Monitoring Procedural Safety

Esophageal Proximity can be monitored to guide locations of ablation to help minimize risk of esophageal damage. The entire length of esophagus that is contiguous with the left atrial posterior wall can be visualized with intra left atrial ICE to monitor ablation delivery and power titration. [1] Figure 1A shows the typical location of the esophagus during an atrial fibrillation ablation. Ablation over the esophagus is avoided or power is titrated to minimize risk of esophageal damage. Endocardial thrombi or coagulum can be detected using radial ICE as shown in Figure 1B. Left atrial damage can also be monitored using radial ICE. Figure 1C shows an unusual case of a tear or rent in the endocardium discovered during an atrial fibrillation ablation. Finally, though radial ICE is not the ideal imaging modality to evaluate for pericardial effusions given its limited far-field resolution. Figure 1D shows the pericardial space in view when an intra-left ventricular ICE position is utilized.

Radial ICE to Monitor for Intraprocedural Complications.
Radial ICE to Monitor for Intraprocedural Complications.

Figure 1 Radial ICE to Monitor for Intraprocedural Complications. Image A shows the left pulmonary vestibule with catheter evident at 9 o’clock and the esophagus viewed obliquely at ~7 o’clock. Image B shows a coagulum versus thrombus adherent to the endocardium. Image C shows a left atrial endocardial tear that did not result in pericardial effusion. Image D shows the pericardial space when ICE catheter positioned across the mitral annulus in the LV.

 

References:

1    Ren JF, Lin D, Marchlinski FE, Callans DJ, Patel V. Esophageal imaging and strategies for avoiding injury during left atrial ablation for atrial fibrillation. Heart Rhythm. 2006;3: 1156-1161.

Left Atrial Intraprocedural Radial ICE Guidance:

Transseptal Punctures can be safely performed using radial ICE guidance.  A suitably sized Mullins introducer sheath (10-11 French) can be used to position the radial ICE catheter along the interatrial septum as shown in Figure 1.  The Mullins sheath provides enough maneuverability to adjust the ICE catheter position in both inferior-superior and anterior-posterior directions to optimize the location of transseptal puncture in the fossa ovalis.  Once ICE localization of transseptal needle showing tenting of the septum in suitable fossa is obtained LAO fluoroscopy is then used to guide the transseptal puncture and advancement of left atrial sheath.

 Radial ICE Guidance of Transseptal Puncture for Left Atrial Access
Radial ICE Guidance of Transseptal Puncture for Left Atrial Access

Figure 1 Radial ICE Guidance of Transseptal Puncture for Left Atrial Access.  The left and right atria are well-visualized with the ICE catheter in the right atrium along the interatrial septum in the fossa ovalis.  One can see the tenting evident when transseptal needle is in good contact with the interatrial septum.

 

Left Atrial Ablations can be enhanced and accomplished using intra left atrial radial ICE (with intraprocedural heparinization for ACT>300).  [1,2,3] Radial ICE is a useful adjunct imaging technique for several reasons.  First, direct visualization of the electrode-endocardial interface allows precise positioning of the ablation electrode to guide lesion formation.  Second, radial ICE permits the delivery of “focal” left atrial ablative lesions; the electrode kept in same location throughout energy application by manipulating the ablation electrode into firm, stable endocardial contact during continuous ICE imaging of the electrode–endocardial interface.  Third, the use of continuous radial ICE during atrial fibrillation ablations allows close monitoring of catheter position and endocardial contact while minimizing dependence on fluoroscopy.  Figure 2 depicts a typical view obtained when radial ICE is positioned in the left atrium using a steerable sheath (Agilis, St. Jude Medical, Inc., St. Paul, MN).

Intra Left Atrial Radial ICE Imaging During Atrial Fibrillation Ablation Left Pulmonary Venous Antrum Isolation
Intra Left Atrial Radial ICE Imaging During Atrial Fibrillation Ablation Left Pulmonary Venous Antrum Isolation

Figure 2  Intra Left Atrial Radial ICE Imaging During Atrial Fibrillation Ablation Left Pulmonary Venous Antrum Isolation. The radial ICE catheter is positioned at the entrance to the left PV antrum with the tip of the ablation catheter (Thermocool irrigated tip, Biosense Webster Inc, Diamond Bar, CA) located at ~9 o’clock on the antrum.  The inset shows the analogous location of ablation catheter on 3D CT reconstruction of the left PV antrum.

Detailed anatomy of the pulmonary veins can also aid in catheter positioning and stability as well as monitor for procedural complications (discussed later). Figure 3 provides views of the left and right pulmonary vestibules. The left upper (LUPV) and lower pulmonary veins (LLPV) are visualized as are the saddles. The right intervenous saddle is not as clearly differentiated as the left in this particular example to give the reader a better overall view of the structures surrounding the right pulmonary vestibule such as SVC, main PA, and Waterston’s groove (WG). Waterston’s groove is a fat-filled depression formed as the left and right atria fold into one another; Waterston’s groove is often dissected by surgeons to expose the left atrium. Radial ICE can be carefully placed within each individual pulmonary veins to guide catheter ablation as previously described. [1,2,3]

 

Radial ICE Anatomy of Left and Right Pulmonary Vestibules
Radial ICE Anatomy of Left and Right Pulmonary Vestibules

Figure 3  Radial ICE Anatomy of Left and Right Pulmonary Vestibules. The right pulmonary vestibule is shown with the early portions of the upper and lower pulmonary veins. Superior to the right pulmonary veins one can see the main pulmonary artery and superior vena cava. The approximate location of Waterston’s groove is depicted by the solid line.  A more distal view of the left pulmonary vestibule (compared to Figure 2) clearly differentiates the upper and lower PV’s as well as the intervenous saddle.

Radial ICE can also help guide linear ablation along the LA posterior wall for mitral annular flutter.  Direct visualization of the left lower pulmonary vein, the posterior wall of the LA, the mitral annulus, and CS during ablation (both intra LA and CS) can improve catheter contact allowing for complete linear ablation and bidirectional block (see Figure 4).

Ablation Near Mitral Annulus
Ablation Near Mitral Annulus

Figure 4  Ablation Near Mitral Annulus.  A depicts the intra-LA radial ICE catheter with ablation catheter along the floor of left atrium near mitral annulus. B shows a similar view demonstrating the ablation catheter in the CS.  Endocardial (and CS) contact and possible ablation injury can be visualized during lesion delivery.

Note: This is adapted from work I did with Dr. Sheetal Chandhok.

References:

1     Schwartzman D, Nosbisch J, Housel D. Echocardiographically guided left atrial ablation: characterization of a new technique. Heart Rhythm, V. 3 (2006), pp. 930–938.

2     Schwartzman D, Williams JL, “On the Electroanatomic Properties of Pulmonary Vein Antral Regions Enclosed by Encircling Ablation Lesions,” Europace , V. 11 (2009), pp. 435–444.

3     Chandhok S, Williams JL, Schwartzman DS, “Anatomical analysis of recurrent conduction after circumferential ablation,” J Intervent Card Electrophysiol, V. 27, No. 1 (January 2010), pp. 41-50.

This is an interesting finding observed during a recent atrial fibrillation ablation performed in our Heart Rhythm Center.  The ablation paradigm has been previously described [1] and consists of a pulmonary venous antrum isolation using entrance and exit block criteria guided by intra left atrial radial intracardiac echocardiography (ICE). During the initial antrum encircling lesion asystole developed (see following figure), ablation was stopped, and sinus rhythm recovered within 10seconds.

Asystole During Ganglionic Plexi Ablation in LSPV

The following radial ICE image demonstrates the ablation catheter location in the superior aspect of the left pulmonary venous antrum near the left atrial appendage.

Radial ICE View LSPV Ganglion

Bradycardia is often seen during atrial fibrillation ablations when proximate to autonomic ganglionic plexi.  [2]  I routinely see fluctuations in basal sinus rate during pulmonary venous antrum ablations but this was more dramatic than the sinus rate changes I usually observe.  This location as seen on the intra left atrial radial ICE shot is slightly more anterior than the left superior ganglionic plexus is usually expected.  The following figure shows a CT reconstruction of the posterior left atrium and pulmonary venous antra.  The red dots depict a typical venous antrum ablation lesion set and the yellow areas denote the approximate locations of the ganglionic plexi. [3]  Discontinuation of ablation led to quick restoration of sinus rhythm and repeat ablation near this location to finalize lesion set did not result in repeat asystole or significant fluctuations in sinus rate.

 

Approximate Locations of Ganglionic Plexi

Another possible explanation for this finding is acute sinus node dysfunction (from damage to the sinus node artery, SNA) during ablation in the anterior left atrium.  Chugh et al present an excellent review of coronary arterial injury during ablation of atrial fibrillation. [4]  Though there was no obvious PR prolongation prior to the pause suggesting an autonomic effect, there was also no obvious sinus tachycardia or acceleration serving as a “harbinger of impending [sinus node] dysfunction.”    Though the SNA arises from the RCA in two-thirds of patients, the remainder of SNA arise from an early branch of the circumflex which “passes superiorly and to the right of the LAA and courses over the anterior LA before terminating at the cavoatrial junction.”  Less commonly, the SNA branches off a more distal portion of the circumflex and ascends in the lateral ridge between the appendage and the left pulmonary veins.  The patient had an uneventful post-ablation recovery.

 

References:

1                     Schwartzman D, Williams JL, “On the Electroanatomic Properties of Pulmonary Vein Antral Regions Enclosed by Encircling Ablation Lesions,” Europace , V. 11 (2009), pp. 435–444.

2                     Pappone C, et al “Pulmonary vein denervation enhances long-term benefit after circumferential ablation for paroxysmal atrial fibrillation,” Circulation, V. 109 (2004), p. 327.

3                     Katritsis DG et al, “Autonomic Denervation Added to Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation A Randomized Clinical Trial,” JACC, V. 62 (December 2013), pp. 2318–25.

4                     Chugh A et al, “Manifestations of coronary arterial injury during catheter ablation of atrial fibrillation and related arrhythmias,” Heart Rhythm, V. 10, No. 11 (November 2013), pp. 1638-1645.

The effects of intracardiac ablation have been well characterized (See Effects of RFA) and prior work has suggested that it can be used to repair mitral valve prolapse causing severe mitral regurgitation (MR).  Minimally invasive repair of mitral valve prolapse (MVP) causing severe mitral regurgitation (MR) should increase the rigidity of the valve leaflet, decrease the leaflet surface area, and decrease redundant chordal length. Ex-vivo studies suggest that direct application of radiofrequency ablation (RFA) to mitral leaflets and chordae can effect these repair goals to decrease MR.  We used a naturally occurring model of MVP (similar macroscopically and microscopically to primary MVP in humans) causing severe MR.  RFA was applied to the prolapsed leaflets of the mitral valve and any associated elongated chordae. Mitral regurgitant volume was calculated using the proximal isovelocity surface area method on pre- and post-ablation echocardiograms.  Subjects found to have anterior leaflet, posterior leaflet, and bileaflet MVP prolapse causing severe MR with a mean ejection fraction of 66±3%(±SD) underwent direct RFA. Echocardiograms performed before and after RFA demonstrated a 66.9±20.6% reduction in mitral regurgitant volume.  The first video below shows the severe MR prior to RFA application to leaflets and chordae.  The second video shows the degree of MR 6weeks after RFA applied.  One can note the qualitative decrease in MR that was quantified by doppler.

These data suggest that myxomatous mitral valve repair using radiofrequency energy delivered via catheter may be feasible. Further investigation is necessary to evaluate whether such a technique could be adapted to a percutaneous, closed chest, beating heart environment.

More information about this study can be found at:  http://www.lebanoncardiology.com/downloads/JLW%20JOIC%202008.pdf.

Radiofrequency catheter ablation (RFA) of cardiac tissue has been well-characterized in animal models. Both unipolar (HUA88) and bipolar (TAN91) radiofrequency ablation cause similar acute and chronic effects, the extent of which is determined by the amount of energy applied to the tissue. It has been shown that the application of microwave (LIE98,WOR02), cryogenic (DUB98,WOR02), laser, (WOR02), and ultrasonic (WOR02) energy result in similar cellular damage as radiofrequency energy.

Radiofrequency energy produces cell damage by heating the tissue and causing coagulative necrosis (cell death). These areas of cell death will eventually be replaced with fibrosis (scar tissue). (WOL94,REM98,LIE00) As one increases the energy applied to tissue, one will see an increase in the coagulation area and an increase in thermal damage. (REM98) Interestingly, this technique has been used to stiffen the palate (roof of the mouth) to prevent snoring. (MAI00) It has been speculated that RFA may cause direct valve tissue injury in patients undergoing ablation of accessory pathways.(MIN92) In fact, Wolfsohn et al (WOL94) found that when they accidentally applied energy to one of the valves of the heart they caused a fibrous scar. Another group (TAN91) found pathologic changes in the tricuspid valve when AV node or His bundle ablation was attempted in dogs. These changes included edema, swelling of the spongiosa, degenerative change of collagen fibers, endocardial thickening, and slight fibrosis and destruction of the valvular tissue. Additionally, collagen is the substance in the body that forms the support structure of tissue. Collagen in heart tissue denatures (breaks down) and contracts when heated to >65° CelciusVIC02. In fact, the chordae tendinae also contract when heated to >65° Celcius (VIC02). This contraction of heart tissue has also been noted by another group.LIE00 Though this technique has not been studied on heart valves one can infer that similar cellular changes may occur when this energy is applied to cardiac valves. RFA has been used to stiffen the palate (roof of the mouth) to prevent snoring. (MAI00) In fact, Wolfsohn et al (WOL94) found that when they accidentally applied energy to one of the valves of the heart they caused a similar fibrous scar.

The acute (1-7 days) effects of RFA (50-300J) include a lesion that is round-oval in shape, centrally-pale with varying amounts of a hemorrhagic rim.(HUA88) Occasionally, there is a mural thrombus over the lesion (~20% occurrence). There is central coagulation necrosis, peripheral contraction band necrosis, and interstitial edema and fibrinous material on the endocardium. (TAN91) During days 3-7, one observes a rim of granulation tissue composed of proliferating capillaries and fibroblasts admixed with acute and mononuclear inflammatory cells. (HUA88) Finally, the chronic effects are usually evident at 4-6 weeks after RFA. Chronic lesions are round-oval to irregular in shape, well-circumscribed, and fibrotic.(HUA88) The acute edema has almost disappeared and there are almost mature collagen fibers and a mild increase in elastic fibers.(TAN91) Much of these pathological observations were made in dog models however, Huang et al (HUA88) found that dog tissue damage was very similar to the tissue damage found in postmortem humans. RFA lesion size is, in part, determined by the amount of energy applied (typically, 50-700Joules). However, energy levels of 100-300J have been shown to cause similar lesion sizes (LxWxDepth, ~4.8×4.6×4.3mm) (HUA91). Earlier work by Huang et al (HUA87), demonstrated the application of unipolar RFA with an energy level of 50J caused an average subacute (7-10d) lesion size of 4x4x2mm.

References:

WOL94 Wolfsohn AL, Green MS, and Walley VM, “Pathology of Radiofrequency Catheter Ablation of the Atrioventricular Node,” Modern Pathology, Vol. 7, No. 4 (1994), pp. 494-496.

REM98 Remorgida V, “Tissue thermal damage caused by bipolar forceps can be reduced with a combination of plastic and metal,” Surgical Endoscopy, Vol. 12 (1998), pp. 936-939.

LIE00 Liem LB, Pomeranz M, et al, “Electrophysiological Correlates of Transmural Linear Ablation,” PACE, Vol. 23 (January 2000), pp. 40-46. MAI00 Mair EA and Day RH, “Cautery-assisted palatal stiffening operation,” Otolaryngol Head Neck Surg, Vol. 122 (April 2000), pp. 547-555.

MIN92 Minich LL, Snider AR, Dick M II, “Doppler Detection of Valvular Regurgitation After Radiofrequency Ablation of Accessory Connections,” Am J Cardiol, V. 70 (July 1, 1992), pp. 116-117.

VIC02 Victal OA, Teerlink JR, et al, “Left Ventricular Volume Reduction by Radiofrequency Heating of Chronic Myocardial Infarction in Patients with Congestive Heart Failure,” Circulation, Vol. 105 (March 19, 2002), pp. 1317-1322.

LIE98 Liem LB and Mead RH, “Microwave Linear Ablation of the Isthmus Between the Inferior Vena Cava and Tricuspid Annulus,” PACE, Vol. 21 (November 1998, Part I), pp. 2079-2086.

WOR02 Liem LB, “Catheter Ablation Using Alternative Energy Sources,” EP Lab Digest, (September/October 2002), pp. 10-12. DUB98 Dubuc M, Talajic M, et al, “Feasibility of Cardiac Cryoablation Using a Transvenous Steerable Electrode Catheter,” J Interventional Cardiac Electrophysiology, Vol. 2 (1998), pp. 285-292.

TAM95 Tamura K, Fukuda Y, Ishizaki M, Masuda Y, Yamanaka N, Ferrans V. “Abnormalities in elastic fibers and other connective-tissue components of floppy mitral valve,” Am Heart J, V. 129, No. 6 (June 1995), pp. 1149-1158.

NAS04 Nasuti JF, Zhang PJ, Feldman MD, Pasha T, Khurana JS, Gorman JH III, Gorman RC, Narula J, and Narula N, “Fibrillin and Other Matrix Proteins in Mitral Valve Prolapse Syndrome,” Ann Thorac Surg, V. 77 (2004), pp. 532-536.

DAV78 Davies MJ, Moore BP, Braimbridge MV, “The floppy mitral valve – Study of incidence, pathology, and complications in surgical, necropsy, and forensic material,” Br Heart J, V. 40 (1978), pp. 468-481.

WHI87 Whittaker P, Boughner DR, Perkins DG, Canham PB, “Quantitative structural analysis of collagen in chordae tendinae and its relation to floppy mitral valves and proteoglycan infiltration,” Br Heart J, V. 57 (1987), pp. 264-269.

BAK88 Baker PB, Bansal G, Boudoulas H, Kolibash AJ, Kilman J, Wooley CF, “Floppy Mitral Valve Chordae Tendinae: Histopathologic Alterations,” Hum Pathol, V. 19 (1988), pp. 507-512.

GRA03 Grande-Allen KJ, Griffin BP, Ratliff NB, Cosgrove DM, Vesely I, “Glycosaminoglycan Profiles of Myxomatous Mitral Leaflets and Chordae Parallel the Severity of Mechanical Alterations,” JACC, V. 42, No. 2 (July 16, 2003), pp. 271-277.

HUA88 Huang SKS, Graham AR, Bharati S, Lee MA, Gorman G, and Lev M, “Short- and Long-Term Effects of Transcatheter Ablation of the Coronary Sinus By Radiofrequency Energy,” Circulation, V. 78, No. 2 (August 1988), pp. 416-427.

TAN91 Tanaka M, Satake S, Kawahara Y, Sugiura M, Hirao K, Tanaka K, Kawara T, Masuda A, Nishikawa T, and Kasajima T, “Pathological Aspects of Radiofrequency Ablation of the Canine Atrioventricular Node and Bundle of His: With Special Reference to Chronic Incomplete Atrioventricular Block,” Acta Pathol Jpn, V. 41, No. 7 (1991), pp. 487-498.

HUA91 Huang SKS, Graham AR, Lee MA, Ring ME, Gorman GD, and Schiffman R, “Comparison of Catheter Ablation Using Radiofrequency Versus Direct Current Energy: Biophysical, Electrophysiologic and Pathologic Observations,” JACC, V. 18, No. 4 (October 1991), pp. 1091-1097.

HUA87 Huang SK, Bharati S, Graham AR, Lev M, Marcus FI, and Odell RC, “Closed Chest Catheter Dessication of the Atrioventricular Junction Using Radiofrequency Energy- A New Method of Catheter Ablation,” JACC, V. 9, No. 2 (February 1987), pp. 349-358.

DAV78 Davies MJ, Moore BP, and Braimbridge MV, “The floppy mitral valve: Study of incidence, pathology, and complications in surgical, necropsy, and forensic material,” British Heart Journal, V. 40 (1978), pp. 468-481.

KIN82 King BD, Clark MA, Baba N, Kilman JW, Wooley CF, “Myxomatous Mitral Valves: Collagen Dissolution as the Primary Defect,” Circulation, V. 66, No. 2 (August 1982), pp. 288-296.

COS89 Cosgrove DM and Stewart WJ, “Mitral Valvuloplasty,” Curr Probl Cardiol, V. 14, No. 7 (July 1989), pp. 353-416.

ZOO83 Zook BC, Blackbourne BD, Katz RJ, and Bradley EW, “Mitral Valve Prolapse,” Comparative Pathology Bulletin, Vo. 15 (August 1983), pp.3-4.

Most intracardiac EP procedures are analogous to painting the inside of a room; I have found that in many procedures, without ICE you are painting in the dark. Charles Darwin said, “It is not the strongest of the species that survives, nor the most intelligent, but rather the one most responsive to change.”  Within the last decade, the field of Electrophysiology has progressed in term of technology and breadth of procedural variety.  Part of this development has been the use of adjunctive imaging during EP procedures.  The following video depicts an ex-vivo heart preparation undergoing a radio frequency ablation.

One can imagine the trauma that a steam pop could cause during an EP study in which the ablation catheter is confined within a small trabeculation in the right or left atrium.  Direct visualization of the ablation electrode-endocardial interface is possible with intracardiac echo (ICE).  ICE permits us to watch for increasing echogenicity of endocardium and possible overheating.  In addition, the development of catheter or sheath thrombus can be detected by direct visualization with ICE.

There are two main types of ICE:  Phased-Array and Radial.

 

1.  Phased Array:  8-10 French, 5.5–10 Mega Hertz catheter with 90° sectorial sector image and Doppler capability (AcuNav®, Acuson, a Siemens Corporation, Mountain View, California). Phased-array generally offers better image resolution/definition and doppler capability.  The doppler capability permits assessment of valve disorders such as stenosis (blockage) or regurgitation (leaking).  The cost is higher.

2.  Radial (mechanical rotation of the transducer):  8.5 French, 9 MHz catheter with 360° radial image (Ultra ICE, Boston Scientific, Natick, Massachusetts). This catheter has no Doppler capability and image definition is not as good. 360° scan has a larger field of view and allows for a more comprehensive depiction of both atrial chambers and atrioventricular valves with their relationships and it also can be used as IVUS for great vessels.

Atrial fibrillation ablations are often like exploring a new forest; there are interesting findings unique to every patient and it is “what keeps you coming back.”  This is an electrogram recorded during an ablation after completing a left atrial pulmonary venous antrum isolation and assessing the left superior pulmonary vein for entrance/exit block. On first exam, it looks as if some work needs to be done but on closer inspection there is evidence of a “floating potential” and far-field sensing of atrial appendage activity.  The longer cycle length electrogram (~3100msec) is a pulmonary vein potential that is firing regularly but not conducting out to the left atrium (exit block).  In addition, the shorter cycle length (~1000msec) is a slightly lower frequency left atrial appendage signal that is often recorded from the proximate left superior pulmonary vein.  I get the “floating potentials” less than 10-20% of cases but it is a welcome finding.

High-frequency jet ventilation (HFJV) is used to decrease respiratory motion during atrial fibrillation ablations; however, the patient safety and efficacy of HFJV has not been evaluated during routine electrophysiology (EP) studies with radiofrequency ablation. This is a retrospective chart review of consecutive patients who underwent EP studies and ablations for supraventricular and ventricular arrhythmias while using HFJV. Any EP studies performed using HFJV where ablation was attempted were included for analysis; EP studies where no ablation was performed were not included. Patients underwent induction of general anesthesia with endotracheal intubation using intermittent positive pressure ventilation with sevoflurane in the EP laboratory prior to vascular access. HFJV was then provided by a commercial system with initial settings: ventilation rate at 100 cycles/min and driving pressure at 20–25 psi. Total intravenous anesthesia was then provided with dexmedetomidine and propofol as well as fentanyl and rocuronium titrated to bispectral index (Bis) score <60. The overall mean age of patients (n=72) was 55+/-18 years (ranges 18–84 years). The mean creatinine (mg/dl) was 1.0+/-0.3, the mean ejection was 0.58+/-0.08, and mean post-EP study length of stay was 1.4+/-0.9 days (range 1–5 days). There were no intraprocedural or major complications. There was a 6.9% rate of minor complications (n=5). There was a 97.2% overall ablation success rate (70 of 72 ablations). Ablations were successful in all subjects except for one left atrial flutter and one right atrial tachycardia. Only one of 72 (1.4%) procedures required discontinuation of general anesthesia and HFJV to induce arrhythmia (right ventricular outflow tract ventricular tachycardia). No patient experienced procedural awareness and the mean Bis score was 40+/-5.3. This report provides further evidence the routine use of jet ventilation in the electrophysiology laboratory is safe, well tolerated, and efficacious, with ablation success rates similar to traditional sedation/ventilation techniques with a variety of arrhythmias.

For Full Study Please See:  http://www.innovationsincrm.com/cardiac-rhythm-management/2011/november/157-high-frequency-jet-ventilation

The performance of complex cardiac procedures, such as advanced defibrillator placement, structural heart interventions, or arrhythmia ablation, is facilitated by the visualization of 3D anatomy.

     The performance of complex cardiac procedures, such as advanced defibrillator placement, structural heart interventions, or arrhythmia ablation, is facilitated by the visualization of 3D anatomy.  Providing 3D views of internal body structures and interventional devices in one image, this state-of-the-art system assists physicians in diagnosis, surgical planning, interventional procedures and treatment follow-up.     It permits better management of structural heart disease, streamlines interventional procedures, and minimizes radiation dose to physicians, staff and patients by selecting working views without fluoroscopy.  Patients can undergo 3D angiography of the coronary sinus to guide a biventricular defibrillator implantation with a left ventricular pacemaker lead.  Patients can also undergo 3D angiography of the left atrium and pulmonary veins to plan an atrial fibrillation arrhythmia ablation.