Preventing complicated transseptal puncture with intracardiac echocardiography: case report

BACKGROUND: Recently, intracardiac echocardiography emerged as a useful tool in the electrophysiology laboratories for guiding transseptal left heart catheterizations, for avoiding thromboembolic and mechanical complications and assessing the ablation lesions characteristics. Although the value of ICE is well known, it is not a universal tool for achieving uncomplicated access to the left atrium. We present a case in which ICE led to interruption of a transseptal procedure because several risk factors for mechanical complications were revealed. CASE PRESENTATION: A case of a patient with paroxysmal atrial fibrillation and atrial flutter, and distorted intracardiac anatomy is presented. Intracardiac echocardiography showed a small oval fossa abouting to an enlarged aorta anteriorly. A very small distance from the interatrial septum to the left atrial free wall was seen. The latter two conditions were predisposing to a complicated transseptal puncture. According to fluoroscopy the transseptal needle had a correct position, but the intracardiac echo image showed that it was actually pointing towards the aortic root and most importantly, that it was virtually impossible to stabilize it in the fossa itself. Based on intracardiac echo findings a decision was made to limit the procedure only to ablation of the cavotricuspid isthmus and not to proceed further so as to avoid complications. CONCLUSION: This case report illustrates the usefulness of the intracardiac echocardiography in preventing serious or even fatal complications in transseptal procedures when the cardiac anatomy is unusual or distorted. It also helps to understand the possible mechanisms of mechanical complications in cases where fluoroscopic images are apparently normal

ZNAČAJ INTRAKARDIJALNIH EHOGENIH ŽARIŠTA FETALNOG SRCA: SADAŠNJE SHVAĆANJE I KLINIČKA VRIJEDNOST

Objective. To estimate the degree of risk of the echogenic intracardiac foci (IEF) for fetal chromosomopathies and to determine its association with structural anomalies of the fetus. Material and methods. During the period of two years 190 pregnant patients had been send for fetal echocardiography. Examination had been performed by transvaginal¬ (12–17 weeks of gestation) or transabdominal approach (18 weeks or more of gestation). Results. IEF was observed in 17 fetuses, multifocal appearance was found in 2 out of 17 fetuses. In 3 cases IEF had resolved during the 8 weeks period of time. Additional structural anomalies were detected in 11 fetuses. In 2 fetuses trisomy 21 had been confirmed. Conclusion. A single soft marker as IEF is commonly encountered during the second trimester among the fetuses with chromosomal aberation. As do many sonographic markers IEF can be resolved during the pregnancy and often can be found in normal fetuses.Cilj rada je bio na vlastitom uzorku utvrditi u kojoj mjeri ultrazvučni nalaz hiperehogenih intrakardijalnih žarišta (IEF) pridonosi dijagnostici kromosomopatija i strukturalnih anomalija. Uzorak i metode. Tijekom dvije godine 190 trudnica između 12. i 39. tjedna trudnoće je primljeno radi fetalne ehokardiografije. Pregled je obavljen vaginalnom sondom od 5 MHz pri trudnoćama 12.–17. tjedna ili zavinutom abdominalnom sondom od 3,5 MHz nakon 17. tjedna trudnoće. Rezultati. IEF su nađeni u 17 fetusa, multifokalni u 2 od njih. U 3 fetusa su IEF u roku od osam tjedana nestali. U 11 fetusa su nađene dodatne strukturalne anomalije. Trisomija 21 je potvrđena u 2 fetusa. Zaključak. IEF su »meki« ultrazvučni biljezi fetalne aneuploidije, često su prolazni, a nalaze se i u eukariotičnih fetusa

Advanced ablation strategies for management of post-surgical atrial arrhythmias.

Post-surgical arrhythmias include a wide range of arrhythmias occurring late after cardiac surgery and represent a complex substrate for catheter ablation either because of extended scar and remodeling or because of limited access to the area of interest. Novel image integration and ablation tools have made the catheter ablation in this population both feasible and successful. We review a structured approach to catheter ablation of post-surgical atrial arrhythmias in various patient cohorts including the most common congenital heart defects

Novel Strategies in the Ablation of Typical Atrial Flutter: Role of Intracardiac Echocardiography

Radiofrequency ablation (RFA) of the cavo-tricuspid isthmus (CTI) is one of the most frequently performed procedures in electrophysiology. Despite a high success rate, ablation of the CTI can be unusually difficult in some cases. Multiple tools like angiography, 3D mapping, remote navigation and intracardiac echocardiography (ICE) have been introduced to facilitate typical flutter ablation. This review article summarizes the clinical value of different strategies and tools used for CTI ablation focusing on the importance of approaches utilizing ICE

Ultrasonic characterization of the pulmonary venous wall: echographic and histological correlation

Background: Pulmonary vein isolation with radiofrequency catheter ablation techniques is used to prevent recurrences of human atrial fibrillation. Visualization of the architecture at the venoatrial junction could be crucial for these ablative techniques. Our study assesses the potential for intravascular ultrasound to provide this information. Methods and Results: We retrieved 32 pulmonary veins from 8 patients dying from noncardiac causes. We obtained cross-sectional intravascular ultrasound (IVUS) images with a 3.2F, 30-MHz ultrasound catheter at intervals on each vein. Histological cross-sections at the intervals allowed comparisons with ultrasonic images. The pulmonary venous wall at the venoatrial junction revealed a 3-layered ultrasonic pattern. The inner echogenic layer represents both endothelium and connective tissue of the media (mean maximal thickness, 1.4±0.3 mm). The middle hypoechogenic stratum corresponds to the sleeves of left atrial myocardium surrounding the external aspect of the venous media. This layer was thickest at the venoatrial junction (mean maximal thickness, 2.6±0.8 mm) and decreased toward the lung hilum. The outer echodense layer corresponds to fibro-fatty adventitial tissue (mean maximal thickness, 2.15±0.36 mm). We found a close agreement among the IVUS and histological measurements for maximal luminal diameter (mean difference, -0.12±1.3 mm) and maximal muscular thickness (mean difference, 0.17±0.13 mm) using the Bland and Altman method. Conclusions: Our experimental study demonstrates for the first time that IVUS images of the pulmonary veins can provide information on the distal limits and thickness of the myocardial sleeves and can be a valuable tool to help accurate targeting during ablative procedures

Clinical application of intracardiac echocardiography in the ablation of atrial fibrillation

Background: The application of intracardiac echocardiography (ICE) in atrial fibrillation (AF) ablation may increase the success rate and decrease the complication rate of the procedure. We present our preliminary observations concerning the utility of ICE in AF ablation. Methods: In February and July 2004 we performed 6 radiofrequency (RF) ablations guided by ICE (EP Med Systems) in patients with atrial tachyarrhythmia. All patients had undergone at least three months of oral anticoagulation therapy before the procedure. For three days before ablation enoxaparin was administered. During each procedure the ICE catheter was placed in the right atrium. Transseptal puncture was guided by fluoroscopy and ICE imaging. After placement of the introducer in the left atrium a bolus of heparin (100 IU/kg) was administered followed by additional boluses (1000 IU/h). Electroanatomical isolation of the pulmonary vein ostia was performed with a 4 mm ablation catheter (RF energy was set at 50–55oC and 25–35 W). RF energy was titrated if microbubble formation was observed and delivery was immediately terminated when a brisk shower of bubbles was detected. Results: Transseptal puncture was performed at a typical location in all patients (atypical anatomy was not revealed by ICE). The microbubble effect was observed in all patients. In 1 patient the effect was observed despite a power reduction and the RF application had to be terminated. The following short (15-20 s) applications were performed with low RF energy. During the same procedure ICE imaging revealed 2 thrombi (2 and 5 mm) on the Lasso electrode. None of the patients experienced thromboembolic complications. Conclusions: Intracardiac echocardiography is a useful imaging method in RF ablation. Low RF-energy and standard anticoagulation treatment do not prevent the microbubble effect and the formation of small thrombi