalignments between 3D anatomical models overlaid onto fluoroscopy. Methods: The authors propose a novel and potentially clinically useful retrospective cardiorespiratory gating technique. The principal component analysis (PCA) statistical method is used in combination with other image processing operations to make our proposed masked-PCA technique suitable for cardiorespiratory gating. Unlike many previously proposed techniques, our technique is robust to varying image-content, thus it does not require specific catheters or any other optically opaque structures to be visible. Therefore, it works without any knowledge of catheter geometry. The authors demonstrate the application of our technique for the purposes of retrospective cardiorespiratory gating of normal and very low dose x-ray fluoroscopy images. Results: For normal dose x-ray images, the algorithm was validated using 28 clinical electrophysiology x-ray fluoroscopy sequences (2168 frames), from patients who underwent radiofrequency ablation (RFA) procedures for the treatment of atrial fibrillation and cardiac resynchronization therapy procedures for heart failure. The authors established end-systole, end-expiration, and end-inspiration success rates of 97.0%, 97.9%, and 97.0%, respectively. For very low dose applications, the technique was tested on ten x-ray sequences from the RFA procedures with added noise at signal to noise ratio (SNR) values of√(5)0, √(1)0, √(8), √(6), √(5), √(2), and √(1) to simulate the image quality of increasingly lower dose x-ray images. Even at the low SNR value of √(2), representing a dose reduction of more than 25 times, gating success rates of 89.1%, 88.8%, and 86.8% were established. Conclusions: The proposed

  15. Central venous catheter - dressing change

    MedlinePlus

    ... will need: Sterile gloves Cleaning solution A special sponge A special patch, called a Biopatch A clear ... around the catheter. Clean the skin with the sponge and cleaning solution. Air dry after cleaning. Place ...

  16. Peripherally inserted central catheter - insertion

    MedlinePlus

    PICC - insertion ... A PICC is a long, thin tube (called a catheter) that goes into your body through a vein in ... into a large vein near your heart. The PICC helps carry nutrients and medicines into your body. ...

  17. Peripherally inserted central catheter - flushing

    MedlinePlus

    ... To flush your catheter, you will need: Clean paper towels Saline syringes (clear), and maybe heparin syringes ( ... your fingers before washing. Dry with a clean paper towel. Set up your supplies on a clean ...

  18. Hemodialysis catheter exit site care.

    PubMed

    Astle, Colleen M

    2007-01-01

    Tunneled, cuffed central venous catheters are used extensively throughout the hemodialysis patient population as a permanent arterio-venous access. One of the major complications associated with these devices is infection. The strategies aimed at reducing catheter-related infection include nurse-patient ratio, use of barrier precautions, hand washing, ointments, dressings, and skin antiseptics. The intent of this paper is to examine the types of skin antiseptics and compare their effectiveness.

  19. Photoacoustic characterization of radiofrequency ablation lesions

    NASA Astrophysics Data System (ADS)

    Bouchard, Richard; Dana, Nicholas; Di Biase, Luigi; Natale, Andrea; Emelianov, Stanislav

    2012-02-01

    Radiofrequency ablation (RFA) procedures are used to destroy abnormal electrical pathways in the heart that can cause cardiac arrhythmias. Current methods relying on fluoroscopy, echocardiography and electrical conduction mapping are unable to accurately assess ablation lesion size. In an effort to better visualize RFA lesions, photoacoustic (PA) and ultrasonic (US) imaging were utilized to obtain co-registered images of ablated porcine cardiac tissue. The left ventricular free wall of fresh (i.e., never frozen) porcine hearts was harvested within 24 hours of the animals' sacrifice. A THERMOCOOLR Ablation System (Biosense Webster, Inc.) operating at 40 W for 30-60 s was used to induce lesions through the endocardial and epicardial walls of the cardiac samples. Following lesion creation, the ablated tissue samples were placed in 25 °C saline to allow for multi-wavelength PA imaging. Samples were imaged with a VevoR 2100 ultrasound system (VisualSonics, Inc.) using a modified 20-MHz array that could provide laser irradiation to the sample from a pulsed tunable laser (Newport Corp.) to allow for co-registered photoacoustic-ultrasound (PAUS) imaging. PA imaging was conducted from 750-1064 nm, with a surface fluence of approximately 15 mJ/cm2 maintained during imaging. In this preliminary study with PA imaging, the ablated region could be well visualized on the surface of the sample, with contrasts of 6-10 dB achieved at 750 nm. Although imaging penetration depth is a concern, PA imaging shows promise in being able to reliably visualize RF ablation lesions.

  20. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  1. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  2. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  3. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  4. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  5. Measurement of radiofrequency fields

    SciTech Connect

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs.

  6. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L.; Elliott, Thomas S.

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  7. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, Harry Lawrence; Elliott, Thomas S.

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  8. Cardiac rehabilitation

    MedlinePlus

    ... Coronary artery disease - cardiac rehab; Angina - cardiac rehab; Heart failure - cardiac rehab ... have had: Heart attack Coronary heart disease (CHD) Heart failure Angina (chest pain) Heart or heart valve surgery ...

  9. Successful catheter ablation of a left anterior accessory pathway from the non-coronary cusp of the aortic valve.

    PubMed

    Laranjo, Sérgio; Oliveira, Mário; Trigo, Conceição

    2015-08-01

    Left anterior accessory pathways are considered to be rare findings. Catheter ablation of accessory pathways in this location remains a challenging target, and few reports about successful ablation of these accessory pathways are available. We describe our experience regarding a case of a manifest left anterior accessory pathway ablation using radiofrequency energy at the junction of the left coronary cusp with the non-coronary cusp.

  10. Fetal cardiac interventions: clinical and experimental research

    PubMed Central

    Humuruola, Gulimila

    2016-01-01

    Fetal cardiac interventions for congenital heart diseases may alleviate heart dysfunction, prevent them evolving into hypoplastic left heart syndrome, achieve biventricular outcome and improve fetal survival. Candidates for clinical fetal cardiac interventions are now restricted to cases of critical aortic valve stenosis with evolving hypoplastic left heart syndrome, pulmonary atresia with an intact ventricular septum and evolving hypoplastic right heart syndrome, and hypoplastic left heart syndrome with an intact or highly restrictive atrial septum as well as fetal heart block. The therapeutic options are advocated as prenatal aortic valvuloplasty, pulmonary valvuloplasty, creation of interatrial communication and fetal cardiac pacing. Experimental research on fetal cardiac intervention involves technical modifications of catheter-based cardiac clinical interventions and open fetal cardiac bypass that cannot be applied in human fetuses for the time being. Clinical fetal cardiac interventions are plausible for midgestation fetuses with the above-mentioned congenital heart defects. The technical success, biventricular outcome and fetal survival are continuously being improved in the conditions of the sophisticated multidisciplinary team, equipment, techniques and postnatal care. Experimental research is laying the foundations and may open new fields for catheter-based clinical techniques. In the present article, the clinical therapeutic options and experimental fetal cardiac interventions are described. PMID:27279868

  11. Fetal cardiac interventions: clinical and experimental research.

    PubMed

    Yuan, Shi-Min; Humuruola, Gulimila

    2016-01-01

    Fetal cardiac interventions for congenital heart diseases may alleviate heart dysfunction, prevent them evolving into hypoplastic left heart syndrome, achieve biventricular outcome and improve fetal survival. Candidates for clinical fetal cardiac interventions are now restricted to cases of critical aortic valve stenosis with evolving hypoplastic left heart syndrome, pulmonary atresia with an intact ventricular septum and evolving hypoplastic right heart syndrome, and hypoplastic left heart syndrome with an intact or highly restrictive atrial septum as well as fetal heart block. The therapeutic options are advocated as prenatal aortic valvuloplasty, pulmonary valvuloplasty, creation of interatrial communication and fetal cardiac pacing. Experimental research on fetal cardiac intervention involves technical modifications of catheter-based cardiac clinical interventions and open fetal cardiac bypass that cannot be applied in human fetuses for the time being. Clinical fetal cardiac interventions are plausible for midgestation fetuses with the above-mentioned congenital heart defects. The technical success, biventricular outcome and fetal survival are continuously being improved in the conditions of the sophisticated multidisciplinary team, equipment, techniques and postnatal care. Experimental research is laying the foundations and may open new fields for catheter-based clinical techniques. In the present article, the clinical therapeutic options and experimental fetal cardiac interventions are described. PMID:27279868

  12. Radiofrequency Renal Denervation Protects the Ischemic Heart via Inhibition of GRK2 and Increased Nitric Oxide Signaling

    PubMed Central

    Polhemus, David J.; Gao, Juan; Scarborough, Amy L.; Trivedi, Rishi; McDonough, Kathleen H.; Goodchild, Traci T.; Smart, Frank

    2016-01-01

    Rationale: Catheter-based renal denervation (RDN) is currently under development for the treatment of resistant hypertension and is thought to reduce blood pressure via interruption of sympathetic pathways that modulate cardiovascular function. The sympathetic nervous system also plays a critical role in the pathogenesis of acute myocardial infarction and heart failure. Objective: We examined whether treatment with radiofrequency (RF)-RDN would protect the heart against subsequent myocardial ischemia/reperfusion injury via direct effects on the myocardium. Methods and Results: Spontaneously hypertensive rats received either bilateral RF-RDN or sham-RDN. At 4 weeks after RF-RDN (n=14) or sham-RDN (n=14) treatment, spontaneously hypertensive rats were subjected to 30 minutes of transient coronary artery occlusion and 24 hours –7 days reperfusion. Four weeks after RF-RDN, myocardial oxidative stress was markedly attenuated, and transcription and translation of antioxidants, superoxide dismutase 1 and glutathione peroxidase-1, were significantly upregulated compared with sham-RDN spontaneously hypertensive rats. RF-RDN also inhibited myocardial G protein–coupled receptor kinase 2 pathological signaling and enhanced myocardial endothelial nitric oxide synthase function and nitric oxide signaling. RF-RDN therapy resulted in a significant reduction in myocardial infarct size per area at risk compared with sham-RDN (26.8 versus 43.9%; P<0.01) at 24 hours postreperfusion and significantly improved left ventricular function at 7 days after myocardial ischemia/reperfusion. Conclusions: RF-RDN reduced oxidative stress, inhibited G protein–coupled receptor kinase 2 signaling, increased nitric oxide bioavailability, and ameliorated myocardial reperfusion injury in the setting of severe hypertension. These findings provide new insights into the remote cardioprotective effects of RF-RDN acting directly on cardiac myocytes to attenuate cell death and protect against ischemic

  13. Intracardiac Acoustic Radiation Force Impulse Imaging: A Novel Imaging Method for Intraprocedural Evaluation of Radiofrequency Ablation Lesions

    PubMed Central

    Eyerly, Stephanie A.; Bahnson, Tristram D.; Koontz, Jason I.; Bradway, David P.; Dumont, Douglas M.; Trahey, Gregg E.; Wolf, Patrick D.

    2012-01-01

    Background Arrhythmia recurrence after cardiac radiofrequency ablation (RFA) for atrial fibrillation (AF) has been linked to conduction through discontinuous lesion lines. Intraprocedural visualization and corrective ablation of lesion line discontinuities could decrease post-procedure AF recurrence. Intracardiac acoustic radiation force impulse (ARFI) imaging is a new imaging technique that visualizes RFA lesions by mapping the relative elasticity contrast between compliant-unablated and stiff-RFA treated myocardium. Objective To determine if intraprocedure ARFI images can identify RFA treated myocardium in vivo. Methods In eight canines, an electroanatomical mapping (EAM) guided intracardiac echo catheter (ICE) was used to acquire 2D ARFI images along right atrial ablation lines before and after RFA. ARFI images were acquired during diastole with the myocardium positioned at the ARFI focus (1.5 cm) and parallel to the ICE transducer for maximal and uniform energy delivery to the tissue. Three reviewers categorized each ARFI image as depicting no lesion, non-contiguous, or contiguous lesion. For comparison, three separate reviewers confirmed RFA lesion presence and contiguity based on functional conduction block at the imaging plane location on EAM activation maps. Results Ten percent of ARFI images were discarded due to motion artifacts. Reviewers of the ARFI images detected RFA-treated sites with high sensitivity (95.7%) and specificity (91.5%). Reviewer identification of contiguous lesion had 75.3% specificity and 47.1% sensitivity. Conclusions Intracardiac ARFI imaging was successful in identifying endocardial RFA treatment when specific imaging conditions were maintained. Further advances in ARFI imaging technology would facilitate a wider range of imaging opportunities for clinical lesion evaluation. PMID:22772134

  14. Light modulated electron beam driven radiofrequency emitter

    DOEpatents

    Wilson, M.T.; Tallerico, P.J.

    1979-10-10

    The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

  15. New-generation radiofrequency technology.

    PubMed

    Krueger, Nils; Sadick, Neil S

    2013-01-01

    Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation. PMID:23461058

  16. The supraclavicular fossa ultrasound view for central venous catheter placement and catheter change over guidewire.

    PubMed

    Kim, Se-Chan; Klebach, Christian; Heinze, Ingo; Hoeft, Andreas; Baumgarten, Georg; Weber, Stefan

    2014-12-23

    The supraclavicular fossa ultrasound view can be useful for central venous catheter (CVC) placement. Venipuncture of the internal jugular veins (IJV) or subclavian veins is performed with a micro-convex ultrasound probe, using a neonatal abdominal preset with a probe frequency of 10 Mhz at a depth of 10-12 cm. Following insertion of the guidewire into the vein, the probe is shifted to the right supraclavicular fossa to obtain a view of the superior vena cava (SVC), right pulmonary artery and ascending aorta. Under real-time ultrasound view, the guidewire and its J-tip is visualized and pushed forward to the lower SVC. Insertion depth is read from guidewire marks using central venous catheter. CVC is then inserted following skin and venous dilation. The supraclavicular fossa view is most suitable for right IJV CVC insertion. If other insertion sites are chosen the right supraclavicular fossa should be within the sterile field. Scanning of the IJVs, brachiocephalic veins and SVC can reveal significant thrombosis before venipuncture. Misplaced CVCs can be corrected with a change over guidewire technique under real-time ultrasound guidance. In conjunction with a diagnostic lung ultrasound scan, this technique has a potential to replace chest radiograph for confirmation of CVC tip position and exclusion of pneumothorax. Moreover, this view is of advantage in patients with a non-p-wave cardiac rhythm were an intra-cardiac electrocardiography (ECG) is not feasible for CVC tip position confirmation. Limitations of the method are lack of availability of a micro-convex probe and the need for training.

  17. Urinary Retention: Catheter Drainage Bag or Catheter Valve?

    PubMed Central

    Virdi, Gurnam; Hendry, David

    2016-01-01

    The management of patients with intractable urinary incontinence presents as a challenging priority in the ageing population. To preserve the antibacterial mechanisms of the bladder, a urine collection that enables the bladder to fill and empty regularly and completely, should be used. This mimics the action of the healthy bladder. We compared the success rates of two widely used urinary-collection systems (catheter with drainage bag or a catheter valve) at our institution for those patients undergoing a trial of void. PMID:26989368

  18. Radiofrequency ablation of lung tumours

    PubMed Central

    Goh, PYT

    2006-01-01

    Radiofrequency ablation (RFA) is a well-established local therapy for hepatic malignancies. It is rapidly emerging as an effective treatment modality for small lesions elsewhere in the body, in particular, the kidney and the lung. It is a relatively safe and minimally invasive treatment for small lung malignancies, both primary and secondary. In particular, it is the preferred form of treatment for non-surgical candidates. This paper describes the technique employed for radiofrequency ablation of lung tumours, as well as the protocol established, at the Mount Elizabeth Hospital, Singapore. PMID:21614247

  19. Catheter Ablation of Atrial Fibrillation Raises the Plasma Level of NGF-β Which Is Associated with Sympathetic Nerve Activity

    PubMed Central

    Park, Jae Hyung; Wi, Jin; Lee, Da Lyung; Joung, Boyoung; Lee, Moon Hyoung

    2015-01-01

    Purpose The expression of nerve growth factor-β (NGF-β) is related to cardiac nerve sprouting and sympathetic hyper innervation. We investigated the changes of plasma levels of NGF-β and the relationship to follow-up heart rate variability (HRV) after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Materials and Methods This study included 147 patients with AF (117 men, 55.8±11.5 years, 106 paroxysmal AF) who underwent RFCA. The plasma levels of NGF-β were quantified using double sandwich enzyme linked immunosorbent assay method before (NGF-βpre) and 1 hour after RFCA (NGF-βpost-1hr). HRV at pre-procedure (HRVpre), 3 months (HRVpost-3mo), and 1 year post-procedure (HRVpost-1yr) were analyzed and compared with plasma levels of NGF-β. Results 1) The plasma levels of NGF-β significantly increased after RFCA (20.05±11.09 pg/mL vs. 29.60±19.43 pg/mL, p<0.001). The patients who did not show increased NGF-βpost-1hr were older (p=0.023) and had greater left atrial volume index (p=0.028) than those with increased NGF-βpost-1hr. 2) In patients with NGF-βpre >18 pg/mL, low frequency components (LF)/high-frequency components (HF) (p=0.003) and the number of atrial premature contractions (APCs, p=0.045) in HRVpost-3mo were significantly higher than those with ≤18 pg/mL. 3) The LF/HF at HRVpost-3mo was linearly associated with the NGF-βpre (B=4.240, 95% CI 1.114-7.336, p=0.008) and the NGF-βpost-1hr (B=7.617, 95% CI 2.106-13.127, p=0.007). 4) Both NGF-βpre (OR=1.159, 95% CI 1.045-1.286, p=0.005) and NGF-βpost-1hr (OR=1.098, 95% CI 1.030-1.170, p=0.004) were independent predictors for the increase of LF/HF at HRVpost-3mo. Conclusion AF catheter ablation increases plasma level of NGF-β, and high plasma levels of NGF-βpre was associated with higher sympathetic nerve activity and higher frequency of APCs in HRVpost-3mo. PMID:26446633

  20. Isolated Disruption of the Right Coronary Artery Following a Steam Pop during Cavotricuspid Linear Ablation with a Contact Force Catheter.

    PubMed

    Brunelli, Michele; Frommhold, Markus; Back, Dieter; Mierzwa, Marco; Lauer, Bernard; Geller, J Christoph

    2016-07-01

    A 70-year-old woman with persistent atrial fibrillation underwent pulmonary vein isolation and linear ablation with a contact sensor catheter. During cavotricuspid isthmus ablation, a steam pop resulted in cardiac tamponade, and the patient developed severe hypotension despite successful pericardial puncture and minimal residual pericardial effusion. Right coronary artery angiography revealed extravasal contrast medium accumulation posterior of the Crux Cordis. Emergent cardiac surgery confirmed isolated disruption of the artery in the absence of additional heart perforation. Although contact sensor catheters may reduce complications, steam pops can still occur and result in dramatic complications. PMID:27378561

  1. Catheter-based photoacoustic endoscope

    NASA Astrophysics Data System (ADS)

    Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

    2014-06-01

    We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique's benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument's flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system.

  2. A systematic review of surgical ablation versus catheter ablation for atrial fibrillation

    PubMed Central

    Kearney, Katherine; Stephenson, Rowan; Phan, Kevin; Chan, Wei Yen; Huang, Min Yin

    2014-01-01

    Background Atrial fibrillation (AF) is an increasingly prevalent condition in the ageing population, with significantly associated morbidity and mortality. Surgical and catheter ablative strategies both aim to reduce mortality and morbidity through freedom from AF. This review consolidates all currently available comparative data to evaluate these two interventions. Methods A systematic search was conducted across MEDLINE, PubMed, Embase, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews from January 2000 until August 2013. All studies were critically appraised and only those directly comparing surgical and catheter ablation were included. Results Seven studies were deemed suitable for analysis according to the inclusion criteria. Freedom from AF was significantly higher in the surgical ablation group versus the catheter ablation group at 6-month, 12-month and study endpoint follow-up periods. Subgroup analysis demonstrated similar trends, with higher freedom from AF in the surgical ablation group for paroxysmal AF patients. The incidence of pacemaker implantation was higher, while no difference in stroke or cardiac tamponade was demonstrated for the surgical versus catheter ablation groups. Conclusions Current evidence suggests that epicardial ablative strategies are associated with higher freedom from AF, higher pacemaker implantation rates and comparable neurological complications and cardiac tamponade incidence to catheter ablative treatment. Other complications and risks were poorly reported, which warrants further randomized controlled trials (RCTs) of adequate power and follow-up duration. PMID:24516794

  3. [RADIOFREQUENCY ABLATION FOR THE TREATMENT OF VARICOSE VEINS].

    PubMed

    Sugiyama, Satoru; Miyade, Yoshio; Inaki, Yasuhiko

    2015-05-01

    Significant advances in the endovenous technique for treating incompetent saphenous veins could change the surgical strategy in patients with varicose veins. Radiofrequency ablation (RFA) was approved as a new technique for the treatment of varicose veins in Japan in June 2014. In RFA, the ablation temperature is controlled by a sensor at the upper end of the catheter. The vein wall is heated with stable conductive power of 120 degrees C, resulting in endothelial denudation. The RFA method was approved in 1998 in Europe and in 1999 in the USA. The ClosurePLUS catheter was developed in 2003 and ClosureFAST in 2006. High occlusion rates and lower postoperative complication rates were reported with ClosureFAST than with ClosurePLUS. It is expected that this new ablation technique will control saphenous vein reflux with less pain and less ecchymosis after surgery. The treatment of varicose veins is less invasive with RFA devices and will become widely accepted as an alternative to conventional surgery for varicose veins in Japan.

  4. [Risk management in cardiac anesthesia].

    PubMed

    Inada, Eiichi

    2008-05-01

    Cardiac anesthesia carries high risk because of the patient's cardiac and coexisting diseases and rapid and complex hemodynamic changes during surgery. We should be ready to treat hemodynamic changes which may rapidly deteriorate into a vicious cycle. Many potent drugs and life-support devices are used. The drugs should be properly labeled to avoid drug error. Prefilled drug syringes and ready-to-use bags are helpful to avoid mixture error. Syringe and infusion pumps should be properly set. All the infusion systems should be checked in a systematical way. Blood management including blood transfusion and coagulation is important. Heparin-induced thrombocytopenia (HIT) may cause thrombosis. Heparin and heparin-coated catheter should be avoided in patients with HIT. Causes of bleeding tendency should be sort out and treated accordingly. Protamine reactions including hypotension and pulmonary hypertension can be catastrophic. Lastly, intimate communication between surgeons, anesthesiologists, medical engineers, and nurses is essential to perform cardiac surgery safely.

  5. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter. (a) Identification. A nasopharyngeal catheter is a device consisting of a bougie or filiform catheter that is intended for use in probing or dilating the eustachian tube. This generic type of device...

  6. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter. (a) Identification. A nasopharyngeal catheter is a device consisting of a bougie or filiform catheter that is intended for use in probing or dilating the eustachian tube. This generic type of device...

  7. Right atrial thrombus associated with subclavian catheter developed due to total parenteral nutrition application

    PubMed Central

    Sahin, Nursel; Basarici, Ibrahim; Erbasan, Ozan

    2016-01-01

    Central venous catheterization as a frequent routine clinical procedure may have significant complications. Mechanical complications may occur during catheter placement, whereas thromboembolic and infectious complications can be seen during follow-up. Total parenteral nutrition (TPN) associated central venous catheterizations may result in early mechanical complications and thrombotic and infectious complications in the long term. This paper describes a patient diagnosed as mitochondrial neurogastrointestinal encephalomyopathy requiring long-term central venous catheterization for TPN implementation, who had an infected thrombus on the catheter tip resected by cardiac surgery. PMID:27212985

  8. Effectiveness of different central venous catheters for catheter-related infections: a network meta-analysis.

    PubMed

    Wang, H; Huang, T; Jing, J; Jin, J; Wang, P; Yang, M; Cui, W; Zheng, Y; Shen, H

    2010-09-01

    We aimed to compare the effectiveness of various catheters for prevention of catheter-related infection and to evaluate whether specific catheters are superior to others for reducing catheter-related infections. We identified randomised, controlled trials that compared different types of central venous catheter (CVC), evaluating catheter-related infections in a systematic search of articles published from January 1996 to November 2009 via Medline, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. Network meta-analysis with a mixed treatment comparison method using Bayesian Markov Chain Monte Carlo simulation was used to combine direct within-trial, between-treatment comparisons with indirect trial evidence. Forty-eight clinical trials (12 828 CVCs) investigating 10 intervention catheters contributed to the analyses. For prevention of CVC colonisation, adjusted silver iontophoretic catheters (odds ratio: 0.58; 95% confidence interval: 0.33-0.95), chlorhexidine and silver sulfadiazine catheters (0.49; 0.36-0.64), chlorhexidine and silver sulfadiazine blue plus catheters (0.37; 0.17-0.69), minocycline-rifampicin catheters (0.28; 0.17-0.43) and miconazole-rifampicin catheters (0.11; 0.02-0.33) were associated with a significantly lower rate of catheter colonisation compared with standard catheters. For prevention of CRBSI, adjusted heparin-bonded catheters (0.20; 0.06-0.44) and minocycline-rifampicin catheters (0.18; 0.08-0.34) were associated with a significantly lower rate of CRBSI with standard catheters. Rifampicin-based impregnated catheters seem to be better for prevention of catheter-related infection compared with the other catheters.

  9. A method for guiding ablation catheters to arrhythmogenic sites using body surface electrocardiographic signals.

    PubMed

    Barley, Maya E; Armoundas, Antonis A; Cohen, Richard J

    2009-03-01

    Treatment of hemodynamically unstable ventricular arrhythmias requires rapid and accurate localization of the reentrant circuit. We have previously described an algorithm that uses the single-equivalent moving dipole model to rapidly identify both the location of cardiac sources from body surface electrocardiographic signals and the location of the ablation catheter tip from current pulses delivered at the tip. However, during catheter ablation, in the presence of sources of systematic error, even if the exit site and catheter tip dipole are superposed in real space, their calculated positions may be separated by as much as 5 mm if their orientations are not exactly matched. In this study, we present a method to compensate for the effect of dipole orientation and examine the method's ability to guide a dipole at a catheter tip to an arrhythmogenic dipole corresponding to the exit site. In computer simulations, we show that the new method enables the user to guide the catheter tip to within 1.5 mm of the arrhythmogenic dipole using a realistic number of movements of the ablation catheter. These results suggest that this method has the potential to greatly facilitate RF ablation procedures, especially in the significant patient population with hemodynamically unstable arrhythmias. PMID:19272900

  10. Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation.

    PubMed

    Yamagata, Kenichiro; Aldhoon, Bashar; Kautzner, Josef

    2016-08-01

    Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures. PMID:27617094

  11. Successful non-operative management of left atrioesophageal fistula following catheter ablation.

    PubMed

    Shiraishi, Manabu; Morita, Hideki; Muramatsu, Kenichi; Sato, Akira; Nitta, Junichi; Yamaguchi, Atsushi; Adachi, Hideo

    2014-08-01

    Atrioesophageal fistula (AEF) is a potentially lethal complication of catheter radiofrequency ablation for atrial fibrillation. A 49-year-old man with paroxysmal atrial fibrillation who underwent catheter ablation around the pulmonary vein was admitted 31 days after the procedure, suffering seizures and fever. Magnetic resonance imaging of the brain showed ischemia and multiple lesions of acute infarction in the right occipital lobe of the cerebrum. Computed tomography (CT) of the chest showed a small accumulation of air between the posterior left atrium and the esophagus, suggesting an AEF. Endoscopic snaring of the esophageal mucosa, repeated a few times, supported by nil by mouth and antibiotic therapy, resulted in improvement of his condition with no recurrence of symptoms. Subsequent chest CT scans confirmed disappearance of the leaked air and the patient was discharged home 45 days after admission with no neurological compromise.

  12. Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

    PubMed Central

    Aldhoon, Bashar; Kautzner, Josef

    2016-01-01

    Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures.

  13. Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

    PubMed Central

    Aldhoon, Bashar; Kautzner, Josef

    2016-01-01

    Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures. PMID:27617094

  14. JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

    SciTech Connect

    Ricci, Carmelo; Ceccherini, Claudio Leonini, Sara; Cini, Marco; Vigni, Francesco; Neri, Eugenio; Tucci, Enrico; Benvenuti, Antonio; Tommasino, Giulio; Sassi, Carlo

    2012-02-15

    An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

  15. Percutaneously inserted central catheter - infants

    MedlinePlus

    ... the PICC through the needle into a larger (central) vein, putting its tip near (but not in) the heart. Take an x-ray to place the needle. Remove the needle after the catheter is placed. WHAT ARE THE RISKS OF HAVING ...

  16. Aging of silastic peritoneal catheters.

    PubMed

    Poisetti, P; Bergonzi, G; Ballocchi, S; Fontana, F; Scarpioni, L

    1991-12-01

    Increasing the survival of patients on CAPD is related to the long-term reliability of the peritoneal access. Six silicone Tenckhoff catheters (with strip or diffuse barium sulphate inclusion) removed after 39-69 months because of the appearance of external segment fissures, were analysed by scanning electron microscopy (SEM) and infra-red spectroscopy with attenuated total refractance (ATR). The extracorporeal portion of the catheters showed (by ATR) a more prominent oxidation peak on the external than the internal surface; SEM showed marks and cracks on the external surface and exfoliation and flattening of the silastic reticle on the intraluminal surface. No evidence of oxidation was found in the intra-abdominal portion of the catheters but biofilm was found. We suggest that barium sulphate may render the silastic brittle and physiological and environmental long-term factors (such as uv-rays, temperature, sweat and disinfectants) could cause oxidation and loss of physico-chemical properties, with critical aging of the silastic and loss of catheter resistance to mechanical injury. PMID:1783450

  17. Cytometric Catheter for Neurosurgical Applications

    SciTech Connect

    Evans III, Boyd Mccutchen; Allison, Stephen W; Fillmore, Helen; Broaddus, William C; Dyer, Rachel L; Gillies, George

    2010-01-01

    Implantation of neural progenitor cells into the central nervous system has attracted strong interest for treatment of a variety of pathologies. For example, the replacement of dopamine-producing (DA) neural cells in the brain appears promising for the treatment of patients affected by Parkinson's disease. Previous studies of cell-replacement strategies have shown that less than 90% of implanted cells survive longer than 24 - 48 hours following the implantation procedure. However, it is unknown if these cells were viable upon delivery, or if they were affected by other factors such as brain pathology or an immune response. An instrumented cell-delivery catheter has been developed to assist in answering these questions by facilitating quantification and monitoring of the viability of the cells delivered. The catheter uses a fiber optic probe to perform flourescence-based cytometric measurments on cells exiting the port at the catheter tip. The current implementation of this design is on a 3.2 mm diameter catheter with 245 micrometer diameter optical fibers. Results of fluorescence testing data are presented and show that the device can characterize the quantity of cell densities ranging from 60,000 cells/ml to 600,000 cells/ml with a coefficient of determination of 0.93.

  18. Patency and complications of translumbar dialysis catheters

    PubMed Central

    Liu, Fanna; Bennett, Stacy; Arrigain, Susana; Schold, Jesse; Heyka, Robert; McLennan, Gordon; Navaneethan, Sankar D.

    2016-01-01

    Background Translumbar tunneled dialysis catheter (TLDC) is a temporary dialysis access for patients exhausted traditional access for dialysis. While few small studies reported successes with TLDC, additional studies are warranted to understand the short and long-term patency and safety of TLDC. Methods We conducted a retrospective analysis of adult patients who received TLDC for hemodialysis access from June 2006 to June 2013. Patient demographics, comorbid conditions, dialysis details, catheter insertion procedures and associated complications, catheter patency, and patient survival data were collected. Catheter patency was studied using Kaplan-Meier curve; catheter functionality was assessed with catheter intervals and catheter related complications were used to estimate catheter safety. Results There were 84 TLDCs inserted in 28 patients with 28 primary insertions and 56 exchanges. All TLDC insertions were technically successful with good blood flow during dialysis (>300 ml/min) and no immediate complications (major bleeding or clotting) were noted. The median number of days in place for initial catheter, secondary catheter and total catheter were 65, 84 and 244 respectively. The catheter patency rate at 3, 6 and 12 months were 43%, 25% and 7% respectively. The main complications were poor blood flow (40%) and catheter related infection (36%), which led to 30.8% and 35.9% catheter removal respectively. After translumbar catheter, 42.8% of the patients were successfully converted to another vascular access or peritoneal dialysis. Conclusion This study data suggests that TLDC might serve as a safe, alternate access for dialysis patients in short-term who have exhausted conventional vascular access. PMID:25800550

  19. Pathophysiology and clinical management of cardiac sarcoidosis.

    PubMed

    Hamzeh, Nabeel; Steckman, David A; Sauer, William H; Judson, Marc A

    2015-05-01

    Cardiac sarcoidosis is a potentially life-threatening condition characterized by formation of granulomas in the heart, resulting in conduction disturbances, atrial and ventricular arrhythmias, and ventricular dysfunction. The presentation of cardiac sarcoidosis ranges from asymptomatic with an abnormal imaging scan, to palpitations, syncope, symptoms of congestive heart failure, and sudden cardiac death. Screening for cardiac sarcoidosis has not been standardized, but the presence of cardiac symptoms on medical history and physical examination, and an abnormal electrocardiogram (ECG), Holter monitoring, or echocardiogram has been shown to be highly sensitive for detecting cardiac sarcoidosis. A signal-averaged ECG might also have a role in screening for cardiac sarcoidosis in asymptomatic patients. Although endomyocardial biopsies are highly specific for the diagnosis of cardiac sarcoidosis, procedural yield is very low and appropriate findings on cardiac MRI or PET are, therefore, often used as diagnostic surrogates. Treatment for cardiac sarcoidosis usually involves immunosuppressive therapy, particularly corticosteroids. Additional therapy might be required, depending on the clinical presentation, including implantation of an internal defibrillator, antiarrhythmic agents, and catheter ablation.

  20. Catheter Ablation of Ventricular Tachycardia

    MedlinePlus

    ... like to see the Circulation web site. Your Personal Message Send Message ... Scholar Cited By... Cardiac tachyarrhythmias and patient values and preferences for their management: the European Heart ...

  1. Respiratory motion influence on catheter contact force during radio frequency ablation procedures

    NASA Astrophysics Data System (ADS)

    Koch, Martin; Brost, Alexander; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive catheter ablation is a common treatment option for atrial fibrillation. A common treatment strategy is pulmonary vein isolation. In this case, individual ablation points need to be placed around the ostia of the pulmonary veins attached to the left atrium to generate transmural lesions and thereby block electric signals. To achieve a durable transmural lesion, the tip of the catheter has to be stable with a sufficient tissue contact during radio-frequency ablation. Besides the steerable interface operated by the physician, the movement of the catheter is also influenced by the heart and breathing motion - particularly during ablation. In this paper we investigate the influence of breathing motion on different areas of the endocardium during radio frequency ablation. To this end, we analyze the frequency spectrum of the continuous catheter contact force to identify areas with increased breathing motion using a classification method. This approach has been applied to clinical patient data acquired during three pulmonary vein isolation procedures. Initial findings show that motion due to respiration is more pronounced at the roof and around the right pulmonary veins.

  2. Catheter related infections in Damas Hospital.

    PubMed

    Lugo, L J; Zapata, N J; Ramírez Ronda, C H

    1994-01-01

    The purpose of this study is to investigate the extent of catheter-related infections in our Institution. We examined retrospectively 89 medical records of patients in whom an intravascular catheter tip culture were obtained during January through December 1991. Forty-seven catheter related infections were identified in 43 patients. There were 33 multiple lumen infected catheters and 14 single lumen. Catheters for hemodialysis were infected in 38.3% of the patients. Twenty catheters were inserted into the subclavian vein. Fifty percent of the reinserted catheters were placed in the same site, of which 28.6% became infected. Staphylococcus epidermis was isolated in 28.1% of the patients, while in 50% of the patients with Staphylococcus aureus, bacteremia was identified. Staphylococci and Enterococci were more sensitive to Vancomycin than to any other antibiotic. PMID:7916776

  3. A cost effectiveness based safety and efficacy study of resterilized intra-parenchymal catheter based intracranial pressure monitoring in developing world

    PubMed Central

    Gupta, Deepak Kumar; Bisht, Ajay; Batra, Priyam; Mathur, Purva; Mahapatra, Ashok Kumar

    2016-01-01

    Background: The management of traumatic brain injury (TBI) aims to maintain the normal cerebral perfusion in spite of the mass lesions that may occur (haematoma, contusion, and oedema). The monitoring of the intracranial pressure (ICP) is a step in that direction. The intra-parenchymal catheters have the lowest incidence of infection compared to intra-ventricular/subdural catheters with reliable and accurate pressure recordings. The major disadvantage of the intra-parenchymal catheters is the cost, especially in developing nations. Hypothesis: Resterilized intra-parenchymal strain gauge catheters can be used safely for ICP monitoring without any added risk of meningitis. The reusage of catheters can bring down the costs. Resterilized catheters/equipment have been approved for usage in cardiac usage, but such study on ICP catheters has not been carried out so far in any part of the world. Methodology: A total of 100 consecutive cases of severe TBI receiving ICP monitoring at a level 1 trauma center of a developing nation were prospectively studied (34 cases had fresh catheters, and 66 had resterilized [using ethylene oxide] catheters). Observations: The use of reused resterilized catheters was not associated with increased incidence of meningitis or fever (the surrogate marker for infection in this study). Also, there was concordance between the pressure recording of reused catheters and operative finding/subsequent computed tomography scans. These catheters after sterilization could be reused 2–4 times and reliably recorded the ICP (insignificant drift) with no increase in the incidence of meningitis. Conclusions: Usage of resterilized intra-parenchymal ICP catheters is feasible, safe, efficacious, and cost effective and brings down the cost of monitoring significantly. PMID:27695548

  4. A cost effectiveness based safety and efficacy study of resterilized intra-parenchymal catheter based intracranial pressure monitoring in developing world

    PubMed Central

    Gupta, Deepak Kumar; Bisht, Ajay; Batra, Priyam; Mathur, Purva; Mahapatra, Ashok Kumar

    2016-01-01

    Background: The management of traumatic brain injury (TBI) aims to maintain the normal cerebral perfusion in spite of the mass lesions that may occur (haematoma, contusion, and oedema). The monitoring of the intracranial pressure (ICP) is a step in that direction. The intra-parenchymal catheters have the lowest incidence of infection compared to intra-ventricular/subdural catheters with reliable and accurate pressure recordings. The major disadvantage of the intra-parenchymal catheters is the cost, especially in developing nations. Hypothesis: Resterilized intra-parenchymal strain gauge catheters can be used safely for ICP monitoring without any added risk of meningitis. The reusage of catheters can bring down the costs. Resterilized catheters/equipment have been approved for usage in cardiac usage, but such study on ICP catheters has not been carried out so far in any part of the world. Methodology: A total of 100 consecutive cases of severe TBI receiving ICP monitoring at a level 1 trauma center of a developing nation were prospectively studied (34 cases had fresh catheters, and 66 had resterilized [using ethylene oxide] catheters). Observations: The use of reused resterilized catheters was not associated with increased incidence of meningitis or fever (the surrogate marker for infection in this study). Also, there was concordance between the pressure recording of reused catheters and operative finding/subsequent computed tomography scans. These catheters after sterilization could be reused 2–4 times and reliably recorded the ICP (insignificant drift) with no increase in the incidence of meningitis. Conclusions: Usage of resterilized intra-parenchymal ICP catheters is feasible, safe, efficacious, and cost effective and brings down the cost of monitoring significantly.

  5. Efficacy comparison between cryoablation and radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Chen, Yi-He; Lin, Hui; Xie, Cheng-Long; Zhang, Xiao-Ting; Li, Yi-Gang

    2015-06-01

    We perform this meta-analysis to compare the efficacy and safety of cryoablation versus radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter. By searching EMBASE, MEDLINE, PubMed and Cochrane electronic databases from March 1986 to September 2014, 7 randomized clinical trials were included. Acute (risk ratio[RR]: 0.93; P = 0.14) and long-term (RR: 0.94; P = 0.08) success rate were slightly lower in cryoablation group than in radiofrequency ablation group, but the difference was not statistically significant. Additionally, the fluoroscopy time was nonsignificantly reduced (weighted mean difference[WMD]: -2.83 P = 0.29), whereas procedure time was significantly longer (WMD: 25.95; P = 0.01) in cryoablation group compared with radiofrequency ablation group. Furthermore, Pain perception during the catheter ablation was substantially less in cryoabaltion group than in radiofrequency ablation group (standardized mean difference[SMD]: -2.36 P < 0.00001). Thus, our meta-analysis demonstrated that cryoablation and radiofrequency ablation produce comparable acute and long-term success rate for patients with cavotricuspid valve isthmus dependent atrial flutter. Meanwhile, cryoablation ablation tends to reduce the fluoroscopy time and significantly reduce pain perception in cost of significantly prolonged procedure time.

  6. Cardiac arrest

    MedlinePlus

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  7. Compensation of motion artifacts in catheter-based optical frequency domain imaging

    PubMed Central

    Ha, J. Y.; Shishkov, M.; Colice, M.; Oh, W. Y.; Yoo, H.; Liu, L.; Tearney, G. J.; Bouma, B. E.

    2010-01-01

    A novel heterodyne Doppler interferometer method for compensating motion artifacts caused by cardiac motion in intracoronary optical frequency domain imaging (OFDI) is demonstrated. To track the relative motion of a catheter with regard to the vessel, a motion tracking system is incorporated with a standard OFDI system by using wavelength division multiplexing (WDM) techniques. Without affecting the imaging beam, dual WDM monochromatic beams are utilized for tracking the relative radial and longitudinal velocities of a catheter-based fiber probe. Our results demonstrate that tracking instantaneous velocity can be used to compensate for distortion in the images due to motion artifacts, thus leading to accurate reconstruction and volumetric measurements with catheter-based imaging. PMID:20589002

  8. Radiofrequency treatment of cervicogenic headache

    PubMed Central

    Peñarrocha, Miguel; Peñarrocha, Maria; Calvo, Ana; Jiménez, Alejandro; March, Rafael

    2013-01-01

    Objectives: In the clinical management of facial pain, a possible cervical origin must be considered. A clinical exploration is therefore essential. The disorder originates in the intimate connections between the cranial portion of the spinal cord and the trigeminal system. Although solid evidence supporting the use of radiofrequency (RF) treatment is lacking, it remains one of the management options to be taken into account. The present study evaluates the efficacy of RF in application to cervicogenic headache. Study design: We present three cases of severe facial pain arising from different cervical structures. Results: In two cases the pain originated in cervical roots C2 and C3, while in the third patient the trigger point was located at the level of the atlantoaxial joint. Pulsed RF was applied for 4 minutes at the dorsal ganglion of C2 and C3 in the first two cases, and for 8 minutes at intraarticular level in the third patient. The pain gradually subsided during the first month in all cases. The first two patients reported 70% improvement after one month, 60% improvement after 6 months, and 30-50% after one year, versus baseline. The third patient reported complete pain resolution lasting approximately 5 months, after which the pain reappeared with the same intensity as before. Conclusions: Radiofrequency is a satisfactory treatment option, affording adequate analgesia, though the effects are sometimes temporary. Key words:Cervicogenic headache, pulsed radiofrequency, analgesia. PMID:23229235

  9. [Clinical analysis of pediatric shunt catheter fracture].

    PubMed

    Morishita, Akitsugu; Nagashima, Tatsuya; Kurata, Hiromitsu; Eguchi, Takahiro; Tamaki, Norihiko

    2002-08-01

    Between 1985 and 1998, 415 shunt dysfunctions occurred at Kobe Children's Hospital. The main reasons for shunt revision were obstruction of the catheter, shunt infection, and shunt disconnection. This report presents an analysis of 35 patients (36 cases) who underwent a ventriculoperitoneal (VP) shunt revision because of shunt catheter fracture. All patients were less than 18 years old. We researched their age at the time of revision, site of disruption, postoperative period, shunt system, clinical symptoms, and other factors. The mechanical aspects of shunt catheter fracture are also discussed in this report. The peak time of shunt catheter fracture was the time when children were growing up and were entering elementary school. In other words, when their height was increasing rapidly. At that time, the distal catheter is subjected to traction between the valve and the abdomen at the site of insertion in either the upper or lower direction. However, physical examination of the shunt catheter showed normal range. Additional contributory factors were chronic stimulation at the occipital bone, clavium bone, and costal arch, while movement of the neck and body rotation also caused shunt catheter fracture. These factors all originated from shearing strain at the shunt catheter. We look forward to the introduction of a stronger shunt catheter, because surgical repair time must be minimized to protect the child's mental development. In addition, shearing strain at the shunt catheter needs special attention.

  10. Evaluation of left ventricular scar identification from contrast enhanced magnetic resonance imaging for guidance of ventricular catheter ablation therapy

    NASA Astrophysics Data System (ADS)

    Rettmann, M. E.; Lehmann, H. I.; Johnson, S. B.; Packer, D. L.

    2016-03-01

    Patients with ventricular arrhythmias typically exhibit myocardial scarring, which is believed to be an important anatomic substrate for reentrant circuits, thereby making these regions a key target in catheter ablation therapy. In ablation therapy, a catheter is guided into the left ventricle and radiofrequency energy is delivered into the tissue to interrupt arrhythmic electrical pathways. Low bipolar voltage regions are typically localized during the procedure through point-by-point construction of an electroanatomic map by sampling the endocardial surface with the ablation catheter and are used as a surrogate for myocardial scar. This process is time consuming, requires significant skill, and has the potential to miss low voltage sites. This has led to efforts to quantify myocardial scar preoperatively using delayed, contrast-enhanced MRI. In this paper, we evaluate the utility of left ventricular scar identification from delayed contrast enhanced magnetic resonance imaging for guidance of catheter ablation of ventricular arrhythmias. Myocardial infarcts were created in three canines followed by a delayed, contrast enhanced MRI scan and electroanatomic mapping. The left ventricle and myocardial scar is segmented from preoperative MRI images and sampled points from the procedural electroanatomical map are registered to the segmented endocardial surface. Sampled points with low bipolar voltage points visually align with the segmented scar regions. This work demonstrates the potential utility of using preoperative delayed, enhanced MRI to identify myocardial scarring for guidance of ventricular catheter ablation therapy.

  11. A MODIFIED OPEN SURGERY TECHNIQUE FOR PERITONEAL DIALYSIS CATHETER PLACEMENT DECREASES CATHETER MALFUNCTION.

    PubMed

    Jiang, Chunming; Xu, Linfeng; Chen, Yun; Yan, Xiang; Zhang, Miao; Sun, Cheng

    2013-06-01

    BACKGROUND: This retrospective study was conducted to evaluate the effect of a new, modified open surgery technique on catheter-related malfunction. METHODS: During the period from January 1997 to June 2009, 216 patients received initial peritoneal catheters. For the present study, patients were divided into four groups according to the catheter types and the surgery techniques: • TO-S: traditional open surgery, straight Tenckhoff catheter • TO-C: traditional open surgery, coiled Tenckhoff catheter • TO-SN: traditional open surgery, swan-neck catheter • MO-S: modified open surgery, straight Tenckhoff catheter The modified surgery was characterized by a low incision site, a short intra-abdominal catheter segment and an additional upward straight subcutaneous tunnel. All patients were followed up for 2 years or until death. Survival rates, complications caused by catheter placement, and the probability of malfunction-free catheter survival were compared between the groups. RESULTS: Catheter malfunction was the most frequent mechanical complication, found in 31 patients (14.4%), who experienced 38 malfunctions. Only 2 episodes of catheter malfunction were found in the MO-S group, representing a rate significantly less than those in the TO-S and TO-C groups (both p < 0.05). Kaplan-Meier curves for malfunction-free PD catheter survival showed a significantly different malfunction-free probability for the various groups (p = 0.009). After 2 years of follow-up, 136 patients (63.0%) survived with their initial PD catheter. The initial catheter survival rate was 76.8% in the MO-S group. Kaplan-Meier curves for initial catheter survival showed that the highest survival rate was found in the MO-S group (p = 0.001). CONCLUSIONS: The modified open surgery technique is a reliable method for catheter placement. PMID:23733661

  12. Temporary hemodialysis catheters: recent advances.

    PubMed

    Clark, Edward G; Barsuk, Jeffrey H

    2014-11-01

    The insertion of non-tunneled temporary hemodialysis catheters (NTHCs) is a core procedure of nephrology practice. While urgent dialysis may be life-saving, mechanical and infectious complications related to the insertion of NTHCs can be fatal. In recent years, various techniques that reduce mechanical and infectious complications related to NTHCs have been described. Evidence now suggests that ultrasound guidance should be used for internal jugular and femoral vein NTHC insertions. The implementation of evidence-based infection-control 'bundles' for central venous catheter insertions has significantly reduced the incidence of bloodstream infections in the intensive care unit setting with important implications for how nephrologists should insert NTHCs. In addition, the Cathedia Study has provided the first high-level evidence about the optimal site of NTHC insertion, as it relates to the risk of infection and catheter dysfunction. Incorporating these evidence-based techniques into a simulation-based program for training nephrologists in NTHC insertion has been shown to be an effective way to improve the procedural skills of nephrology trainees. Nonetheless, there are some data suggesting nephrologists have been slow to adopt evidence-based practices surrounding NTHC insertion. This mini review focuses on techniques that reduce the complications of NTHCs and are relevant to the practice and training of nephrologists.

  13. Occipital lobe infarction following cardiac ablation.

    PubMed

    Mirza, Rukhsana G; Biller, Jose; Jay, Walter M

    2004-01-01

    A 60-year-old man presented with the chief complaint of seeing a blurred area just up and to the left of the center of his vision. The patient noted this visual field defect immediately after he awoke from a cardiac electrophysiologic study with a catheter ablation procedure. On neuro-ophthalmologic testing, a small scotoma was present superior and left of fixation in both eyes. MRI showed a small irregular area of abnormal signal in the right occipital lobe consistent with an ischemic lesion. To the best of our knowledge, this represents the first case report of a homonymous visual field defect secondary to an occipital lobe infarction following a cardiac catheter ablation procedure.

  14. Infections associated with the central venous catheters.

    PubMed

    Drasković, Biljana; Fabri, Izabella; Benka, Anna Uram; Rakić, Goran

    2014-01-01

    Central venous catheters are of an essential importance to critically ill patients who require long-term venous access for various purposes. Their use made the treatment much easier, but still they are not harmless and are prone to numerous complications. Catheter infections represent the most significant complication in their use. The frequency of infections varies in different patient care settings, but their appearance mostly depends on the patient's health condition, catheter insertion time, localization of the catheter and type of the used catheter. Since they are one of the leading causes of nosocomial infections and related to significant number of morbidity and mortality in intensive care units, it is very important that maximal aseptic precautions are taken during the insertion and the maintenance period. Prevention of infection of the central venous catheters demands several measures that should be applied routinely.

  15. Tensile set behavior of Foley catheter balloons.

    PubMed

    Joseph, R; Ramesh, P; Sivakumar, R

    1999-01-01

    The removal of indwelling urinary balloon catheters from patients is usually associated with many problems. The problems such as balloon deflation failure; encrustations on balloons, eyes, and lumen; and catheter associated infections are widely discussed in the literature. The tensile set exhibited by the catheter balloon material could also play a role and further complicate the removal process. This article addresses this issue by comparing the tensile set behavior of the balloon material from three commercially available Foley catheters. The balloon materials were subjected to aging in synthetic urine at 37 degrees C for 28 days to simulate clinical conditions. The deflation time of catheter balloons aged in similar conditions were also measured. It was found that different brands of catheters exhibited statistically significant differences in their properties. The tensile set data of the aged samples could be correlated with the deflation time of the balloons. The clinical significance of the tensile set is also highlighted.

  16. Temperature-controlled cooled-tip radiofrequency linear ablation of the atria guided by a realtime position management system.

    PubMed

    Watanabe, Ichiro; Min, Nuo; Okumura, Yasuo; Ohkubo, Kimie; Kofune, Masayoshi; Ashino, Sonoko; Nagashima, Koichi; Nakai, Toshiko; Kasamaki, Yuji; Hirayama, Atsushi

    2011-01-01

    Due to the difficulty in producing a transmural linear lesion and the possibility of complications such as thrombus formation leading to thromboembolism, the catheter-based maze procedure remains problematic. We tested, in pigs, the possibility of using a temperature-controlled cooled-tip radiofrequency (RF) ablation system together with a realtime position management (RPM) system to create a transmural linear lesion uncomplicated by thrombus formation.Nine pigs underwent insertion of two electrode catheters (each with two ultrasound electrodes), one into the coronary sinus (CS) and one into the right ventricular apex (references for ultrasound-based non-fluoroscopic three-dimensional mapping). A cooled-tip catheter (with two ultrasound electrodes) was introduced into the right atrium. Linear right atrial ablation was performed with a custom radiofrequency (RF) generator. The catheter was perfused with 0.66 mL/second of saline. RF was delivered for 60 seconds at a target temperature of 40°C. A linear ablation line was created between the superior vena cava and inferior vena cava. Three-dimensional isochronal maps were created during CS pacing before and after ablation. In 4 of the 9 pigs, a transmural linear ablation line was confirmed by three-dimensional mapping and postmortem macroscopic examination. No endocardial thrombus formation was noted. Temperature-controlled cooled-tip RF linear ablation guided by an RPM system appears to have potential for creating linear lesions in the atria. Further studies are needed to determine whether such an ablation technique and the parameters used will facilitate successful completion of the catheter-based maze procedure.

  17. Translumbar placement of paired hemodialysis catheters (Tesio Catheters) and follow-up in 10 patients

    SciTech Connect

    Biswal, Rajiv; Nosher, John L.; Siegel, Randall L.; Bodner, Leonard J.

    2000-01-15

    For lack of other suitable access, 10 consecutive patients received paired hemodialysis catheters for long-term hemodialysis using a translumbar approach to the inferior vena cava (IVC). All attempts were successful. Five paired catheters were placed using the single-puncture technique, and five using the dual-puncture technique. Catheters were in place for a total of 2252 catheter days. The average duration of catheter placement was 250 days (range 30-580 days). All catheters were functioning up to the time the study was completed or the patient died. The most common complication was partial dislodgment of the catheter in 3 of 23 catheters (13%), all occurring in obese patients. One episode of retroperitoneal hemorrhage was noted in a patient having the single-access technique. There were no episodes of infection or IVC thrombosis.

  18. Accidental Entrapment of Electrical Mapping Catheter by Chiari's Network in Right Atrium during Catheter Ablation Procedure

    PubMed Central

    Sakamoto, Atsushi; Urushida, Tsuyoshi; Sakakibara, Tomoaki; Sano, Makoto; Suwa, Kenichiro; Saitoh, Takeji; Saotome, Masao; Katoh, Hideki; Satoh, Hiroshi; Hayashi, Hideharu

    2016-01-01

    A 78-year-old male was admitted to our hospital due to frequent palpitation. His electrocardiogram (ECG) presented regular narrow QRS tachycardia with 170 bpm, and catheter ablation was planned. During electroanatomical mapping of the right atrium (RA) with a multiloop mapping catheter, the catheter head was entrapped nearby the ostium of inferior vena cava. Rotation and traction of the catheter failed to detach the catheter head from the RA wall. Exfoliation of connective tissue twined around catheter tip by forceps, which were designed for endomyocardial biopsy, succeeded to retract and remove the catheter. Postprocedural echocardiography and pathologic examination proved the existence of Chiari's network. The handling of complex catheters in the RA has a potential risk of entrapment with Chiari's network. PMID:27366332

  19. Candida utilis catheter-related bloodstream infection

    PubMed Central

    Scoppettuolo, Giancarlo; Donato, Concetta; De Carolis, Elena; Vella, Antonietta; Vaccaro, Luisa; La Greca, Antonio; Fantoni, Massimo

    2014-01-01

    Central venous catheter-related fungemia are increasing in the last years, also due to rare fungi. We report the case of a Candida utilis catheter-related bloodstream infection in a patient with metastatic carcinoma of the bladder and a long term totally implanted venous catheter. The diagnosis was done by paired blood cultures and differential time to positivity. The Candida species was rapidly identified by MALDI-TOF mass spectrometry. The patient was successfully treated with anidulafungine. PMID:25473600

  20. Guide Wire Induced Cardiac Tamponade: The Soft J Tip Is Not So Benign

    PubMed Central

    Patel, Milan

    2016-01-01

    Central venous catheter (CVC) insertion rarely causes cardiac tamponade due to perforation. Although it is a rare complication, it can be lethal if not identified early. We report a case of cardiac tamponade caused by internal jugular (IJ) central venous catheter (CVC) insertion using a soft J-tipped guide wire which is considered safe and rarely implicated with cardiac tamponade. A bedside transthoracic echocardiogram (TTE) revealed a pericardial effusion with tamponade. An emergent bedside pericardiocentesis was done revealing bloody fluid and resulted in clinical stabilization. PMID:27597903

  1. Guide Wire Induced Cardiac Tamponade: The Soft J Tip Is Not So Benign.

    PubMed

    Dwivedi, Sankalp; Siddiqui, Fayez; Patel, Milan; Cardozo, Shaun

    2016-01-01

    Central venous catheter (CVC) insertion rarely causes cardiac tamponade due to perforation. Although it is a rare complication, it can be lethal if not identified early. We report a case of cardiac tamponade caused by internal jugular (IJ) central venous catheter (CVC) insertion using a soft J-tipped guide wire which is considered safe and rarely implicated with cardiac tamponade. A bedside transthoracic echocardiogram (TTE) revealed a pericardial effusion with tamponade. An emergent bedside pericardiocentesis was done revealing bloody fluid and resulted in clinical stabilization. PMID:27597903

  2. Impact of different catheter lock strategies on bacterial colonization of permanent central venous hemodialysis catheters.

    PubMed

    Erb, Stefan; Widmer, Andreas F; Tschudin-Sutter, Sarah; Neff, Ursula; Fischer, Manuela; Dickenmann, Michael; Grosse, Philipp

    2013-12-01

    Thirty-nine hemodialysis patients with permanent central venous catheters were analyzed for bacterial catheter colonization comparing different catheter-lock strategies. The closed needleless Tego connector with sodium chloride lock solution was significantly more frequently colonized with bacteria than the standard catheter caps with antimicrobially active citrate lock solution (odds ratio, 0.22 [95% confidence interval, 0.07-0.71]; P = .011).

  3. 3D model-based catheter tracking for motion compensation in EP procedures

    NASA Astrophysics Data System (ADS)

    Brost, Alexander; Liao, Rui; Hornegger, Joachim; Strobel, Norbert

    2010-02-01

    Atrial fibrillation is the most common sustained heart arrhythmia and a leading cause of stroke. Its treatment by radio-frequency catheter ablation, performed using fluoroscopic image guidance, is gaining increasingly more importance. Two-dimensional fluoroscopic navigation can take advantage of overlay images derived from pre-operative 3-D data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of these static overlay images for catheter navigation. We developed an approach for image-based 3-D motion compensation as a solution to this problem. A bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3-D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3-D. This step involves bi-plane fluoroscopy and 2-D/3-D registration. Phantom data and clinical data were used to assess our model-based catheter tracking method. Experiments involving a moving heart phantom yielded an average 2-D tracking error of 1.4 mm and an average 3-D tracking error of 1.1 mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2-D tracking error of 1.0 mm +/- 0.4 mm and an average 3-D tracking error of 0.8 mm +/- 0.5 mm. These results demonstrate that model-based motion-compensation based on 2-D/3-D registration is both feasible and accurate.

  4. Orthogonal electrode catheter array for mapping of endocardial focal site of ventricular activation

    SciTech Connect

    Desai, J.M.; Nyo, H.; Vera, Z.; Seibert, J.A.; Vogelsang, P.J. )

    1991-04-01

    Precise location of the endocardial site of origin of ventricular tachycardia may facilitate surgical and catheter ablation of this arrhythmia. The endocardial catheter mapping technique can locate the site of ventricular tachycardia within 4-8 cm2 of the earliest site recorded by the catheter. This report describes an orthogonal electrode catheter array (OECA) for mapping and radiofrequency ablation (RFA) of endocardial focal site of origin of a plunge electrode paced model of ventricular activation in dogs. The OECA is an 8 F five pole catheter with four peripheral electrodes and one central electrode (total surface area 0.8 cm{sup 2}). In eight mongrel dogs, mapping was performed by arbitrarily dividing the left ventricle (LV) into four segments. Each segment was mapped with OECA to find the earliest segment. Bipolar and unipolar electrograms were obtained. The plunge electrode (not visible on fluoroscopy) site was identified by the earliest wave front arrival times of -30 msec or earlier at two or more electrodes (unipolar electrograms) with reference to the earliest recorded surface ECG (I, AVF, and V1). Validation of the proximity of the five electrodes of the OECA to the plunge electrode was performed by digital radiography and RFA. Pathological examination was performed to document the proximity of the OECA to the plunge electrode and also for the width, depth, and microscopic changes of the ablation. To find the segment with the earliest LV activation a total of 10 {plus minus} 3 (mean {plus minus} SD) positions were mapped. Mean arrival times at the two earlier electrodes were -39 {plus minus} 4 msec and -35 {plus minus} 3 msec. Digital radiography showed the plunge electrode to be within the area covered by all five electrodes in all eight dogs. The plunge electrode was within 1 cm2 area of the region of RFA in all eight dogs.

  5. Type of peritoneal dialysis catheter and outcomes.

    PubMed

    Gallieni, Maurizio; Giordano, Antonino; Pinerolo, Cristina; Cariati, Maurizio

    2015-01-01

    In peritoneal dialysis (PD), a well-functioning catheter is of great importance, because a dysfunctional catheter may be associated with incidence of peritonitis, efficiency of dialysis, and to the overall quality of treatment, representing one of the main barriers to optimal use of PD. When considering the relationship between PD catheter type and outcomes, we should keep in mind the different types of available PD catheters, those that are most commonly used in clinical practice, and the available head-to-head comparisons in the literature. The main differences in PD catheter design include the number of cuffs, the shape of subcutaneous tract (straight vs. swan neck), and the shape of intraperitoneal tract (straight vs. coiled). The availability of the best catheter design and materials, along with a skillful management of PD access, may have the greatest impact on long-term patient outcome on PD. It is now established that the use of straight catheters may improve outcomes and technique survival, but further advances in PD catheter technology can potentially improve technique survival. The self-locating PD catheter is a well established device that has not been fully studied and it may represent, based on the available observational evidence and on the clinical experience, an already existing technological advance deserving further studies. PMID:25751555

  6. Predicting nurses' acceptance of radiofrequency identification technology.

    PubMed

    Norten, Adam

    2012-10-01

    The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

  7. Radiofrequency Physics for Minimally Invasive Aesthetic Surgery.

    PubMed

    Levy, Adam S; Grant, Robert T; Rothaus, Kenneth O

    2016-07-01

    Radiofrequency energy has a wide range of medical applications, including noninvasive treatment of wrinkles and body contouring. This technology works by differential heating of skin and soft tissue layers causing dermal remodeling or adipolysis, ultimately leading to observable effects. This article reviews the physics of radiofrequency as applied clinically.

  8. Systems biology and cardiac arrhythmias

    PubMed Central

    Grace, Andrew A; Roden, Dan M

    2013-01-01

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence. PMID:23101717

  9. Systems biology and cardiac arrhythmias.

    PubMed

    Grace, Andrew A; Roden, Dan M

    2012-10-27

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence.

  10. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  11. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  12. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  13. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  14. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  15. 21 CFR 880.5210 - Intravascular catheter securement device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... catheter securement device is a device with an adhesive backing that is placed over a needle or catheter and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin....

  16. 21 CFR 880.5210 - Intravascular catheter securement device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... catheter securement device is a device with an adhesive backing that is placed over a needle or catheter and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin....

  17. 21 CFR 880.5210 - Intravascular catheter securement device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... catheter securement device is a device with an adhesive backing that is placed over a needle or catheter and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin....

  18. 21 CFR 880.5210 - Intravascular catheter securement device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... catheter securement device is a device with an adhesive backing that is placed over a needle or catheter and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin....

  19. 21 CFR 880.5210 - Intravascular catheter securement device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... catheter securement device is a device with an adhesive backing that is placed over a needle or catheter and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin....

  20. Interventional cardiac catheterization.

    PubMed

    Pihkala, J; Nykanen, D; Freedom, R M; Benson, L N

    1999-04-01

    Over the past decade, transcatheter interventions have become increasingly important in the treatment of patients with congenital heart lesions. These procedures may be broadly grouped as dilations (e.g., septostomy, valvuloplasty, angioplasty, and endovascular stenting) or as closures (e.g., vascular embolization and device closure of defects). Balloon valvuloplasty has become the treatment of choice for patients in all age groups with simple valvar pulmonic stenosis and, although not curative, seems at least comparable to surgery for congenital aortic stenosis in newborns to young adults. Balloon angioplasty is successfully applied to a wide range of aortic, pulmonary artery, and venous stenoses. Stents are useful in dilating lesions of which the intrinsic elasticity results in vessel recoil after balloon dilation alone. Catheter-delivered coils are used to embolize a wide range of arterial, venous, and prosthetic vascular connections. Although some devices remain investigational, they have been successfully used for closure of many arterial ducts and atrial and ventricular septal defects. In the therapy for patients with complex CHD, best results may be achieved by combining cardiac surgery with interventional catheterization. The cooperation among interventional cardiologists and cardiac surgeons was highlighted in a report of an algorithm to manage patients with tetralogy of Fallot or pulmonary atresia with diminutive pulmonary arteries, involving balloon dilation, coil embolization of collaterals, and intraoperative stent placement. In this setting, well-planned catheterization procedures have an important role in reducing the overall number of procedures that patients may require over a lifetime, with improved outcomes.

  1. Cardiac Sarcoidosis.

    PubMed

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  2. Percutaneous Intraductal Radiofrequency Ablation is a Safe Treatment for Malignant Biliary Obstruction: Feasibility and Early Results

    SciTech Connect

    Mizandari, Malkhaz; Pai, Madhava Xi Feng; Valek, Vlastimil; Tomas, Andrasina; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Ao Guokun; Kyriakides, Charis; Dickinson, Robert; Nicholls, Joanna; Habib, Nagy

    2013-06-15

    Purpose. Previous clinical studies have shown the safety and efficacy of this novel radiofrequency ablation catheter when used for endoscopic palliative procedures. We report a retrospective study with the results of first in man percutaneous intraductal radiofrequency ablation in patients with malignant biliary obstruction. Methods. Thirty-nine patients with inoperable malignant biliary obstruction were included. These patients underwent intraductal biliary radiofrequency ablation of their malignant biliary strictures following external biliary decompression with an internal-external biliary drainage. Following ablation, they had a metal stent inserted. Results. Following this intervention, there were no 30-day mortality, hemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the 39 patients, 28 are alive and 10 patients are dead with a median survival of 89.5 (range 14-260) days and median stent patency of 84.5 (range 14-260) days. One patient was lost to follow-up. All but one patient had their stent patent at the time of last follow-up or death. One patient with stent blockage at 42 days postprocedure underwent percutaneous transhepatic drain insertion and restenting. Among the patients who are alive (n = 28) the median stent patency was 92 (range 14-260) days, whereas the patients who died (n = 10) had a median stent patency of 62.5 (range 38-210) days. Conclusions. In this group of patients, it appears that this new approach is feasible and safe. Efficacy remains to be proven in future, randomized, prospective studies.

  3. Central venous catheter malposition due to dialysis catheter: a case report

    PubMed Central

    Singh, Neha; Samson, Sumanth

    2016-01-01

    A 56-year-old man on maintenance hemodialysis was admitted to the intensive care unit with septic shock and coagulopathy. As there was a dialysis catheter in the right internal jugular vein, the left internal jugular vein was cannulated with a central venous catheter to initiate vasopressor therapy. A chest X-ray showed formation of a catheter loop inside the left brachiocephalic vein, probably due to hindrance by the dialysis catheter. This report describes the hurdles encountered, repeated cannulation attempts, and serial chest X-ray findings required to obtain acceptable placement of the catheter tip. PMID:27703638

  4. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency...

  5. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency...

  6. Use of ultrasound guidance to remove entrapped stimulating popliteal catheters

    PubMed Central

    Hulin, James B.; Daniels, Don J.

    2016-01-01

    Peripheral nerve catheters are beneficial for continuous pain relief following surgery or trauma to an extremity. However, spring-loaded peripheral nerve catheters can become uncoiled and entrapped, resulting in difficulty in catheter removal. We present two cases where ultrasound guidance provided significant assistance in the safe removal of entrapped peripheral nerve catheters without neurologic sequelae. One of the catheters was adhered to nearby tissue, and one had become uncoiled and anchored in place by the distal tip. Guidelines for the safe management of entrapped catheters are suggested, including the use of saline injections through the catheter under ultrasound guidance to assist in the evaluation and removal of the catheters. PMID:27034548

  7. Alternatives to Indwelling Catheters Cause Unintended Complications.

    PubMed

    Nguyen, Jessica; Harvey, Ellen M; Lollar, Daniel I; Bradburn, Eric H; Hamill, Mark E; Collier, Bryan R; Love, Katie M

    2016-08-01

    To reduce the risk of catheter-associated urinary tract infection (CAUTI), limiting use of indwelling catheters is encouraged with alternative collection methods and early removal. Adverse effects associated with such practices have not been described. We also determined if CAUTI preventative measures increase the risk of catheter-related complications. We hypothesized that there are complications associated with early removal of indwelling catheters. We described complications associated with indwelling catheterization and intermittent catheterization, and compared complication rates before and after policy updates changed catheterization practices. We performed retrospective cohort analysis of trauma patients admitted between August 1, 2009, and December 31, 2013 who required indwelling catheter. Associations between catheter days and adverse outcomes such as infection, bladder overdistention injury, recatheterization, urinary retention, and patients discharged with indwelling catheter were evaluated. The incidence of CAUTI and the total number of catheter days pre and post policy change were similar. The incidence rate of urinary retention and associated complications has increased since the policy changed. Practices intended to reduce the CAUTI rate are associated with unintended complications, such as urinary retention. Patient safety and quality improvement programs should monitor all complications associated with urinary catheterization practices, not just those that represent financial penalties. PMID:27657581

  8. Robust pigtail catheter tip detection in fluoroscopy

    NASA Astrophysics Data System (ADS)

    Tzoumas, Stratis; Wang, Peng; Zheng, Yefeng; John, Matthias; Comaniciu, Dorin

    2012-02-01

    The pigtail catheter is a type of catheter inserted into the human body during interventional surgeries such as the transcatheter aortic valve implantation (TAVI). The catheter is characterized by a tightly curled end in order to remain attached to a valve pocket during the intervention, and it is used to inject contrast agent for the visualization of the vessel in fluoroscopy. Image-based detection of this catheter is used during TAVI, in order to overlay a model of the aorta and enhance visibility during the surgery. Due to the different possible projection angles in fluoroscopy, the pigtail tip can appear in a variety of different shapes spanning from pure circular to ellipsoid or even line. Furthermore, the appearance of the catheter tip is radically altered when the contrast agent is injected during the intervention or when it is occluded by other devices. All these factors make the robust real-time detection and tracking of the pigtail catheter a challenging task. To address these challenges, this paper proposes a new tree-structured, hierarchical detection scheme, based on a shape categorization of the pigtail catheter tip, and a combination of novel Haar features. The proposed framework demonstrates improved detection performance, through a validation on a data set consisting of 272 sequences with more than 20,000 images. The detection framework presented in this paper is not limited to pigtail catheter detection, but it can also be applied successfully to any other shape-varying object with similar characteristics.

  9. Catheter ablation of parahisian premature ventricular complex.

    PubMed

    Kim, Jun; Kim, Jeong Su; Park, Yong Hyun; Kim, June Hong; Chun, Kook Jin

    2011-12-01

    Catheter ablation is performed in selected patients with a symptomatic premature ventricular complex (PVC) or PVC-induced cardiomyopathy. Ablation of PVC from the His region has a high risk of inducing a complete atrioventricular block. Here we report successful catheter ablation of a parahisian PVC in a 63-year-old man.

  10. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  11. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  12. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  13. Spontaneous Intravesical Knotting of Urethral Catheter

    PubMed Central

    2011-01-01

    Infant feeding tubes (IFT) have been universally used as urethral catheters in neonates and children for several decades. Though generally a safe procedure, it may cause significant morbidity if the catheter spontaneously knots inside the bladder. We report this complication in three children including a neonate. PMID:22953288

  14. Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation

    PubMed Central

    Marai, Ibrahim; Suleiman, Mahmoud; Blich, Miry; Lessick, Jonathan; Abadi, Sobhi; Boulos, Monther

    2016-01-01

    AIM: To investigate the impact of using computed tomography (CT) and contact force (CF) technology on recurrence of atrial tachyarrhythmia after atrial fibrillation (AF) ablation. METHODS: This non-randomized study included 2 groups of patients. All patients had symptomatic recurrent paroxysmal or persistent AF and were treated with at least 1 anti arrhythmic medication or intolerant to medication. The first group included 33 patients who underwent circumferential pulmonary veins isolation (PVI) for AF during 2012 and 2013 guided by CT image integration (Cartomerge, Biosense Webster, Diamond Bar, CA, United States) of left atrium and pulmonary veins into an electroanatomic mapping (EAM) system (CT group) using standard irrigated radiofrequency catheter (ThermoCool, Carto, Biosense Webster, Diamond Bar, CA, United States) or irrigated catheter with integrated CF sensor (Smart Touch, Carto, Biosense Webster, Diamond Bar, CA, United States). The second group included immediately preceding 32 patients who had circumferential PVI by standard irrigated catheter (ThermoCool) using only EAM (Carto) system (EAM group). Linear lesions were performed according to the discretion of operator. RESULTS: Sex, age, and persistent AF were not different between groups. PVI was achieved in all patients in both groups. Linear ablations including cavo-tricuspid isthmus and or roof line ablation were not different between groups. Free of atrial tachyarrhythmia during follow-up of 24 mo was significantly higher among CT group compared to EAM group (81% vs 55%; respectively; P = 0.027). When 11 patients from CT group who had ablation using Smart Touch catheter were excluded, the difference between CT group and EAM became non significant (73% vs 55%; respectively; P = 0.16). Sub analysis of CT group showed that patients who had ablation using Smart Touch catheter tend to be more free of atrial tachyarrhythmia compared to patients who had ablation using standard irrigated catheter during

  15. Intraluminal fluorescence spectroscopy catheter with ultrasound guidance

    NASA Astrophysics Data System (ADS)

    Stephens, Douglas N.; Park, Jesung; Sun, Yang; Papaioannou, Thanassis; Marcu, Laura

    2009-05-01

    We demonstrate the feasibility of a time-resolved fluorescence spectroscopy (TRFS) technique for intraluminal investigation of arterial vessel composition under intravascular ultrasound (IVUS) guidance. A prototype 1.8-mm (5.4 Fr) catheter combining a side-viewing optical fiber (SVOF) and an IVUS catheter was constructed and tested with in vitro vessel phantoms. The prototype catheter can locate a fluorophore in the phantom vessel wall, steer the SVOF in place, perform blood flushing under flow conditions, and acquire high-quality TRFS data using 337-nm wavelength excitation. The catheter steering capability used for the coregistration of the IVUS image plane and the SVOF beam produce a guiding precision to an arterial phantom wall site location of 0.53+/-0.16 mm. This new intravascular multimodal catheter enables the potential for in vivo arterial plaque composition identification using TRFS.

  16. Development of Bend Sensor for Catheter Tip

    NASA Astrophysics Data System (ADS)

    Nagano, Yoshitaka; Sano, Akihito; Fujimoto, Hideo

    Recently, a minimally invasive surgery which makes the best use of the catheter has been becoming more popular. In endovascular coil embolization for a cerebral aneurysm, the observation of the catheter's painting phenomenon is very important to execute the appropriate manipulation of the delivery wire and the catheter. In this study, the internal bend sensor which consists of at least two bending enhanced plastic optical fibers was developed in order to measure the curvature of the catheter tip. Consequently, the painting could be more sensitively detected in the neighborhood of the aneurysm. In this paper, the basic characteristics of the developed sensor system are described and its usefulness is confirmed from the comparison of the insertion force of delivery wire and the curvature of catheter tip in the experiment of coil embolization.

  17. Catheter-related urinary tract infection.

    PubMed

    Nicolle, Lindsay E

    2005-01-01

    Indwelling urinary catheters are used frequently in older populations. For either short- or long-term catheters, the infection rate is about 5% per day. Escherichia coli remains the most common infecting organism, but a wide variety of other organisms may be isolated, including yeast species. Bacteria tend to show increased resistance because of the repeated antimicrobial courses. Urinary tract infection (UTI) usually follows formation of biofilm on both the internal and external catheter surface. The biofilm protects organisms from both antimicrobials and the host immune response. Morbidity from UTI with short-term catheter use is limited if appropriate catheter care is practised. In patients with long-term catheters, fever from a urinary source is common with a frequency varying from 1 per 100 to 1 per 1000 catheter days. Long-term care facility residents with chronic indwelling catheters have a much greater risk for bacteraemia and other urinary complications than residents without catheters. Asymptomatic catheter-acquired UTI should not be treated with antimicrobials. Antimicrobial treatment does not decrease symptomatic episodes but will lead to emergence of more resistant organisms. For treatment of symptomatic infection, many antimicrobials are effective. Wherever possible, antimicrobial selection should be delayed until culture results are available. Whether to administer initial treatment by an oral or parenteral route is determined by clinical presentation. If empirical therapy is required, antimicrobial selection is based on variables such as route of administration, anticipated infecting organism and susceptibility, and patient tolerance. Renal function, concomitant medications, local formulary and cost may also be considered in selection of the antimicrobial agent. The duration of therapy is usually 10-14 days, but patients who respond promptly and in whom the catheter must remain in situ may be treated with a shorter 7-day course to reduce

  18. Effect of percutaneous renal sympathetic nerve radiofrequency ablation in patients with severe heart failure.

    PubMed

    Dai, Qiming; Lu, Jing; Wang, Benwen; Ma, Genshan

    2015-01-01

    This study aimed to investigate the clinical feasibility and effects of percutaneous renal sympathetic nerve radiofrequency ablation in patients with heart failure. A total of 20 patients with heart failure were enrolled, aged from 47 to 75 years (63±10 years). They were divided into the standard therapy (n = 10), and renal nerve radiofrequency ablation groups (n = 10). There were 15 males and 5 female patients, including 8 ischemic cardiomyopathy, 8 dilated cardiomyopathy, and 8 hypertensive cardiopathy. All of the patients met the criteria of New York Heart Association classes III-IV cardiac function. Patients with diabetes and renal failure were excluded. Percutaneous renal sympathetic nerve radiofrequency ablation was performed on the renal artery wall under X-ray guidance. Serum electrolytes, neurohormones, and 24 h urine volume were recorded 24 h before and after the operation. Echocardiograms were performed to obtain left ventricular ejection fraction at baseline and 6 months. Heart rate, blood pressure, symptoms of dyspnea and edema were also monitored. After renal nerve ablation, 24 h urine volume was increased, while neurohormone levels were decreased compared with those of pre-operation and standard therapy. No obvious change in heart rate or blood pressure was recorded. Symptoms of heart failure were improved in patients after the operation. No complications were recorded in the study. Percutaneous renal sympathetic nerve radiofrequency ablation may be a feasible, safe, and effective treatment for the patients with severe congestive heart failure.

  19. Cardiac transplantation.

    PubMed

    Shanewise, Jack

    2004-12-01

    Cardiac transplantation is a proven, accepted mode of therapy for selected patients with end-stage heart failure, but the inadequate number of suitable donor hearts available ultimately limits its application. This chapter reviews adult cardiac transplantation, with an emphasis on the anesthetic considerations of the heart transplant operation itself.

  20. Cardiac metastases

    PubMed Central

    Bussani, R; De‐Giorgio, F; Abbate, A; Silvestri, F

    2007-01-01

    Tumours metastatic to the heart (cardiac metastases) are among the least known and highly debated issues in oncology, and few systematic studies are devoted to this topic. Although primary cardiac tumours are extremely uncommon (various postmortem studies report rates between 0.001% and 0.28%), secondary tumours are not, and at least in theory, the heart can be metastasised by any malignant neoplasm able to spread to distant sites. In general, cardiac metastases are considered to be rare; however, when sought for, the incidence seems to be not as low as expected, ranging from 2.3% and 18.3%. Although no malignant tumours are known that diffuse preferentially to the heart, some do involve the heart more often than others—for example, melanoma and mediastinal primary tumours. This paper attempts to review the pathophysiology of cardiac metastatic disease, epidemiology and clinical presentation of cardiac metastases, and pathological characterisation of the lesions. PMID:17098886

  1. Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the pro perspective.

    PubMed

    Pappone, Carlo; Santinelli, Vincenzo

    2015-09-01

    Important advances in the natural history and diagnosis of, and therapy for, asymptomatic Wolff-Parkinson-White (WPW) syndrome have been made in the last decade by our group. These data have necessitated revisiting current practice guidelines to decide on the optimal management of the asymptomatic WPW population. There has also been an emphasis on identifying initially asymptomatic individuals who are at risk by nationwide screening programs using the electrocardiogram for prophylactic catheter ablation to prevent the lifetime risk of sudden cardiac death, particularly in young asymptomatic people, because only a subgroup of them is at high risk, requiring early catheter ablation.

  2. Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes

    PubMed Central

    Kocaturk, Ozgur; Saikus, Christina E; Guttman, Michael A; Faranesh, Anthony Z; Ratnayaka, Kanishka; Ozturk, Cengizhan; McVeigh, Elliot R; Lederman, Robert J

    2009-01-01

    Background Catheter visualization and tracking remains a challenge in interventional MR. Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance. Results The incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2°C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo. Conclusion We have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures. PMID:19674464

  3. Refinements in the coating of urethral catheters reduces the incidence of catheter-associated bacteriuria. An experimental and clinical study.

    PubMed

    Liedberg, H; Lundeberg, T; Ekman, P

    1990-01-01

    The tendency to develop bacteriuria during the use of various forms of indwelling catheters was evaluated in a randomized trial in 90 patients. A silver alloy and hydrogel-coated Foley catheter (SHC) was compared to a non-coated catheter (NC) and a catheter coated only with hydrogel (HC). Three patients (10%) with SHC catheters, 10 (33%) patients with HC catheters, and 15 (50%) patients with NC catheters developed bacteriuria (greater than 10(5) organisms/ml). The difference in the rate of bacteriuria after 5 days of catheterization was statistically significant between the SHC catheter and the NC catheter (p less than 0.002). There was no significant difference between the SHC catheter and the HC catheter, nor was there a significant difference between the HC catheter and the NC catheter. The toxic effects, as estimated by the IC50 value, of the urinary catheter material used was elucidated in an experimental fibroblast model. The IC50 value for the NC catheter was 33.9%, HC catheter 72.2% and for the SHC catheter 98.1%.

  4. [Multifunctional testing of PTCA balloon catheters].

    PubMed

    Kraft, M; Schmitz, H; Schulte, R; Boenick, U

    2000-06-01

    New in vitro measuring methods for balloon catheters used for percutaneous transluminal coronary angioplasty (PTCA) and their verification in a complex test device are presented. This system can mimic all relevant application situations. The central element of the test device is a coronary vessel model matching the physiological situation in terms of geometrical structure and frictional properties. Reactive force sensors are used to measure the application-relevant forces exerted by the catheter on the model vessel walls and accessories, such as guide wire and guiding catheter. To generate a kink-free advancement of the catheter and permit measurement of the active forces, an alternating drive unit has been specially developed. The testing and application of the newly developed methods revealed statistically significant differences between various types of catheter. The test device closes a gap between complex but subjective clinical tests, and individual objective, but application-removed in vitro test setups for PTCA catheters. While the initial prototype had shortcomings with regard to the reproducibility of measurements, successor systems developed for industrial use are now in production. The properties of these measuring systems developed for the benefit of manufacturer and reprocessor of PTCA catheters are discussed. PMID:10925517

  5. Catheter associated infections in hemodialysis patients.

    PubMed

    Sanavi, Suzan; Ghods, Ahad; Afshar, Reza

    2007-03-01

    Hemodialysis catheter related infections (HCRI) are one of the major causes of increasing mortality, morbidity and cost of therapy in hemodialysis patients. Prevention of HCRI requires the identification of predisposing risk factors. To determine the frequency of HCRI risk factors, we studied 116 patients (54% male, mean age of 49.5+/-16 years) patients with HCRI between 2003-2004. Forty one percent of the patients were diabetic. There was a history of previous catheter placement and infection in 41% and 32% of patients, respectively. Pathogenic organisms isolated from blood cultures included Staphylococcus-aureus 42%, Coagulase-negative Staphylococci 20%, E. Coli 19%, Enterococci 7%, Streptococcus D 7%, Pseudomonas aeruginosa 4%, and Klebsiella 1%. Bacterial resistance to vancomycin and amikacin was present in 7% and 4% of the cases, respectively. Hemodialysis catheter related blood borne infections comprised 67% of the total blood-borne infections in our hospital. No significant statistical association was found between HCRI and age, gender, diabetes mellitus, serum albumin level <30 g/L, leukocyte count, erythrocyte sedimentation rate, anatomical location of catheter, mean duration of antibiotic therapy, mean catheter duration, frequency of hemodialysis sessions, pathogenic organisms, and history of previous catheter infection. We conclude that the prevalence of pathogenic organisms of HCRI were similar to previous studies. However, bacterial resistance to antibiotics was low. The mean duration of catheter usage was longer than previously reported. PMID:17237890

  6. ATLS: Catheter and tube placement

    NASA Technical Reports Server (NTRS)

    Gosbee, John; Krupa, Debra T.; Pepper, L.; Orsak, Debra

    1991-01-01

    The specific objectives of this experiment are: to evaluate the rack mounted equipment and medical supplies necessary for medical procedures; to evaluate the attachments, mounting points, and inner drawer assemblies for the medical supplies; and to evaluate the procedures for performing medical scenarios. The resources available in the HMF miniracks to accomplish medical scenarios and/or procedures include: medical equipment mounted in the racks; a patch panel with places to attach tubing and catheters; self contained drawers full of critical care medical supplies; and an ALS 'backpack' for deploying supplies. The attachment lines, tubing and associated medical supplies will be deployed and used with the equipment and a patient mannequin. Data collection is provided by direct observations by the inflight experimenters, and analysis of still and video photography.

  7. Catheters for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Atif, M.; Ullah, H.; Hamza, M. Y.; Ikram, M.

    2011-09-01

    The objective of this review article is to overview technology, clinical evidence, and future applications to date optical coherence tomography (OCT) probes to yield the diagnostic purpose. We have reviewed the designing, construction and working of different categories of OCT probes developed for optical diagnostics having a potential for non invasive and improved detection of different types of cancer as well as other neoplasm. Rotational and balloon catheters, imaging needles and hand-held, linear scanning, multichannel, micro electro mechanical systems (MEMS) technology based, dynamic focusing, forward view imaging, and common path interferometer based probes have been discussed in details. The fiber probes have shown excellent performance for two dimensional and three dimensional higher resolution, cross-sectional imaging of interior and exterior body tissues that can be compared with histopathology to provide the information about the angiogenesis and other lesions in the tissue. The MEMS-technology based probes are found to be more suitable for three dimensional morphological imaging.

  8. Association of physical examination with pulmonary artery catheter parameters in acute lung injury*

    PubMed Central

    Grissom, Colin K.; Morris, Alan H.; Lanken, Paul N.; Ancukiewicz, Marek; Orme, James F.; Schoenfeld, David A.; Thompson, B. Taylor

    2016-01-01

    Objective To correlate physical examination findings, central venous pressure, fluid output, and central venous oxygen saturation with pulmonary artery catheter parameters. Design Retrospective study. Setting Data from the multicenter Fluid and Catheter Treatment Trial of the National Institutes of Health Acute Respiratory Distress Syndrome Network. Patients Five hundred thirteen patients with acute lung injury randomized to treatment with a pulmonary artery catheter. Interventions Correlation of physical examination findings (capillary refill time >2 secs, knee mottling, or cool extremities), central venous pressure, fluid output, and central venous oxygen saturation with parameters from a pulmonary artery catheter. Measurements We determined association of baseline physical examination findings and on-study parameters of central venous pressure and central venous oxygen saturation with cardiac index <2.5 L/min/m2 and mixed venous oxygen saturation <60%. We determined correlation of baseline central venous oxygen saturation and mixed venous oxygen saturation and predictive value of a low central venous oxygen saturation for a low mixed venous oxygen saturation. Measurements and Main Results Prevalence of cardiac index <2.5 and mixed venous oxygen saturation <60% was 8.1% and 15.5%, respectively. Baseline presence of all three physical examination findings had low sensitivity (12% and 8%), high specificity (98% and 99%), low positive predictive value (40% and 56%), but high negative predictive value (93% and 86%) for cardiac index <2.5 and mixed venous oxygen saturation <60%, respectively. Central venous oxygen saturation <70% predicted a mixed venous oxygen saturation <60% with a sensitivity 84%, specificity 70%, positive predictive value 31%, and negative predictive value of 96%. Low cardiac index correlated with cool extremities, high central venous pressure, and low 24-hr fluid output; and low mixed venous oxygen saturation correlated with knee mottling and

  9. Cardiac catheterization - discharge

    MedlinePlus

    A catheter was inserted into an artery in your groin or arm. Then it was carefully guided up to your heart. Once it reached your heart, the catheter was placed into the arteries that deliver blood ...

  10. RF HEATING OF MRI-ASSISTED CATHETER STEERING COILS FOR INTERVENTIONAL MRI

    PubMed Central

    Settecase, Fabio; Hetts, Steven W.; Martin, Alastair J.; Roberts, Timothy P. L.; Bernhardt, Anthony F.; Evans, Lee; Malba, Vincent; Saeed, Maythem; Arenson, Ronald L.; Kucharzyk, Walter; Wilson, Mark W.

    2010-01-01

    RATIONALE AND OBJECTIVES To assess magnetic resonance imaging (MRI) radiofrequency (RF) related heating of conductive wire coils used in magnetically steerable endovascular catheters. MATERIALS AND METHODS A 3-axis microcoil was fabricated onto a 1.8 Fr catheter tip. In vitro testing was performed in a 1.5 T MRI system using an agarose gel filled vessel phantom, a transmit/receive body RF coil and a steady state free precession (SSFP) pulse sequence, and a fluoroptic thermometry system. Temperature was measured without simulated blood flow at varying distances from magnet isocenter and varying flip angles. Additional experiments were performed with laser-lithographed single-axis microcoil-tipped microcatheters in air and in a saline bath with varied grounding of the microcoil wires. Preliminary in vivo evaluation of RF heating was performed in pigs at 1.5 T with coil-tipped catheters in various positions in the common carotid arteries with SSFP pulse sequence on and off, and under physiologic flow and zero flow conditions. RESULTS In tissue-mimicking agarose gel, RF heating resulted in a maximal temperature increase of 0.35°C after 15 minutes of imaging, 15 cm from magnet isocenter. For a single axis microcoil, maximal temperature increases were 0.73-1.91°C in air and 0.45-0.55°C in saline. In vivo, delayed contrast enhanced MRI revealed no evidence of vascular injury and histopathological sections from the common carotid arteries confirmed the lack of vascular damage. CONCLUSIONS Microcatheter tip microcoils for endovascular catheter steering in MRI experience minimal RF heating under the conditions tested. These data provide the basis for further in vivo testing of this promising technology for endovascular interventional MRI. PMID:21075019

  11. Catheter-directed Thrombolysis in Acute Superior Vena Cava Syndrome Caused by Central Venous Catheters.

    PubMed

    Cui, Jie; Kawai, Tasuo; Irani, Zubin

    2015-01-01

    Indwelling central venous catheters have been reported to increase the risk of superior venous cava (SVC) syndrome. This case report describes the development of acute SVC syndrome in a 28-year-old woman with end-stage renal disease implanted with a left-side hemodialysis reliable outflow graft and a right-side double lumen hemodialysis catheter via internal jugular veins. Her symptoms were not alleviated after catheter removal and systemic anticoagulation therapy. She was eventually treated with catheter-directed thrombolysis and a predischarge computer tomographic venogram on postthrombolytic procedure day 7 showed patent central veins and patient remained asymptomatic. This case demonstrates that catheter-directed thrombolysis can be safely employed to treat refractory catheter-induced acute SVC syndrome in end-stage renal disease patients.

  12. Guidewire catheter change in central venous catheter biofilm formation in a burn population.

    PubMed

    Kowalewska-Grochowska, K; Richards, R; Moysa, G L; Lam, K; Costerton, J W; King, E G

    1991-10-01

    This study was designed to assess the risk of colonization and biofilm formation of central venous catheters left in situ for seven days vs those changed over a guidewire at three days and removed at seven days. Colonization was determined using scanning and transmission electron microscopy and compared to a special scraping/sonication culture method. Thirty-one catheters were examined, and no difference was found between catheters left in situ (9 of 16 colonized) and those changed over a guidewire (11 of 15 colonized). Colonization rates rose significantly from 4 of 15 catheters at the time of guidewire change to 11 of 15 at 7 days (p less than 0.001). Of the catheters defined as colonized by SEM, the special culture technique showed bacterial growth in only 35 percent, making a negative culture result of dubious value in ruling out catheter colonization. No beneficial effect of guidewire changes in reducing colonization could be demonstrated.

  13. Retained Urethral Catheter Secondary to Placement in Proximal Ureter.

    PubMed

    McGregor, Thomas B; Sharda, Rajan

    2016-01-01

    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter.

  14. Retained Urethral Catheter Secondary to Placement in Proximal Ureter

    PubMed Central

    Sharda, Rajan

    2016-01-01

    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter. PMID:27144050

  15. Cardiac amyloidosis

    MedlinePlus

    ... the way electrical signals move through the heart (conduction system). This can lead to abnormal heartbeats ( arrhythmias ) ... due to medicine) Sick sinus syndrome Symptomatic cardiac conduction system disease (arrhythmias related to abnormal conduction of ...

  16. Cardiac Sarcoidosis

    MedlinePlus

    ... is Cardiac Sarcoidosis? Sarcoidosis is a poorly understood disease that commonly affects the lungs. It can also involve the lymph nodes, liver, spleen, eyes, skin, bones, salivary glands and heart. ...

  17. Real time assessment of RF cardiac tissue ablation with optical spectroscopy

    SciTech Connect

    Demos, S G; Sharareh, S

    2008-03-20

    An optical spectroscopy approach is demonstrated allowing for critical parameters during RF ablation of cardiac tissue to be evaluated in real time. The method is based on incorporating in a typical ablation catheter transmitting and receiving fibers that terminate at the tip of the catheter. By analyzing the spectral characteristics of the NIR diffusely reflected light, information is obtained on such parameters as, catheter-tissue proximity, lesion formation, depth of penetration of the lesion, formation of char during the ablation, formation of coagulum around the ablation site, differentiation of ablated from healthy tissue, and recognition of micro-bubble formation in the tissue.

  18. Intracardiac Forward-Looking Ultrasound Imaging Catheters Using Capacitive Micromachined Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    Nikoozadeh, A.; Wygant, I. O.; Lin, D.-S.; Oralkan, Ö.; Thomenius, K.; Dentinger, A.; Wildes, D.; Akopyan, G.; Shivkumar, K.; Mahajan, A.; Stephens, D. N.; O'Donnell, M.; Sahn, D.; Khuri-Yakub, P. T.

    Atrial fibrillation is the most common sustained arrhythmia that now affects approximately 2.2 million adults in the United States alone. Minimally invasive catheter-based electrophysiological interventions have revolutionized the management of cardiac arrhythmias. We are developing forward-viewing ultrasound imaging catheters based on two types of transducer arrays using the capacitive micromachined ultrasonic transducer technology: A 10-MHz, 24-element MicroLinear (ML) array with a footprint of 1.7 mm × 1.3 mm, and a 10-MHz, 64-element annular ring array with an outside diameter of 2.6 mm and inner diameter of 1.6 mm. Both arrays are integrated with custom-designed front-end electronic circuitry to overcome the performance degradation associated with long cables in the catheter. The ML and ring arrays provide real-time 2-D and 3-D images, respectively, in front of the catheter tip. Using the ML array, we demonstrated ex-vivo images of the left atrial appendage in an isolated Langendorff-perfused rabbit heart model and in-vivo images of heart through the open chest in a porcine animal model. We used the ring array to demonstrate 3-D images of coronary stents and an anatomic cast of a left atrial model.

  19. Double Ring Array Catheter for In Vivo Real-Time 3D Ultrasound.

    PubMed

    Smith, Stephen W; Gardea, Paul; Patel, Vivek; Douglas, Stephen J; Wolf, Patrick D

    2014-03-12

    We developed new forward-viewing matrix transducers consisting of double ring arrays of 118 total PZT elements integrated into catheters used to deploy medical interventional devices. Our goal is 3D ultrasound guidance of medical device implantation to reduce x-ray fluoroscopy exposure. The double ring arrays were fabricated on inner and outer custom polyimide flexible circuits with inter-element spacing of 0.20 mm and then wrapped around an 11 French (Fr) catheter to produce a 15 Fr catheter (outer diameter [O.D.]). We used a braided cabling technology to connect the elements to the Volumetrics Medical Imaging (VMI) real-time 3D ultrasound scanner. Transducer performance yielded an average -6 dB fractional bandwidth of 49% ± 11% centered at 4.4 MHz for 118 elements. Real-time 3D cardiac scans of the in vivo pig model yielded good image quality including en face views of the tricuspid valve and real-time 3D guidance of an endo-myocardial biopsy catheter introduced into the left ventricle. PMID:24626564

  20. Visualization of cardiac wavefronts using data fusion

    NASA Astrophysics Data System (ADS)

    Kynor, David B.; Dietz, Anthony; Friets, Eric; Peterson, Jon; Bergstrom, Ursula; Triedman, John; Hammer, Peter

    2002-05-01

    Catheter ablation has emerged as a highly effective treatment for arrhythmias that are constrained by known, easily located, anatomic landmarks. However, this treatment has enjoyed limited success for arrhythmias that are characterized by complex activation patterns or are not anatomically constrained. This class of arrhythmias, which includes atrial fibrillation and ventricular tachycardia resulting from ischemic heart disease, demands improved mapping tools. Current technology forces the cardiologist to view cardiac anatomy independently from the functional information contained in the electrical activation patterns. This leads to difficulties in interpreting the large volumes of data provided by high-density recording catheters and in mapping patients with abnormal anatomy (e.g., patients with congenital heart disease). The goal of this is work is development of new data processing and display algorithms that will permit the clinician to view activation sequences superimposed onto existing fluoroscopic images depicting the location of recording catheters within the heart. In cases where biplane fluoroscopic images and x-ray camera position data are available, the position of the catheters can be reconstructed in three-dimensions.

  1. Using urokinase to restore patency in double lumen catheters.

    PubMed

    Northsea, C

    1994-08-01

    All hemodialysis patients with temporary or permanent double lumen catheters are at risk for catheter occlusion. Clinical outcomes and cost-effectiveness of using urokinase, a thrombolytic agent, to declot occluded double lumen dialysis catheters were evaluated for 2 years. Patency was restored in 95 of 102 catheters. These data support the use of urokinase to safely and effectively restore patency, thereby extending the length of time a catheter can be used for dialysis.

  2. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  3. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  4. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  5. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  6. 21 CFR 882.4100 - Ventricular catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identification. A ventricular catheter is a device used to gain access to the cavities of the brain for injection of material into, or removal of material from, the brain. (b) Classification. Class II...

  7. Advanced Imaging Catheter: Final Project Report

    SciTech Connect

    Krulevitch, P; Colston, B; DaSilva, L; Hilken, D; Kluiwstra, J U; Lee, A P; London, R; Miles, R; Schumann, D; Seward, K; Wang, A

    2001-07-20

    Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area. The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body) relative to

  8. Something's missing: peripheral intravenous catheter fracture.

    PubMed

    Glassberg, Elon; Lending, Gadi; Abbou, Benyamine; Lipsky, Ari M

    2013-01-01

    We describe a case of peripheral intravenous catheter fracture occurring during a routine training exercise. The supervising instructor immediately placed a venous tourniquet proximal to the insertion site and urgently transported the patient to the hospital. The missing catheter segment was identified within the median cubital vein under ultrasonography and was removed by venous cutdown under local anesthesia. An investigation determined that reinsertion of the needle into the advanced catheter likely caused the fracture and that application of a tourniquet may have prevented embolism of the fractured segment. Our literature review suggested that peripheral intravenous catheter fracture is likely vastly underreported, with only one prior case identified in the English literature. Action was taken following the event to educate all Israeli Defense Force medical providers regarding both proper preventive measures and recognition and treatment of catheter fracture should it occur. This case highlights the importance of health care providers being aware of the possibility of catheter fracture, as well as steps to take to prevent and mitigate its occurrence.

  9. Determination of urethral catheter surface lubricity.

    PubMed

    Kazmierska, Katarzyna; Szwast, Maciej; Ciach, Tomasz

    2008-06-01

    Device for in-vitro measurement of static and kinetic friction coefficient of catheter surface was developed. Tribometer was designed and constructed to work with exchangeable counter-faces (polymers, tissue) and various types of tubes, in wet conditions in order to mimic in-vivo process. Thus seven commercially available urethral catheters, made from vinyl polymers, natural latex with silicone coating, all-silicone or hydrogel coated, and one made from polyvinylchloride with polyurethane/polyvinylpyrrolidone hydrogel coating obtained in our laboratory, were tested against three various counter faces: polymethacrylate (organic glass), inner part of porcine aorta and porcine bladder mucosa. Additionally, the hydrophility/hydrophobity of tested catheters was stated via water wetting contact angle measurement. Super-hydrophilic biomaterials revealed low friction on tissue and hydrophobic counter-face; slightly hydrophobic showed higher friction in both cases, while more hydrophobic manifested low friction on tissue but high on hydrophobic polymer. The smoothest friction characteristic was achieved in all cases on tissue counter-faces. The measured values of the static coefficient of friction of catheters on bladder mucosa counter-face were as follows: the highest (0.15) for vinyl and siliconised latex catheters and 3 folds lower (0.05) for all-silicone ones. Hydrogel coated catheters exhibited the lowest static and kinetic friction factors. PMID:18071872

  10. The history of cardiac catheterization.

    PubMed

    Bourassa, Martial G

    2005-10-01

    The evolution of cardiac catheterization has occurred over at least four centuries. One of the first major steps was the description of the circulation of the blood by William Harvey in 1628. The next milestone was the measurement of arterial pressure by Stephen Hales, one century later. However, the 19th century represented the golden age of cardiovascular physiology, highlighted by the achievements of Carl Ludwig, Etienne-Jules Marey and Claude Bernard, among others. Human cardiac catheterization developed during the 20th century. The first right heart catheterization in a human was performed by Werner Forssmann on himself in 1929. Diagnostic cardiac catheterization was introduced by André Cournand and Dickinson Richards in the early 1940s, and selective coronary angiography was described by Mason Sones in the early 1960s. More recently, with the advent of catheter-based interventions, pioneered by Andreas Gruentzig in the late 1970s, there has been considerable progress in the refinement and expansion of these techniques. Currently, the Sones technique is used only infrequently, and coronary angiography and percutaneous coronary intervention rely mainly on percutaneous femoral and percutaneous radial artery approaches. On the occasion of the 50th anniversary of the Montreal Heart Institute, it seems appropriate to highlight the contribution of this institution in these two areas. PMID:16234881

  11. Radiofrequency Ablation Beyond the Liver

    PubMed Central

    Neeman, Ziv; Wood, Bradford J.

    2008-01-01

    Radiofrequency ablation (RFA) has begun to show promise for extrahepatic indications. Although much of the reported work on image-guided RFA of liver neoplasms is quite promising, it is even earlier in the evaluation and validation process for extrahepatic RFA, with few short-term and no long-term studies reported. Although there are much more data for liver RFA with almost 3,000 cases reported in the literature, there are a number of ongoing investigations of RFA for tumors in the kidney, lung, bone, breast, bone, and adrenal gland. Debulking and pain control with RFA present palliative options becoming increasingly popular weapons in the interventionalist's oncology arsenal. Metastatic disease with a wide variety of primary histologies in a myriad of locations may be treated with RFA after a careful consideration of the risk-to-benefit ratio balance. The RFA technique can be slightly different outside the liver. Specifically, differing dielectric tissue characteristics may markedly alter the RFA treatment. Each different RFA system has a unique risk and advantage profile. Extrahepatic indications and contraindications will be suggested. Treatment tips and the unique complications and considerations will be introduced for some of the more common extrahepatic locations. PMID:12524646

  12. The radiofrequency magnetic dipole discharge

    NASA Astrophysics Data System (ADS)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  13. The Implantable Cardiac Pacemaker

    PubMed Central

    Trimble, A. S.; Heimbecker, R. O.; Bigelow, W. G.

    1964-01-01

    The transistorized implanted pacemaker is proving to be an effective and reliable method for long-term pacing of the heart. All patients suffering from Stokes-Adams seizures were first given a trial period of conservative therapy, including isoproterenol (Isuprel), ephedrine, atropine and steroids. Twenty-four pacemaker implants were performed on 23 patients over a 21-month period. The preoperative insertion of a pacemaker cardiac catheter was a very valuable safety precaution. In this way the heart could be safely and reliably paced during the period of preoperative assessment and during the critical periods of anesthetic induction and thoracotomy. Infection did not occur, probably because of careful gas sterilization of the units. Various models of pacemakers are compared, and the reasons for two pacemaker failures are presented. There were two early deaths and one late death in the series. The relationship of progressive coronary disease to recent infarction is stressed. Patients having intermittent heart block frequently showed the picture of “competing pacemakers” postoperatively, but without deleterious effect. Twenty patients, between 54 and 88 years of age, are alive and well at the time of reporting, with excellent pacemaker response and no further Stokes-Adams attacks. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:14118681

  14. Magnetocardiographically-guided catheter ablation.

    PubMed

    Fenici, R R; Covino, M; Cellerino, C; Di Lillo, M; De Filippo, M C; Melillo, G

    1995-12-01

    After more than 30 years since the first magnetocardiographic (MCG) recording was carried out with induction coils, MCG is now approaching the threshold of clinical use. During the last 5 years, in fact, there has been a growing interest of clinicians in this new method which provides an unrivalled accuracy for noninvasive, three-dimensional localization of intracardiac source. An increasing number of laboratories are reporting data validating the use of MCG as an effective method for preoperative localization of arrhythmogenic substrates and for planning the best catheter ablation approach for different arrhythmogenic substrates. In this article, available data from literature have been reviewed. We consider the clinical use of MCG to localize arrhythmogenic substrates in patients with Wolff-Parkinson-White syndrome and in patients with ventricular tachycardia in order to assess the state-of-the-art of the method on a large number of patients. This article also addresses some suggestions for industrial development of more compact, medically oriented MCG equipments at reasonable cost.

  15. Reducing inappropriate urinary catheter use: quality care initiatives.

    PubMed

    Buckley, Catherine; Clements, Charlotte; Hopper, Adrian

    Healthcare-acquired urinary infection presents a substantial burden for patients and the healthcare system. Urinary tract infections have not gained the same level of media attention as other healthcare-associated infections, yet interventions to reduce urinary catheter use are one of the top ten recommended patient safety strategies. To improve practice around urinary catheter placement and removal requires interventions to change the expectations and habits of nurses, medical teams and patients regarding the need for a urinary catheter. In the authors' trust, a redesign of the existing urinary catheter device record was undertaken to help avoid unnecessary placement of catheters, and resulted in a reduction of urinary catheters in situ longer than 48 hours. Other strategies included implementation of catheter rounds in a high-usage area, and credit-card-sized education cards. A catheter 'passport' was introduced for patients discharged with a catheter to ensure information for insertion and ongoing use were effectively communicated. PMID:25978469

  16. Audit of catheter-associated UTI using silver alloy-coated Foley catheters.

    PubMed

    Seymour, Coral

    Catheter-associated urinary tract infection (CAUTI) is the most common and most costly healthcare-associated infection, and possibly the most preventable (Salgado et al, 2003). The Cochrane Review of silver alloy-coated Foley catheters concluded that they are successful at reducing the rate of this healthcare-associated infection, which can be potentially fatal (Brosnahan et al, 2004). This article discusses the merits of using the silver alloy-coated Foley catheter in reducing the risk of CAUTI in an acute general hospital. A pre- and post-intervention design was used to audit CAUTI rates. During the pre-intervention period of 10 weeks, the Trust's standard catheters were used and CAUTI rates captured. Silver alloy-coated Foley catheters were introduced and their use monitored for a further period of 10 weeks. A total of 117 newly catheterized patients were actively monitored for signs and symptoms of CAUTI. The audit met and exceeded its aim of reducing the CAUTI rate by 20&. The CAUTI risk rate and device rate fell during the evaluation period. The use of the silver alloy-coated Foley catheters proved to be cost-effective given the recognized additional costs of CAUTI and prolonged in-patient stay (Plowman et al, 1999). Given the results of this audit it is recommended that the silver alloy-coated Foley catheter be the catheter of choice for use with acute patient admissions requiring short-term catheterization.

  17. Catheter Ablation of Arrhythmias Exclusively Using Electroanatomic Mapping: A Series of Cases

    PubMed Central

    Pires, Leonardo Martins; Leiria, Tiago Luiz Luz; Kruse, Marcelo Lapa; Ronsoni, Rafael; Gensas, Caroline Saltz; de Lima, Gustavo Glotz

    2013-01-01

    Background Catheter ablation is a treatment that can cure various cardiac arrhythmias. Fluoroscopy is used to locate and direct catheters to areas that cause arrhythmias. However, fluoroscopy has several risks. Electroanatomic mapping (EAM) facilitates three-dimensional imaging without X-rays, which reduces risks associated with fluoroscopy. Objective We describe a series of patient cases wherein cardiac arrhythmia ablation was exclusively performed using EAM. Methods Patients who presented with cardiac arrhythmias that were unresponsive to pharmacological therapy were prospectively selected between March 2011 and March 2012 for arrhythmia ablation exclusively through EAM. Patients with indications for a diagnostic electrophysiology study and ablation of atrial fibrillation, left atrial tachyarrhythmias as well as hemodynamically unstable ventricular arrhythmia were excluded. We documented the procedure time, success rate and complications as well as whether fluoroscopy was necessary during the procedure. Results In total, 11 patients were enrolled in the study, including seven female patients (63%). The mean age of the patients was 50 years (SD ±16.5). Indications for the investigated procedures included four cases (35%) of atrial flutter, three cases (27%) of pre-excitation syndrome, two cases (19%) of paroxysmal supraventricular tachycardia and two cases (19%) of ventricular extrasystoles. The mean procedure duration was 86.6 min (SD ± 26 min). Immediate success (at discharge) of the procedure was evident for nine patients (81%). There were no complications during the procedures. Conclusion This study demonstrates the feasibility of performing an arrhythmia ablation exclusively using EAM with satisfactory results. PMID:23877742

  18. Conversion of Non-Tunneled to Tunneled Hemodialysis Catheters

    SciTech Connect

    Ha, Thuong G. Van Fimmen, Derek; Han, Laura; Funaki, Brian S.; Santeler, Scott; Lorenz, Jonathan

    2007-04-15

    Purpose. To determine the safety and efficacy of conversion of non-tunneled (temporary) catheters to tunneled catheters in hemodialysis patients. Methods. A retrospective review of 112 consecutive conversions in 111 patients was performed over a period of 4 years. Fourteen patients were lost to follow-up. The remaining 97 patients had clinical follow-up. Temporary catheters were converted to tunneled catheters utilizing the same internal jugular venotomy sites and a modified over-the-wire technique with use of a peel-away sheath . Follow-up clinical data were reviewed. Results. Technical success was achieved in all 112 procedures. None of the 97 patients with follow-up suffered early infection within 30 days. The total number of follow-up catheter days was 13,659 (range 2-790). Cases of confirmed and suspected bacteremia requiring catheter removal occurred at a frequency of 0.10 per 100 catheter days. Suspected catheter infection treated with antibiotics but not requiring catheter intervention occurred at a frequency of 0.04 per 100 catheter days. Frequency of all suspected or confirmed infections was 0.14 per 100 catheter days. Catheter interventions as a result of poor blood flow, inadvertent removal, catheter fracture, or kinking occurred at a rate of 0.18 per 100 catheter days. Life table analysis revealed primary patency rates of 86%, 64%, and 39% at 30 days, 90 days, and 180 days, respectively. Conclusion. Conversion of temporary catheters to tunneled catheters using the pre-existing venotomy sites is safe and has low rates of infection and malfunction. These rates are comparable to previously published rates for tunneled catheters placed de novo and tunneled catheter exchanges.

  19. Advantages of a workbench reshaped AR1 mod catheter for right coronary angiography by right radial approach.

    PubMed

    Baldi, Cesare; Mirra, Marco; Di Maio, Marco; Attisano, Tiziana; Di Muro, Michele Roberto; Vigorito, Francesco; Farina, Rosario; Polito, Maria Vincenza; Giudice, Pietro; Piscione, Federico

    2014-03-01

    Transradial approach in cardiac catheterization is increasing. In daily practice, coronary angiography via radial artery is usually performed by using catheters designed for femoral approach. The aim of this study was to evaluate advantages in the use of a workbench reshaped AR1 mod catheter, in terms of procedural duration time, number of catheters per procedure, fluoroscopy time, contrast agent administered volume, images quality and costs. Two hundred patients, submitted to coronary angiography via right radial artery in our institution, have been retrospectively reviewed. Patients have been divided in two groups, depending on whether a workbench reshaped Cordis Amplatz AR1 mod catheter (rAR1 mod), or catheters in their original shape (OC) have been employed. In the rAR1 mod group (100 patients) a lower number of catheters per procedure (1.07 ± 0.25 vs. 1.47 ± 1.65; p < 0.001), a more frequent right coronary selective engagement (76.76% vs. 53.12%; p < 0.001), a smaller amount of contrast agent (63.02 ± 27.77 vs. 80.85 ± 29.22 ml, p < 0.001), a reduced fluoroscopy and global procedural time (4.19 ± 2.91 vs. 5.69 ± 3.85 min, p = 0.004; and 34.58 ± 17.05 vs. 42.58 ± 17.26 min, p = 0.001, respectively) were observed. According to our experience, when right coronary angiography via right radial approach is performed, the utilization of rAR1 mod catheter correlates with multiple advantages in terms of procedural parameters.

  20. [Minimally invasive direct cardiac surgery with the jakoscope retractor].

    PubMed

    Galajda, Zoltán; Jakó, Géza; von Jakó, Ronald; Péterffy, Arpád

    2008-01-20

    The authors present a surgical retractor named jakoscope, useful in the field of abdominal, urological, vascular, thoracic and cardiac surgery procedures. This multifunctional device offers the possibility to utilize Minimally Invasive Direct Access Surgical Technology (MIDAST) in the above mentioned surgical specialties. In their department the authors use the jakoscope retractor for aortic valve replacement, off-pump coronary bypass operations and radiofrequency pulmonary vein ablation by mini-thoracotomy approach. In this report they published for the first time their experience with jakoscope device in the field of cardiac surgery. In these operations the device assured adequate minimally invasive direct access, without complications.

  1. EM-navigated catheter placement for gynecologic brachytherapy: an accuracy study

    NASA Astrophysics Data System (ADS)

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-03-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and /or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems.

  2. EM-Navigated Catheter Placement for Gynecologic Brachytherapy: An Accuracy Study

    PubMed Central

    Mehrtash, Alireza; Damato, Antonio; Pernelle, Guillaume; Barber, Lauren; Farhat, Nabgha; Viswanathan, Akila; Cormack, Robert; Kapur, Tina

    2014-01-01

    Gynecologic malignancies, including cervical, endometrial, ovarian, vaginal and vulvar cancers, cause significant mortality in women worldwide. The standard care for many primary and recurrent gynecologic cancers consists of chemoradiation followed by brachytherapy. In high dose rate (HDR) brachytherapy, intracavitary applicators and/or interstitial needles are placed directly inside the cancerous tissue so as to provide catheters to deliver high doses of radiation. Although technology for the navigation of catheters and needles is well developed for procedures such as prostate biopsy, brain biopsy, and cardiac ablation, it is notably lacking for gynecologic HDR brachytherapy. Using a benchtop study that closely mimics the clinical interstitial gynecologic brachytherapy procedure, we developed a method for evaluating the accuracy of image-guided catheter placement. Future bedside translation of this technology offers the potential benefit of maximizing tumor coverage during catheter placement while avoiding damage to the adjacent organs, for example bladder, rectum and bowel. In the study, two independent experiments were performed on a phantom model to evaluate the targeting accuracy of an electromagnetic (EM) tracking system. The procedure was carried out using a laptop computer (2.1GHz Intel Core i7 computer, 8GB RAM, Windows 7 64-bit), an EM Aurora tracking system with a 1.3mm diameter 6 DOF sensor, and 6F (2 mm) brachytherapy catheters inserted through a Syed-Neblett applicator. The 3D Slicer and PLUS open source software were used to develop the system. The mean of the targeting error was less than 2.9mm, which is comparable to the targeting errors in commercial clinical navigation systems. PMID:25076828

  3. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Radiofrequency radiation exposure limits. 1... Radiofrequency radiation exposure limits. (a) Specific absorption rate (SAR) shall be used to evaluate the environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within...

  4. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Radiofrequency radiation exposure limits. 1... Radiofrequency radiation exposure limits. (a) Specific absorption rate (SAR) shall be used to evaluate the environmental impact of human exposure to radiofrequency (RF) radiation as specified in § 1.1307(b) within...

  5. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of...

  6. [Radiofrequency ablation of an unresectable abdominal tumor].

    PubMed

    Sézeur, Alain; Fritsch, Sylvie; Louvet, Christophe; Kujas, Albert; Mosnier, Henri; Talbot, Jean-Noël; Grimberg, Sylvie

    2003-02-01

    Remnant malignant tissue is left behind after conventional surgery for an unresectable intraperitoneal malignant tumor. Standard radiotherapy or chemotherapy rarely enables good tumor control. We report the case of a 74-year-old man who developed a local recurrence of a sigmoid tumor located 5 to 6 cm from the anus. The tumor was fixed to the pelvic wall and could not be totally eradicated with conventional surgery. Preoperative peroperative assessment confirmed the absence of metastatic spread. Radiotherapy could not be performed due to risk of bowel injury. Peroperative radiofrequency ablation was followed by surgical colorectal resection without restoration of intestinal continuity, leaving only tumor tissue destroyed by radiofrequency. No adjuvant treatment was proposed because of intolerance to chemotherapy. Clinical assessment and thoracic and abdominal CT scan confirmed the absence of recurrence 26 months after radiofrequency ablation. Serum markers remained normal.

  7. [Cardiac amyloidosis].

    PubMed

    Hoyer, Caroline; Angermann, Christiane E; Knop, Stefan; Ertl, Georg; Störk, Stefan

    2008-03-15

    Amyloidoses are a heterogeneous group of multisystem disorders, which are characterized by an extracellular deposition of amyloid fibrils. Typically affected are the heart, liver, kidneys, and nervous system. More than half of the patients die due to cardiac involvement. Clinical signs of cardiac amyloidosis are edema of the lower limbs, hepatomegaly, ascites and elevated jugular vein pressure, frequently in combination with dyspnea. There can also be chest pain, probably due to microvessel disease. Dysfunction of the autonomous nervous system or arrhythmias may cause low blood pressure, dizziness, or recurrent syncope. The AL amyloidosis caused by the deposition of immunoglobulin light chains is the most common form. It can be performed by monoclonal gammopathy. The desirable treatment therapy consists of high-dose melphalan therapy twice followed by autologous stem cell transplantation. Due to the high peritransplantation mortality, selection of appropriate patients is mandatory. The ATTR amyloidosis is an autosomal dominant disorder caused by the amyloidogenic form of transthyretin, a plasmaprotein that is synthesized in the liver. Therefore, liver transplantation is the only curative therapy. The symptomatic treatment of cardiac amyloidosis is based on the current guidelines for chronic heart failure according to the patient's New York Heart Association (NYHA) state. Further types of amyloidosis with possible cardiac involvement comprise the senile systemic amyloidosis caused by the wild-type transthyretin, secondary amyloidosis after chronic systemic inflammation, and the beta(2)-microglobulin amyloidosis after long-term dialysis treatment. PMID:18344065

  8. Nonholonomic catheter path reconstruction using electromagnetic tracking

    NASA Astrophysics Data System (ADS)

    Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor

    2015-03-01

    Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.

  9. Catheter Ablation for Long-Standing Persistent Atrial Fibrillation.

    PubMed

    Romero, Jorge; Gianni, Carola; Di Biase, Luigi; Natale, Andrea

    2015-01-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines). PMID:26306125

  10. Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

    PubMed Central

    Romero, Jorge; Gianni, Carola; Di Biase, Luigi; Natale, Andrea

    2015-01-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines). PMID:26306125

  11. [The radiofrequency ablation of accessory pathways. The initial experience in Mexico].

    PubMed

    Molina, L; Morales, A; Alvarez, L M; Avila, L

    1993-01-01

    Thirteen patients with paroxysmal supraventricular tachycardia (SVT) due to an accessory pathway were submitted to an electrophysiological study and radiofrequency ablation of the Kent bundle. There were 9 males and 4 females. The mean age was 22 years. Other than their SVT, none had any structural heart disease. Ten of them had Wolff-Parkinson-White syndrome, and three had concealed accessory pathways. Two different types of radiofrequency devices were used: one generating damped sinusoid waves, and two other generators producing pure continuous sinusoid waves. With the first type, two attempts were made: one patient with a concealed pathway and one with overt preexcitation. The successful ablation was not achieved because this wave type is 100 times more powerful, it desiccates the tissue, and thus does not produce the right kind of lesion. The other eleven patients were divided in three groups: I) With left overt preexcitation (7 pts) II) Concealed left Kent bundles (2 pts) III) Right Kent bundles. Ablation was 100% successful in group I, while in the other two groups, only one patient of each was successfully ablated. The overall successful rate of these 3 groups was 81.8%. Of the two patients that could not be treated, one had an anterior septal Kent bundle and the other had a concealed left Kent bundle. We believe that catheter ablation is a very promising therapeutic procedure for patients with SVT, besides being a extraordinary instrument that will enable us to be able to understand further clinical electrophysiology. PMID:8466363

  12. Six-year experience with swan neck catheters.

    PubMed

    Twardowski, Z J; Prowant, B F; Nichols, W K; Nolph, K D; Khanna, R

    1992-01-01

    From the beginning of our continuous ambulatory peritoneal dialysis (CAPD) program in January 1977 until June 1985, we used Tenckhoff and Toronto Western Hospital catheters. Throughout these years catheter survival probabilities of about 30% at three years persisted unchanged and were similar to survival probabilities reported by the National CAPD Registry special survey for these catheters. The first improvement in catheter results regarding leaks was noted after the adoption of lateral catheter insertion. Malfunction was less using swan neck prototypes from August 1985 to April 1986. The latter catheters were made of 80 degrees arc angle tubing between 8.5 cm spaced cuffs and were inserted in a reversed U-shape tunnel with the incision at the top of the tunnel. The use of these catheters was abandoned because of high cuff extrusion and exit infection rates. The next generation of swan neck catheters, the swan neck Missouri 2 and 3 catheters with straight intraperitoneal segments, improved the results dramatically. These catheters were made of 180 degrees arc angle tubing between 5 or 3 cm spaced cuffs. The estimated survival probability of 61% at three years more than doubled compared to previously used catheters. Recently we modified the intraperitoneal segment of the catheters, replacing the straight segment with a coiled one. These modified catheters, the swan neck Missouri coiled catheters, have been used exclusively since February 1990. In addition to an acceptable survival probability of 88% at one year, there are two major advantages of these catheters, the same as for other coiled catheters: elimination of infusion pain due to a jet effect and pain related to straight catheter tip pressure on the peritoneum experienced by some patients.

  13. Almanac 2013: cardiac arrhythmias and pacing.

    PubMed

    Liew, Reginald

    2013-10-01

    Important advances have been made in the past few years in the fields of clinical cardiac electrophysiology and pacing. Researchers and clinicians have a greater understanding of the pathophysiological mechanisms underlying atrial fibrillation (AF), which has transpired into improved methods of detection, risk stratification, and treatments. The introduction of novel oral anticoagulants has provided clinicians with alternative options in managing patients with AF at moderate to high thromboembolic risk and further data has been emerging on the use of catheter ablation for the treatment of symptomatic AF. Another area of intense research in the field of cardiac arrhythmias and pacing is in the use of cardiac resynchronisation therapy (CRT) for the treatment of patients with heart failure. Following the publication of major landmark randomised controlled trials reporting that CRT confers a survival advantage in patients with severe heart failure and improves symptoms, many subsequent studies have been performed to further refine the selection of patients for CRT and determine the clinical characteristics associated with a favourable response. The field of sudden cardiac death and implantable cardioverter defibrillators also continues to be actively researched, with important new epidemiological and clinical data emerging on improved methods for patient selection, risk stratification, and management. This review covers the major recent advances in these areas related to cardiac arrhythmias and pacing.

  14. Catheter tip force transducer for cardiovascular research

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H. (Inventor)

    1976-01-01

    A force transducer for measuring dynamic force activity within the heart of a subject essentially consists of a U-shaped beam of low elastic compliance material. Two lines extend from the beams's legs and a long coil spring is attached to the beam. A strain gauge is coupled to one of the beam's legs to sense deflections thereof. The beam with the tines and most of the spring are surrounded by a flexible tube, defining a catheter, which is insertable into a subject's heart through an appropriate artery. The tines are extractable from the catheter for implantation into the myocardium by pushing on the end of the spring which extends beyond the external end of the catheter.

  15. The importance of effective catheter securement.

    PubMed

    Fisher, Jayne

    This article examines the importance of securing/fixing indwelling urinary catheters. The Oxford English dictionary interlinks the two words-'secure' and 'fix'-as having the same meaning. To secure the catheter should not be confused with 'support', whereby the weight of the urine drainage bag is supported with the use of velcro straps or a sleeve. The author introduces the need for the concept of this practice to be at the forefront of nurses' minds in all settings, and this is demonstrated through the use of case studies. Current guidance in this area is reviewed, as well as the problems that can arise when catheters are not secured properly and the available products for health professionals to use. PMID:20948482

  16. The importance of effective catheter securement.

    PubMed

    Fisher, Jayne

    This article examines the importance of securing/fixing indwelling urinary catheters. The Oxford English dictionary interlinks the two words-'secure' and 'fix'-as having the same meaning. To secure the catheter should not be confused with 'support', whereby the weight of the urine drainage bag is supported with the use of velcro straps or a sleeve. The author introduces the need for the concept of this practice to be at the forefront of nurses' minds in all settings, and this is demonstrated through the use of case studies. Current guidance in this area is reviewed, as well as the problems that can arise when catheters are not secured properly and the available products for health professionals to use.

  17. Risk of Ionizing Radiation in Women of Childbearing Age undergoing Radiofrequency Ablation

    PubMed Central

    de Lima, Gustavo Glotz; Gomes, Daniel Garcia; Gensas, Caroline Saltz; Simão, Mariana Fernandez; Rios, Matheus N.; Pires, Leonardo Martins; Kruse, Marcelo Lapa; Leiria, Tiago Luiz Luz

    2013-01-01

    Background The International Commission of Radiology recommends a pregnancy screening test to all female patients of childbearing age who will undergo a radiological study. Radiation is known to be teratogenic and its effect is cumulative. The teratogenic potential starts at doses close to those used during these procedures. The prevalence of positive pregnancy tests in patients undergoing electrophysiological studies and/or catheter ablation in our midst is unknown. Objective To evaluate the prevalence of positive pregnancy tests in female patients referred for electrophysiological study and/or radiofrequency ablation. Methods Cross-sectional study analyzing 2,966 patients undergoing electrophysiological study and/or catheter ablation, from June 1997 to February 2013, in the Institute of Cardiology of Rio Grande do Sul. A total of 1490 procedures were performed in women, of whom 769 were of childbearing age. All patients were screened with a pregnancy test on the day before the procedure. Results Three patients tested positive, and were therefore unable to undergo the procedure. The prevalence observed was 3.9 cases per 1,000 women of childbearing age. Conclusion Because of their safety and low cost, pregnancy screening tests are indicated for all women of childbearing age undergoing radiological studies, since the degree of ionizing radiation needed for these procedures is very close to the threshold for teratogenicity, especially in the first trimester, when the signs of pregnancy are not evident. PMID:24061686

  18. Adjunctive radiofrequency ablation for the endoscopic treatment of ampullary lesions with intraductal extension (with video)

    PubMed Central

    Suarez, Alejandro L.; Coté, Gregory A.; Elmunzer, B. Joseph

    2016-01-01

    Background and study aims: Catheter-based radiofrequency ablation (RFA) delivered during endoscopic retrograde cholangiopancreatography (ERCP) may represent a viable treatment option for intraductal extension of ampullary neoplasms, however, clinical experience with this modality is limited. After ampullary resection, 4 patients with intraductal extension underwent adjunctive RFA of the distal bile duct. All patients received a temporary pancreatic stent to reduce the risk of pancreatitis, as well as a plastic biliary stent to prevent biliary obstruction. Three patients were treated for adenoma and 1 for adenoma with a focus of adenocarcinoma. During a short follow-up period, 3 patients experienced complete eradication of the target lesion, whereas the patient with a focus of adenocarcinoma had progression to overt invasive cancer. There were no immediate adverse events. One patient developed a post-RFA bile duct stricture, which has required additional endoscopic therapy. Catheter-based RFA of ampullary lesions that extend up the bile duct is technically feasible. Additional research is necessary to understand the risks and long-term benefits of this technique. PMID:27556089

  19. Contact Force-Guided Deep Engagement with a Steerable Sheath in the Distal Great Cardiac Vein: A Case Report.

    PubMed

    Kumagai, Y U; Arimoto, Takanori; Iwayama, Tadateru; Hashimoto, Naoaki; Watanabe, Tetsu; Kubota, Isao

    2016-05-01

    Ablation of ventricular tachycardia originating from the great cardiac vein involves the difficult step of deep engagement with an ablation catheter. The catheter and a steerable sheath (MobiCath, Biosense Webster, Diamond Bar, CA, USA) were advanced alternately only when the contact force vector was parallel to the coronary venous system. Deep engagement with a steerable sheath ensured a powerful backup force during ablation. PMID:26854279

  20. Data fusion for catheter tracking using Kalman filtering: applications in robot-assisted catheter insertion

    NASA Astrophysics Data System (ADS)

    Azizian, Mahdi; Patel, Rajni

    2011-03-01

    X-ray image guided angioplasty is a minimally invasive procedure that involves the insertion of a catheter into a blood vessel to remove blockages to blood flow. There are several issues associated with conventional angioplasty which cause risks for the patient (damage to blood vessels, dislodging plaques, etc.) and difficulties for the clinician (X-ray exposure, fatigue, etc.). Autonomous or semi-autonomous robot-assisted catheter insertion is a solution that can reduce these problems substantially. To perform autonomous catheter insertion, closed-loop position control of the distal tip of the catheter is required during insertion. Therefore accurate real-time position feedback is needed for this purpose. We have developed a real-time image processing algorithm for catheter tip position tracking which has an acceptable performance but is sensitive to X-ray image artifacts caused by bones and dense tissues. A magnetic tracking system (MTS) is another modality that has also been used for catheter tip position tracking, but it is sensitive to external electromagnetic interferences and ferromagnetic material. Combining the measurement data provided by both imaging and magnetic sensors can compensate for the deficiencies of each and can also improve the robustness of catheter tip position tracking. We have developed a Kalman filter based sensor fusion scheme to overcome deficiencies of both of these methods and create a reliable real-time tracking of a catheter tip. Experiments have been performed by inserting a guide catheter into a model of the vasculature. The method has been tested in presence of occlusion in the images and also electromagnetic interference.

  1. 21 CFR 870.1240 - Flow-directed catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) Identification. A flow-directed catheter is a device that incorporates a gas-filled balloon to help direct the catheter to the desired position. (b) Classification. Class II (performance standards)....

  2. 21 CFR 870.1240 - Flow-directed catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) Identification. A flow-directed catheter is a device that incorporates a gas-filled balloon to help direct the catheter to the desired position. (b) Classification. Class II (performance standards)....

  3. Catheter ablation of accessory pathways near the coronary sinus: Value of defining coronary arterial anatomy

    PubMed Central

    Mao, Jessica; Moriarty, John M.; Mandapati, Ravi; Boyle, Noel G.; Shivkumar, Kalyanam; Vaseghi, Marmar

    2015-01-01

    BACKGROUND Accessory pathways can lie near or within the coronary sinus (CS). Radiofrequency catheter ablation of accessory pathways is a well-established treatment option, but this procedure can cause damage to adjacent coronary arteries. OBJECTIVE The purpose of this study was to evaluate the anatomic relationship between the coronary arteries and the CS. METHODS Retrospective data of patients who underwent catheter ablation of supraventricular tachycardia between June 2011 and August 2013 was reviewed. In addition, detailed analysis of coronary computed tomographic angiography (CTA) data from 50 patients was performed. RESULTS Between June 2011 and August 2013, 427 patients underwent catheter ablation of supraventricular tachycardia, of whom 105 (age 28 ± 17 years, 60% male) had accessory pathway–mediated tachycardia. Of these, 23 patients had accessory pathways near the CS, and 60% (N = 14) underwent concurrent coronary angiography. In 4 patients, the posterolateral (inferolateral) branch (PLA) of the right coronary artery was in close proximity to the CS, and 2 patients (18%) had stenosis of the PLA at the site of ablation. On CTA at their closest proximity, the PLA was 1.9 ± 1.3 mm and the left circumflex artery (LCx) was 2.0 ± 0.8 mm from the body of the CS, in right and left coronary artery–dominant patients, respectively. CS ostium and PLA were 3.6 ± 1.9 mm apart. In left-dominant patients, LCx and CS ostium were 3.8 ± 1.2 mm apart. CONCLUSION The PLA and LCx are in close proximity to the anteroinferior aspect of the CS ostium and proximal CS. The relationship of the CS and coronary arteries should be evaluated before ablation at these sites. PMID:25485779

  4. Optimization of Catheter Ablation of Atrial Fibrillation: Insights Gained from Clinically-Derived Computer Models

    PubMed Central

    Zhao, Jichao; Kharche, Sanjay R.; Hansen, Brian J.; Csepe, Thomas A.; Wang, Yufeng; Stiles, Martin K.; Fedorov, Vadim V.

    2015-01-01

    Atrial fibrillation (AF) is the most common heart rhythm disturbance, and its treatment is an increasing economic burden on the health care system. Despite recent intense clinical, experimental and basic research activity, the treatment of AF with current antiarrhythmic drugs and catheter/surgical therapies remains limited. Radiofrequency catheter ablation (RFCA) is widely used to treat patients with AF. Current clinical ablation strategies are largely based on atrial anatomy and/or substrate detected using different approaches, and they vary from one clinical center to another. The nature of clinical ablation leads to ambiguity regarding the optimal patient personalization of the therapy partly due to the fact that each empirical configuration of ablation lines made in a patient is irreversible during one ablation procedure. To investigate optimized ablation lesion line sets, in silico experimentation is an ideal solution. 3D computer models give us a unique advantage to plan and assess the effectiveness of different ablation strategies before and during RFCA. Reliability of in silico assessment is ensured by inclusion of accurate 3D atrial geometry, realistic fiber orientation, accurate fibrosis distribution and cellular kinetics; however, most of this detailed information in the current computer models is extrapolated from animal models and not from the human heart. The predictive power of computer models will increase as they are validated with human experimental and clinical data. To make the most from a computer model, one needs to develop 3D computer models based on the same functionally and structurally mapped intact human atria with high spatial resolution. The purpose of this review paper is to summarize recent developments in clinically-derived computer models and the clinical insights they provide for catheter ablation. PMID:25984605

  5. Development of a Novel Shock Wave Catheter Ablation System -The First Feasibility Study in Pigs-

    PubMed Central

    Hasebe, Yuhi; Yamamoto, Hiroaki; Fukuda, Koji; Nishimiya, Kensuke; Hanawa, Kenichiro; Shindo, Tomohiko; Kondo, Masateru; Nakano, Makoto; Wakayama, Yuji; Takayama, Kazuyoshi; Shimokawa, Hiroaki

    2015-01-01

    Introduction Radio-frequency catheter ablation (RFCA) using Joule heat has two fundamental weaknesses: the limited depth of treatment and the risk of thrombus formation. In contrast, focused shock wave (SW) therapy could damage tissues at arbitrary depths without heat generation. Thus, we aimed to develop a SW catheter ablation (SWCA) system that could compensate for the weaknesses of RFCA therapy. Methods and Results We developed a SWCA system where the SW generated by a Q-switched Holmium: yttrium aluminum garnet (YAG) laser beam was reflected by a reflector attached to 14-Fr catheter tip and then was converged onto the focus. We examined the feasibility of our system on pigs in vivo. When applied using the epicardial approach, the SWCA caused persistent spheroidal lesions with mild superficial injury than the RFCA. The lesions were created to a depth based on the focal length (2.0 mm) [2.36 ± 0.45 (SD) mm immediately after procedure, n = 16]. When applied to the atrioventricular (AV) node using the endocardial approach, the SWCA caused junctional escape rhythms in 2 pigs and AV block in 12 pigs (complete AV block in 9) in acute phase (n = 14). Nine of the 14 pigs survived with pacemakers for the long-term study, and the AV block persisted for 12.6 ± 3.9 (SD) days in all surviving pigs. Histological examination showed AV nodal cell body atrophy in the acute phase and fibrotic lesions in the chronic phase. Importantly, no acute or chronic fatal complications were noted. Conclusions Our novel SWCA system could be a promising modality as a non-thermal ablation method to compensate for the weaknesses of RFCA therapy. However, further research and development will be necessary as the current prototype still exhibited the presence of micro-thrombus formation in the animal studies. PMID:25633373

  6. Ventriculoperitoneal Shunt Peritoneal Catheter Knot Formation

    PubMed Central

    Ul-Haq, Anwar; Al-Otaibi, Faisal; Alshanafey, Saud; Sabbagh, Mohamed Diya; Al Shail, Essam

    2013-01-01

    The ventriculoperitoneal (VP) shunt is a common procedure in pediatric neurosurgery that carries a risk of complications at cranial and abdominal sites. We report on the case of a child with shunt infection and malfunction. The peritoneal catheter was tethered within the abdominal cavity, precluding its removal. Subsequently, laparoscopic exploration identified a knot at the distal end of the peritoneal catheter around the omentum. A new VP shunt was inserted after the infection was healed. This type of complication occurs rarely, so there are a limited number of case reports in the literature. This report is complemented by a literature review. PMID:24109528

  7. Major complications of cryoballoon catheter ablation for atrial fibrillation and their management.

    PubMed

    Bhat, Tariq; Baydoun, Hassan; Asti, Deepak; Rijal, Jharendra; Teli, Sumaya; Tantray, Mohmad; Bhat, Hilal; Kowalski, Marcin

    2014-09-01

    Atrial fibrillation (AF) is the most common symptomatic and sustained cardiac arrhythmia. It affects approximately 2-3 million people in the USA alone with an increased incidence and prevalence worldwide. It is associated, in addition to worsening quality of life, with increased morbidity and mortality especially in poorly controlled AF, affecting mostly those older than 65 years of age. Radiofrequency ablation was found to be a good strategy for focal isolation of pulmonary veins triggering from the vulnerable atrial substrate but is a time-consuming procedure and carries the risk of multiple complications like tamponade which could be fatal, atrioesophageal fistula and local thrombus formation at the site of ablation. Cryoballoon ablation with pulmonary vein isolation has emerged in the past few years as a breakthrough novel technology for the treatment of drug-refractory AF. It is a relatively simple alternative for point-by-point radiofrequency ablation of paroxysmal AF and is associated with fewer incidences of fatal complications such as cardiac perforation. As experience with this new tool accumulates, the field faces new challenges in the form of rare compilations including gastroparesis, phrenic nerve palsy, atrioesophageal fistula, pulmonary vein stenosis, thromboembolism pericardial effusion, and tamponade. PMID:25115140

  8. Echinocandin and ethanol lock therapy treatment of fungal catheter infections.

    PubMed

    Pieroni, Kevin P; Nespor, Colleen; Poole, Robert L; Kerner, John A; Berquist, William E

    2013-03-01

    Ethanol lock therapy has been implemented to prevent infections of central venous catheters as well as to treat infections. Fungal catheter-associated blood stream infections are historically more difficult to treat and have required removal of central venous catheters. We report the largest case series to date, successfully treating 5 of 7 fungal catheter-associated blood stream infections with ethanol lock therapy and systemic echinocandin administration.

  9. Novel uses of the Proxis embolic protection catheter.

    PubMed

    Brilakis, Emmanouil S; Banerjee, Subhash

    2009-09-01

    The Proxis catheter has been designed for proximal embolic protection during saphenous vein graft interventions. The Proxis catheter's flexible and kink-resistant design, lubricity, and atraumatic tip allow deep seating in target vessels. We describe six challenging percutaneous coronary intervention cases, in which the Proxis catheter was used in arterial grafts, sequential saphenous vein grafts, and native coronary arteries. Deep seating of the Proxis catheter enabled vessel visualization and equipment delivery, allowing successful completion of each case.

  10. New methods for image guidance and visualization for cardiac procedures

    NASA Astrophysics Data System (ADS)

    Guttman, Michael A.; McVeigh, Elliot R.

    2007-03-01

    Interventional cardiac MRI has been undergoing rapid development because of the availability of MRI compatible interventional catheters, and the increased performance of the MRI systems. Intravascular techniques do not require an open access scanner, and hence higher imaging performance during procedures can be achieved. Now, with the availability of a short, relatively open cylindrical bore scanner high imaging performance is also available to guide direct surgical procedures.

  11. Managing turbinate hypertrophy: coblation vs. radiofrequency treatment.

    PubMed

    Passali, D; Loglisci, M; Politi, L; Passali, G C; Kern, E

    2016-06-01

    The role of inferior turbinate hypertrophy in the reduction of nasal airflow is well established. Although chronic nasal obstruction is not life- threatening, it significantly impairs patients' quality of life, affecting many aspects of daily activities; therefore, patients seek medical intervention. 40 patients were selected (27 males and 13 females) between 27 and 64 years of age with a symptom of nasal obstruction. The patients were divided in two groups: Group 1: coblation, 25 patients (18 males and 7 females); Group 2: radiofrequency, 15 patients (7 males and 6 females). These 40 patients were followed for 3 years. Patients were analyzed using both subjective and objective methods. The visual analog scale (VAS) subjective data and objective data including both active anterior rhinomanometry and acoustic rhinometry were recorded and analyzed. Data were collected pre-operatively and at 1 and 3 years post-operatively. According to our data, both coblation and radiofrequency turbinate reduction benefit patients with good results. The complications, found during the follow-up, are limited to minimal bleeding and crusting. Coblation and radiofrequency were significantly less painful than others procedures during the early post-operative period. In our study, both coblation and radiofrequency provide an improvement in nasal airflow with a reduction in nasal obstructive symptoms in the short term, but their efficacy tended to decrease within 3 years.

  12. Issues in methods and measurement of thermodilution cardiac output.

    PubMed

    Sommers, M S; Woods, S L; Courtade, M A

    1993-01-01

    Criterion-related validity of the thermodilution cardiac output technique for cardiac output measurement has to have a high correlation (r = .91 to .98) with the direct Fick method, the gold standard of cardiac output measurement. Issues that can affect validity of the measurements include the position of the pulmonary artery catheter, the rate of injection of the indicator solution, the volume and temperature of the injectate, the timing of the injection of indicator solution during the respiratory cycle, the position of the subject, and the presence of concomitant infusions. Variation in measurement can be limited by considering the delivery system for the indicator solution, by recording time-temperature cardiac output curves, and by considering normal biologic variations. PMID:8337161

  13. Small Bowel Obstruction Due to Suprapubic Catheter Placement.

    PubMed

    Bonasso, Patrick C; Lucke-Wold, Brandon; Khan, Uzer

    2016-07-01

    Suprapubic catheter placement has associated complications such as bowel injury, bladder injury, or bleeding. This case describes the management of an elderly patient who had suprapubic catheter placement complicated by small bowel obstruction. The catheter had continued production of urine. Further patient treatment required abdominal exploration and bowel resection. PMID:27335801

  14. Small Bowel Obstruction Due to Suprapubic Catheter Placement.

    PubMed

    Bonasso, Patrick C; Lucke-Wold, Brandon; Khan, Uzer

    2016-07-01

    Suprapubic catheter placement has associated complications such as bowel injury, bladder injury, or bleeding. This case describes the management of an elderly patient who had suprapubic catheter placement complicated by small bowel obstruction. The catheter had continued production of urine. Further patient treatment required abdominal exploration and bowel resection.

  15. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of...

  16. 21 CFR 870.1230 - Fiberoptic oximeter catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiberoptic oximeter catheter. 870.1230 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1230 Fiberoptic oximeter catheter. (a) Identification. A fiberoptic oximeter catheter is a device used to estimate the...

  17. 21 CFR 870.1230 - Fiberoptic oximeter catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fiberoptic oximeter catheter. 870.1230 Section 870...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1230 Fiberoptic oximeter catheter. (a) Identification. A fiberoptic oximeter catheter is a device used to estimate the...

  18. 21 CFR 868.5120 - Anesthesia conduction catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to...

  19. 21 CFR 868.5120 - Anesthesia conduction catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anesthesia conduction catheter. 868.5120 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5120 Anesthesia conduction catheter. (a) Identification. An anesthesia conduction catheter is a flexible tubular device used to...

  20. 21 CFR 870.1290 - Steerable catheter control system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Steerable catheter control system. 870.1290... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification. A steerable catheter control system is a device that...

  1. 21 CFR 870.1290 - Steerable catheter control system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Steerable catheter control system. 870.1290... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification. A steerable catheter control system is a device that...

  2. 21 CFR 870.1290 - Steerable catheter control system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Steerable catheter control system. 870.1290... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification. A steerable catheter control system is a device that...

  3. 21 CFR 870.1290 - Steerable catheter control system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Steerable catheter control system. 870.1290... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification. A steerable catheter control system is a device that...

  4. 21 CFR 870.1290 - Steerable catheter control system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Steerable catheter control system. 870.1290... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1290 Steerable catheter control system. (a) Identification. A steerable catheter control system is a device that...

  5. 21 CFR 870.1240 - Flow-directed catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Flow-directed catheter. 870.1240 Section 870.1240...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1240 Flow-directed catheter. (a) Identification. A flow-directed catheter is a device that incorporates a gas-filled balloon...

  6. 21 CFR 870.1240 - Flow-directed catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Flow-directed catheter. 870.1240 Section 870.1240...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1240 Flow-directed catheter. (a) Identification. A flow-directed catheter is a device that incorporates a gas-filled balloon...

  7. 21 CFR 870.1240 - Flow-directed catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Flow-directed catheter. 870.1240 Section 870.1240...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1240 Flow-directed catheter. (a) Identification. A flow-directed catheter is a device that incorporates a gas-filled balloon...

  8. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of...

  9. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of...

  10. 21 CFR 876.4020 - Fiberoptic light ureteral catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Fiberoptic light ureteral catheter. 876.4020... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4020 Fiberoptic light ureteral catheter. (a) Identification. A fiberoptic light ureteral catheter is a device that consists of...

  11. 21 CFR 884.6110 - Assisted reproduction catheters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction catheters. 884.6110 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6110 Assisted reproduction catheters. (a) Identification. Assisted reproduction catheters are devices used in...

  12. 21 CFR 884.6110 - Assisted reproduction catheters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction catheters. 884.6110 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6110 Assisted reproduction catheters. (a) Identification. Assisted reproduction catheters are devices used in...

  13. 21 CFR 884.6110 - Assisted reproduction catheters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction catheters. 884.6110 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6110 Assisted reproduction catheters. (a) Identification. Assisted reproduction catheters are devices used in...

  14. 21 CFR 884.6110 - Assisted reproduction catheters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction catheters. 884.6110 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6110 Assisted reproduction catheters. (a) Identification. Assisted reproduction catheters are devices used in...

  15. 21 CFR 884.6110 - Assisted reproduction catheters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction catheters. 884.6110 Section... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6110 Assisted reproduction catheters. (a) Identification. Assisted reproduction catheters are devices used in...

  16. Ultrasound assessment of caudal catheter position in infants.

    PubMed

    Roberts, Stephen A; Galvez, Ignacio

    2005-05-01

    The positioning of caudally inserted epidural catheters is crucial to their effectiveness. However, level assessment can be difficult and time consuming. We report the use of ultrasound to assess the catheter position in three patients aged between 1 and 10 months. The advantages and disadvantages of this technique are discussed in relation to other methods of assessing caudal catheter placement. PMID:15828997

  17. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  18. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  19. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  20. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  1. Cardiac Surgery

    PubMed Central

    Weisse, Allen B.

    2011-01-01

    Well into the first decades of the 20th century, medical opinion held that any surgical attempts to treat heart disease were not only misguided, but unethical. Despite such reservations, innovative surgeons showed that heart wounds could be successfully repaired. Then, extracardiac procedures were performed to correct patent ductus arteriosus, coarctation of the aorta, and tetralogy of Fallot. Direct surgery on the heart was accomplished with closed commissurotomy for mitral stenosis. The introduction of the heart-lung machine and cardiopulmonary bypass enabled the surgical treatment of other congenital and acquired heart diseases. Advances in aortic surgery paralleled these successes. The development of coronary artery bypass grafting greatly aided the treatment of coronary heart disease. Cardiac transplantation, attempts to use the total artificial heart, and the application of ventricular assist devices have brought us to the present day. Although progress in the field of cardiovascular surgery appears to have slowed when compared with the halcyon times of the past, substantial challenges still face cardiac surgeons. It can only be hoped that sufficient resources and incentive can carry the triumphs of the 20th century into the 21st. This review covers past developments and future opportunities in cardiac surgery. PMID:22163121

  2. Non-invasive Mapping of Cardiac Arrhythmias.

    PubMed

    Shah, Ashok; Hocini, Meleze; Haissaguerre, Michel; Jaïs, Pierre

    2015-08-01

    Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome).

  3. [EVOLUTION OF MINIMALLY INVASIVE CARDIAC SURGERY].

    PubMed

    Fujita, Tomoyuki; Kobayashi, Junjiro

    2016-03-01

    Minimally invasive surgery is an attractive choice for patients undergoing major cardiac surgery. We review the history of minimally invasive valve surgery in this article. Due to many innovations in surgical tools, cardiopulmonary bypass systems, visualization systems, and robotic systems as well as surgical techniques, minimally invasive cardiac surgery has become standard care for valve lesion repair. In particular, aortic cross-clamp techniques and methods for cardioplegia using the Chitwood clamp and root cannula or endoballoon catheter in combination with femoro-femoral bypass systems have made such procedures safer and more practical. On the other hand, robotically assisted surgery has not become standard due to the cost and slow learning curve. However, along with the development of robotics, this less-invasive technique may provide another choice for patients in the near future. PMID:27295770

  4. Prophylaxis of indwelling urethral catheter infection: clinical experience with a modified Foley catheter and drainage system.

    PubMed

    Akiyama, H; Okamoto, S

    1979-01-01

    With the application of the oligodynamic bactericidal property of silver ions, modification of the urinary catheter and drainage system has been found effective in the prevention of urinary tract infections owing to prolonged bladder catheterization. The newly devised catheter and open drainage system were used in 102 patients for bladder catheterization postoperatively or in those with urinary retention for periods ranging from 4 to 77 days. During the period of indwelling catheterization usually no antibiotics were administered and no patient had overt bacteriuria (more than 10(5) bacteria per ml.) or symptoms of urethritis. In contrast, all 20 patients in the control group who had the conventional type of indwelling catheters had bacteriuria within 4 days of catheterization. The data obtained indicate that effective prevention of urinary tract infection, which frequently is associated with indwelling urethral catheterization, can be achieved by the use of the modified catheter and drainage system.

  5. N-butyl cyanoacrylate embolization with blood flow control of an arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma.

    PubMed

    Sonomura, Tetsuo; Kawai, Nobuyuki; Kishi, Kazushi; Ikoma, Akira; Sanda, Hiroki; Nakata, Kouhei; Minamiguchi, Hiroki; Nakai, Motoki; Hosokawa, Seiki; Tamai, Hideyuki; Sato, Morio

    2014-01-01

    We present a case of a patient with rapid deterioration of esophageal varices caused by portal hypertension accompanied by a large arterioportal shunt that developed after radiofrequency ablation of hepatocellular carcinoma. We used n-butyl cyanoacrylate (NBCA) as an embolic material to achieve pinpoint embolization of the shunt, because the microcatheter tip was 2 cm away from the shunt site. Under hepatic arterial flow control using a balloon catheter, the arterioportal shunt was successfully embolized with NBCA, which caused an improvement in the esophageal varices.

  6. Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter.

    PubMed

    Chuang, Ming-Tsung; Wu, Ding-Kwo; Chang, Cheng-Ang; Shih, Ming-Chen Paul; Ou-Yang, Fu; Chuang, Chien-Han; Tsai, Yi-Fan; Hsu, Jui-Sheng

    2011-11-01

    The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010), a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days). The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days). All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

  7. Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC).

    PubMed

    Abdullah, B J J; Mohammad, N; Sangkar, J V; Abd Aziz, Y F; Gan, G G; Goh, K Y; Benedict, I

    2005-07-01

    The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).

  8. Ocular effects of radiofrequency energy.

    PubMed

    Elder, J A

    2003-01-01

    Radiofrequency (RF) energy has been reported to cause a variety of ocular effects, primarily cataracts but also effects on the retina, cornea, and other ocular systems. Cataracts have been observed in experimental animals when one eye was exposed to a localized, very high RF field and the other eye was the unexposed control. The results show that 2450 MHz exposures for >or=30 min at power densities causing extremely high dose rates (>or=150 W/kg) and temperatures (>or=41 degrees C) in or near the lens caused cataracts in the rabbit eye. However, cataracts were not observed in the monkey eye exposed to similar exposure conditions, reflecting the different patterns of energy absorption (SAR, specific absorption rate) distribution, due to their different facial structure. Since the monkey head is similar in structure to the human head, the nonhuman primate study showed that the incident power density levels causing cataracts in rabbits and other laboratory animals cannot be directly extrapolated to primates, including human beings. It is reasonable to assume that an SAR that would induce temperatures >or=41 degrees C in or near the lens in the human eye would produce cataracts by the same mechanism (heating) that caused cataracts in the rabbit lens; however, such an exposure would greatly exceed the currently allowable limits for human exposure and would be expected to cause unacceptable effects in other parts of the eye and face. Other ocular effects including corneal lesions, retinal effects, and changes in vascular permeability, have been observed after localized exposure of the eye of laboratory animals to both continuous wave (CW) and pulsed wave (PW) exposures, but the inconsistencies in these results, the failure to independently confirm corneal lesions after CW exposure, the failure to independently confirm retinal effects after PW exposure, and the absence of functional changes in vision are reasons why these ocular effects are not useful in defining an

  9. SvO2 Trigger in Transfusion Strategy After Cardiac Surgery

    ClinicalTrials.gov

    2016-05-18

    Undergoing Nonemergent Cardiac Surgery; Central Venous Catheter on the Superior Vena Cava (to Perform ScVO2 Measure); Anemia (<9g/dL) Requiring Blood Transfusion; Hemodynamic and Respiratory Stability; Bleeding Graded as Insignificant, Mild, Moderate of Universal Definition of Perioperative Bleeding

  10. The risks and benefits of suprapubic catheters.

    PubMed

    Yates, Ann

    Suprapubic catheterisation can improve some patients' quality of life but the insertion procedure, as well as changing and managing the catheter, carry risks of infection and other negative patient outcomes. This article highlights the advantages and disadvantages, indications and contraindications, and the potential benefits, so health professionals can understand the relevant issues and assess and inform patients accordingly.

  11. Lymphatic Leak Complicating Central Venous Catheter Insertion

    SciTech Connect

    Barnacle, Alex M. Kleidon, Tricia M.

    2005-12-15

    Many of the risks associated with central venous access are well recognized. We report a case of inadvertent lymphatic disruption during the insertion of a tunneled central venous catheter in a patient with raised left and right atrial pressures and severe pulmonary hypertension, which led to significant hemodynamic instability. To our knowledge, this rare complication is previously unreported.

  12. 21 CFR 870.5175 - Septostomy catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Septostomy catheter. 870.5175 Section 870.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... enlarge the atrial septal defect found in the heart of certain infants. (b) Classification. Class...

  13. 21 CFR 870.5175 - Septostomy catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Septostomy catheter. 870.5175 Section 870.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... enlarge the atrial septal defect found in the heart of certain infants. (b) Classification. Class...

  14. 21 CFR 870.5175 - Septostomy catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Septostomy catheter. 870.5175 Section 870.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... enlarge the atrial septal defect found in the heart of certain infants. (b) Classification. Class...

  15. 21 CFR 870.5175 - Septostomy catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Septostomy catheter. 870.5175 Section 870.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... enlarge the atrial septal defect found in the heart of certain infants. (b) Classification. Class...

  16. 21 CFR 870.5175 - Septostomy catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Septostomy catheter. 870.5175 Section 870.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... enlarge the atrial septal defect found in the heart of certain infants. (b) Classification. Class...

  17. The risks and benefits of suprapubic catheters.

    PubMed

    Yates, Ann

    Suprapubic catheterisation can improve some patients' quality of life but the insertion procedure, as well as changing and managing the catheter, carry risks of infection and other negative patient outcomes. This article highlights the advantages and disadvantages, indications and contraindications, and the potential benefits, so health professionals can understand the relevant issues and assess and inform patients accordingly. PMID:27017651

  18. The single equivalent moving dipole model does not require spatial anatomical information to determine cardiac sources of activation.

    PubMed

    Sohn, Kwanghyun; Lv, Wener; Lee, Kichang; Galea, Anna M; Hirschman, Gordon B; Hayward, Alison M; Cohen, Richard J; Armoundas, Antonis A

    2014-01-01

    Radio-frequency catheter ablation (RCA) is an established treatment for ventricular tachycardia (VT). A key feature of the RCA procedure is the need for a mapping approach that facilitates the identification of the target ablation site. In this study, we investigate the effect of the location of the reference potential and spatial anatomical constraints on the accuracy of an algorithm to identify the target site for ablation therapy of VT. This algorithm involves processing body surface potentials using the single equivalent moving dipole (SEMD) model embedded in an infinite homogeneous volume conductor to model cardiac electrical activity. We employed a swine animal model and an electrode array of nine electrodes that was sutured on the epicardial surface of the right ventricle. We identified two potential reference electrode locations: at an electrode most far away from the heart (R1) and at the average of all 64 body surface electrode potentials (R2). Also, we developed three spatial "constraining" schemes of the algorithm used to obtain the SEMD location: one that does not impose any constraint on the inverse solution (S1), one that constrains the solution into a volume that corresponds to the heart (S2), and one that constrains the solution into a volume that corresponds to the body surface (S3). We have found that R2S1 is the most accurate approach (p < 0.05 versus R1S1 at earliest activation time-EAT) for localizing epicardial electrical sources of known locations in vivo. Although the homogeneous volume conductor introduces systematic error in the estimated compared to the true dipole location, we have observed that the overall error of the estimated interelectrode distance compared to the true one was 0.4 ± 0.4 cm and 0.4 ± 0.1 cm for the R1S1 and R2S1 combinations, respectively, at the EAT (p = N.S.) and 1.0 ± 0.6 and 0.5 ± 0.4 cm, respectively, at the pacing spike time (PST, ). In conclusion, our algorithm to estimate the SEMD parameters from body

  19. Causes and nursing countermeasures in pediatric PICC catheter complications.

    PubMed

    Xiang, Mingli; Li, Na; Yi, Lan; Liu, Bin

    2016-01-01

    To analyze the complications and nursing countermeasures of PICC (Peripherally Inserted Central Catheter) catheters using children PICC catheter technique 40 cases, complications were observed, and analyze the original causes, in order to propose a solution. There were 10 cases of catheter blockage, 5 cases of catheter infection, 6 cases of phlebitis, 5 cases of puncture difficulties, 2 cases of poor feeding tube, 2 cases of bleeding puncture site with the continuous exploration and research of nursing intervention, the production of clinical complications from PICC has been used in children were greatly reduced.

  20. Considerations in Catheter Retrieval From the Arterial System

    SciTech Connect

    Best, Irwin M Butler, Karin L; Bumpers, Harvey L

    2005-01-15

    Catheter-based techniques have become commonplace in the diagnosis and treatment of cardiovascular disease. Despite the significant improvements in materials and techniques, catheter separation or fracture may occur and result in catheter embolization or intravascular retention. We present such an occurrence during antegrade access to the common femoral artery. Although the sheared catheter was visualized fluoroscopically, attempts at percutaneous recovery were futile. Our findings at exploration confirmed total intravascular retention and impaction of the catheter. Practitioners should recognize this problem and avoid the dangers associated with percutaneous recovery.

  1. Retrospective analysis of risks associated with an umbilical artery catheter system for continuous monitoring of arterial oxygen tension.

    PubMed

    Cohen, R S; Ramachandran, P; Kim, E H; Glasscock, G F

    1995-01-01

    We reviewed retrospectively the incidence of complications encountered with two different umbilical artery catheters (UACs): a silicone-rubber end-hole catheter and an electrode-tipped, side-hole catheter for continuous, invasive monitoring of arterial oxygen tension (PaO2). During calendar year 1989, there were 457 admissions to the neonatal intensive care unit: 168 patients had placement of a UAC. Two of these were admitted only briefly for cardiac catheterization and were eliminated from analysis. One patient had both types of catheters placed sequentially. Thus the data on 166 patients with 51 PaO2 monitors and 116 silicone-rubber UACs were evaluated. The patients who had a PaO2 monitor UAC had a lower mean birth weight than those in the other group (1621 +/- 1043 gm vs 1972 +/- 1048 gm; p = 0.0473). The catheter life span was not different between the groups, with a range of 1 to 16 days for PaO2 monitors and 1 to 27 days for silicone-rubber UACs. Inability to withdraw blood, poor blood pressure tracing, or both conditions resulted in catheter removal for 5 of 51 PaO2 monitor UACs and 4 of 116 end-hole UACs. The incidence of these problems did not differ significantly between the two groups. There were no cases of thromboembolic complications in the patients who had a PaO2 monitor UAC, whereas two of the silicone-rubber UACs were removed because of perfusion problems in the lower limbs, which resolved with decannulation. We conclude that the use of the PaO2 monitor UAC allows for continuous, invasive monitoring of PaO2 without any significant increase in risk compared with that for the silicone-rubber end-hole UAC.

  2. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation.

    PubMed

    Kwiecinski, Wojciech; Bessière, Francis; Colas, Elodie Constanciel; N'Djin, W Apoutou; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-21

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8

  3. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation.

    PubMed

    Kwiecinski, Wojciech; Bessière, Francis; Colas, Elodie Constanciel; N'Djin, W Apoutou; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-21

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion's extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n = 11) and mapped (n = 7). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n = 2) and ventricular (left n = 1, right n = 1) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8

  4. Cardiac shear-wave elastography using a transesophageal transducer: application to the mapping of thermal lesions in ultrasound transesophageal cardiac ablation

    NASA Astrophysics Data System (ADS)

    Kwiecinski, Wojciech; Bessière, Francis; Constanciel Colas, Elodie; Apoutou N'Djin, W.; Tanter, Mickaël; Lafon, Cyril; Pernot, Mathieu

    2015-10-01

    Heart rhythm disorders, such as atrial fibrillation or ventricular tachycardia can be treated by catheter-based thermal ablation. However, clinically available systems based on radio-frequency or cryothermal ablation suffer from limited energy penetration and the lack of lesion’s extent monitoring. An ultrasound-guided transesophageal device has recently successfully been used to perform High-Intensity Focused Ultrasound (HIFU) ablation in targeted regions of the heart in vivo. In this study we investigate the feasibility of a dual therapy and imaging approach on the same transesophageal device. We demonstrate in vivo that quantitative cardiac shear-wave elastography (SWE) can be performed with the device and we show on ex vivo samples that transesophageal SWE can map the extent of the HIFU lesions. First, SWE was validated with the transesophageal endoscope in one sheep in vivo. The stiffness of normal atrial and ventricular tissues has been assessed during the cardiac cycle (n=11 ) and mapped (n= 7 ). Second, HIFU ablation has been performed with the therapy-imaging transesophageal device in ex vivo chicken breast samples (n  =  3), then atrial (left, n= 2 ) and ventricular (left n=1 , right n=1 ) porcine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. During the cardiac cycle stiffness varied from 0.5   ±   0.1 kPa to 6.0   ±   0.3 kPa in the atrium and from 1.3   ±   0.3 kPa to 13.5   ±   9.1 kPa in the ventricles. The thermal lesions were visible on all SWE maps performed after ablation. Shear modulus of the ablated zones increased to 16.3   ±   5.5 kPa (versus 4.4   ±   1.6 kPa before ablation) in the chicken breast, to 30.3   ±   10.3 kPa (versus 12.2   ±   4.3 kPa) in the atria and to 73.8   ±   13

  5. Distal end of the atrioventricular nodal artery predicts the risk of atrioventricular block during slow pathway catheter ablation of atrioventricular nodal re-entrant tachycardia

    PubMed Central

    Lin, J; Huang, S; Lai, L; Lin, L; Chen, J; Tseng, Y; Lien, W

    2000-01-01

    OBJECTIVE—To search for a reliable anatomical landmark within Koch's triangle to predict the risk of atrioventricular (AV) block during radiofrequency slow pathway catheter ablation of AV nodal re-entrant tachycardia (AVNRT).
PATIENTS AND METHODS—To test the hypothesis that the distal end of the AV nodal artery represents the anatomical location of the AV node, and thus could be a useful landmark for predicting the risk of AV block, 128 consecutive patients with AVNRT receiving slow pathway catheter ablation were prospectively studied in two phases. In phase I (77 patients), angiographic demonstration of the AV nodal artery and its ending was performed at the end of the ablation procedure, whereas in the subsequent phase II study (51 patients), the angiography was performed immediately before catheter ablation to assess the value of identifying this new landmark in reducing the risk of AV block. Multiple electrophysiologic and anatomical parameters were analysed. The former included the atrial activation sequence between the His bundle recording site (HBE) and the coronary sinus orifice or the catheter ablation site, either during AVNRT or during sinus rhythm. The latter included the spatial distances between the distal end of the AV nodal artery and the HBE and the final catheter ablation site, and the distance between the HBE and the tricuspid border at the coronary sinus orifice floor.
RESULTS—In phase I, nine of the 77 patients had complications of transient (seven patients) or permanent (two patients) complete AV block during stepwise, anatomy guided slow pathway catheter ablation. These nine patients had a wider distance between the HBE and the distal end of the AV nodal artery, and a closer approximation of the catheter ablation site to the distal end of the AV nodal artery, which independently predicted the risk of AV block. In contrast, none of the available electrophysiologic parameters were shown to be reliable. When the distance between

  6. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective

    PubMed Central

    Klimas, Aleksandra; Entcheva, Emilia

    2014-01-01

    Abstract. The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo. PMID:25117076

  7. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective.

    PubMed

    Klimas, Aleksandra; Entcheva, Emilia

    2014-08-01

    The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.

  8. Toward microendoscopy-inspired cardiac optogenetics in vivo: technical overview and perspective

    NASA Astrophysics Data System (ADS)

    Klimas, Aleksandra; Entcheva, Emilia

    2014-08-01

    The ability to perform precise, spatially localized actuation and measurements of electrical activity in the heart is crucial in understanding cardiac electrophysiology and devising new therapeutic solutions for control of cardiac arrhythmias. Current cardiac imaging techniques (i.e. optical mapping) employ voltage- or calcium-sensitive fluorescent dyes to visualize the electrical signal propagation through cardiac syncytium in vitro or in situ with very high-spatiotemporal resolution. The extension of optogenetics into the cardiac field, where cardiac tissue is genetically altered to express light-sensitive ion channels allowing electrical activity to be elicited or suppressed in a precise cell-specific way, has opened the possibility for all-optical interrogation of cardiac electrophysiology. In vivo application of cardiac optogenetics faces multiple challenges and necessitates suitable optical systems employing fiber optics to actuate and sense electrical signals. In this technical perspective, we present a compendium of clinically relevant access routes to different parts of the cardiac electrical conduction system based on currently employed catheter imaging systems and determine the quantitative size constraints for endoscopic cardiac optogenetics. We discuss the relevant technical advancements in microendoscopy, cardiac imaging, and optogenetics and outline the strategies for combining them to create a portable, miniaturized fiber-based system for all-optical interrogation of cardiac electrophysiology in vivo.

  9. Cardiac conduction system

    MedlinePlus

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals ... to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle ...

  10. Chronic peritoneal dialysis catheters: challenges and design solutions.

    PubMed

    Ash, S R

    2006-01-01

    Although highly successful as transcutaneous access devices, today's peritoneal dialysis catheters still have imperfect hydraulic function, biocompatibility and resistance to infection. Success of Tenckhoff catheters is greatly improved by the proper positioning of deep and subcutaneous cuffs and intraperitoneal segment. Newer peritoneal catheter designs are intended to improve hydraulic function, avoid outflow failure, and diminish exit site infection. These catheter designs serve as excellent alternatives for patients with various types of failure of Tenckhoff catheters. Catheters have been designed for Continuous Flow Peritoneal Dialysis, and have generally been successful in providing high peritoneal dialysis flow rate, but not always successful in optimally distributing flow of peritoneal fluid. Improvements in catheter design may expand the use of peritoneal dialysis as a successful home dialysis therapy. PMID:16485243

  11. Catheter-based high-intensity ultrasound for epicardial ablation of the left ventricle: device design and in vivo feasiblity

    NASA Astrophysics Data System (ADS)

    Salgaonkar, Vasant A.; Nazer, Babak; Jones, Peter D.; Tanaka, Yasuaki; Martin, Alastair; Ng, Bennett; Duggirala, Srikant; Diederich, Chris J.; Gerstenfeld, Edward P.

    2015-03-01

    The development and in vivo testing of a high-intensity ultrasound thermal ablation catheter for epicardial ablation of the left ventricle (LV) is presented. Scar tissue can occur in the mid-myocardial and epicardial space in patients with nonischemic cardiomyopathy and lead to ventricular tachycardia. Current ablation technology uses radiofrequency energy, which is limited epicardially by the presence of coronary vessels, phrenic nerves, and fat. Ultrasound energy can be precisely directed to deliver targeted deep epicardial ablation while sparing intervening epicardial nerve and vessels. The proof-of-concept ultrasound applicators were designed for sub-xyphoid access to the pericardial space through a steerable 14-Fr sheath. The catheter consists of two rectangular planar transducers, for therapy (6.4 MHz) and imaging (5 MHz), mounted at the tip of a 3.5-mm flexible nylon catheter coupled and encapsulated within a custom-shaped balloon for cooling. Thermal lesions were created in the LV in a swine (n = 10) model in vivo. The ultrasound applicator was positioned fluoroscopically. Its orientation and contact with the LV were verified using A-mode imaging and a radio-opaque marker. Ablations employed 60-s exposures at 15 - 30 W (electrical power). Histology indicated thermal coagulation and ablative lesions penetrating 8 - 12 mm into the left ventricle on lateral and anterior walls and along the left anterior descending artery. The transducer design enabled successful sparing from the epicardial surface to 2 - 4 mm of intervening ventricle tissue and epicardial fat. The feasibility of targeted epicardial ablation with catheter-based ultrasound was demonstrated.

  12. Catheter-based intervention for pulmonary vein stenosis due to fibrosing mediastinitis: The Mayo Clinic experience

    PubMed Central

    Ponamgi, Shiva P.; DeSimone, Christopher V.; Lenz, Charles J.; Coylewright, Megan; Asirvatham, Samuel J.; Holmes, David R.; Packer, Douglas L.

    2016-01-01

    Introduction Fibrosing mediastinitis (FM) is a rare but fatal disease characterized by an excessive fibrotic reaction in the mediastinum, which can lead to life-threatening stenosis of the pulmonary veins (PV). Catheter-based intervention is currently the only viable option for therapy. However, the current literature on how best to manage these difficult cases, especially in regards to sequential interventions and their potential complications is very limited. Methods We searched through a database of all patients who have undergone PV interventions at the Earl H. Wood Cardiac Catheterization Laboratory in Mayo Clinic, Rochester. From this collection, we selected patients that underwent PV intervention to relieve stenosis secondary to FM. Results Eight patients were identified, with a mean age of 41 years (24–59 years). Five were men, and three were women. Three patients underwent balloon angioplasty alone, and five patients had stents placed. The majority of patients had acute hemodynamic and symptomatic improvement. More than one intervention was required in five patients, four patients had at least one episode of restenosis, and four patients died within four weeks of their first PV intervention. Conclusions We describe the largest reported case series of catheter-based intervention for PV stenosis in FM. Although catheter-based therapy improved hemodynamics, short-term vascular patency, and patient symptoms, the rate of life-threatening complications, restenosis, and mortality associated with these interventions was found to be high. Despite these associated risks, catheter-based intervention is the only palliative option available to improve quality of life in severely symptomatic patients with PV stenosis and FM. Patients with PV stenosis and FM (especially those with bilateral disease) have an overall poor prognosis in spite of undergoing these interventions due to the progressive and recalcitrant nature of the disease. This underscores the need for

  13. The optimal radiofrequency temperature in radiofrequency thermocoagulation for idiopathic trigeminal neuralgia

    PubMed Central

    Tang, Yuan-Zhang; Yang, Li-Qiang; Yue, Jian-Ning; Wang, Xiao-Ping; HE, Liang-Liang; NI, Jia-Xiang

    2016-01-01

    Abstract Objective: Our previous study evaluated the effectiveness and safety of radiofrequency thermocoagulation (RFT) of trigeminal gasserian ganglion for idiopathic trigeminal neuralgia (ITN). The aim of this study was to evaluate the optimal radiofrequency temperature of computed tomography (CT)-guided RFT for treatment of ITN. Methods: A retrospective study of patients with ITN treated with a single CT-guided RFT procedure between January 2002 and December 2013. Patients were divided into ≤75 °C, 75 °C, and ≥80 °C groups according to the highest radiofrequency temperature used. Pain relief was graded from poor to excellent, and facial numbness/dysesthesia from I (absent) to IV (most severe). Results: A total of 1161 RFT procedures were undertaken in the 1137 patients. The mean follow-up time was 46 ± 31 months. There were no significant differences in the rate of excellent pain relief according to the radiofrequency temperature used. However, more patients experienced with no facial numbness or facial numbness gradually resolved and those patients treated at 75 °C had a lower rate of grade IV facial numbness/dysesthesia than other groups. Conclusions: The optimal radiofrequency temperature to maximize pain relief and minimize facial numbness or dysesthesia may be 75 °C, but this requires confirmation. PMID:27428194

  14. Translational aspects of cardiac cell therapy

    PubMed Central

    Chen, Cheng-Han; Sereti, Konstantina-Ioanna; Wu, Benjamin M; Ardehali, Reza

    2015-01-01

    Cell therapy has been intensely studied for over a decade as a potential treatment for ischaemic heart disease. While initial trials using skeletal myoblasts, bone marrow cells and peripheral blood stem cells showed promise in improving cardiac function, benefits were found to be short-lived likely related to limited survival and engraftment of the delivered cells. The discovery of putative cardiac ‘progenitor’ cells as well as the creation of induced pluripotent stem cells has led to the delivery of cells potentially capable of electromechanical integration into existing tissue. An alternative strategy involving either direct reprogramming of endogenous cardiac fibroblasts or stimulation of resident cardiomyocytes to regenerate new myocytes can potentially overcome the limitations of exogenous cell delivery. Complimentary approaches utilizing combination cell therapy and bioengineering techniques may be necessary to provide the proper milieu for clinically significant regeneration. Clinical trials employing bone marrow cells, mesenchymal stem cells and cardiac progenitor cells have demonstrated safety of catheter based cell delivery, with suggestion of limited improvement in ventricular function and reduction in infarct size. Ongoing trials are investigating potential benefits to outcome such as morbidity and mortality. These and future trials will clarify the optimal cell types and delivery conditions for therapeutic effect. PMID:26119413

  15. Diagnosis and treatment of cardiac sarcoidosis.

    PubMed

    Kusano, Kengo F; Satomi, Kazuhiro

    2016-02-01

    Sarcoidosis is a systemic granulomatous disease of unknown aetiology. The frequency of cardiac involvement (cardiac sarcoidosis (CS)) varies in the different geographical regions, but it has been reported that it is an absolutely important prognostic factor in this disease. Complete atrioventricular block is the most common, and ventricular tachycardia/ventricular fibrillation the second most common arrhythmia in this disease, both of which are associated with cardiac sudden death. Diagnosing CS is sometimes difficult because of the non-specific ECG and echocardiographic findings, and CS is sometimes misdiagnosed as dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or an idiopathic ventricular aneurysm, and therefore, endomyocardial biopsy is important, but has a low sensitivity. Another problem is the recognition of isolated types of CS. Recently, MRI and (18)F-fluorodeoxyglucose positron emission tomography have been demonstrated to be useful tools for the non-invasive diagnosis of CS as well as therapeutic evaluation tools, but are still unsatisfactory. Treatment of CS is usually done by corticosteroid therapy to control inflammation, prevent fibrosis and protect from any deterioration of the cardiac function, but the long-term outcome is still in debate. Despite the advancement of non-pharmacological approaches for CS (pacing, defibrillators and catheter ablation) to improve the prognosis, there are still many issues remaining to resolve diagnosing and managing CS. Here, we attempt a review of the clinical evidence, with special focus on the current understanding of this disease and showing the current strategies and remaining problems of diagnosing and managing CS. PMID:26643814

  16. Bilateral vision loss associated with radiofrequency exposure

    PubMed Central

    Liu, Dianna; Cruz, Franz Marie; Subramanian, Prem S

    2012-01-01

    A 57-year-old otherwise healthy woman presented with painless binocular vision loss 1 week after direct application of radiofrequency energy to her orbits. She had no light perception bilaterally. Pupils were dilated and not reactive to light. Fundoscopic exam initially showed optic disc swelling in the right eye and a normal-appearing disc in the left eye. Magnetic resonance imaging of the brain and orbits showed gadolinium enhancement of both intraorbital optic nerves. She underwent a course of high-dose steroid treatment without recovery of vision. Optic discs were pale 11 weeks after injury. With exclusion of other possible causes, this represents a unique case of irreversible binocular optic nerve damage and blindness secondary to radiofrequency exposure. PMID:23271888

  17. Pulmonary radiofrequency ablation (Part 1): current state.

    PubMed

    Plasencia Martínez, J M

    2015-01-01

    The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence. PMID:25766072

  18. Fraxelated radiofrequency device for acne scars

    NASA Astrophysics Data System (ADS)

    Rao, Babar K.; Khokher, Sairah

    2012-09-01

    Acne scars can be improved with various treatments such as topical creams, chemical peels, dermal fillers, microdermabrasion, laser, and radiofrequency devices. Some of these treatments especially lasers and deep chemical peels can have significant side effects such as post inflammatory hyperpigmentation in darker skin types. Fraxelated RF Laser devices have been reported to have lower incidence of side effects in all skin phototypes. Nine patients between ages 18 and 35 of various skin phototypes were selected from a private practice and treated with a RF fraxelated device (E-matrix) for acne scars. Outcomes were measured by physician observation, subjective feedback received by patients, and comparison of before and after photographs. In this small group of patients with various skin phototypes, fraxelated radiofrequency device improved acne scars with minimal side effects and downtime.

  19. Pulmonary radiofrequency ablation (Part 1): current state.

    PubMed

    Plasencia Martínez, J M

    2015-01-01

    The risks involved in surgical treatment and conventional radiotherapy in patients with early lung cancer or lung metastases often make these treatments difficult to justify. However, on the other hand, it is also unacceptable to allow these lesions to evolve freely because, left untreated, these neoplasms will usually lead to the death of the patient. In recent years, alternative local therapies have been developed, such as pulmonary radiofrequency ablation, which has proven to increase survival with a minimal risk of complications. There are common recommendations for these treatments, and although the specific indications for using one technique or another have yet to be established, there are clearly defined situations that will determine the outcome of the treatment. It is important to know these situations, because appropriate patient selection is essential for therapeutic success. This article aims to describe the characteristics and constraints of pulmonary radiofrequency ablation and to outline its role in thoracic oncology in light of the current evidence.

  20. Radiofrequency-oxidation treatment of sewage sludge.

    PubMed

    Srinivasan, Asha; Young, Chris; Liao, Ping H; Lo, Kwang V

    2015-12-01

    A novel thermal-chemical treatment technology using radiofrequency heating and oxidants (hydrogen peroxide, ozone and a combination of both) was used for the treatment of sewage sludge. This was to evaluate the process effectiveness on cell disintegration and nutrient release of sludge, physical property changes such as particle size distribution, dewaterability and settleability, and their inter-relationships. The effectiveness of treatment processes was in the following order, from the most to least: thermal-oxidation process, oxidation process and thermal process. The thermal-oxidation process greatly increased cell disintegration and nutrient release, improved settleability, and decreased particle sizes. The treatment scheme involving ozone addition followed by hydrogen peroxide and radiofrequency heating yielded the highest soluble chemical oxygen demand, volatile fatty acids, ammonia and metals, while proffering the shortest capillary suction time and excellent settling properties. PMID:26233925

  1. A Three-Dimensional Shape-Based Force and Stiffness-Sensing Platform for Tendon-Driven Catheters.

    PubMed

    Kouh Soltani, Minou; Khanmohammadi, Sohrab; Ghalichi, Farzan

    2016-01-01

    This paper presents an efficient shape-based three-axial force and stiffness estimator for active catheters commonly implemented in cardiac ablation. The force-sensing capability provides important feedback for catheterization procedures including real-time control and catheter steering in autonomous navigation systems. The proposed platform is based on the introduced accurate and computationally efficient Cosserat rod model for tendon-driven catheters. The proposed nonlinear Kalman filter formulation for contact force estimation along with the developed catheter model provides a real-time force observer robust to nonlinearities and noise covariance uncertainties. Furthermore, the proposed platform enables stiffness estimation in addition to tip contact force sensing in different operational circumstances. The approach incorporates pose measurements which can be achieved using currently developed pose-sensing systems or imaging techniques. The method makes the approach compatible with the range of forces applied in clinical applications. The simulation and experimental results verify the viability of the introduced force and stiffness-sensing technique. PMID:27367685

  2. A Three-Dimensional Shape-Based Force and Stiffness-Sensing Platform for Tendon-Driven Catheters

    PubMed Central

    Kouh Soltani, Minou; Khanmohammadi, Sohrab; Ghalichi, Farzan

    2016-01-01

    This paper presents an efficient shape-based three-axial force and stiffness estimator for active catheters commonly implemented in cardiac ablation. The force-sensing capability provides important feedback for catheterization procedures including real-time control and catheter steering in autonomous navigation systems. The proposed platform is based on the introduced accurate and computationally efficient Cosserat rod model for tendon-driven catheters. The proposed nonlinear Kalman filter formulation for contact force estimation along with the developed catheter model provides a real-time force observer robust to nonlinearities and noise covariance uncertainties. Furthermore, the proposed platform enables stiffness estimation in addition to tip contact force sensing in different operational circumstances. The approach incorporates pose measurements which can be achieved using currently developed pose-sensing systems or imaging techniques. The method makes the approach compatible with the range of forces applied in clinical applications. The simulation and experimental results verify the viability of the introduced force and stiffness-sensing technique. PMID:27367685

  3. Radiofrequency tonsillotomy in Sweden 2009-2012.

    PubMed

    Sunnergren, Ola; Hemlin, Claes; Ericsson, Elisabeth; Hessén-Söderman, Anne-Charlotte; Hultcrantz, Elisabeth; Odhagen, Erik; Stalfors, Joacim

    2014-06-01

    The Swedish National Registry for Tonsil Surgery has been operational since 1997. All ENT clinics in Sweden are encouraged to submit data for all patients scheduled for tonsil surgery. Preoperatively, age, gender and indication are recorded. Postoperatively, method (tonsillectomy or tonsillotomy), technique, and perioperative complications are recorded. Postoperative bleedings, pain, infections, and symptom relief are assessed through questionnaires. An earlier report from this registry showed that tonsillotomy had become more common than tonsillectomy in children with tonsil-related upper airway obstruction. The aim of this study was to categorize which instruments were used for tonsillotomy in Sweden and to compare their outcome and complication rate. All children 2-18 years, reported to the registry from March 2009 until September 2012, who underwent tonsillotomy on the indication upper airway obstruction, were included in the study. 1,676 patients were identified. In 1,602 cases (96%), a radiofrequency instrument was used. The postoperative bleeding rate was low (1.2%) and the degree of symptom relief was high (95.1%). Three different radiofrequency instruments (ArthroCare Coblation(®), Ellman Surgitron(®), and Sutter CURIS(®)) were used in 96% of the patients. There were no significant differences in the number of postoperative bleedings, postoperative infections or symptom relief between the instruments. The only difference found was in the number of days on analgesics, where more days were registered after use of Coblation(®). In Sweden, radiofrequency tonsillotomy is the dominant surgical technique used for tonsil hypertrophy causing upper airway obstruction in children. There are no significant differences in outcome between the different radiofrequency instruments except for number of days on analgesics after surgery.

  4. Superconducting surface impedance under radiofrequency field

    DOE PAGESBeta

    Xiao, Binping P.; Reece, Charles E.; Kelley, Michael J.

    2013-04-26

    Based on BCS theory with moving Cooper pairs, the electron states distribution at 0K and the probability of electron occupation with finite temperature have been derived and applied to anomalous skin effect theory to obtain the surface impedance of a superconductor under radiofrequency (RF) field. We present the numerical results for Nb and compare these with representative RF field-dependent effective surface resistance measurements from a 1.5 GHz resonant structure.

  5. Oleanolic acid alleviated pressure overload-induced cardiac remodeling.

    PubMed

    Liao, Hai-Han; Zhang, Nan; Feng, Hong; Zhang, Ning; Ma, Zhen-Guo; Yang, Zheng; Yuan, Yuan; Bian, Zhou-Yan; Tang, Qi-Zhu

    2015-11-01

    Previous study has demonstrated that oleanolic acid (OA) possessing the anti-inflammatory and anti-oxidant properties blunted high-glucose-induced diabetic cardiomyopathy and ameliorated experimental autoimmune myocarditis in mice. However, little is known about its effects on pressure overload-induced cardiac remodeling. Herein, we investigated the effect of OA on cardiac remodeling and underlying mechanism. Mice, subjected to aortic banding (AB), were randomly assigned into control group and experimental group. OA premixed in diets was administered to mice after 3 days of AB. Echocardiography and catheter-based measurements of hemodynamic parameters were performed after 8 weeks' treatment of OA. Histologic examination and molecular analyses were used to assess cardiac hypertrophy and tissue fibrosis. In addition, the inhibitory effects of OA on H9c2 cardiomyocytes and cardiac primary fibroblast responded to the stimulation of AngII were also investigated. OA ameliorated the systolic and diastolic dysfunction induced by pressure overload evidenced by echocardiography and catheter-based measurements. OA also decreased the mRNA expression of cardiac hypertrophy and fibrosis markers evidenced by RT-PCR. It has been shown in our study that pressure overload activated the phosphorylations of Akt, mTOR, p70s6k, S6, GSK3β, and FoxO3a, and treatment of OA attenuated the phosphorylation of these proteins. In addition, hypertrophy of cardiomyocytes and fibrosis markers induced by AngII was inhibited by OA in vitro. Our findings uncover that OA suppressed AB-induced cardiac hypertrophy, partly by inhibiting the activity of Akt/mTOR pathway, and suggest that treatment of OA may have a benefit on retarding the progress of cardiac remodeling under long terms of pressure overload. PMID:26215454

  6. [Inferior vena cava thrombosis reaching the right atrium after removal of the central venous catheter at femoral vein in a patient with diabetic ketoacidosis].

    PubMed

    Morita, Yoko; Ariyama, Jun; Mieda, Tsutomu; Terao, Kazuhisa; Ueshima, Hironobu; Imanishi, Hirokazu; Kitamura, Akira

    2014-05-01

    A 19-year-old male was admitted with diabetic ketoacidosis. A central venous catheter for fluid loading and insulin administration was inserted from the right femoral vein. The catheter was placed for 4days and was removal. Three days after removal thrombus was pointed out with echocardiography. Cardiac ultrasound revealed floating thrombi in the right atrium. Venography demonstrated a large thrombus from the right femoral vein to the end of the inferior vena cava. Emergency surgery was performed. A tubular thrombus was trapped from the inferior vena cava departure at the right atrium under cardiopulmonary bypass. The surgeon also implanted an inferior vena caval filter. The patient was weaned from ventilator assist next day and was discharged from the hospital 13 days later. This case suggests that deep vein thrombosis should be checked in diabetic ketoacidosis even after removal of a central venous catheter implanted at the femoral vein.

  7. Radiofrequency Microtenotomy for Elbow Epicondylitis: Midterm Results.

    PubMed

    Tasto, James P; Richmond, John M; Cummings, Jeffrey R; Hardesty, Renee; Amiel, David

    2016-01-01

    We conducted a prospective, nonrandomized, single-center clinical study to evaluate the safety and midterm effectiveness of microtenotomy using a radiofrequency probe to treat chronic tendinosis of the elbow. All patients had failed conservative treatment for 6 months. The radiofrequency-based microtenotomy was performed using the Topaz Microdebrider (ArthroCare). Patients were followed annually for up to 9 years postoperatively. Pain status was documented using a visual analog scale self-reported measure. Eighty consecutive patients with tendinosis of the elbow were enrolled; 69 patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The duration of follow-up ranged from 6 months to 9 years (mean, 2.5 years). Ninety-one percent of the patients reported a successful outcome. Within the lateral epicondylitis group, the preoperative visual analog scale improved from 6.9 to 1.3 postoperatively and demonstrated an 81% improvement (P ≤ .01). For the medial epicondylitis patients, the preoperative visual analog scale improved from 6.1 to 1.3 after surgery, a 79% improvement (P ≤ .01). No complications were reported. Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed at 9 years after surgery.

  8. Radiofrequency Microtenotomy for Elbow Epicondylitis: Midterm Results.

    PubMed

    Tasto, James P; Richmond, John M; Cummings, Jeffrey R; Hardesty, Renee; Amiel, David

    2016-01-01

    We conducted a prospective, nonrandomized, single-center clinical study to evaluate the safety and midterm effectiveness of microtenotomy using a radiofrequency probe to treat chronic tendinosis of the elbow. All patients had failed conservative treatment for 6 months. The radiofrequency-based microtenotomy was performed using the Topaz Microdebrider (ArthroCare). Patients were followed annually for up to 9 years postoperatively. Pain status was documented using a visual analog scale self-reported measure. Eighty consecutive patients with tendinosis of the elbow were enrolled; 69 patients were treated for lateral epicondylitis and 11 for medial epicondylitis. The duration of follow-up ranged from 6 months to 9 years (mean, 2.5 years). Ninety-one percent of the patients reported a successful outcome. Within the lateral epicondylitis group, the preoperative visual analog scale improved from 6.9 to 1.3 postoperatively and demonstrated an 81% improvement (P ≤ .01). For the medial epicondylitis patients, the preoperative visual analog scale improved from 6.1 to 1.3 after surgery, a 79% improvement (P ≤ .01). No complications were reported. Radiofrequency-based microtenotomy is a safe and effective procedure for elbow epicondylitis. The results are durable with successful outcomes observed at 9 years after surgery. PMID:26761915

  9. [Complications related to epidural catheter in caesarean delivery].

    PubMed

    Leykin, Y; Lucca, M

    2001-09-01

    A review of complications related to epidural catheters in caesarean delivery is presented. Catheters for prolongation of nerve blocks were first used in 1940s. Thereafter, there has been steady development in the design and plastic material technology of the different catheters. In the last decade the regional anaesthesia for caesarean section became very popular, as well as continuous increase in the use of epidural catheters. The anatomical changes of pregnancy like marked distension of the epidural veins resulted in increased risk of the complications due to the epidural catheter placement. It is likely that permanent neurologic sequelae due to regional anaesthesia in obstetrics almost never occur, while minor self-limiting complications do occur. The possible complications of epidural catheter techniques are: trauma, malposition and migration of the catheter, knotting and breaking, radiculopathy, dural puncture, subdural injection, abscess and infection, haematoma and wrong solution injection. Most of the malpositions of the epidural catheter can be avoided by a careful technique, advancing the catheter with no forceful movement and not more than 3 to 4 cm into epidural space. Broken parts of the catheters should be left as a rule within the spinal space. Test dose should be always done for continuous epidural anaesthesia. Early diagnosis and prompt appropriate treatment will usually lead to complete resolution of the neurological deficit even in cases of epidural haematoma or abscess.

  10. Pancreas tumor interstitial pressure catheter measurement

    NASA Astrophysics Data System (ADS)

    Nieskoski, Michael D.; Gunn, Jason; Marra, Kayla; Trembly, B. Stuart; Pogue, Brian W.

    2016-03-01

    This paper highlights the methodology in measuring interstitial pressure in pancreatic adenocarcinoma tumors. A Millar Mikrotip pressure catheter (SPR-671) was used in this study and a system was built to amplify and filter the output signal for data collection. The Millar pressure catheter was calibrated prior to each experiment in a water column at 37°C, range of 0 to 60 inH2O (112 mmHg), resulting in a calibration factor of 33 mV / 1 inH2O. The interstitial pressures measured in two orthotopically grown pancreatic adenocarcinoma tumor were 57 mmHg and 48 mmHg, respectively. Verteporfin uptake into the pancreatic adenocarcinoma tumor was measured using a probe-based experimental dosimeter.

  11. Soft Robotic Concepts in Catheter Design: an On-demand Fouling-release Urinary Catheter

    PubMed Central

    Leveri, Vrad; Wang, Qiming; Shivapooja, Phanindhar; Zhao, Xuanhe; L00F3;pez, Gabriel P.

    2014-01-01

    Infectious biofilms are problematic in many healthcare-related devices, and are especially challenging and ubiquitous in urinary catheters. This report presents an on-demand fouling-release methodology to mechanically disrupt and remove biofilms, and proposes this method for the active removal of infectious biofilms from the previously-inaccessible main drainage lumen of urinary catheters. Mature Proteus mirabilis crystalline biofilms detach from silicone elastomer substrates upon application of strain to the substrate, and increasing the strain rate increases biofilm detachment. The study presents a quantitative relationship between applied strain rate and biofilm debonding through an analysis of biofilm segment length and the driving force for debonding. Based on this mechanism, hydraulic and pneumatic elastomer actuation was used to achieve surface strain selectively within the lumen of prototypes of sections of a fouling-release urinary catheter. Proof-of-concept prototypes of sections of active, fouling-release catheters were constructed using techniques typical to soft robotics including 3D printing and replica molding, and those prototypes demonstrate release of mature P. mirabilis crystalline biofilms (e.g., ≈90%) from strained surfaces. These results provide a basis for the development of a new urinary catheter technology in which infectious biofilms are effectively managed through new methods that are entirely complementary to existing approaches. PMID:24668920

  12. Incidence of phlebitis associated with the use of peripheral IV catheter and following catheter removal

    PubMed Central

    Urbanetto, Janete de Souza; Peixoto, Cibelle Grassmann; May, Tássia Amanda

    2016-01-01

    ABSTRACT Objective: to investigate the incidence of phlebitis and its association with risk factors when using peripheral IV catheters (PIC) and following their removal - (post-infusion phlebitis) in hospitalized adults. Method: a cohort study of 171 patients using PIC, totaling 361 punctures. Sociodemographic variables and variables associated with the catheter were collected. Descriptive and analytical statistical analyses were performed. Results: average patient age was 56.96 and 51.5% of the sample population was male. The incidence of phlebitis was 1.25% while using PIC, and 1.38% post-infusion. The incidence of phlebitis while using PIC was associated with the length of time the catheter remained in place, whereas post-infusion phlebitis was associated with puncture in the forearm. Ceftriaxone, Clarithromycin and Oxacillin are associated with post-infusion phlebitis. Conclusions: this study made it possible to investigate the association between risk factors and phlebitis during catheter use and following its removal. The frequency of post-infusion phlebitis was larger than the incidence of phlebitis with the catheter in place, with Phlebitis Grade III and II being the most frequently found in each of these situations, respectively. Aspects related to post-infusion phlebitis can be explained, given the limited number of studies addressing this theme from this perspective. PMID:27508916

  13. Soft robotic concepts in catheter design: an on-demand fouling-release urinary catheter.

    PubMed

    Levering, Vrad; Wang, Qiming; Shivapooja, Phanindhar; Zhao, Xuanhe; López, Gabriel P

    2014-10-01

    Infectious biofilms are problematic in many healthcare-related devices and are especially challenging and ubiquitous in urinary catheters. This report presents an on-demand fouling-release methodology to mechanically disrupt and remove biofilms, and proposes this method for the active removal of infectious biofilms from the previously inaccessible main drainage lumen of urinary catheters. Mature Proteus mirabilis crystalline biofilms detach from silicone elastomer substrates upon application of strain to the substrate, and increasing the strain rate increases biofilm detachment. The study presents a quantitative relationship between applied strain rate and biofilm debonding through an analysis of biofilm segment length and the driving force for debonding. Based on this mechanism, hydraulic and pneumatic elastomer actuation is used to achieve surface strain selectively within the lumen of prototypes of sections of a fouling-release urinary catheter. Proof-of-concept prototypes of sections of active, fouling-release catheters are constructed using techniques typical to soft robotics including 3D printing and replica molding, and those prototypes demonstrate release of mature P. mirabilis crystalline biofilms (e.g., ≈90%) from strained surfaces. These results provide a basis for the development of a new urinary catheter technology in which infectious biofilms are effectively managed through new methods that are entirely complementary to existing approaches. PMID:24668920

  14. Enteral alimentation using fluoroscopically placed catheters.

    PubMed

    Rutledge, R; Buckwalter, J A

    1983-09-01

    Proximal gastrointestinal disease or injury that prevents adequate enteral alimentation is a difficult management problem. Recently, total parenteral nutrition has been shown to be important in maintaining these patients and the management of these problems. However, central intravenous hyperalimentation is associated with well-described problems and has other advantages. This article describes a technique for catheterizing a distal portion of the gastrointestinal tract for the provision of adequate enteral alimentation using an angiographic catheter and fluoroscopy.

  15. Flow Structure Associated with Hemodialysis Catheters

    NASA Astrophysics Data System (ADS)

    Foust, Jason

    2005-11-01

    Insertion of a hemodialysis catheter into the superior vena cava (SVC) gives rise to complex flow patterns, which arise from the simultaneous injection and extraction of blood through different holes (ports) of the catheter. Techniques of high-image-density particle image velocimetry are employed in a scaled-up water facility. This approach allows characterization of both the instantaneous and time-averaged flow structure due to generic classes of side hole geometries. The trajectory of the injection jet is related to the ratio of the initial jet velocity to the mainstream velocity through the SVC, and to the type of distortion of the jet cross-section. Furthermore, the mean and fluctuating velocity and vorticity fields are determined. Significant turbulent stresses develop rapidly in the injection jet, which can impinge upon the wall of the simulated SVC. Immediately downstream of the injection hole, a recirculation cell of low velocity exists adjacent to the catheter surface. These and other representations of the flow structure are first evaluated for a steady throughflow, then for the case of a pulsatile waveform in the SVC, which matches that of a normal adult.

  16. Catheter ablation of recurrent polymorphic tachycardia: Use of sodium channel blockade to organize the tachycardia: A case report

    PubMed Central

    Saggu, Daljeet Kaur; Nair, Sandeep G.; Shelke, Abhijeet; Yalagudri, Sachin; Narasimhan, Calambur

    2015-01-01

    A 55 year old male presented with recurrent implantable cardioverter defibrillator (ICD) shocks due to polymorphic ventricular tachycardia (PMVT). He had undergone prior catheter ablation for VT three years ago. During the prior attempt he underwent voltage guided substrate ablation. With programmed ventricular extrastimulation (PVES), PMVT was repeatedly induced requiring DC shock. Intravenous procainamide was administered and PVES was repeated which induced sustained monomorphic ventricular tachycardia (MMVT). This VT had pseudo delta waves with maximum deflection index of 0.68, suggestive of epicardial origin. Activation mapping was performed epicardially. Presystolic potentials were recorded in mid anterolateral wall of left ventricular epicardial region. Radiofrequency (RF) ablation at this site terminated the VT. Post ablation there was no inducible tachycardia and patient is free of arrhythmias during 2 years of follow-up. PMID:27479202

  17. Comparison between qualitative and semiquantitative catheter-tip cultures: laboratory diagnosis of catheter-related infection in newborns

    PubMed Central

    Marconi, Camila; de Lourdes RS Cunha, Maria; Lyra, João C; Bentlin, Maria R; Batalha, Jackson EN; Sugizaki, Maria Fátima; Rugolo, Lígia MSS

    2008-01-01

    This prospective study evaluated semiquantitative and qualitative catheter-culture methods for diagnosis of catheter-related infection (CRI) in newborns. Catheter tips from newborns admitted to the Neonatal Unit of the University Hospital of the Botucatu Medical School, UNESP were included in the study. Catheter cultures were performed with both semiquantitative and qualitative techniques. For CRI diagnosis, microorganisms isolated from catheter cultures and from peripheral blood cultures were identified and submitted to agent susceptibility test. The gold standard was the certain CRI diagnosis when same microorganism (specie and profile of susceptibility to agents) was isolated from both catheter tips and peripheral blood culture. A total of 85 catheters from 63 newborns were included in the study. The semiquantitative culture method, despite presenting lower sensitivity (90%), showed higher specificity (71%) when compared to 100% of sensitivity and 60% of specificity in the qualitative method. The identification of the microorganisms obtained from the catheter cultures showed a prevalence of coagulase-negative staphylococci (CNS) species. The specie Staphylococcus epidermidis (77.5%) was the prevalent in the catheters with positive semiquantitative cultures. Among 11 episodes with CRI diagnosis, 8 (72.7%) were associated with CNS species, of which 6 were S. epidermidis. Two episodes of CRI by S. aureus and one by Candida parapsilosis were also detected. The semiquantitative catheter-culture method showed advantages for CRI diagnosis in newborns when compared to the conservative qualitative method. PMID:24031213

  18. A comparison of the microbiologic profile of indwelling versus external urinary catheters.

    PubMed

    Grigoryan, Larissa; Abers, Michael S; Kizilbash, Quratulain F; Petersen, Nancy J; Trautner, Barbara W

    2014-06-01

    We studied the microbiology reports of urine cultures collected from external (condom catheters) versus indwelling (Foley) catheters. The equal prevalence of Enterobacteriaceae and Enterococci in samples from both catheter types calls into question the practice of switching from indwelling to external catheters to decrease catheter-associated bacteriuria.

  19. Does Heparin Coating Improve Patency or Reduce Infection of Tunneled Dialysis Catheters?

    PubMed Central

    Jain, Gaurav; Allon, Michael; Saddekni, Souheil; Barker, Jill-Finkel

    2009-01-01

    Background and objectives: Tunneled dialysis catheters are prone to frequent malfunction and infection. Catheter thrombosis occurs despite prophylactic anticoagulant locks. Catheter thrombi may also serve as a nidus for catheter infection, thereby increasing the risk of bacteremia. Thus, heparin coating of catheters may reduce thrombosis and infection. This study evaluated whether heparin-coated hemodialysis catheters have fewer infections or greater cumulative survival than noncoated catheters. Design, setting, participants, & measurements: We retrospectively queried a prospective access database to analyze the outcomes of 175 tunneled dialysis catheters placed in the internal jugular vein, including 89 heparin-coated catheters and 86 noncoated catheters. The primary outcome was cumulative catheter survival, and the secondary outcome was infection-free catheter survival. Results: The two patient groups were similar in demographics and clinical and catheter features. Catheter-related bacteremia occurred less frequently with heparin-coated catheters than with noncoated catheters (34 versus 60%, P < 0.001). Cumulative catheter survival was similar in heparin-coated and noncoated catheters (hazard ratio, 0.87; 95% confidence interval, 0.55 to 1.36; P = 0.53). On multiple variable survival analysis including catheter type, age, sex, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, catheter location, and previous catheter, only catheter location predicted cumulative catheter survival (hazard ratio, 2.03; 95% CI, 1.27 to 3.25, with the right internal jugular location being the reference group, P = 0.003). The frequency of thrombolytic instillation was 1.8 per 1000 catheter-days in both groups. Conclusions: Heparin coating decreases the frequency of catheter-related bacteremia but does not reduce the frequency of catheter malfunction. PMID:19729425

  20. Protein adsorption to hydrocephalus shunt catheters: CSF protein adsorption

    PubMed Central

    Brydon, H.; Keir, G.; Thompson, E.; Bayston, R.; Hayward, R.; Harkness, W.

    1998-01-01

    OBJECTIVE—To assess the quantity and nature of the proteins that adsorb to hydrocephalus shunt catheters after implantation, and to determine whether sufficient could accumulate to obstruct the catheter.
DESIGN—Elution of proteins from 102 explanted shunt catheters, with protein assay and electrophoresis of the eluate, and scanning electron microscopy (SEM) of the catheters.
RESULTS—The amount of protein elutable was extremely low, and significant protein, apart from a thin film, was not found on SEM. Qualitative analysis disclosed that most of the adsorbed protein was albumin.
CONCLUSIONS—Protein deposition on hydrocephalus catheters does not occur in sufficient quantities to cause catheter obstruction.

 PMID:9598681

  1. Is it feasible to diagnose catheter-related candidemia without catheter withdrawal?

    PubMed

    Fernández-Cruz, Ana; Martín-Rabadán, Pablo; Suárez-Salas, Marisol; Rojas-Wettig, Loreto; Pérez, María Jesús; Guinea, Jesús; Guembe, María; Peláez, Teresa; Sánchez-Carrillo, Carlos; Bouza, Emilio

    2014-07-01

    Many bloodstream infections (BSI) in patients with central venous catheters (CVC) are not catheter-related (CR). Assessment of catheter involvement without catheter withdrawal has not been studied in candidemia. We assessed the value of conservative techniques to evaluate catheters as the origin of candidemia in patients with CVC in a prospective cohort study (superficial Gram stain and culture, Kite technique (Gram stain and culture of the first 1 cm blood drawn from the CVC), proportion of positive blood cultures (PPBCs), differential time to positivity (DTP), and minimal time to positivity (MTP)). All catheters were cultured at withdrawal. From June 2008 to January 2012, 22 cases fulfilled the inclusion criteria. CR-candidemia (CRC) was confirmed in 10. Validity values for predicting CRC were: superficial Gram stain (S, 30%; Sp, 81.83%; PPV, 60%; NPV, 56.3%; Ac, 57.1%), superficial cultures (S, 40%; Sp, 75%; PPV, 57.1%; NPV, 60%; Ac, 59.1%), Kite Gram stain (S, 33.3%; Sp, 66.7%; PPV, 50%; NPV, 50%; Ac, 50%), Kite culture (S, 80%; Sp, 66.7%; PPV, 66.7%; NPV, 80%; Ac, 72.7%), PPBC (S, 50%; Sp, 41.7%; PPV, 41.7%; NPV, 50.0%; Ac, 45.5%), DTP (S, 100%; Sp, 33.3%; PPV, 55.6%; NPV, 100%; Ac, 63.6%), and MTTP (S, 70%; Sp, 58.3%; PPV, 58.3%; NPV, 70%; Ac, 63.6%). While combinations of two tests improved sensitivity and NPV, more than two tests did not improve validity values. Classic tests to assess CR-BSI caused by bacteria cannot be reliably used to diagnose CRC. Combinations of tests could be useful, but more and larger studies are required.

  2. Imaging of cardiac sarcoidosis.

    PubMed

    Erthal, Fernanda; Juneau, Daniel; Lim, Siok P; Dwivedi, Girish; Nery, Pablo B; Birnie, David; Beanlands, Rob S

    2016-09-01

    Sarcoidosis is a multisystem inflammatory disease. Cardiac involvement is described in up to 50% of the cases. The disease spectrum is wide and cardiac manifestations ranges from being asymptomatic to heart failure, arrhythmias and sudden cardiac death. The diagnosis of cardiac sarcoidosis can be challenging due to its non-specific nature and the focal involvement of the heart. In this review, we discuss the utility of a stepwise approach with multimodality cardiac imaging in the diagnosis and management of CS. PMID:27225318

  3. Rotors and the Dynamics of Cardiac Fibrillation

    PubMed Central

    Pandit, Sandeep V.; Jalife, José

    2013-01-01

    The objective of this article is to present a broad review on the role of cardiac electrical rotors and their accompanying spiral waves in the mechanism of cardiac fibrillation. At the outset, we present a brief historical overview regarding reentry, and then discuss the basic concepts and terminologies pertaining to rotors and their initiation. Thereafter, the intrinsic properties of rotors and spiral waves, including phase singularities, wavefront curvature and dominant frequency maps are discussed. The implications of rotor dynamics for the spatio-temporal organization of fibrillation, independent of the species being studied are touched upon next. The knowledge gained regarding the role of cardiac structure in the initiation and/or maintenance of rotors and the ionic bases of spiral waves in the last two decades, and its significance for drug therapy is reviewed subsequently. We conclude by looking at recent evidence suggesting that rotors are critical in sustaining both atrial and ventricular fibrillation (AF, VF) in the human heart, and its implications for treatment with radio-frequency ablation. PMID:23449547

  4. Respecting shape memory to optimize peritoneal dialysis catheter outcomes.

    PubMed

    Briggs, Victoria R; Shrestha, Badri M; Wilkie, Martin E

    2014-11-01

    Disruption of the shape memory of a peritoneal dialysis catheter at the time of insertion may be a factor responsible for tip migration and catheter dysfunction. The use of postimplantation radiology to confirm the preservation of both the swan neck angle and the inclination angle may have a role in standardizing insertion technique with the potential to reduce the impact of operator variation on catheter outcomes. PMID:25360492

  5. Complications of Catheter Drainage for Amoebic Liver Abscess

    PubMed Central

    Sharma, Navneet; Kaur, Harpreet; Kalra, Naveen; Bhalla, Ashish; Kumar, Susheel; Singh, Virendra

    2015-01-01

    Per-cutaneously inserted catheter drainage is an accepted treatment modality for a large amoebic liver abscess. Complications that can arise are; secondary infection, bleeding into the abscess cavity, inadvertent catheter misplacement into the IVC and rupture of abscess with spillage into the peritoneal cavity. We report a case of a large amoebic liver abscess that presented with complications related to per-cutaneously inserted catheter drainage. PMID:26628843

  6. Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial

    PubMed Central

    De Greef, Yves; Dekker, Lukas; Boersma, Lucas; Murray, Stephen; Wieczorek, Marcus; Spitzer, Stefan G.; Davidson, Neil; Furniss, Steve; Hocini, Mélèze; Geller, J. Christoph; Csanádi, Zoltan

    2016-01-01

    Aims This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. Methods and results A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16–72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (<3 W) ablations (15 vs. 23%, 5 vs. 10% and 2 vs. 7% in 4:1, 2:1, and 1:1 bipolar:unipolar energy modes, respectively). Mini-Mental State Exam was unchanged in all patients. Conclusion Atrial fibrillation ablation with PVAC GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. Trial registration ClinicalTrials.gov NCT01767558. PMID:26826134

  7. Transmission of nosocomial infection by intravenous catheters: preventive strategies.

    PubMed

    Peleman, R; Vogelaers, D

    1994-12-01

    Intravascular catheter-related bacteraemia puts a major burden on health care due to its associated morbidity and mortality. Because of difficulties in the diagnosis and the consequences of catheter infections, prevention of infection is of the utmost importance. Depending on the setting, the intrinsic and extrinsic risk factors and the patient's personal characteristics, different strategies can be used, but they all focus on catheter care during placement and maintenance of the lines. In this review of the literature, recent data on the aetiology, diagnosis and prevention of catheter-related infections will be discussed.

  8. Risks and complications of peripherally and centrally inserted intravenous catheters.

    PubMed

    Schmid, M W

    2000-06-01

    Increased nursing vigilance is needed while caring for critically ill patients who have i.v. catheters. All i.v. sites should be selected based upon the i.v. therapy needs of the patient, using the shortest catheter and smallest size possible to meet the treatment needs of the patient while avoiding excessive repeated insertions of peripheral IVs. Meticulous handwashing, site preparation, and the use of sterile technique during insertion and maintenance are essential to minimize the risk of infection. Use multilumen catheters only when necessary because these catheters have an increased manipulation and associated infection risk. Observe for signs and symptoms of localized, systemic, mechanical, and metastatic (e.g., vertebral osteomyelitis and endocarditis) foci of infection. Additionally, remove all unnecessary or poorly performing i.v. catheters. I.v. sites that do not yield a blood return but will accept i.v. solutions are in the process of becoming occluded. Most likely, there is a fibrin sheath that is developing along the catheter's inner lumen and opening, decreasing the catheter's effectiveness. Accommodate the need to replace a catheter into the patient's plan of care rather than allowing the catheter to occlude and then replacing it under emergent or rushed conditions.

  9. Multifunctional Catheters Combining Intracardiac Ultrasound Imaging and Electrophysiology Sensing

    PubMed Central

    Stephens, Douglas N.; Cannata, Jonathan; Liu, Ruibin; Zhao, Jian Zhong; Shung, K. Kirk; Nguyen, Hien; Chia, Raymond; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai E.; Mahajan, Aman; Shivkumar, Kalyanam; Kim, Kang; O’Donnell, Matthew; Nikoozadeh, Amin; Oralkan, Omer; Khuri-Yakub, Pierre T.; Sahn, David J.

    2015-01-01

    A family of 3 multifunctional intracardiac imaging and electrophysiology (EP) mapping catheters has been in development to help guide diagnostic and therapeutic intracardiac EP procedures. The catheter tip on the first device includes a 7.5 MHz, 64-element, side-looking phased array for high resolution sector scanning. The second device is a forward-looking catheter with a 24-element 14 MHz phased array. Both of these catheters operate on a commercial imaging system with standard software. Multiple EP mapping sensors were mounted as ring electrodes near the arrays for electrocardiographic synchronization of ultrasound images and used for unique integration with EP mapping technologies. To help establish the catheters’ ability for integration with EP interventional procedures, tests were performed in vivo in a porcine animal model to demonstrate both useful intracardiac echocardiographic (ICE) visualization and simultaneous 3-D positional information using integrated electroanatomical mapping techniques. The catheters also performed well in high frame rate imaging, color flow imaging, and strain rate imaging of atrial and ventricular structures. The companion paper of this work discusses the catheter design of the side-looking catheter with special attention to acoustic lens design. The third device in development is a 10 MHz forward-looking ring array that is to be mounted at the distal tip of a 9F catheter to permit use of the available catheter lumen for adjunctive therapy tools. PMID:18986948

  10. Natural history of tunneled dialysis catheters placed for hemodialysis initiation

    PubMed Central

    Shingarev, Roman; Barker-Finkel, Jill; Allon, Michael

    2014-01-01

    PURPOSE Over 80% of US patients initiate HD with a tunneled dialysis catheter (TDC). Published data on TDC outcomes are based on a case-mix of prevalent and incident TDCs. We analyzed factors affecting patency and complications of first TDCs ever placed in a large cohort of incident HD patients. MATERIALS AND METHODS We retrospectively queried a prospective, computerized vascular access database to identify 472 patients receiving a first ever TDC. Multiple variable survival analysis was used to identify clinical parameters affecting TDC patency (from placement to non-elective removal) and infection (from placement to first episode of catheter-related bacteremia). RESULTS The median patency of all TDCs was 202 days. Left-sided placement of TDCs was the only variable associated with inferior TDC patency (hazard ratio 1.98; 95% CI, 1.39–2.81, p<0.0001). The 6-month TDC patency was 37% for left interval jugular (LIJ) vein catheters vs 54% for right internal jugular (RIJ) vein catheters. The one-year patency was 6% for LIJ catheters vs 35% for RIJ catheters. Catheter patency was not associated with patient age, sex, race, hypertension, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, or heart failure. The median time to the first episode of catheter-related bacteremia was 163 days. None of the clinical variables was associated with TDC infection. CONCLUSIONS TDCs are plagued by high rates of infection. Right IJ vein TDC should be used preferentially to maximize catheter patency. PMID:23871694

  11. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency lesion probe. 882.4725 Section 882.4725 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A...

  12. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an...

  13. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an...

  14. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency electrosurgical cautery apparatus....

  15. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency electrosurgical cautery apparatus. 886.4100 Section 886.4100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency electrosurgical cautery apparatus....

  16. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to...

  17. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to...

  18. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to...

  19. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to...

  20. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiofrequency lesion generator. 882.4400 Section 882.4400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to...

  1. Navigated DENSE strain imaging for post-radiofrequency ablation lesion assessment in the swine left atria

    PubMed Central

    Schmidt, Ehud J.; Fung, Maggie M.; Ciris, Pelin Aksit; Song, Ting; Shankaranarayanan, Ajit; Holmvang, Godtfred; Gupta, Sandeep N.; Chaput, Miguel; Levine, Robert A.; Ruskin, Jeremy; Reddy, Vivek Y.; D'avila, Andre; Aletras, Anthony H.; Danik, Stephan B.

    2014-01-01

    Aims Prior work has demonstrated that magnetic resonance imaging (MRI) strain can separate necrotic/stunned myocardium from healthy myocardium in the left ventricle (LV). We surmised that high-resolution MRI strain, using navigator-echo-triggered DENSE, could differentiate radiofrequency ablated tissue around the pulmonary vein (PV) from tissue that had not been damaged by radiofrequency energy, similarly to navigated 3D myocardial delayed enhancement (3D-MDE). Methods and results A respiratory-navigated 2D-DENSE sequence was developed, providing strain encoding in two spatial directions with 1.2 × 1.0 × 4 mm3 resolution. It was tested in the LV of infarcted sheep. In four swine, incomplete circumferential lesions were created around the right superior pulmonary vein (RSPV) using ablation catheters, recorded with electro-anatomic mapping, and imaged 1 h later using atrial-diastolic DENSE and 3D-MDE at the left atrium/RSPV junction. DENSE detected ablation gaps (regions with >12% strain) in similar positions to 3D-MDE (2D cross-correlation 0.89 ± 0.05). Low-strain (<8%) areas were, on average, 33% larger than equivalent MDE regions, so they include both injured and necrotic regions. Optimal DENSE orientation was perpendicular to the PV trunk, with high shear strain in adjacent viable tissue appearing as a sensitive marker of ablation lesions. Conclusions Magnetic resonance imaging strain may be a non-contrast alternative to 3D-MDE in intra-procedural monitoring of atrial ablation lesions. PMID:24014803

  2. CARDIAC MUSCLE

    PubMed Central

    Sommer, Joachim R.; Johnson, Edward A.

    1968-01-01

    With light and electron microscopy a comparison has been made of the morphology of ventricular (V) and Purkinje (P) fibers of the hearts of guinea pig, rabbit, cat, dog, goat, and sheep. The criteria, previously established for the rabbit heart, that V fibers are distinguished from P fibers by the respective presence and absence of transverse tubules is shown to be true for all animals studied. No evidence was found of a permanent connection between the sarcoplasmic reticulum and the extracellular space. The sarcoplasmic reticulum (SR) of V fibers formed couplings with the sarcolemma of a transverse tubule (interior coupling) and with the peripheral sarcolemma (peripheral coupling), whereas in P fibers the SR formed only peripheral couplings. The forms of the couplings were identical. The significance, with respect to excitation-contraction coupling, of the difference in the form of the couplings in cardiac versus skeletal muscle is discussed together with the electrophysiological implications of the differing geometries of bundles of P fibers from different animals. PMID:5645545

  3. Influence of catheter orientation on lesion formation in bovine myocardium by using an open-irrigated laser ablation catheter.

    PubMed

    Sagerer-Gerhardt, Michaela; Weber, Helmut P

    2016-09-01

    Lesion sizes and quality are crucial for successful catheter ablation procedures. We sought to test the influence of catheter orientation towards the endocardial surface on lesion formation in bovine myocardium by using an open-irrigated laser ablation catheter. Continuous wave 1064-nm laser catheter applications at 15 W (4.5 W/mm²)/30 s, (135 J/mm²), irrigation flow 30 mL/min, were aimed at the left ventricular endocardial surface of bovine myocardium. The catheter was kept in vertical, in slanting (67.5°, 45°, 22.5°), and in flat positions; in flat position, also 60 s of radiation times were applied (n = 10, each). Lesions were evaluated morphometrically. Maximum depth of lesion was achieved with the catheter in a vertical orientation. Catheter inclination of <22.5 showed a highly significant decrease of lesion depth from 5.6 ± 1.1 to 3.7 ± 0.5 mm (p = 0.0001). In a flat catheter position, laser radiation of 30 s achieved the smallest lesions. However, after 60 s of radiation, the flat lesions were similar in depth (p = 087) and were larger in width (p = 0.0004) and in volumes (p = 0.0025) as compared to the lesions achieved with the catheter in vertical position after 30 s of radiation. Steam-pop with intramural cavitation or tissue vaporization with crater formation did not occur. Longer radiation times can achieve larger lesions regardless of catheter orientation. Catheter orientation is not a major determinant for laser ablation lesion size and quality, and a steerable support may not be needed when using the open-irrigated electrode-laser mapping and ablation (ELMA) catheter RytmoLas. PMID:27286865

  4. Advancement of epidural catheter from lumbar to thoracic space in children: Comparison between 18G and 23G catheters

    PubMed Central

    Baidya, Dalim Kumar; Pawar, Dilip Kumar; Dehran, Maya; Gupta, Arun Kumar

    2012-01-01

    Backgrounds and Objectives: Lumbar-to-thoracic advancement of epidural catheter is a safe alternative to direct thoracic placement in children. In this prospective randomized study, success rate of advancement of two different types and gauges of catheter from lumbar-to-thoracic space were studied. Materials and Methods: Forty ASA I and II children (up to 6 years) undergoing thoracic or upper-abdominal surgery were allocated to either Group I (18G catheter) or Group II (23G catheter). After induction of general anesthesia a pre-determined length of catheter was inserted. Successful catheter placement was defined as the catheter tip within two segment of surgical incision in radio-contrast study. Intra-operative analgesia was provided by epidural bupivacaine and intravenous morphine. Post-operative analgesia was provided with epidural infusion of 0.1% bupivacaine+1mcg/ml fentanyl. Observations and Results: Catheter advancement was successful in 3 cases in Group I and 2 cases in Group II. Five different types of catheter positions were found on X-ray. Negative correlation was found between age and catheter advancement [significance (2-tailed) =0.03]. However, satisfactory post-operative analgesia was obtained in 35 cases. Positive correlation was found between infusion rate, the number of segment of gap between desired level and the level reached [significance (2-tailed) =0.00]. 23G catheter use was associated with more technical complications. Conclusion: Advancement of epidural catheter from lumbar to thoracic level was successful in only 10-15% cases but satisfactory analgesia could be provided by increasing the infusion rates. PMID:22345940

  5. Effect of Substrate Modification in Catheter Ablation of Paroxysmal Atrial Fibrillation

    PubMed Central

    Nam, Gi-Byoung; Jin, Eun-Sun; Choi, HyungOh; Song, Hae-Geun; Kim, Sung-Hwan; Kim, Ki-Hun; Hwang, Eui-Seock; Park, Kyoung-Min; Kim, Jun; Rhee, Kyoung-Suk; Choi, Kee-Joon; Kim, You-Ho

    2012-01-01

    Catheter ablation of atrial fibrillation that targets complex fractionated electrogram sites has been widely applied in the management of persistent atrial fibrillation. The clinical outcomes of pulmonary vein isolation alone and pulmonary vein isolation plus the use of complex fractionated electrogram-guided ablation (CFEA) have not been fully compared in patients with paroxysmal atrial fibrillation. This prospective study included 70 patients with symptomatic paroxysmal atrial fibrillation that remained inducible after pulmonary vein isolation. For radio-frequency catheter ablation, patients were nonrandomly assigned to a control group (pulmonary vein isolation alone, Group 1, n=35) or a CFEA group (pulmonary vein isolation plus additional CFEA, Group 2, n=35). The times to first recurrence of atrial tachyarrhythmias were compared between the 2 groups. In Group 2, CFEA rendered atrial fibrillation noninducible in 16 patients (45.7%) and converted inducible atrial fibrillation into inducible atrial flutters in 12 patients (34.3%). Atrial fibrillation remained inducible in 7 patients (20%) after the combined ablation procedures. After a mean follow-up of 23 months, freedom from recurrence of atrial tachyarrhythmias was significantly higher in Group 2 than in Group 1 (P=0.037). In Group 1, all of the recurrent tachyarrhythmias were atrial fibrillation, whereas regular tachycardia was the major mechanism of recurrent arrhythmias in Group 2 (atrial tachycardia or atrial flutter in 5 of 6 patients and atrial fibrillation in 1 patient). We found that CFEA after pulmonary vein isolation significantly reduced recurrent atrial tachyarrhythmia and might modify the pattern of arrhythmia recurrence in patients with paroxysmal atrial fibrillation. PMID:22719147

  6. Catheter ablation of ventricular tachycardia related to a septo-apical left ventricular aneurysm

    PubMed Central

    Rosu, Radu; Cismaru, Gabriel; Muresan, Lucian; Puiu, Mihai; Andronache, Marius; Gusetu, Gabriel; Pop, Dana; Mircea, Petru-Adrian; Zdrenghea, Dumitru

    2015-01-01

    A 60-year-old male patient with previous myocardial infarction (30 years ago) presented to our cardiology department for sustained monomorphic ventricular tachycardia. The patient presented multiple episodes of tachycardia treated by his internal cardiac defibrillator. Radiofrequency ablation was proposed as curative treatment. The mechanism of the ventricular tachycardia was demonstrated by electrophysiological study using three-dimensional mapping system: Carto 3 (Biosense Webster). Ventricular tachycardia was induced either mechanically or by programmed ventricular stimulation. The tachycardia cycle length was 380 msec. The voltage map confirmed the presence of the septo-apical aneurysm with a local voltage < 0.5 mV. Activation mapping revealed a figure-in-8 circuit of VT with the entrance point inside the dense scar and the exit point at the border zone (between the aneurysm and the healthy tissue of the left ventricular septo-apical region). Radiofrequency energy was delivered at the isthmus of the tachycardia rendering it uniducible by programmed ventricular stimulation. PMID:26770613

  7. Reduction of radiation exposure in catheter ablation of atrial fibrillation: Lesson learned

    PubMed Central

    De Ponti, Roberto

    2015-01-01

    Over the last decades, the concern for the radiation injury hazard to the patients and the professional staff has increased in the medical community. Since there is no magnitude of radiation exposure that is known to be completely safe, the use of ionizing radiation during medical diagnostic or interventional procedures should be as low as reasonably achievable (ALARA principle). Nevertheless, in cardiovascular medicine, radiation exposure for coronary percutaneous interventions or catheter ablation of cardiac arrhythmias may be high: for ablation of a complex arrhythmia, such as atrial fibrillation, the mean dose can be > 15 mSv and in some cases > 50 mSv. In interventional electrophysiology, although fluoroscopy has been widely used since the beginning to navigate catheters in the heart and the vessels and to monitor their position, the procedure is not based on fluoroscopic imaging. Therefore, non-fluoroscopic three-dimensional systems can be used to navigate electrophysiology catheters in the heart with no or minimal use of fluoroscopy. Although zero-fluoroscopy procedures are feasible in limited series, there may be difficulties in using no fluoroscopy on a routine basis. Currently, a significant reduction in radiation exposure towards near zero-fluoroscopy procedures seems a simpler task to achieve, especially in ablation of complex arrhythmias, such as atrial fibrillation. The data reported in the literature suggest the following three considerations. First, the use of the non-fluoroscopic systems is associated with a consistent reduction in radiation exposure in multiple centers: the more sophisticated and reliable this technology is, the higher the reduction in radiation exposure. Second, the use of these systems does not automatically lead to reduction of radiation exposure, but an optimized workflow should be developed and adopted for a safe non-fluoroscopic navigation of catheters. Third, at any level of expertise, there is a specific learning curve for

  8. Radiofrequency in Cosmetic Dermatology: An Update.

    PubMed

    Dunbar, Scott W; Goldberg, David J

    2015-11-01

    Treatment options for cosmetic improvement of the skin and body continue to grow more numerous with each passing year. The decline in utilization of invasive surgical treatments for aging and body contour correlates with the recent rise in laser and light devices. These light based technologies transmit either a single or broad wavelength of amplified light to the skin, resulting in volumetric tissue heating. Depending on the chromophore targeted and wavelength applied, varied applications exist to treat numerous cosmetic concerns. Radiofrequency (RF) devices have become more popular recently as science has advanced and brought new, safer, and better therapies. PMID:26580871

  9. SCAI expert consensus statement for advanced training programs in pediatric and congenital interventional cardiac catheterization.

    PubMed

    Armsby, Laurie; Beekman, Robert H; Benson, Lee; Fagan, Thomas; Hagler, Donald J; Hijazi, Ziyad M; Holzer, Ralf; Ing, Frank; Kreutzer, Jacqueline; Lang, Peter; Levi, Daniel S; Latson, Larry; Moore, Phillip; Mullins, Charles; Ruiz, Carlos; Vincent, Robert

    2014-11-01

    Pediatric and Congenital Interventional Cardiology is the practice of catheter-based techniques that improve cardiac physiology and circulation through the treatment of heart disease in children and adults with congenital or acquired heart defects. Over the last decade, and since last published training guidelines for pediatric cardiac catheterization and interventional cardiology were published in 2005 [1] the field of Pediatric and Congenital Cardiac Catheterization has evolved into a predominantly interventional discipline. As there is no sub-specialty certification for interventional cardiac catheterization in pediatrics, the Congenital Heart Disease Committee of the Society of Cardiovascular Angiography and Interventions has put together this consensus statement for advanced training in pediatric and congenital interventional cardiac catheterization. The statement puts forth recommendations for program infrastructure in terms of teaching, personnel, equipment, facilities, conferences, patient volume and trainee assessment. This is meant to set a standard for training programs as well as giving applicants a basis on which to judge and compare programs.

  10. Theoretical modeling for radiofrequency ablation: state-of-the-art and challenges for the future

    PubMed Central

    Berjano, Enrique J

    2006-01-01

    Radiofrequency ablation is an interventional technique that in recent years has come to be employed in very different medical fields, such as the elimination of cardiac arrhythmias or the destruction of tumors in different locations. In order to investigate and develop new techniques, and also to improve those currently employed, theoretical models and computer simulations are a powerful tool since they provide vital information on the electrical and thermal behavior of ablation rapidly and at low cost. In the future they could even help to plan individual treatment for each patient. This review analyzes the state-of-the-art in theoretical modeling as applied to the study of radiofrequency ablation techniques. Firstly, it describes the most important issues involved in this methodology, including the experimental validation. Secondly, it points out the present limitations, especially those related to the lack of an accurate characterization of the biological tissues. After analyzing the current and future benefits of this technique it finally suggests future lines and trends in the research of this area. PMID:16620380

  11. Irrigated and non-irrigated radiofrequency ablation systems and ways of non-irrigated RF systems development

    NASA Astrophysics Data System (ADS)

    Evtushenko, A. V.; Evtushenko, V. V.; Bykov, A. N.; Sergeev, V. S.; Syryamkin, V. I.; Kistenev, Yu. V.; Anfinogenova, Ya. D.; Smyshlyaev, K. A.; Kurlov, I. O.

    2015-11-01

    Improving of radiofrequency ablation systems for the myocardium is one of the fundamental problems of cardiac surgery. We used pig left ventricular myocardium as a working model. Mean thickness of the left ventricular wall was 10.1 ± 5.6 mm. The studies were performed on 10 hearts. The mean weight of hearts was 294.7 ± 21g. Research is being done on the electrophysical bench in 2 stages. In the first stage the hearts were placed on the electrophysical bench and heated to 36.6°C. In the second stage heart cooled to 20°C. The monopolar radiofrequency exposure was processing on the myocardium by two types of electrodes: spherical irrigated electrode and non-irrigated penetrating one within 20 seconds. The electrical resistance of the myocardium was measured at different temperatures before and after exposure. This paper shows that the decrease in ambient temperature combined with using of new penetrating electrodes for radiofrequency ablation gives better results than using of irrigated and non-irrigated systems. This method allows significantly reduce time exposure for a maximum depth of destruction in the myocardium.

  12. Does the Heparin Lock Concentration Affect Hemodialysis Catheter Patency?

    PubMed Central

    Ivan, D. Maya; Smith, Tamorie

    2010-01-01

    Background and objectives: Concentrated heparin solutions are instilled into the catheter lumens after each hemodialysis session to prevent catheter thrombosis. The heparin lock concentration at many centers has been decreased recently to reduce the risk of systemic bleeding and contain costs. However, the effect of this change on catheter patency is unknown. We compared catheter patency between two heparin lock solutions: 1000 versus 5000 units/ml. Design, setting, participants, & measurements: With use of a prospective, computerized, vascular access database, 105 patients with newly placed tunneled hemodialysis catheters, including 58 patients receiving a 5000 units/ml heparin lock and 47 patients receiving a 1000 units/ml heparin lock, were retrospectively identified. The primary endpoint was cumulative catheter patency and the secondary endpoint was frequency of thrombolytic instillation. Results: Cumulative catheter survival was similar in the two groups, being 71% versus 73% at 120 days in the low- and high-concentration heparin lock groups (hazard ratio of catheter failure, 0.97; 95% confidence interval, 0.45 to 2.09; P = 0.95). The frequency of tissue plasminogen activator instillation was significantly greater in the low-concentration heparin group (hazard ratio, 2.18; 95% CI, 1.26 to 3.86; P = 0.005). No major bleeding complications were observed in either treatment group. The overall drug cost for maintaining catheter patency was 23% lower with the low-concentration heparin lock ($1418 versus $1917) to maintain catheter patency for 1000 days. Conclusions: Low-concentration heparin lock solutions do not decrease cumulative dialysis catheter patency, but require a twofold increase in thrombolytic instillation to maintain long-term patency. PMID:20498241

  13. 2D/3D registration using only single-view fluoroscopy to guide cardiac ablation procedures: a feasibility study

    NASA Astrophysics Data System (ADS)

    Fallavollita, Pascal

    2010-02-01

    The CARTO XP is an electroanatomical cardiac mapping system that provides 3D color-coded maps of the electrical activity of the heart, however it is expensive and it can only use a single costly magnetic catheter for each patient intervention. Aim: To develop an affordable fluoroscopic navigation system that could shorten the duration of RF ablation procedures and increase its efficacy. Methodology: A 4-step filtering technique was implemented in order to project the tip electrode of an ablation catheter visible in single-view C-arm images in order to calculate its width. The width is directly proportional to the depth of the catheter. Results: For phantom experimentation, when displacing a 7- French catheter at 1cm intervals away from an X-ray source, the recovered depth using a single image was 2.05 +/- 1.47 mm, whereas depth errors improved to 1.55 +/- 1.30 mm when using an 8-French catheter. In clinic experimentation, twenty posterior and left lateral images of a catheter inside the left ventricle of a mongrel dog were acquired. The standard error of estimate for the recovered depth of the tip-electrode of the mapping catheter was 13.1 mm and 10.1 mm respectively for the posterior and lateral views. Conclusions: A filtering implementation using single-view C-arm images showed that it was possible to recover depth in phantom study and proved adequate in clinical experimentation based on isochronal map fusion results.

  14. Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the con perspective.

    PubMed

    Skanes, Allan C; Obeyesekere, Manoj; Klein, George J

    2015-09-01

    The association between asymptomatic Wolff-Parkinson-White (WPW) syndrome and sudden cardiac death (SCD) has been well documented. The inherent properties of the accessory pathway determine the risk of SCD in WPW, and catheter ablation essentially eliminates this risk. An approach to WPW syndrome is needed that incorporates the patient's individualized considerations into the decision making. Patients must understand that there is a trade-off of a small immediate risk of an invasive approach for elimination of a small lifetime risk of the natural history of asymptomatic WPW. Clinicians can minimize the invasive risk by only performing ablation for patients with at-risk pathways.

  15. Transanal protrusion of a ventriculoperitoneal shunt catheter.

    PubMed

    Ozturk, Hulya; Is, Merih; Ozturk, Hayrettin; Kucuk, Adem; Dosoglu, Murat

    2012-11-01

    A two years old boy presented with a transanal protrusion of the ventriculoperitoneal (VP) shunt catheter. A VP shunt was inserted when the boy was six-month-old for congenital hydrocephalus. He was active and neurologically normal, with no signs of meningitis and peritoneal irritation. During laparotomy, the tube was seen entering the sigmoid colon, so the tube was cut at the point where it entered the sigmoid colon. The distal end of the protruding tube was pulled out from the anus. The sigmoid colon was repaired, and a delayed shunt revision was completed. The patient was discharged without abdominal and neurological deterioration.

  16. Transanal protrusion of a ventriculoperitoneal shunt catheter.

    PubMed

    Ozturk, Hulya; Is, Merih; Ozturk, Hayrettin; Kucuk, Adem; Dosoglu, Murat

    2012-11-01

    A two years old boy presented with a transanal protrusion of the ventriculoperitoneal (VP) shunt catheter. A VP shunt was inserted when the boy was six-month-old for congenital hydrocephalus. He was active and neurologically normal, with no signs of meningitis and peritoneal irritation. During laparotomy, the tube was seen entering the sigmoid colon, so the tube was cut at the point where it entered the sigmoid colon. The distal end of the protruding tube was pulled out from the anus. The sigmoid colon was repaired, and a delayed shunt revision was completed. The patient was discharged without abdominal and neurological deterioration. PMID:23146859

  17. [Clinical study on efficacy of a Foley catheter coated with silver-protein in prevention of urinary tract infections].

    PubMed

    Takeuchi, H; Hida, S; Yoshida, O; Ueda, T

    1993-03-01

    We evaluated the clinical efficacy and safety of a Foley catheter coated with silver-protein (ProAg catheter) in the prevention of catheter-associated bacteriuria. ProAg catheter significantly reduced the incidence of extraluminal catheter-associated bacteriuria compared with usual latex Foley catheter although it did not inhibit intraluminal bacteriuria. There was no difference between ProAg catheter and latex catheter in the side effects such as urethral discharge, catheter-associated pain and allergic reaction. The ProAg catheter may be useful as an indwelling urethral catheter.

  18. MRI for patients with cardiac implantable electrical devices.

    PubMed

    Chow, Grant V; Nazarian, Saman

    2014-05-01

    MRI has become an invaluable tool in the evaluation of soft tissue and bony abnormalities. The presence of a cardiac implantable electrical device (CIED) may complicate matters, however, because these devices are considered a contraindication to MRI scanning. When MRI is performed in patients with a CIED, risks include reed switch activation in older devices, lead heating, system malfunction, and significant radiofrequency noise resulting in inappropriate inhibition of demand pacing, tachycardia therapies, or programming changes. This report reviews indications and risk-benefit evaluation of MRI in patients with CIED and provides a clinical algorithm for performing MRI in patients with implanted devices. PMID:24793805

  19. Radio-frequency scanning tunnelling microscopy.

    PubMed

    Kemiktarak, U; Ndukum, T; Schwab, K C; Ekinci, K L

    2007-11-01

    The scanning tunnelling microscope (STM) relies on localized electron tunnelling between a sharp probe tip and a conducting sample to attain atomic-scale spatial resolution. In the 25-year period since its invention, the STM has helped uncover a wealth of phenomena in diverse physical systems--ranging from semiconductors to superconductors to atomic and molecular nanosystems. A severe limitation in scanning tunnelling microscopy is the low temporal resolution, originating from the diminished high-frequency response of the tunnel current readout circuitry. Here we overcome this limitation by measuring the reflection from a resonant inductor-capacitor circuit in which the tunnel junction is embedded, and demonstrate electronic bandwidths as high as 10 MHz. This approximately 100-fold bandwidth improvement on the state of the art translates into fast surface topography as well as delicate measurements in mesoscopic electronics and mechanics. Broadband noise measurements across the tunnel junction using this radio-frequency STM have allowed us to perform thermometry at the nanometre scale. Furthermore, we have detected high-frequency mechanical motion with a sensitivity approaching approximately 15 fm Hz(-1/2). This sensitivity is on par with the highest available from nanoscale optical and electrical displacement detection techniques, and the radio-frequency STM is expected to be capable of quantum-limited position measurements.

  20. Microwave Treatment for Cardiac Arrhythmias

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Carl, James R. (Inventor); Raffoul, George W. (Inventor); Pacifico, Antonio (Inventor)

    1999-01-01

    Method and apparatus are provided for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue to treat ventricular tachycardia and other arrhythmias while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In operation, microwave energy between about 1 Gigahertz and 12 Gigahertz is applied to monopole microwave radiator having a surface wave limiter. A test setup provides physical testing of microwave radiators to determine the temperature profile created in actual heart tissue or ersatz heart tissue. Saline solution pumped over the heart tissue with a peristaltic pump simulates blood flow. Optical temperature sensors disposed at various tissue depths within the heart tissue detect the temperature profile without creating any electromagnetic interference. The method may be used to produce a desired temperature profile in other body tissues reachable by catheter such as tumors and the like.