A very unusual wide QRS tachycardia: VT or SVT?

INTRODUCTION: A 13 old girl presented with recurrent wide QRS tachycardia since she was 4. METHODS: An electrophysiologic study was performed. RESULTS: The electrophysiologic study showed that QRS complexes identical to those of the tachycardia could be elicited with premature atrial extrastimuli but with a shorter atrioventricular (AV) delay when the QRS was wide compared with narrow QRS complexes. The tachycardia was ablated at 9 o'clock on the tricuspid annulus demonstrating the presence of an atriofascicular fiber. CONCLUSION: We believe that this atypical behavior can be explained by AV nodal like longitudinal dissociation of a slowly conducting accessory pathway.

Quality assessment in Belgian arrhythmology: the Belgian heart rhythm association (BeHRA) databases.

This report presents and discusses, on behalf of the Belgian College of Cardiology, the evolution of the peer review process in arrhythmology, focussing on pacemaker implantation. Data from the last 22 years are compared. The national annual increase in implants is around 1%, clinical patient characteristics remained stable over the years while dual chamber pacing was proportionally increasing. Analyses of the normalised sick sinus and complete atrioventricular block ratios revealed a quite homogenous practice between centres and patient district with the only exception of the two more crowded districts. Battery longevity and infection rate were also assessed. With an incidence of 1/1000 device-years follow-up, Belgium remains below accepted European levels.

Multicentre evaluation of non-invasive biatrial mapping for persistent atrial fibrillation ablation: the AFACART study.

AIMS: Non-invasive electrocardiogram (ECG) mapping allows the activation of the entire atrial epicardium to be recorded simultaneously, potentially identifying mechanisms critical for atrial fibrillation (AF) persistence. We sought to evaluate the utility of ECG mapping as a practical tool prior to ablation of persistent AF (PsAF) in centres with no practical experience of the system. METHODS AND RESULTS: A total of 118 patients with continuous AF duration <1 year were prospectively studied at 8 European centres. Patients were on a median of 1 antiarrhythmic drug (AAD) that had failed to restore sinus rhythm. Electrocardiogram mapping (ECVUE™, CardioInsight, USA) was performed prior to ablation to map AF drivers (local re-entrant circuits or focal breakthroughs). Ablation targeted drivers depicted by the system, followed by pulmonary vein (PV) isolation, and finally left atrial linear ablation if AF persisted. The primary endpoint was AF termination. Totally, 4.9 ± 1.0 driver sites were mapped per patient with a cumulative mapping time of 16 ± 2 s. Of these, 53% of drivers were located in the left atrium, 27% in the right atrium, and 20% in the anterior interatrial groove. Driver-only ablation resulted in AF termination in 75 of the 118 patients (64%) with a mean radiofrequency (RF) duration of 46 ± 28 min. Acute termination rates were not significantly different amongst all 8 centres (P = 0.672). Ten additional patients terminated with PV isolation and lines resulting in a total AF termination rate of 72%. Total RF duration was 75 ± 27 min. At 1-year follow-up, 78% of the patients were off AADs and 77% of the patients were free from AF recurrence. Of the patients with no AF recurrence, 49% experienced at least one episode of atrial tachycardia (AT) which required either continued AAD therapy, cardioversion, or repeat ablation. CONCLUSION: Non-invasive mapping identifies biatrial drivers that are critical in PsAF. This is validated by successful AF termination in the majority of patients treated in centres with no experience of the system. Ablation targeting these drivers results in favourable AF-free survival at 1 year, albeit with a significant rate of AT recurrence requiring further management.

Does diffuse irrigation result in improved radiofrequency catheter ablation? A prospective randomized study of right atrial typical flutter ablation.

AIMS: Recent developments of open irrigated catheters have sought to create uniform cooling of the entire ablating electrode. The aim of this randomized study was to assess whether the diffuse irrigation of the Coolflex(®) (CF) catheter results in improved short-term procedural benefits in patients undergoing ablation of right atrial typical flutter. METHODS AND RESULTS: Sixty consecutive patients (age 62 ± 13) with typical atrial flutter were prospectively randomized to ablation of the cavotricuspid isthmus (CTI) using either a standard 3.5 mm tip ablation catheter with six distal irrigation channels (6C) (30 patients) or a 4 mm tip fully irrigated ablation catheter (CF) (30 patients). There were no significant differences seen between procedures performed with the diffusely irrigated CF catheter and the standard six-channel irrigated-tip catheter. This concerned the total procedural duration RF duration, fluoroscopic duration, the total amount of irrigation fluid, and the occurrence of steam pop. CONCLUSIONS: The use of a diffuse irrigation at the ablation catheter tip does neither facilitate lesion formation nor reduce the amount of irrigation during RF ablation for typical right atrial flutter using recommended flow and power settings.

Radiofrequency atrial flutter and atrial fibrillation ablation in a patient with deep brain stimulation.

Radiofrequency ablation for atrial fibrillation or atrial flutter is feasible in patients with deep brain stimulation but with extreme caution given the possibility of life-threatening complications.

Does congenital heart disease severely jeopardise family life and pregnancies? Obstetrical history of women with congenital heart disease in a single tertiary centre.

AIM: Women with congenital heart disease are often considered to be restricted in their obstetrical life and even their marital life. Our single-centre study aimed to determine the real-life situation of these women with regard to successful family life and any pregnancy complications they may experience. METHODS: From our database of adults with congenital heart disease, 160 of 178 women completed a questionnaire and had their files reviewed. They were classified into three groups according to their pregnancy risk - "good condition" group, no pregnancy restriction; "at-risk" group, pregnancy allowed with close follow-up at a tertiary centre; and "contraindicated" group, pregnancy inadvisable. RESULTS: The proportion of women in a relationship was 46% with no difference between the three groups. In the groups where pregnancy was allowed, 55% of women conceived a child. The total incidence of spontaneous abortion was 21%. The rate of caesarean section was 15%. The incidence of cardiac failure was 4.7%, arrhythmia 1.2%, endocarditis 1.2%, hypertension 2.4%, and preeclampsia 1.2%. Foetal complications included prematurity and/or low birth weight (9.5%) and one foetal malformation (0.82%). CONCLUSION: Women with severe congenital heart disease are willing to start a family and are successful in this enterprise. Although the complication rate during pregnancy in congenital heart disease remains high, with good monitoring these pregnancies occur without severe complications and a low rate of medical abortion or caesarean section.

Is there a potential benefit to increased irrigation channels during radiofrequency ablation? Results from a two-center prospective randomized study.

INTRODUCTION: Open irrigation during radiofrequency (RF) application allows a higher power delivery in the setting of temperature-controlled ablation, without causing blood clots. This study sought to evaluate the clinical value of the additional 6 supplementary channels at the proximal catheter tip compared to a standard irrigated RF catheter with 6 conventional channels present at the distal tip only. METHODS AND RESULTS: Ninety-five consecutive patients were prospectively randomized to cavotricuspid isthmus ablation using an 3.5 mm tip ablation catheter with 6 distal irrigation channels (6C; 48 patients) or an 4 mm tip ablation catheter with 12 irrigation channels (12C; 47 patients) disposed at the distal (6 channels) and proximal (6 additional channels) catheter tip. There was no significant difference between the 12C and the 6C irrigated-tip catheter concerning the total procedural duration, the RF duration, the fluoroscopic duration, and the amount of irrigation. Conversely, there were significantly more patients who experienced at least one steam pop while using the 12C as compared to the 6C irrigated-tip catheter (0% vs 13%, respectively, P = 0.018). CONCLUSION: The addition of proximal irrigation holes at the catheter tip do not facilitate lesion formation during RF ablation, but significantly increases the risk of steam pop. This is probably the consequence of an increase distortion of the temperature feedback.

Complicated forms of tachycardia-mediated cardiomyopathy associated with idiopathic left ventricular tachycardia.

Idiopathic left ventricular tachycardia is an infrequent form of ventricular tachycardia associated with a structurally normal heart. The prognosis is usually benign; however, sustained cases have been reported. In this report, we describe two cases of persistent idiopathic left ventricular tachycardia complicated by tachycardia-mediated cardiomyopathy. In the first case, the patient developed a right ventricular thrombus with subsequent pulmonary embolism. In the second case, the patient developed acute pulmonary edema. Both cases were cured by catheter ablation.

Long-term electrocardiographic follow-up after repair of tetralogy of Fallot.

BACKGROUND: Fallot patients with conduction disturbances are prone to sudden cardiac death. However, knowledge about long-term electrocardiographic changes after Fallot repair is limited. METHODS: Measurements were performed on electrocardiograms recorded preoperatively, postoperatively, and during annual follow-up in 35 Fallot patients included in three groups: G1 if they received no patch (n = 7), G2 if they received a transannular patch (n = 13), and G3 if they received a pulmonary homograft (n = 15). RESULTS: PR interval increased over the study period in all groups (Z-score: from 0.9 ± 1.1 to 1.3 ± 0.9 in G1, 0.9 ± 1.2 to 1.7 ± 1.6 in G2, and 0.7 ± 0.7 to 1.4 ± 1.3 in G3). The QRS duration increased during the follow-up at a rate of 1.78 msec/year in G1, 2.34 msec/year in G2 despite pulmonary valve replacement in 10 patients, and 1.81 msec/year in G3 despite conduit replacement in 9. At the later follow-up, the QRS duration was significantly increased (Z= 4.5 ± 3.6 in G1, 5.7 ± 1.4 in G2, and 4.6 ± 1.9 in G3). One patient in each group had QRS duration of 170 msec or longer and the one in G3 had a history of serious ventricular arrhythmia. Three patients had a QTc duration above 460 msec. CONCLUSIONS: Progressive conduction disorders are noted during long-term follow-up in Fallot patients who received transannular patch but also in those who received no patch or a pulmonary homograft. It suggests that volume overloading related to the transannular patch but also pressure overloading and myocardial injury related to surgery contribute to their development.

Uncommon presentation of a common arrhythmia.

This case report demonstrates that atrioventricular and ventricular atrial conduction at rest may be unreliable in assessing the presence of reentrant atrioventricular nodal tachycardia.

Slow pseudo sinus rhythm and atrial tachycardia of right superior venous pulmonary origin.

Paroxysmal atrial tachycardia usually presents as a sudden acceleration of the atrial rate combined with modifications of the P wave morphology. A 22-year-old patient presented with very fast and very slow atrial ectopic activity. He complained of repetitive episodes of fast tachycardia, some accompanied with dizziness. When the ectopic discharge was slow, no clear-cut difference between the sinus rate and the ectopic rate was seen and thus the atrial rhythm appeared quite regular. The ectopic focus was situated deep inside the right upper pulmonary vein (RSPV). After RSPV isolation a persistent sinus rhythm was established and since then the patient has been asymptomatic for 3 years. Thus, subtle changes in the P wave morphology without a significant change in the heart rate in patients presenting with palpitations can give a clue to the diagnosis of the tachycardia and the localization of the ectopic focus.

D-dimer blood concentrations to exclude left atrial thrombus in patients with atrial fibrillation.

OBJECTIVE: Left atrial (LA) thrombus is routinely excluded by transoesophageal echocardiography (TOE) before cardioversion for non-valvular atrial fibrillation (AF). In the D-dimer blood concentrations to exclude LA thrombus in patients with AF study, two D-dimer cut-offs were compared to exclude LA thrombus prior to cardioversion. One was fixed to 500 ng/mL (DD500), based on clinical practice where such values are commonly accepted to exclude a thrombus. The other cut-off was adjusted to 10 times the patient's age (DDAge), based on the cut-off used to exclude pulmonary embolism. METHODS: 142 consecutive patients with non-valvular AF aged 69.7±11.4 years (52% with paroxysmal AF) referred for precardioversion TOE to exclude LA thrombus were prospectively enrolled. D-dimers were measured at the time of TOE by an ELISA test. RESULTS: LA thrombus was excluded with TOE in 129 (91%) and confirmed in 13 (9%) patients. D-dimers were significantly lower in patients without LA thrombus (729±611 vs 2376±1081 ng/L; p<0.05). DDAge indicated absence of LA thrombus with higher specificity than DD500 (66.4% vs 50.4%; p<0.05). Both cut-offs were able to identify all 13 patients with LA thrombus (false negative 0%). Patients with D-dimers

Prevalence of preoperative arrhythmias in children with delayed treatment of severe congenital heart disease.

AIM: Our aim was to determine the real importance of rhythm and conduction disorders in children with unoperated severe congenital heart disease. METHODS: Consecutive children with delayed treatment of severe congenital heart disease were prospectively studied for the occurrence of arrhythmias before any invasive investigation or surgical procedure was performed. RESULTS: All 168 children were in sinus rhythm. One hundred and fifty-eight patients (94%) had no significant preoperative findings. One child with double discordance had an intermittent complete atrioventricular block, and another one had a long QT syndrome. Children with severe ventricular dysfunction had paroxysmal atrioventricular re-entry tachycardia in 3 cases and abnormally frequent premature ventricular complexes in 3 other cases. Children with severe left atrial dilatation had periods of atrial ectopic tachycardia in one case and atrial fibrillation in another case. CONCLUSIONS: The prevalence of rhythm and conduction disorders is relatively low in children with delayed treatment of severe congenital heart disease. Only those with congenital heart disease classically combined with such disorders and those with prolonged severe ventricular dysfunction and/or atrial dilatation are at risk of developing significant arrhythmias and should undergo a preoperative assessment of arrhythmias.

A recurrent concealed parahisian accessory pathway.

This case demonstrates the interest of ablating in the aortic root in case of resistant parahisian accessory pathways with failure of the right side approach. Failure on the right side may be due to fear of creating an AV block of failure to ablate critical fibers in the parahisian position.

Multidetector 16-slice CT scan evaluation of cavotricuspid isthmus anatomy before radiofrequency ablation.

INTRODUCTION: The anatomy of the cavotricuspid isthmus (CTI) is an important determinant of the ease of radiofrequency ablation. We evaluated the anatomy of the region with a multidetector 16-slice computed tomography (CT) scan and correlated this with subsequent procedural difficulty. METHODS: Twenty-nine patients (mean age 64 +/- 15 years) with typical atrial flutter or paroxysmal atrial fibrillation underwent ablation of the CTI. A multidetector 16-slice CT scan with contrast injection was performed in all before the procedure. RESULTS: The CTI showed marked variability as evidenced by the following measurements: length (8.2 to 32.2 mm), width (26 to 56.5 mm), depth (0 to 11 mm), thickness (0.2 to 7.5 mm), the angle between the inferior vena cava and the CTI (59.9 to 129.5 degrees ), and the length of the Eustachian valve (4.8 to 26.1 mm) present in 72% of patients. The appearance of the CTI was classified as follows into three categories: concave (72%), flat (17%), or with a sub-Eustachian recess (28%). Procedures were classified as difficult in case of failure to achieve bidirectional block or if radiofrequency duration was greater than 99% confidence interval. In the multivariate analysis, a significant correlation was present between the thickness of the CTI and procedural difficulty (p = 0.0005). CONCLUSIONS: The multidetector 16-slice CT scan with contrast injection accurately evaluates the anatomy of the CTI. The only independent anatomic parameter that predicts a more difficult procedure is the thickness of the CTI.

The left atrial septal pouch as a risk factor for stroke: A systematic review.

The left atrial septal pouch (LASP) is formed by incomplete fusion of the septum primum and septum secundum, leaving a cavity open towards the left atrium, but without interatrial shunting. There is no recommendation concerning strategy in the presence of a LASP, especially in the setting of stroke. The aim of this review was to determine whether the LASP could be incriminated as the aetiology of a stroke. We included all pertinent publications on the subject, and calculated hazard ratios for ischaemic stroke and cryptogenic stroke. There were only five case-control studies concerning the LASP, involving 516 stroke patients and 779 controls. Overall LASP prevalence was 21%, with a slightly higher prevalence in the cryptogenic stroke group (26%), but this difference was not statistically significant (P=0.27). In a random-effects meta-analysis, there was no difference between controls and patients with ischaemic stroke (hazard ratio 1.20, 95% confidence interval 0.96-1.53; P=0.14). Cryptogenic stroke appeared more frequently in patients with LASP (hazard ratio 1.53, 95% confidence interval 1.07-2.24; P=0.02), but this was driven by only one severely underpowered study. The published case reports demonstrated that thrombus formation inside the pouch can occur in the presence of major predisposing factors. The LASP can be a site for thrombus formation, leading to embolic events, but its presence does not correlate with an increased incidence of stroke. Associated factors should be taken into consideration in the setting of stroke. Further studies are necessary to validate a possible relationship with cryptogenic stroke.