Multipolar pulsed-field ablation for the treatment of left atrial reentry tachycardia

Funding Acknowledgements

Type of funding sources: None.

Background

A multipolar pulsed field ablation (PFA) catheter was recently introduced for pulmonary vein isolation and combines the benefits of high procedural efficacy and safety. It may also be used to treat left atrial (LA) reentry tachycardia.

Purpose

To describe our initial experience using a multipolar PFA catheter for the treatment of LA reentry tachycardia.

Methods

We included all patients with LA reentry tachycardia treated with a multipolar PFA catheter at our institution. Using 3D electro-anatomical mapping (3D-EAM), we identified the tachycardia mechanism and applied linear lesions either at the left atrial roof, mitral isthmus or on the anterior wall, as appropriate. Positioning of the PFA catheter was verified by integration into 3D-EAM. Applications were performed using 2.0kV with the catheter in basket or flower configuration, depending on ablation site. Bidirectional block across linear lesions was verified using standard criteria. Additional focal radiofrequency ablation (RFA) was used to achieve bidirectional block if necessary.

Results

We treated 17 LA reentry tachycardia with a multipolar PFA catheter in 13 patients (median age 69 (59-73) years; 5 females). The tachycardia mechanism was identified as roof-dependent in five, peri-mitral in eight and anterior scar-related in four cases. PFA lesion sets consisted of 12 posterior wall isolations (i.e. roof lines), four mitral isthmus lines (MIL) and eight anterior lines. For ablation of the mitral side of the anterior line, we always used the PFA catheter in basket configuration, while we targeted the posterior wall and the superior side of the anterior line exclusively with the catheter in flower configuration. To ablate the MIL we used both flower and basket configurations. Three roof-dependent, six peri-mitral, and four anterior scar-related tachycardias were successfully terminated by PFA (76%). Additional RFA was necessary for two MIL, two anterior lines and no roof line (17%). Finally, we achieved bidirectional block across all lines. PFA triggered, vagal-mediated and reversible AV block was observed in one case. Otherwise, there were no acute procedural complications.

Conclusion

Linear lesion sets are feasible and safe using a multipolar PFA catheter. Posterior wall isolation by PFA for the treatment of roof-dependent LA reentry tachycardia is highly efficient while anterior lines and MIL remain challenging and may need complementary RFA or a PFA catheter designed for focal or linear ablations.

Nurse-led compared to physician-led implant of cardiac monitors

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Implantation of an implantable cardiac monitor (ICM) is a simple and straightforward procedure. However, with a growing demand for such implants, workload significantly increases. In January 2020, we established a completely nurse-led ICM implantation service (N-IMPLANT) with a standard operating procedure.

Purpose

The present study aimed to analyze the safety, efficacy, and patient satisfaction of N-IMPLANT compared to implantation of ICMs by a physician (P-IMPLANT).

Method

Consenting patients implanted with an ICM were included in a prospective registry, which collects patient characteristics, procedural and remote monitoring data. All patients were followed-up by phone interview four weeks after ICM implantation and a standardized questionnaire was completed.

Results

Of 321 patients implanted with an ICM (median age 67 years; 33% women), 189 (59%) were N-IMPLANT. Significantly more N-IMPLANT were performed in the outpatient clinic compared to P-IMPLANT (94% vs. 10%; p<0.001). For wound closure, N-IMPLANT used wound glue in 65 (34%) and a single subcutaneous stitch in 124 patients (66%). Two N-IMPLANT patients experienced vaso-vagal reaction during implantation, whereas no adverse events occurred during P-IMPLANT (p=0.51). Two-hundred and fifty-two patients (79%) completed the questionnaire. We found no difference between N-IMPLANT and P-IMPLANT regarding pain after implant, analgesic use, wound closure after 2 weeks and presence and size of patient reported hematoma (see Table). Duration of pain was longer after P-IMPLANT. All N-IMPLANT patients indicated to be satisfied with the implant procedure. Three patients were dissatisfied with P-IMPLANT for the following reasons: ongoing pain at implant site; discomfort at implant site; and too numerous people present during the implant procedure. In three N-IMPLANT (2%) the ICM was explanted prematurely. The reasons for explantation were infection (with reimplantation of another ICM), discomfort at implant site and attempt to avoid interferences during magnetic resonance tomography in one patient each. One P-IMPLANT (1%) was explanted prematurely because of ICM malfunction.

Conclusion

Nurse-led implantation of cardiac monitors is effective without compromising patient safety and has excellent patient satisfaction. N-IMPLANT is a suitable model to reduce the workload of physicians.

Incidental arrhythmias during atrial fibrillation screening in a hospital-based patient population

Funding Acknowledgements

Type of funding sources: None.

Introduction

Screening for atrial fibrillation may reveal other, incidental arrhythmias of relevance. We sought to describe such incidental arrhythmias in the prospective STARFIB cohort study, which screened for silent atrial fibrillation in hospitalized patients aged 65-84 years.

Method

Patients included in the STARFIB cohort study had up to three 7-day Holter ECGs, performed in two-month intervals. We analysed all the 7-day Holter ECGs of study participants for the presence of one of the following incidental arrhythmias: 1) sick-sinus-syndrome (SSS), defined as sinus arrest of ≥3 seconds duration; 2) second or higher degree atrioventricular block (AVB); 3) sustained atrial tachycardia of ≥30 seconds duration (AT); and 4) sustained ventricular tachycardia of ≥30 seconds duration (VT).

Results

A total of 2’077 Holter ECGs were performed in 794 patients (mean age 74.7 years; 49% females), resulting in a mean cumulative duration of an analyzable ECG signal of 414±136 hours per patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were SSS in 14 patients (1.8%), AVB in 41 (5.2%), AT in 41 (5.2%), and VT in two (0.3%). The median pause duration in SSS was 4 seconds and SSS resulted in pacemaker implantation in one patient with a pause of 9 seconds duration. The most severe type of AVB found per patient was second degree AVB type Wenkebach in 23 patients (2.9%), second degree AVB type Mobitz or 2:1 AV conduction in 10 patients (1.3%) and complete AVB in 8 (1%; maximum pause 18 seconds). AVB led to pacemaker implantation in 9 patients (1.1%). The median duration and heart rate of AT was 2.2 minutes and 144 bpm, respectively. Initiation of betablocker therapy was recommended in 3 patients (0.4%) due to symptomatic AT. The duration and heart rate of VT was 3 minutes at 216 bpm in one patient and 38 seconds at 150 bpm in another. The former patient with VT experienced syncope and an ICD was implanted, whereas in the latter the betablocker dose was increased. One patient died from a non-cardiac cause during a Holter ECG, which showed progressive bradycardia and finally asystole.

Conclusion

Incidental arrhythmias were frequently discovered during screening for atrial fibrillation and resulted in device therapy in 1.4% of our cohort patients.

Impact of clinical risk factor profile vs. atrial fibrillation phenotype on outcome after pulmonary vein isolation

Aims

Catheter ablation for atrial fibrillation (AF) is increasingly performed. Both clinical risk factors as well as the AF phenotype have been shown to influence ablation outcomes. The inter-relationship of the two however is incompletely understood.

Methods

In a retrospective analysis of a prospective registry of patients undergoing a first pulmonary vein isolation, the association of 8 predefined clinical risk factors (age >70 years, female gender, hypertension, BMI >30 kg/m2, coronary artery disease, heart failure, chronic kidney disease (CKD; eGFR<60ml/min/1.73m2) and diabetes mellitus) and the AF phenotype (paroxysmal vs. persistent AF) were assessed as well as their impact on AF recurrence during follow-up.

Results

Overall, 715 patients were enrolled (median age 63 years, 27% females, 69% paroxysmal AF). The prevalence of obesity, hypertension, heart failure and CKD was significantly higher in persistent AF, while female gender was more prevalent in paroxysmal AF. After 2 years of follow-up, overall freedom from recurrence was 46%, and was higher in paroxysmal AF compared to persistent AF (54.1% vs. 29.1%, p<0.001). Of the clinical risk factors, obesity (p=0.02), CKD (p=0.01) and heart failure (p=0.01) were significantly associated with lower arrhythmia-free survival, and there was a trend for hypertension and coronary artery disease (both p<0.2). A risk score composed of those 5 factors was associated with recurrences in patients with paroxysmal AF (p=0.04, Figure 1), but not in those with persistent AF (p=0.85, Figure 2).

Conclusion

Clinical risk factors predict outcome after pulmonary vein isolation in patients with paroxysmal, but not persistent AF. This is likely due to a strong association of those risk factors with the occurrence of persistent AF.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Gender-related differences in patient selection for and outcomes after pace and ablate for refractory atrial fibrillation: insights from a large multicenter cohort

Funding Acknowledgements

Type of funding sources: None.

Background

A pace & ablate strategy may be performed in cases of severe refractory atrial arrhythmias.

Purpose

We aimed to assess gender related differences in patient selection and clinical outcomes after pace & ablate.

Methods

In a retrospective multicenter study, patients undergoing AV-junction-ablation between 2011 and 2019 were studied. Gender-related differences in terms of baseline characteristics, device-related complications, heart failure (HF) hospitalisations and death were assessed.

Results

Overall, 513 patients underwent AV-junction-ablation (median age 75 years, 50% males). At baseline, male patients were younger (72 vs. 78 years, p < 0.001), more frequently had non-paroxysmal AF (82% vs. 72%, p = 0.006), a lower LVEF (35% vs. 55%, p < 0.001) and more often received biventricular stimulation (75% vs. 25%, p < 0.001). Interventional complications were rare in both gender (1.2% vs 1.6%, p = 0.72). Following AV-junction-ablation, improvement of EHRA-class by ≥1 and of LVEF by ≥5% occurred in 44% and 19% of patients respectively, without gender differences (p = 0.66 and p = 0.38). Patients were followed for a median of 42 months in survivors (IQR 22-62). Lead-related complications (11 patients, 2.1%), infections (1 patient, 0.2%) and upgrade to ICD or CRT (18 patients, 3.5%) were rare. In Kaplan Meier analysis, HF hospitalisations during 4 years of follow-up were more common in men (22% vs 11%, p = 0.02), as were death (28% vs 21%, p = 0.02) and the combination of death or HF hospitalisation (37% vs. 26%, p = 0.008, Figure). Gender remained an independent predictor of the combined endpoint of death or HF hospitalisation after adjustment for age, LVEF and type of stimulation.

Conclusion

A Pace & Ablate strategy is safe and results in improvement of EHRA class and LVEF in a substantial number of patients. We found significant gender differences in patient selection for pace & ablate. Female patients had a more favorable clinical course after AV-junction-ablation, which was independent of age, EF and type of stimulation. Abstract Figure. Comb. endpoint of death or heart failure

P2855Unexpectedly high rate of lead failure of the Microport (formerly Sorin/Livanova) Beflex and Vega pacemaker electrodes: A single centre experience

Introduction

Pacing leads remain the weak link of current pacemaker systems. Various differences in design and material exist among companies. Lead performance is mainly assessed via post-marketing studies of the manufacturing companies. Reliable independent reports are rare. We aimed to study the early and long-term performance of the Microport (formerly Sorin/Livanova) Beflex and Vega leads at our centre, for which a lead survival >99% at 3 years has been reported by the company.

Method

In this single centre, retrospective study we analysed the performance of all right ventricular Microport pacemaker leads implanted at our centre between January 2014 and January 2018. Only first pacemaker implants were considered. Lead failure was defined as any lead issue requiring reintervention during follow-up (dislocation, perforation, electrical abnormalities such as lead noise or excessively high thresholds).

Results

A total of 271 Microport right ventricular pacing leads were implanted (233 Beflex and 38 Vega leads). Mean patient age was 76±13.1 years (66% men). Dual chamber pacemakers were implanted in 162 patients (60%) and single chamber in 109 (40%). Mean threshold at implant was 0.6V/0.5ms (range 0.3–1.2V), mean R wave 13.2 mV (range 1.5–30mV) and mean impedance 816 Ohm (range 469–1639 Ohm). Patients without available follow-up information were excluded (N=18, 6.6%). The remaining 253 patients (93.4%) were analysed. Median follow-up was 1.26 years, IQR [25%=0.91 and 75%=2.24]. We observed a total of 25 lead failures (10%). Lead dislocation occurred in 2 cases (0.8%), lead perforation in 5 cases (2%), electrical abnormalities in 6 cases (2.4%) and excessively high threshold in 12 cases (4.8%; mean voltage 4V, range 2–7.5V; mean pulse width 0.75ms, range 0.35–1ms). Yearly incidence of lead failure per 100 leads was 6.1% (95%-CI [4.09–8.98] with a failure rate of 12.74% at 3 year in Kaplan-Meier analysis (Figure).

Figure 1

Conclusion

We found an unexpectedly high rate of lead failure of the Microport Beflex and Vega pacing leads at our centre. The two main reasons for premature lead failure were excessively high thresholds as well as electrical abnormalities during follow-up. Comparison of lead performance with other centres and against other leads are needed to further assess the magnitude of the problem.

Ultrasound detection of Apert syndrome: a case report and literature review

Apert Syndrome is characterized by craniosynostosis, bilateral syndactyly, and midfacial hypoplasia. Although it was first described by Wheaton in 1894, it was first diagnosed prenatally only a decade ago-with only five cases reported in the literature. A sixth case is reported here. Prenatal diagnosis of Apert syndrome is reviewed.

Pericentric inversion of chromosome 4 giving rise to dup(4p) and dup(4q) recombinants within a single kindred

Theoretically, every pericentric inversion can give rise, during meiosis, to 2 alternate recombinant chromosomes. One of these will have a duplication of short arm material and deletion of long arm material (dup p), and the other, a duplication of a long arm material and deletion of short arm material (dup q). However, most published cases have been limited to a single recombinant type occurring within a given kindred. Here we document a large pericentric inversion of chromosome 4 which gave rise, within 2 generations of a kindred, to both dup p and dup q recombinants. The family was ascertained by the birth of a baby girl with multiple congenital anomalies suggestive of Wolf-Hirschhorn syndrome, and was found to have a dup 4q recombinant. Subsequent studies of her father and of her 27-year-old mentally retarded aunt showed a balanced inv(4) (p15.32q35) and a dup 4p recombinant, respectively. Given that: (a) the balanced inversion involves approximately 87% of the length of chromosome 4; (b) the predicted meiotic pairing would be homosynapsis with loop formation; (c) the size of the segments distal to the breakpoints of the inversion are of similar and relatively small size; and (d) both recombinants are compatible with life, then the risk for recurrence of a recombinant in this family is high. Genetic counseling addressed these issues, and to date, both chronic villus sampling (CVS) and amniocentesis have been provided for prenatal diagnosis.

Prenatal onset of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease presenting in the fetus or newborn is rare, only 22 cases having been reported in the literature. A case is reported of a premature newborn infant with severe renal involvement and extrarenal associated abnormalities. The literature is reviewed, and the importance of considering this entity in infants with polycystic kidney disease is discussed since it may affect both genetic counseling and surgical management when radiographically detected.

Prenatal diagnosis of trisomy 20 mosaicism indicating an extra embryonic origin

An additional case of amniotic fluid trisomy 20 mosaicism is presented. After careful counselling, the pregnancy continued and a phenotypically normal female was delivered. This case of amniocyte mosaicism establishes the source of aneuploid cell line as amnion. Since an extra-embryonic origin of the mosaicism has been confirmed, this should be carefully considered as a real possibility in counselling such families.

Pseudodeficiency of arylsulfatase A: a counseling dilemma

Arylsulfatase A (ASA) deficiency is the cause of early and late onset metachromatic leukodystrophy (MLD). Low ASA levels are detected in some healthy individuals who are pseudodeficient (PD). PD individuals can be distinguished, because PD fibroblasts hydrolyze 14C-sulfatide at similar rates to normal fibroblasts. This has also been demonstrated in amniocytes and chorionic villi (CV). The genetic basis for PD is not clearly understood and is most likely heterogeneous with respect to allelic mutations of the ASA gene. It is hypothesized that the PD phenotype can either be due to PD/PD or PD/MLD genotypes, only the latter representing a potential risk to offspring. We report an unusual family where two siblings, both carriers of the classic late infantile MLD allele, are married to unrelated PD individuals. One couple has two PD offspring; their "at risk" status, due to the lack of an affected offspring is in question. The other couple terminated a fetus determined to be affected with a "MLD variant", most likely a compound heterozygote. Cautions prenatal counseling of PD families is essential. The population frequency of the PD phenotype is unknown.

Two successive partial trisomies for opposite halves of chromosome 22 in a mother with a balanced translocation

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