Intracardiac Echocardiography (intracardiac + echocardiography)

Distribution by Scientific Domains


Selected Abstracts


Intracardiac Echocardiography in Patients with Pacing and Defibrillating Leads: A Feasibility Study

ECHOCARDIOGRAPHY, Issue 6 2008
Maria Grazia Bongiorni M.D.
Background: Lead extraction, an important and necessary component of treatment for many common device and lead-related complications, is a procedure that can provoke much anxiety in even the most experienced operators given the potentially serious complications. The principal impediment to lead extraction is the body's response to an intravascular foreign body with matrix intravascular neoformation, which causes the lead to adhere to the endocardium or vascular structure, increasing the risk of vascular or myocardial damage with lead removal. Fluoroscopic visualization, the commonly visualization used tool, has several limits in terms of anatomical structures visualization. The aim of this study was to assess the safety and feasibility of intracardiac echocardiography (ICE) in patients undergoing pacing and defibrillating leads before and during a transvenous device removal, and its potential role in detecting intracardiac leads and areas of fibrous adherence. Methods: ICE interrogation was performed in 25 consecutive patients with pacing and defibrillating implantable cardioverter defibrillators (ICD) leads before and during device removal. Results: A programmed ICE analysis was completed in 23 out of 25 patients with excellent resolution, providing a "qualitative-quantitative" information on anatomical structures, cardiac leads, and related areas of fibrous adherence. No ICE-related complications occurred. Conclusions: ICE evaluation is safe and feasible in patients with pacing and defibrillating leads before and during transvenous lead removal, offering an excellent visualization of cardiac leads and related areas of adherence. ICE can assist pacing and ICD lead removal and could improve procedure efficacy and safety. [source]


Proximal Coronary Hemodynamic Changes Evaluated by Intracardiac Echocardiography during Myocardial Ischemia and Reperfusion in a Canine Model

ECHOCARDIOGRAPHY, Issue 3 2008
Beibei Han M.D.
Background: The purpose of this study was to assess whether the dynamic changes in coronary flow velocity and coronary flow velocity reserve (CFVR) by intracardiac echocardiography (ICE) within proximal coronary arteries are related to myocardial perfusion status and infarct size in a myocardial ischemia-reperfusion injury model. Methods: In 14 dogs, left anterior descending coronary artery (LAD) was ligated for 2 hours followed by 2 hours reperfusion. Coronary flow velocity was obtained by ICE within coronary arteries at baseline, and at the end of both occlusion and reperfusion period. The CFVR was calculated as the ratio of hyperemic to resting peak diastolic velocity (PDV). Myocardial perfusion was evaluated by real time myocardial contrast echocardiography (MCE). The infarct area was detected by triphenyltetrazolium chloride (TTC) staining and expressed as the percentage of the whole left ventricular (LV) area. Results: CFVR significantly decreased both in proximal LAD and left circumflex (LCx) artery at the end of occlusion, and did not recover at the end of reperfusion. However, no significant difference in flow parameters was observed between dogs with myocardial perfusion defect and those without. CFVR in LAD at the end of reperfusion did not correlate with the infarct size (r =,0.182, P = NS) either. Conclusions: Decreased CFVR detected by ICE occurs both in ischemic and in nonischemic proximal arteries during myocardial ischemia and early stage of reperfusion. This change in CFVR has poor correlation with the extent of microvascular impairment and cannot be used to predict infarct size. [source]


Intracardiac Echocardiography in the Diagnosis of Right-Sided Partial Anomalous Pulmonary Venous Drainage

ECHOCARDIOGRAPHY, Issue 6 2002
Mario Zanchetta M.D.
No abstract is available for this article. [source]


A Conservative Approach to Performing Transseptal Punctures Without the Use of Intracardiac Echocardiography: Stepwise Approach with Real-Time Video Clips

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2007
ALAN CHENG M.D.
Atrial transseptal puncture as a means of accessing the left heart is a critical component of catheter ablation procedures for atrial fibrillation, left-sided accessory pathways, and access to the left ventricle in patients with certain types of prosthetic aortic valves. Although this technique has been performed successfully since the 1950s, severe and potentially life-threatening complications can still occur, including cardiac tamponade and/or death. Some have adopted the use of intracardiac echocardiography, but our laboratory and many others throughout the world have successfully relied on fluoroscopic imaging alone. The aim of this brief report is to describe in detail our technique for performing transseptal punctures during catheter ablation procedures for atrial fibrillation. We employ a similar approach when targeting left-sided accessory pathways, although only a single transseptal is performed in those cases. Utilizing a series of real-time video clips, we describe our technique of double transseptal puncture and illustrate in detail ways in which to avoid common pitfalls. [source]


Real-time Integration of Intracardiac Echocardiography and Electroanatomic Mapping in PVCs Arising from the LV Anterior Papillary Muscle

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2009
Ph.D., TAKUMI YAMADA M.D.
A 54-year-old woman with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Three-dimensional (3D) geometries of the papillary muscles and chamber of the left ventricle (LV) were reconstructed using a CARTO-based 3D ultrasound imaging system (Biosense Webster Inc., Diamond Bar, CA, USA) during the PVCs. Activation mapping in the LV was then performed during the PVCs and the activation map revealed the earliest ventricular activation on the anterior papillary muscle. An irrigated radiofrequency current delivered at that site with guidance from that system eliminated the PVCs. This case may suggest that the guidance system may be feasible and useful for catheter ablation of PVCs arising from uncommon sites. [source]


Use of Intracardiac Echocardiography in Guiding Radiofrequency Catheter Ablation of Atrial Tachycardia in a Patient After the Senning Operation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2003
ANITA KEDIA
A patient with D-transposition of the great arteries developed drug refractory atrial tachycardia 12 years after a Senning operation. Electrophysiological study confirmed the presence of atrial baffle-tricuspid valve isthmus dependent reentrant intraatrial tachycardia. Intracardiac echocardiography facilitated initial identification of structures, catheter positioning, and identification of the atrial baffle-tricuspid valve isthmus. (PACE 2003; 26:2178,2180) [source]


Phased-Array Intracardiac Echocardiography for Guiding Transseptal Catheter Placement: Utility and Learning Curve

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2002
SUSAN B. JOHNSON
JOHNSON, S.B., et al.: Phased-Array Intracardiac Echocardiography for Guiding Transseptal Catheter Placement: Utility and Learning Curve. The utility of a new intracardiac 64-element, phased-array, longitudinal ultrasound imaging system for guiding transseptal catheterization was assessed during 69 crossing attempts in 45 dogs because of the inherent limitations of fluoroscopy and mechanical ultrasound. Multifrequency (7.5,8.5 MHZ) imaging of the membranous fossa ovalis, posterior left atrium, and left atrial appendage was conducted from the right atrium. Contact of the Brockenbrough needle with the interatrial septum as reflected by membranous fossa ovalis "tenting" was uniformly identified. Transseptal crossing and advancement of the dilator and sheath were adequately imaged because of deeper ultrasound tissue penetration. Transseptal catheterization was successfully accomplished in 44 of 45 dogs: on the first attempt in 40 and with additional attempts in 4 and confirmed by direct far-field imaging of nonagitated saline injection via the sheath. Total transseptal catheterization time was 3.0 ± 1.8 minutes. Unsuccessful first attempts and/or subsequent sheath pullback into the right atrium with catheter manipulation were also readily recognized. Insertion of the transseptal needle beyond the ultrasound imaging plane resulted in perforation of the posterior left atrial wall in three attempts. Accompanying effusions in these animals and three others related to subsequent intracardiac ablation catheter manipulation were readily identified and monitored echocardiographically. In conclusion, phased-array intracardiac imaging provides a highly reliable means of guiding transseptal access to the left atrium. In addition, inadvertent complications such as perforation and pericardial effusion development can be readily recognized. [source]


Synchronous Ventricular Pacing without Crossing the Tricuspid Valve or Entering the Coronary Sinus,Preliminary Results

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2009
BENHUR D. HENZ M.D.
Background: Right ventricular apical (RVA) pacing promotes tricuspid regurgitation (TR), electromechanical dyssynchrony, and ventricular dysfunction. We tested a novel intramyocardial bipolar lead to assess whether stimulation of the atrioventricular septum (AVS) produces synchronous ventricular activation without crossing the tricuspid valve (TV). Methods: A lead with an active external helix and central pin was placed on the AVS and the RVA in three dogs. High-density electroanatomic (EA) mapping was performed of both ventricles endocardially and epicardially. Intracardiac echocardiography was used to access ventricular synchrony. Results: The lead was successfully deployed into the AVS in all cases with consistent capture of the ventricular myocardium without atrial capture or sensing. The QRS duration was less with AVS compared with RVA pacing (89 ± 4 ms vs. 100 ± 11 ms [P < 0.0001, GEE P = 0.03]). There was decreased delay between color Doppler M-mode visualized peak contraction of the septum and the mid left ventricular free wall with AVS compared with RVA pacing (89 ± 91 ms vs. 250 ± 11 ms [P < 0.0001, GEE P = 0.006]). Activation time between the mid septum and mid free wall was shorter with AVS versus RVA pacing (20.4 ± 7.7 vs. 30.8 ± 11.6 [P = 0.01, GEE P = 0.07]). The interval between QRS onset to earliest free wall activation was shorter with AVS vs. RVA pacing (19.2 ± 6.4 ms vs. 31.1 ± 11.7 ms [P = 0.005, GEE P = 0.02]). Conclusion: The AVS was successfully paced in three dogs resulting in synchronous ventricular activation without crossing the TV. [source]


Use of Intracardiac Echocardiography in Guiding Radiofrequency Catheter Ablation of Atrial Tachycardia in a Patient After the Senning Operation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2003
ANITA KEDIA
A patient with D-transposition of the great arteries developed drug refractory atrial tachycardia 12 years after a Senning operation. Electrophysiological study confirmed the presence of atrial baffle-tricuspid valve isthmus dependent reentrant intraatrial tachycardia. Intracardiac echocardiography facilitated initial identification of structures, catheter positioning, and identification of the atrial baffle-tricuspid valve isthmus. (PACE 2003; 26:2178,2180) [source]


Transcatheter Intracardiac Echocardiography-Assisted Closure of Interatrial Shunts: Complications and Midterm Follow-Up

ECHOCARDIOGRAPHY, Issue 2 2009
Gianluca Rigatelli M.D.
Objective: It has been suggested that intracardiac echocardiography (ICE) improves the safety and effectiveness of transcatheter device-based closure of interatrial shunts, but the impact of this technique on midterm follow-up is unknown. We sought to prospectively evaluate midterm follow-up results of ICE-aided transcatheter closure of interatrial shunts in adults. Methods: Over a 48-month period, we prospectively enrolled 140 consecutive patients (mean age 43 ± 15. 5 years, 98 females) who had been referred to our center for catheter-based closure of interatrial shunts. All patients were screened with transesophageal echocardiography (TEE) before the operation. Patients who met the inclusion criteria underwent ICE study and attempted closure. Immediate success rates, predischarge occlusion rates, complication rates, as well as fluoroscopy and procedural times, patients' radiological exposure, midterm complication rates, and midterm occlusion rates were evaluated. Results: One hundred patients out of 140 (71.4%) underwent an attempt at transcatheter closure. After ICE study and measurements, the TEE-planned device type and size was changed in 31 patients with patent foramen ovale whereas the TEE-planned device size was changed in 41 patients with atrial septal defect (globally 72%). Procedural success rate, predischarge occlusion rate, and complication rate were 99, 90.7, and 12%, respectively. On mean follow-up of 36.6 ± 14.8 months the follow-up occlusion rate was 96.5%. No aortic erosion or device thrombosis was observed. Conclusions: ICE-guided interatrial shunt transcatheter closure is safe and effective and appears to have excellent midterm results thus avoiding the complications caused by device oversizing, such as aortic erosion and device thrombosis. [source]


Intracardiac Echocardiography in Patients with Pacing and Defibrillating Leads: A Feasibility Study

ECHOCARDIOGRAPHY, Issue 6 2008
Maria Grazia Bongiorni M.D.
Background: Lead extraction, an important and necessary component of treatment for many common device and lead-related complications, is a procedure that can provoke much anxiety in even the most experienced operators given the potentially serious complications. The principal impediment to lead extraction is the body's response to an intravascular foreign body with matrix intravascular neoformation, which causes the lead to adhere to the endocardium or vascular structure, increasing the risk of vascular or myocardial damage with lead removal. Fluoroscopic visualization, the commonly visualization used tool, has several limits in terms of anatomical structures visualization. The aim of this study was to assess the safety and feasibility of intracardiac echocardiography (ICE) in patients undergoing pacing and defibrillating leads before and during a transvenous device removal, and its potential role in detecting intracardiac leads and areas of fibrous adherence. Methods: ICE interrogation was performed in 25 consecutive patients with pacing and defibrillating implantable cardioverter defibrillators (ICD) leads before and during device removal. Results: A programmed ICE analysis was completed in 23 out of 25 patients with excellent resolution, providing a "qualitative-quantitative" information on anatomical structures, cardiac leads, and related areas of fibrous adherence. No ICE-related complications occurred. Conclusions: ICE evaluation is safe and feasible in patients with pacing and defibrillating leads before and during transvenous lead removal, offering an excellent visualization of cardiac leads and related areas of adherence. ICE can assist pacing and ICD lead removal and could improve procedure efficacy and safety. [source]


Proximal Coronary Hemodynamic Changes Evaluated by Intracardiac Echocardiography during Myocardial Ischemia and Reperfusion in a Canine Model

ECHOCARDIOGRAPHY, Issue 3 2008
Beibei Han M.D.
Background: The purpose of this study was to assess whether the dynamic changes in coronary flow velocity and coronary flow velocity reserve (CFVR) by intracardiac echocardiography (ICE) within proximal coronary arteries are related to myocardial perfusion status and infarct size in a myocardial ischemia-reperfusion injury model. Methods: In 14 dogs, left anterior descending coronary artery (LAD) was ligated for 2 hours followed by 2 hours reperfusion. Coronary flow velocity was obtained by ICE within coronary arteries at baseline, and at the end of both occlusion and reperfusion period. The CFVR was calculated as the ratio of hyperemic to resting peak diastolic velocity (PDV). Myocardial perfusion was evaluated by real time myocardial contrast echocardiography (MCE). The infarct area was detected by triphenyltetrazolium chloride (TTC) staining and expressed as the percentage of the whole left ventricular (LV) area. Results: CFVR significantly decreased both in proximal LAD and left circumflex (LCx) artery at the end of occlusion, and did not recover at the end of reperfusion. However, no significant difference in flow parameters was observed between dogs with myocardial perfusion defect and those without. CFVR in LAD at the end of reperfusion did not correlate with the infarct size (r =,0.182, P = NS) either. Conclusions: Decreased CFVR detected by ICE occurs both in ischemic and in nonischemic proximal arteries during myocardial ischemia and early stage of reperfusion. This change in CFVR has poor correlation with the extent of microvascular impairment and cannot be used to predict infarct size. [source]


Role of Echocardiography in Percutaneous Occlusion of the Left Atrial Appendage

ECHOCARDIOGRAPHY, Issue 4 2007
Mráz M.D.
Percutaneous occlusion of the left atrial appendage (LAA) is a modern alternative for the treatment of patients with atrial fibrillation (AF) and with a high risk of stroke who are not eligible for long-term anticoagulation therapy. Echocardiography plays a significant role in selecting patients, guiding the procedure, and in the postprocedural follow-up. Objectives and methods: To test the role of transesophagoeal echocardiography (TEE) and intracardiac echocardiography (ICE) in facilitating and shortening the procedure. Results: ICE represents a more convenient approach in patients who are not under generally anesthesia and helps to facilitate transseptal puncture. On the other hand, TEE, having the ability to rotate the image plane, helps to better determine the position of the occluder. Conclusions: Echocardiographic guidance of this procedure is essential. Which approach will be preferred will depend on the development of these two methods. [source]


A Conservative Approach to Performing Transseptal Punctures Without the Use of Intracardiac Echocardiography: Stepwise Approach with Real-Time Video Clips

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2007
ALAN CHENG M.D.
Atrial transseptal puncture as a means of accessing the left heart is a critical component of catheter ablation procedures for atrial fibrillation, left-sided accessory pathways, and access to the left ventricle in patients with certain types of prosthetic aortic valves. Although this technique has been performed successfully since the 1950s, severe and potentially life-threatening complications can still occur, including cardiac tamponade and/or death. Some have adopted the use of intracardiac echocardiography, but our laboratory and many others throughout the world have successfully relied on fluoroscopic imaging alone. The aim of this brief report is to describe in detail our technique for performing transseptal punctures during catheter ablation procedures for atrial fibrillation. We employ a similar approach when targeting left-sided accessory pathways, although only a single transseptal is performed in those cases. Utilizing a series of real-time video clips, we describe our technique of double transseptal puncture and illustrate in detail ways in which to avoid common pitfalls. [source]


Conduction Characteristics at the Crista Terminalis During Onset of Pulmonary Vein Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2004
SIMON P. FYNN M.D.
Introduction: Focal atrial fibrillation (AF) may initiate with an irregular rapid burst of atrial ectopic (AE) activity from a pulmonary vein (PV) focus, but how AF is maintained it is not known. The crista terminalis (CT) is an important line of block in atrial flutter (AFL), but its role in AF has not been determined. The aim of this study was to examine the conduction properties of the CT during onset of AF. Methods and Results: In 10 patients (mean age 38 ± 8 years), we analyzed conduction across the CT during onset of focal AF from an arrhythmogenic PV and during pacing from the same PV at cycle lengths of 700 and 300 ms. A 20-pole catheter was positioned on the CT using intracardiac echocardiography. In 10 control patients with no history of AF, we analyzed conduction across the CT during pacing from the distal coronary sinus at 700 and 300 ms. In all 10 AF patients, AF was initiated with 1 to 9 AE beats (median 5) from a PV. During sinus rhythm, there were no split components (SC) recorded on the CT. During PV AE activity, discrete SC were recorded on the CT in all patients over 6.3 ± 0.9 bipoles (3.7 ± 0.3 cm). Maximal splitting of SC was 66 ± 31 ms (37,139). There was an inverse relationship between AE coupling intervals and the degree of splitting between SC in all patients. Degeneration to AF was preceded by progressive decrement across the CT. SC were recorded during PV pacing at 700 and 300 ms (maximal distance between SC of 24 ± 3 ms and 43 ± 5 ms, respectively, P < 0.001). Maximum SC at CT in controls was 13 ± 8 ms at 700 ms (P = 0.06 vs AF patients) and 16 ± 9 ms at 300 ms (P < 0.01 vs AF patients). Conclusion: (1) These observations provide evidence of anisotropic, decremental conduction across the CT during onset of focal AF and during pacing from the same PV. A line of functional conduction block develops along this anatomic structure (CT). Whether this line of block acts as an initiator of AF or simply contributes passively to nonuniform fibrillatory conduction is unknown. (2) In some patients with focal AF, development of conduction block along the CT may provide a substrate for typical AFL. [source]


Entrainment Mapping of Dual-Loop Macroreentry in Common Atrial Flutter:

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2004
New Insights into the Atrial Flutter Circuit
Introduction: The aim of this study was to determine using entrainment mapping whether the reentrant circuit of common type atrial flutter (AFL) is single loop or dual loop. Methods and Results: In 12 consecutive patients with counterclockwise (CCW) AFL, entrainment mapping was performed with evaluation of atrial electrograms from the tricuspid annulus (TA) and the posterior right atrial (RA) area. We hypothesized that a dual-loop reentry could be surmised from "paradoxical delayed capture" of the proximal part of the circuit having a longer interval from the stimulus to the captured beat compared with the distal part of the circuit. In 6 of 12 patients with CCW AFL, during entrainment from the septal side of the posterior blocking line, the interval from the stimulus to the last captured beat was longer at the RA free wall than at the isthmus position. In these six patients with paradoxical delayed capture, flutter cycle length (FCL) was 227 ± 12 ms and postpacing interval minus FCL was significantly shorter at the posterior blocking line than at the RA free wall (20 ± 11 ms vs 48 ± 33 ms, P < 0.05). In two of these patients, early breakthrough occurred at the lateral TA. A posterior block line was confirmed in all six patients in the sinus venosa area by intracardiac echocardiography. Conclusion: Half of the patients with common type AFL had a dual-loop macroreentrant circuit consisting of an anterior loop (circuit around the TA) and a posterior loop (circuit around the inferior vena cava and the posterior blocking line). (J Cardiovasc Electrophysiol, Vol. 15, pp. 679-685, June 2004) [source]


Effect of Electrical and Structural Remodeling on Spatiotemporal Organization in Acute and Persistent Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2002
JOSEPH G. AKAR M.D.
Spatiotemporal Organization in Atrial Fibrillation.Introduction: Atrial fibrillation (AF) may originate from discrete sites of periodic activity. We studied the effect of structural and electrical remodeling on spatiotemporal organization in acute and persistent AF. Methods and Results: Atrial effective refractory periods (AERPs) were recorded from five different sites at baseline and after pacing in acute AF (n = 8 dogs) and persistent AF (n = 8). Four persistent AF dogs subsequently were cardioverted to sinus rhythm to allow AERP recovery. Periodicity was quantified by calculating power spectra on left atrial electrograms obtained from a 64-electrode basket catheter. Left atrial size was measured by intracardiac echocardiography and structural changes were assessed by electron microscopy. Mean AERPs decreased after pacing in acute (128 ± 16 msec to 108 ± 29 msec, P < 0.001) and persistent AF (135 ± 16 msec to 104 ± 24 msec, P < 0.0001). AERP recovery was established after 7 days of sinus rhythm. Structural changes were mild in acute AF, severe in persistent AF, and remained severe after AERP recovery. A single dominant frequency was identified in 94% of acute AF bipoles, 57% in persistent AF, and 76% after AERP recovery. Average correlation coefficient was 0.82 among acute AF bipoles, 0.63 in persistent AF, and 0.73 after AERP recovery. Conclusion: Transition from acute to persistent AF is associated with loss of spatiotemporal organization. A single dominant frequency recruits the majority of the left atrium in acute AF. Persistent AF, however, is associated with structural remodeling and dominant frequency dispersion. Recovery of refractoriness only partially restores spatiotemporal organization, indicating a major role for structural remodeling in the maintenance of persistent AF. [source]


A Comparison of Echocardiographic Modalities to Guide Structural Heart Disease Interventions

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2008
PAUL A. HUDSON M.D.
Percutaneous techniques to treat structural heart disease are rapidly evolving based on innovative interventions and the considerable advancement in image guidance technology. While two-dimensional transthoracic and transesophageal echocardiography have been integral to procedural planning and execution, intracardiac and three-dimensional echocardiography supply unique visualization of target structures with a potential improvement in patient safety and procedural efficacy. The choice of image guidance modality is based on specific differences between imaging systems, as well as other variables including cost, patient safety, operator expertise, and complexity of procedure. We will compare the adjunctive imaging tools for structural heart disease interventions, with a focus on intracardiac echocardiography and real-time three-dimensional transesophageal echocardiography. [source]


Percutaneous Treatment for Mitral Regurgitation: The QuantumCor System

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2008
RICHARD R. HEUSER M.D.
Aims:Percutaneous edge-to-edge techniques and annuloplasty have been used to treat mitral regurgitation (MR). However, neither intervention can be performed reliably a second time and, with annuloplasty, a foreign body is left behind. The mitral and tricuspid annuli are areas of dense collagen (Fig. 1); treatment with radiofrequency (RF) energy in sheep reduces their size, and can be repeated without affecting the coronary sinus. RF energy may also be used in leaflet procedures. Our aim was to improve mitral valve competence using techniques that can be incorporated into a minimally invasive approach. Figure 1. This trichrome stain slide shows the amount of collagen present in the mitral annulus (in green). Methods:In open-heart procedures in 16 healthy sheep (6 with naturally occurring MR), we used a malleable probe (QuantumCor, Inc., Lake Forest, CA) that conforms to the annular shape to deliver RF energy via a standard generator to replicate a surgical mitral annular ring. Four segments of the posterior mitral valve annulus were treated while on cardiopulmonary support via a left thoracotomy with access via the atrial appendage. Seven sheep were followed chronically. Results:All sheep underwent intracardiac echocardiography (ICE) or direct circumferential measurement of the mitral annulus before and after RF therapy. RF therapy was administered in less than 4 minutes in each case, and the mean anteroposterior (AP) annular distance was reduced by a mean of 5.75 ± 0.86 mm (23.8% reduction, P< 0.001). In the 6 sheep with nonischemic MR, regurgitation was eliminated. Acute histopathology (HP) demonstrated no damage to the leaflets, coronary sinuses, or coronary arteries. At 30 days, the AP distance continued to be reduced in the 7 surviving sheep (mean 5.0 ± .6 mm, 21.4% reduction, P< 0.001). Conclusions:In a sheep model, RF energy applied for less than 4 minutes per case at subablative temperatures in four quadrants of the posterior mitral valve annulus reduced the AP and circumferential annular distances significantly, and eliminated nonischemic MR. Results will need to be confirmed in follow-up studies to determine safety and efficacy. RF energy administered as a novel, percutaneous method of mitral valve annuloplasty may have the potential to reduce morbidity and mortality associated with current surgical techniques. [source]


Transesophageal Echocardiography and Intracardiac Echocardiography Differently Predict Potential Technical Challenges or Failures of Interatrial Shunts Catheter-Based Closure

JOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 1 2007
GIANLUCA RIGATELI M.D.
We sought to prospectively assess the role of transesophageal (TEE) and intracardiac echocardiography (ICE) in detecting potential technical difficulties or failures in patients submitted to interatrial shunts percutaneous closure. We prospectively enrolled 46 consecutive patients (mean age 35±28, 8 years, 30 female) referred to our center for catheter-based closure of interatrial shunts. All patients were screened with TEE before the intervention. Patients who met the inclusion criteria underwent ICE study before the closure attempt (40 patients). TEE detected potential technical difficulties in 22.5% (9/40) patients, whereas ICE detected technical difficulties in 32.5% (13/40 patients). In patients with positive TEE/ICE the procedural success (92.4% versus 100% and, P = ns) and follow-up failure rate (7.7% versus 0%, P = ns) were similar to patients with negative TEE/ICE, whereas the fluoroscopy time (7 ± 1.2 versus 5 ± 0.7 minutes, P < 0.03), the procedural time (41 ± 4.1 versus 30 ± 8.2 minutes, P ± 0.03), and technical difficulties rate (23.1% versus 0%, P = 0.013) were higher. Differences between ICE and TEE in the evaluation of rims, measurement of ASD or fossa ovalis, and detection of venous valve and embryonic septal membrane remnants impacted on technical challenges and on procedural and flouroscopy times but did not influence the success rate and follow-up failure rate. [source]


Linear Radiofrequency Microcatheter Ablation Guided by Phased Array Intracardiac Echocardiography Combined with Temperature Decay

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2009
DAVID KEANE M.D., Ph.D.
Background:Fluoroscopy-guided catheter placement is limited in its ability to determine electrode-endocardial contact and involves radiation exposure. We hypothesized that (1) intracardiac echocardiography (ICE) would provide superior assessment of linear electrode contact compared to fluoroscopy and (2) slow temperature decay upon discontinuation of the radiofrequency current (time for temperature to fall 90% after a 10-second test application of the radiofrequency current T90) would indicate optimal electrode-myocardial contact. Methods:Sixty endocardial lesions were created in the atria and ventricles of six goats by simultaneous delivery of the radiofrequency current through two linear electrodes of a microcatheter with a central interelectrode thermocouple. Catheter placement was guided by fluoroscopy. A 7.5-MHz ICE transducer in the right atrium or ventricle assessed electrode contact. T90 and previously reported parameters of electrode contact and lesion formation were recorded. Histomorphometry was performed on the lesions. Results:T90 was 4.27 ± 4.98 seconds. Lesion depth significantly correlated with ICE assessment of electrode contact (r = 0.56, P = 0.001); T90 upon radiofrequency current offset (r = 0.48, P = 0.008), impedance fall upon radiofrequency current onset (r = 0.37, P = 0.008), bipolar pacing threshold preablation (r =,0.56, P = 0.001), bipolar electrogram amplitude preablation (r = 0.43, P = 0.02), but not with fluoroscopic assessment of the electrode contact (r = 0.18, n.s.). For the prediction of achieving a lesion depth of >2 mm, a T90 of >4.0 seconds yielded a specificity of 86% and a sensitivity of 52%, ICE yielded a specificity and sensitivity of 58% and 68%, respectively, while the specificity and sensitivity of fluoroscopy were 26% and 68%, respectively. Both ICE and T90 provide additional clinical relevance during guidance of cardiac microcatheter ablation. [source]


The Effect of Ablation Electrode Length and Catheter Tip to Endocardial Orientation on Radiofrequency Lesion Size in the Canine Right Atrium

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2002
RODRIGO C. CHAN
CHAN, R.C., et al.: The Effect of Ablation Electrode Length and Catheter Tip to Endocardial Orientation on Radiofrequency Lesion Size in the Canine Right Atrium. Although the determinants of radiofrequency lesion size have been characterized in vitro and in ventricular tissue in situ, the effects of catheter tip length and endocardial surface orientation on lesion generation in atrial tissue have not been studied. Therefore, the dimensions of radiofrequency lesions produced with 4-, 6-, 8-, 10-, and 12-mm distal electrode lengths were characterized in 26 closed-chested dogs. The impact of parallel versus perpendicular catheter tip/endocardial surface orientation, established by biplane fluoroscopy and/or intracardiac echocardiography, on lesion dimensions was also assessed. Radiofrequency voltage was titrated to maintain a steady catheter tip temperature of 75°C for 60 seconds. With a perpendicular catheter tip/tissue orientation, the lesion area increased from 29 ± 7 mm2 with a 4-mm tip to 42 ± 12 mm2 with the 10-mm tip, but decreased to 29 ± 8 mm2 with ablation via a 12-mm tip. With a parallel distal tip/endocardial surface orientation, lesion areas were significantly greater: 54 ± 22 mm2 with a 4-mm tip, 96 ± 28 mm2 with a 10- mm tip and 68 ± 24 mm2 with a 12-mm tip (all P < 0.001 vs perpendicular orientation). Lesion lengths and apparent volumes were larger with parallel, compared to perpendicular tip/tissue orientations, although lesion depth was independent of catheter tip length with both catheter tip/tissue orientations. Electrode edge effects were not observed with any tip length. Direct visualization using intracardiac ultrasound guidance was subjectively helpful in insuring an appropriate catheter tip/tissue interface needed to maximize lesion size. Although atrial lesion size is critically dependent on catheter tip length, it is more influenced by the catheter orientation to the endocardial surface. This information may also be helpful in designing electrode arrays for the creation of continuous linear lesions for the elimination of complex atrial tachyarrhythmias. [source]


Percutaneous closure of patent foramen ovale guided by intracardiac echocardiography and performed through the transfemoral approach in the presence of previously placed inferior vena cava filters: A case series

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2004
Hany Awadalla MD
Abstract We present three patients with cryptogenic stroke who underwent transcatheter closure of a patent foramen ovale. All patients have had history of deep venous thrombosis and pulmonary embolism with placement of inferior vena caval filters. The patients were not initially considered suitable candidates for the procedure because of risk of dislodgment of previously implanted inferior vena cava filter. Catheter Cardiovasc Interv 2004;63:242,246. © 2004 Wiley-Liss, Inc. [source]


Catheter-based intracardiac echocardiography in the interventional cardiac laboratory

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2004
Zheng Liu MD
Abstract Recent advances in technology have engendered a renewed enthusiasm in the use of intracardiac echocardiography (ICE) to guide and assess cardiac interventions. AcuNav is a phased-array sector imaging probe equipped with color and spectral Doppler capabilities. Previous-generation imaging catheters yielded unfamiliar limited-depth radial images with no flow information. Current imaging technology such as the AcuNav has not only consolidated the role of ICE but opened newer applications in the interventional laboratory. ICE has clear advantages over transesophageal echocardiography as the imaging modality of choice in the cardiac catheterization and electrophysiological laboratories. We review the technical evolution of ICE and describe the expanded utility of the AcuNav imaging catheter during cardiac interventions. Catheter Cardiovasc Interv 2004;63:63,71. © 2004 Wiley-Liss, Inc. [source]