Lucian Muresan

Missing diagnosis of preexcitation syndrome on ECG: Clinical and electrophysiological significance

UNLABELLED Electrocardiographic criteria of preexcitation syndrome are sometimes not visible on ECG in sinus rhythm (SR). The purpose of the study was to evaluate the significance of unapparent preexcitation syndrome in SR, when overt conduction through accessory pathway (AP) was noted at atrial pacing. METHODS Anterograde conduction through atrioventricular AP was identified at electrophysiological study (EPS) in 712 patients, studied for tachycardia (n=316), syncope (n=89) or life-threatening arrhythmia (n=55) or asymptomatic preexcitation syndrome (n=252). ECG in SR at the time of EPS was analysed. RESULTS 78 patients (11%) (group I) had a normal ECG in SR and anterograde conduction over AP at atrial pacing; 634 (group II) had overt preexcitation in SR. Group I was as frequently asymptomatic (35%) as group II (35%), had as frequently tachycardias, syncope or life-threatening arrhythmia as group II (43, 5, 2% vs 43, 13, 8%). AP was more frequently left lateral in group I (57%) than in group II (36%)(p<0.001). AV re-entrant tachycardia, atrial fibrillation (AF), antidromic tachycardia were induced as frequently in group I (54, 18, 10%) as in group II (54, 27, 7%). Malignant forms (induced AF with RR intervals between preexcited beats <250ms in control state or <200ms after isoproterenol) were as frequent in group I (11.5%) as II (14%). CONCLUSIONS The frequency of unapparent preexcitation syndrome represents 11% of our population with anterograde conduction through an AP and could be underestimated. The risk to have a malignant form is as high as in patients with overt preexcitation syndrome in SR.

Risk of atrial fibrillation according to the initial presentation of a preexcitation syndrome

BACKGROUND Atrioventricular reentrant tachycardia (AVRT) is frequent in Wolff-Parkinson-White syndrome (WPW). Atrial fibrillation (AF) is rare. The purpose of the study was to determine the factors of spontaneous AF in WPW according to the initial presentation. METHODS AND RESULTS Electrophysiological study (EPS) was performed among 709 patients with a preexcitation syndrome. First event was AF in 44 patients. Remaining patients were studied for AVRT (314), syncope (94), adverse presentation without AF (9) or systematically (248 asymptomatic patients). Patients with AF were older than other patients (44 ± 16 years vs 34.5 ± 17) (0.0003); maximal rate conducted over accessory pathway (AP) was higher in patients with AF than in other patients except in adverse presentation (0.0002); AVRT was induced more frequently in patients with AF than in asymptomatic patients (57% vs 14.5%) but less than in patients with AVRT (89%). AF was induced more frequently in patients with AF than in other patients except in adverse presentation (<0.0001). During follow-up AF occurred more frequently in patients with AF (5; 11%) than in patients with AVRT (7; 2%), with syncope (1%) and asymptomatic patients (4; 1.6%). Older age predicted recurrence (54 ± 16 vs 40 ± 17). CONCLUSIONS AF was the first event in only 6% of patients with WPW and was a rare event in other patients. They are older but 10% are less than 18 years and have a more rapid conduction over AP than other patients.

Intravascular pulmonary venous ultrasound imaging for catheter ablation of atrial fibrillation

ABSTRACT Introduction: Atrial fibrillation is the most common cardiac arrhythmia. The development of electroanatomical mapping is an increase demand for advanced intracardiac imaging techniques of the left atrium and pulmonary veins. IVUS can demonstrate quantitative changes like lumen and wall thickness as well as qualitative changes of the pulmonary wall. IVUS could also provide relevant real time imaging of the atrial and pulmonary venous wall during catheter ablation. Areas covered: The Medline and Embase databases were searched for preclinical and clinical studies of IVUS in patients with ablation of atrial fibrillation or left atrial arrhythmias. This article reviews the 15 years of preclinical and clinical experience with IVUS evaluating the pulmonary veins. Expert commentary: IVUS has proven to be a valuable imaging technique in the management of atrial fibrillation ablation. The understanding of the relation between morphological changes and functional results of catheter ablation, combined with the safety profile have made it appealing for interventionists.

Subclinical myocardial impairment in SLE: insights from novel ultrasound techniques and clinical determinants.

AIMS Myocardial damage is frequent and often silent in systemic lupus erythematosus (SLE). The aim of the study was to determine the prevalence of myocardial damage by novel ultrasound techniques and to systematically assess the relationship between subclinical cardiac dysfunction and SLE-related clinical parameters. MATERIAL AND METHODS Seventy-five consecutive SLE patients without evidence of cardiac disease and seventy-three controls underwent standard transthoracic echocardiography using classical and novel ultrasound techniques: tissue Doppler imaging and speckle tracking echocardiography. Patient characteristics, cumulative organ damage and laboratory data were retrieved by medical chart review. RESULTS Within the cohort, 89.3% of the patients were female; mean+/-SD age and median (IQR) disease duration were 43.2+/-12.5 years and 8.03(6.3) years, respectively. SLE patients exhibited a significant decrement in endocardial longitudinal strain (-18.4% vs 19.3%, p=0.001) compared with controls. Diastolic dysfunction was detected in 34 (45.3%) of SLE patients. Major determinants of systolic and diastolic dysfunction were hypertension (p=0.023 and p<0.001, respectively), associated antiphospholipid syndrome (APS) (p<0.001 and p<0.001, respectively), cumulative damage accrual (p<0.001 and p=0.003, respectively), and disease duration (p=0.03 and p<0.001, respectively). Notably, anti-Ro antibodies were present in 37% of the SLE patients who had better systolic longitudinal performance. Neither disease activity, nor specific organ involvement, were associated with myocardial impairment. CONCLUSION Systolic longitudinal and diastolic performance impairments are frequent findings in SLE patients without overt cardiovascular disease. Cumulative organ damage, disease duration, APS, and hypertension are major determinants for early heart involvement in SLE patients.

The value of adrenaline in the induction of supraventricular tachycardia in the electrophysiological laboratory

AIMS The most commonly used drug for the facilitation of supraventricular tachycardia (SVT) induction in the electrophysiological (EP) laboratory is isoprenaline. Despite isoprenalines apparent indispensability, availability has been problematic in some European countries. Alternative sympatomimethic drugs such as adrenaline have therefore been tried. However, no studies have determined the sensitivity and specificity of adrenaline for the induction of SVT. The objective of this study was to determine the sensitivity and specificity of adrenaline for the induction of SVT. METHODS AND RESULTS Between February 2010 and July 2013, 336 patients underwent an EP study for prior documented SVT. In 66 patients, adrenaline was infused because tachycardia was not induced under basal conditions. This group was compared with 30 control subjects with no history of SVT. Programmed atrial stimulation was carried out during baseline state and repeated after an infusion of adrenaline (dose ranging from 0.05 mcg/kgc to 0.3 mcg/kgc). The endpoint was the induction of SVT. Among 66 patients with a history of SVT but no induction under basal conditions, adrenaline facilitated induction in 54 patients (82%, P < 0.001). Among the 30 control subjects, SVT was not induced in any patient (0%) after infusion. Adrenaline was generally well tolerated, except for two patients (3.0%), where it had to be discontinued due to headache and high blood pressure or lumbar pain. CONCLUSION Adrenaline infusion has a high sensitivity (82%) and specificity (100%) for the induction of SVT in patients with prior documented SVT. Therefore, it could serve as an acceptable alternative to isoprenaline, when the latter is not available.

Ablation of a left-sided accessory pathway with near-zero fluoroscopy in a 9-year-old boy

Abstract Catheter ablation of cardiac arrhythmias in pediatric population is associated with the risk of ionizing radiation on the child. Due to a greater radiation sensitivity in children and a longer life expectancy newer techniques try to reduce the radiation exposure. A new technique for zero-fluoroscopy catheter ablation is described in a 9-year-old boy who had a left-sided concealed accessory pathway. The NAVX Ensite 3D mapping system permits catheter placement inside the venous system and movement inside the heart chambers without the use of X-rays. The success rate is similar to the techniques requiring X-rays.

What is the origin of this arrhythmia

PURPOSE The existence of inter-atrial epicardial connections bridging the two atria at different levels has well been described and their implication in some forms of supraventricular arrhythmias is a known fact. However, up to date, little data exists in the literature showing their role in the mechanisms of focal atrial tachycardias, providing at the same time clear electroanatomical and activation maps using a three-dimensional, non-fluoroscopic mapping system. PATIENTS AND METHODS We present the case of a 29-year-old woman with a focal atrial tachycardia with the origin in a pulmonary vein, manifested as a right atrial origin due to the conduction of the electrical impulse form the right inferior pulmonary vein (RIPV) to the postero-inferior right atrium (RA) via inter-atrial epicardial connections. Using a three-dimensional, non-fluoroscopic mapping system (CARTO, Biosense Webster), an RA activation map was created during tachycardia. RESULTS Radiofrequency (RF) application at the earliest endocardial breakthrough site situated in the postero-inferior RA changed the right atrial depolarization sequence without terminating the arrhythmia. Subsequently, a left atrium activation map was created showing the earliest endocardial breakthrough site at the level of the RIPV ostium and RF application at this level abolished the atrial tachycardia. CONCLUSION Inter-atrial epicardial connections can be part of the substrate of some forms of supraventricular arrhythmias. Awareness of their existence is important to the electrophysiologist, since a better understanding of transseptal activation can avoid, in some cases, unnecessary RF applications at the level of the postero-septal right atrium, with a subsequent increase in procedural risk.

Direct ICE imaging from inside the left atrial appendage during ablation of persistent atrial fibrillation

Abstract We present the case of a 59-year-old patient with persistent atrial fibrillation, referred for atrial fibrillation ablation. The procedure was performed with the help of NAVX 3D mapping system (Saint Jude Medical) and iLAB Ultra ICE Plus ultrasound imaging catheter (Boston Scientific). The catheter permits cross-sectional images perpendicular to catheters long axis. From inside left atrial appendage (LAA) looks trabeculated, due to pectinate muscles running parallel to each other. The presence of a thrombus was excluded from the appendage. The contractility of LAA was also assessed using multiple frames recorded on videotape. Our case demonstrates that LAAs morphology and function can be directly assessed by intracardiac ultrasound with the probe inserted inside the appendage.

Intracardiac ultrasound to detect aneurysm in arrhythmogenic right ventricular dysplasia/cardiomyopathy

Abstract Arrhythmogenic right ventricular dysplasia/cardiomyopathy is a genetic disorder characterized by fibrofattty replacement of the right ventricular myocardium. In the revised 2010 Task Force Criteria, a major criteria for ARVD/C is the presence of RV aneurysm by 2D echo. Our report demonstrates that intracardiac ultrasound can detect RV aneurysms and also focal absence of trabeculations which brings additional value to the diagnosis of ARVD/C. A 26-year-old male patient suffering from multiple sustained episodes of ventricular tachycardia was implanted with an internal cardiac defibrillator after confirmation of the disease by cardiac magnetic resonance imaging. Intracardiac ultrasound was performed using a 6F, 9 MHz catheter and the iLAB intravascular system (Boston Scientific). Images of right ventricular inflow tract, outflow tract, apex and pulmonary artery were taken and saved on videotape. ICE revealed loss of trabecular structure at the right ventricular outflow tract with an antero-septal aneurysm at this level. Intravascular ultrasound provides useful information on the presence of aneurysms and of tissue characterization.

Intracardiac echocardiography to guide catheter ablation of an accessory pathway in Ebstein’s anomaly. A case report

We present the case of a 17-year-old girl with Ebstein anomaly and repeated episodes of reentrant tachycardia due to a right posterior accessory pathway. Catheter ablation was performed using intracardiac echocardiography. A ViewFlex Xtra probe was inserted and showed an anormal tricuspid valve with elongated anterior leaflet and low insertion of the septal leaflet towards the apex. The anatomical annulus was identified by the course of the right coronary artery. RF application on the posterior annulus stopped the reentrant arrhythmia. After ablation, programmed stimulation showed absence of both antegrade and retrograde conduction through the accessory pathway.