Placement of electrode catheters into the coronary sinus during electrophysiology procedures using a femoral vein approach

The Dissimilar Impact in Atrial Substrate Modificationof Left and Right Pulmonary Veins Isolation after Catheter Ablation of Paroxysmal Atrial Fibrillation

Since the discovery of pulmonary veins (PVs) as foci of atrial fibrillation (AF), the commonest cardiac arrhythmia, investigation revolves around PVs catheter ablation (CA) results. Notwithstanding, CA process itself is rather neglected. We aim to decompose crucial CA steps: coronary sinus (CS) catheterization and the impact of left and right PVs isolation (LPVI, RPVI), separately. We recruited 40 paroxysmal AF patients undergoing first-time CA and obtained five-minute lead II and bipolar CS recordings during sinus rhythm (SR) before CA (B), after LPVI (L) and after RPVI (R). Among others, duration, amplitude and atrial-rate variability (ARV) were calculated for P-waves and CS local activation waves (LAWs). LAWs features were compared among CS channels for reliability analysis. P-waves and LAWs features were compared after each ablation step (B, L, R). CS channels: amplitude and area were different between distal/medial (p≤0.0014) and distal/mid-proximal channels (p≤0.0025). Medial and distal showed the most and least coherent values, respectively. Correlation was higher in proximal (≥93%) than distal (≤91%) areas. P-waves: duration was significantly shortened after LPVI (after L: p=0.0012, −13.30%). LAWs: insignificant variations. ARV modification was more prominent in LAWs (L: >+73.12%, p≤0.0480, R: <−33.94%, p≤0.0642). Medial/mid-proximal channels are recommended during SR. CS LAWs are not significantly affected by CA but they describe more precisely CA-induced ARV modifications. LPVI provokes the highest impact in paroxysmal AF CA, significantly modifying P-wave duration.

Initial experience with a novel re-sterilisable decapolar electrophysiology catheter

PURPOSE

Diagnostic electrophysiology catheters are single-use and their expense can act as a barrier to their use. A decapolar catheter with a re-sterilisable handle and inner core was developed, along with a disposable outer sheath. This initial experience evaluated the performance of the Khelix partially recyclable steerable decapolar electrophysiology catheter.

METHODS

Sequential patients requiring a decapolar steerable catheter were included in the study. Parameters such as time to positioning from right femoral vein, fluoroscopy time and dose, pacing and sensing thresholds, and the requirement for reposition and/or support sheath were recorded. A retrospective analysis from cases using a standard disposable decapolar catheter was used to compare CS cannulation success, support sheath requirement and cost.

RESULTS

11 re-sterilisable catheter handles were used in 64 patients, each time with a disposable sheath, at two New Zealand centres from December 2017 to June 2018. Pre-defined safety measures were met in all patients, with no catheter-related adverse events. The catheter was successfully positioned in the coronary sinus for 59 cases (92%). Based on initial manufacturer recommendations, the inner recyclable portion of the catheter was able to be re-used successfully up to 12 times with re-sterilisation between cases.

CONCLUSIONS

This initial study of an innovative, partially reusable, steerable decapolar electrophysiology catheter demonstrates that it may be used safely and successfully. Use of such a catheter may decrease the cost required for electrophysiology studies.

Effectiveness and Safety of the Femoral Venous Approach for Coronary Sinus Catheterization in Children

Coronary sinus (CS) catheterization is widely used during electrophysiological studies (EPS) and catheter ablation. The femoral venous (FV) approach to CS catheterization for EPS has been reported in adults but not in children. We report our experience with CS catheter placement through the FV approach in children. The charts of children with normal hearts who underwent EPS with CS cannulation were reviewed. The FV approach was attempted followed by right internal jugular (IJ) vein approach, if unsuccessful. Between 2010 and 2015, 250 patients were studied with an average of 13 ± 3 years. The FV approach to CS catheterization was attempted in 249 patients and was successful in all but 13 (95% successful). The right IJ was used as the primary approach in 1 infant aged 6 weeks and as the backup approach in 11 of the 13 in whom the FV approach failed. There was no appreciable difference between ages of patients in whom FV versus IJ approaches were successful (13 years ± 3 vs 13 years ± 3, respectively). There were no complications from FV sheath placement or from placement of the CS catheter from the FV approach. The right IJ approach was complicated by carotid artery puncture without hematoma in 2 patients (18% of attempts). In conclusion, the FV approach is a safe and effective option for CS cannulation for EPS procedures in children. The IJ and other approaches could be used as back up when the FV approach fails.

Feasibility and procedure-related patient discomfort of peripheral venous access for coronary sinus cannulation during electrophysiology procedures

BACKGROUND

Placement of an electrode catheter in the coronary sinus (CS) through the jugular or subclavian vein, as part of electrophysiology (EP) procedures, increases patient discomfort and the possibility of adverse events. We studied the hypothesis that peripheral venous access for CS cannulation, as part of EP procedures, is feasible and can reduce patient discomfort, eliminating central venous access-associated risks.

METHODS

Consecutive patients submitted to EP procedures were randomly assigned to peripheral or central venous access for CS cannulation. If after 30 min from initial needle insertion the CS was still not catheterized, the attempt was considered unsuccessful. Patient level of discomfort was assessed with a visual analog scale (VAS).

RESULTS

Success rate was 90% in the peripheral versus 95% in the central venous access group (p = 1.00). No complications related to venous access were observed in the peripheral venous access group, whereas one case of pneumothorax and one case of extensive hematoma in the anterior cervical area were recorded in the central venous access group. Patients submitted to central vein catheterization reported higher VAS scores, 46.8 ± 16.3 versus 36.8 ± 12.9 (p = 0.04). No significant difference was observed in fluoroscopy time needed for CS cannulation (51.1 ± 9.2 s versus 51.4 ± 7.9 s; p = 0.71) between the two groups.

CONCLUSION

This small, randomized study indicates that peripheral venous access for CS catheter placement during EP procedures is feasible, with equivalent success rate to the central venous access approach, and associated with lower levels of self-reported patient discomfort.

Evaluation of femoral approach to coronary sinus catheterisation in electrophysiological and ablation procedures: Single centre experience

BACKGROUND

It has been reported that the cannulation of coronary sinus (CS) from the femoral approach is safer than the traditional subclavian approach but is associated with a lower rate of success. We aimed to test the validity of this claim.

METHOD

We evaluated retrospectively 1320 consecutive patients who underwent electrophysiological study (EPS) or ablation over a period of three years using a prospectively collected data. In cases requiring CS cannulation, it was attempted first from the femoral approach, switching if necessary to a subclavian approach when the femoral route failed.

RESULTS

Out of 1320 patients, 1165 (88.3%) required CS cannulation. The CS was successfully cannulated from the femoral approach in 99.3% of the cases in which it was attempted. One patient (0.09%) developed transient first degree atrioventricular block during an ablation procedure for AV nodal re-entrant tachycardia during cannulation of the CS that resolved within 3 min. Femoral access failed in 8 patients. In 4 of these cases, the procedure was concluded using CS cannulation via subclavian or jugular venous access. In the other 4 cases, the procedure was concluded successfully without CS cannulation, including an AF ablation in which CS cannulation proved impossible by either subclavian or femoral approach.

CONCLUSION

Femoral access can be used for CS cannulation with a high rate of procedural success in the vast majority of patients undergoing EPS and ablation. This approach is safe, and associated with a high rate of procedural success.

A streamlined "3-catheter" approach in the electrophysiological study and radiofrequency ablation of narrow complex tachycardia

BACKGROUND

Electrophysiological study (EPS) followed by radiofrequency (RF) ablation has emerged as the treatment of choice for symptomatic narrow complex tachycardia (NCT), for which purpose, 5 catheters are typically used (4 for the initial EPS and an additional one for the subsequent RF ablation). We describe an alternative, streamlined approach using only 3 catheters [2 standard (diagnostic) and 1 deflectable, thermistor tip (mapping)] as the standard configuration for EPS and RF ablation in patients with NCT but no pre-excitation on ECG.

METHODS AND RESULTS

Diagnosis was obtained in all 250 consecutive patients (mean age 45 years, 174 females): atrio-ventricular nodal re-entrant tachycardia (AVNRT) in 188 (75%), concealed accessory pathways (AP's) in 38 patients (15%), ectopic atrial tachycardia in 19 patients (8%), persistent junctional re-entrant tachycardia (PJRT) in 4 patients (2%) and atrial fibrillation in 1 patient. An additional diagnostic catheter was used for optimising atrial pacing in 3 patients and for ventricular pacing in concealed right postero-septal AP's in another 3. An additional mapping catheter was used in 31 patients with concealed left-sided AP's, 2 with multiple AP's and 1 with PJRT. Three patients had complications (1 pulmonary embolism, 1 pericardial effusion and 1 atrio-ventricular node block). Overall, the immediate success rate was 98% (224/229) with a recurrence rate of 4.4% (10/224), and the total success rate (with repeat RF ablation if necessary) was 99.2% (227/229) over a median follow-up period of 31.4 months. The average cost saving was US$474 per procedure. Procedure duration (2.0 +/- 0.1 hours), fluoroscopy time (13 +/- 1 minutes) and the number of radiofrequency applications (5.4 +/- 0.3) also compared favourably with values reported in the literature for RF ablation of AVNRT.

CONCLUSION

Compared to the conventional 5-catheter configuration for the combined EPS and RF ablation procedure in treatment of patients with NCT, the described 3-catheter configuration reduces cost, procedure duration and fluoroscopy time without compromising on success rate and safety. On these bases, we advocate its widespread adoption.

Ultrasound-assisted cannulation of the right internal jugular vein during electrophysiologic studies in children

Percutaneous access of the right internal jugular vein for coronary sinus cannulation in pediatric patients undergoing electrophysiologic studies may be technically difficult. We report the use of an ultrasound-guided technique for obtaining jugular venous access. Forty-five pediatric patients who underwent electrophysiologic study were analyzed. Access was obtained in 100 % of the patients using this technique with no major complications. Ultrasound guidance for access of the internal jugular vein for coronary sinus cannulation during electrophysiologic studies in pediatric patients, may increase the success rate and prevent the development of complications.

Entrapment of an ablation catheter in the cardiac venous system: a case report

Cannulation of the coronary sinus is a common procedure with infrequent complications. We report an unusual case of a steerable "dumb-bell" catheter passed through the ostium of the coronary sinus prior to an intended radiofrequency ablation procedure becoming stuck and requiring general anesthesia for extraction. We caution against the use of such catheters with a "waist" for the cannulation of the coronary sinus.

Catheter ablation of accessory pathways

Radiofrequency catheter ablation is a highly effective, curative treatment for arrhythmias related to accessory atrioventricular connections. Compared with medical therapy, ablation is more definitive, is more cost-effective, and is associated with a lower risk of proarrhythmia. This article updates the reader on the current indications, techniques, and innovations related to ablation of accessory pathways using radiofrequency energy.

Mapping of the coronary sinus and great cardiac vein using a 2-French electrode catheter and a right femoral approach

INTRODUCTION

Local electrograms recorded from the coronary sinus and great cardiac vein provide important information for the diagnosis of various arrhythmias and identification of target sites for ablation of left-sided accessory pathways. One limitation of present techniques is the inability, in many cases, to probe the great cardiac vein at the anterior mitral annulus. We tested the feasibility of a new technique for catheterization of the coronary sinus and great cardiac vein by means of a small-diameter electrode catheter advanced via a right femoral approach through an angiography catheter.

METHODS AND RESULTS

Of 22 patients (12 men and 10 women; ages 44.5 +/- 13.4 years) undergoing radiofrequency ablation of a supraventricular tachycardia, cannulation of the coronary sinus orifice using a 6-French 1L or 2L Amplatz catheter was achieved in 20 patients (91%) within 0.9 +/- 0.6 minutes; after cannulation, a 2-French octapolar electrode catheter with a soft radiopaque tip and a 3-mm interelectrode distance could be advanced in all 20 patients through the guiding catheter to the great cardiac vein in the anterior region of the AV sulcus within 0.8 +/- 0.7 minutes. Atrial and ventricular local potentials were recorded all along the mitral annulus during sinus rhythm, atrial and ventricular pacing, or supraventricular tachycardia. Variation of local potential amplitude never exceeded 20% of the mean and presented similar stability at all annular regions. The arrhythmogenic substrate was identified in all patients. Of 18 patients with 21 left-sided accessory pathways, an accessory pathway potential could be recorded at the ablation site by one or more adjacent epicardial electrode pairs in 10 pathways. No procedure-related complications were observed.

CONCLUSIONS

The technique introduced in this study proved feasible in 91% of patients. Its main advantages are the simplicity and rapidity of coronary sinus cannulation and the ability to advance the electrode catheter to the anterior cardiac vein. In addition, closely spaced bipolar electrograms resulted in enhanced atrial, ventricular, and accessory pathway potential resolution.

Response of type I atrial fibrillation to atrial pacing in humans

BACKGROUND

High-density mapping studies of atrial fibrillation (AF) have suggested the presence of an excitable gap. The purpose of this study was to assess the local and left atrial response to pacing at the high right atrium during type I AF in humans.

METHODS AND RESULTS

Pacing was performed at the high right atrium during type I AF in 24 patients in the electrophysiology laboratory. The response to pacing was assessed at cycle lengths 10, 20, 30, 40, and 50 ms less than the mean baseline atrial cycle length. Digitized tracings of the baseline tachycardia and the response to pacing were recorded from the high right atrium and from the distal coronary sinus. Computer analysis of these signals was used to calculate a left atrial electrogram density before, during, and after pacing. Two hundred eight-eight segments of AF with a duration of 3.9 +/- 0.5 seconds (mean +/- SD) were analyzed. Local capture of the right atrium during AF was demonstrated for at least one pacing cycle length in each patient. The left atrial electrogram density was significantly greater than baseline at each pacing cycle length that resulted in local capture, except when pacing at 50 ms less than the mean AF cycle length. There was no significant change in the baseline left atrial electrogram density compared with baseline when pacing did not result in local capture of AF.

CONCLUSIONS

Local right atrial capture is often possible by pacing during type I AF and consistently influences the left atrial electrograms recorded in the coronary sinus. These results confirm the presence of excitable tissue in the right and left atria in type I AF.

Coronary sinus morphology in patients with atrioventricular junctional reentry tachycardia and other supraventricular tachyarrhythmias

BACKGROUND

Coronary sinus access by electrode catheters is easier in patients with atrioventricular junctional reentry tachycardia (AVJRT) than in patients with other supraventricular tachyarrhythmias. The reason for this has not been addressed.

METHODS AND RESULTS

The size and shape of the proximal coronary sinus were measured in 15 patients with AVJRT and 14 control subjects after angiographic visualization. Coronary sinus dimensions, morphology, and angle of origin from the right atrium were measured. The proximal coronary sinus in patients with AVJRT was larger than in the control population. The mean ostium diameter was 12.2 +/- 2 mm compared with control dimensions of 8.5 +/- 1.5 mm, P = .00001. At a distance of 5 mm from the ostium, the coronary sinus measured 10.2 +/- 1.8 mm compared with 8.1 +/- 1.9 mm, P = .007. The dilatation persisted 10 mm into the coronary sinus, with a measurement of 9 +/- 1.4 mm compared with 7.6 +/- 2 mm, P = .04. In 73% of AVJRT patients, the proximal coronary sinus had the appearance of a wind sock. This morphology was seen only in 7% of control patients, in whom the coronary sinus was tubular (in 93%). There was considerable interindividual variability in the angle of origin.

CONCLUSIONS

The proximal coronary sinus in patients with AVJRT was significantly different from a control population. The ostium was 44% larger and remained more dilated to at least 10 mm from the ostium. The appearance was like a wind sock in AVJRT patients and tubular in the control patients. These findings may have important implications for arrhythmia pathogenesis in such patients.