Head injury in older adults presenting to the ambulance service: who do we convey to the emergency department, and what clinical variables are associated with an intracranial bleed? A retrospective case-control study

OBJECTIVE

Most older adults with traumatic brain injuries (TBI) reach the emergency department via the ambulance service. Older adults, often with mild TBI symptoms, risk being under-triaged and facing poor outcomes. This study aimed to identify whether sufficient information is available on the scene to an ambulance clinician to identify an older adult at risk of an intracranial haemorrhage following a head injury.

METHODS

This was a retrospective case-control observational study involving one regional ambulance service in the UK and eight emergency departments. 3545 patients aged 60 years and over presented to one regional ambulance service with a head injury between the 1st of January 2020 and the 31st of December 2020. The primary outcome was an acute intracranial haemorrhage on head computed tomography (CT) scan in patients conveyed to the emergency department (ED). A secondary outcome was factors associated with conveyance to the ED by the ambulance clinician.

RESULTS

In 2020, 2111 patients were conveyed to the ED and 162 patients were found to have an intracranial haemorrhage on their head CT scan. Falls from more than 2 m (adjusted odds ratio (aOR) 3.45, 95% CI 1.78-6.40), chronic kidney disease (CKD) (aOR 2.80, 95% CI 1.25-5.75) and Clopidogrel (aOR 1.98, 95% CI 1.04-3.59) were associated with an intracranial haemorrhage. Conveyance to the ED was associated with patients taking anticoagulant and antiplatelet medication or a visible head injury or head injury symptoms.

CONCLUSION

This study highlights that while most older adults with a head injury are conveyed to the ED, only a minority will have an intracranial haemorrhage following their head injury. While mechanisms of injury such as falls from more than 2 m remain a predictor, this work highlights that Clopidogrel and CKD are also associated with an increased odds of tICH in older adults following a head injury. These findings may warrant a review of current ambulance head injury guidelines.

Heart rate fragmentation as a marker of altered global autonomic nervous system activity: a novel predictor of atrial fibrillation occurrence in the general population

Background

The dysfunction of the autonomic nervous system (ANS) plays an important role in the initiation and maintenance of atrial fibrillation (AF). However, the meaning of high heart rate variability (HRV) in predicting AF is still under debate due to conflicting results in population-based studies. Short-term HRV is conceptually attributed to vagal tone modulation. But recent data suggest that a component of short-term HRV, called heart rate fragmentation, is related to ANS breakdown. On the other hand, parasympathetic activity could be assess by a novel metric, the deceleration capacity (DC).

Objective

To assess predictive capacity of novel HRV-derived metrics, whether fragmentation indices or parameters of vagal tone, regarding the occurrence of AF in general population during long-term follow-up.

Methods

A cohort study was designed to prospectively assess the predictive value of ANS activity level among a healthy retired French population, regarding cardiovascular events and mortality. 1011 subjects aged 65 were enrolled in the study from 2000 to 2002. The enrolled population had no history of AF and a low cardiovascular risk. A median follow-up of 17.8 years (16.0–18.5) was managed. HRV data were acquired by 24-h Holter electrocardiogram (ECG) monitoring at baseline and assessed by frequency domain and time domain methods. Heart rate fragmentation using the percentage of inflection points (PIP), and assessment of specific parasympathetic activity using DC were then calculated. The study outcome was the onset of AF during follow-up, defined as a standard 12-lead ECG or Holter recording with ≥30 s of AF.

Results

AF was diagnosed in 123 patients along the 18-year follow-up, representing a cumulative incidence of 13.4%. Using univariate analysis (Figure 1A), a higher percentage of NN intervals that differ by more than 50 ms from the previous interval (pnn50) and root mean square differences of successive NN intervals (RMSSD) were associated with AF onset (p<0.01). A lower ratio of low-frequency and high-frequency component (LF/HF) was the only frequency-domain parameter found to predict the AF occurrence (p<0.01). The occurrence of AF was predicted by a higher PIP (p<0.01) and lower DC (p<0.01). Through multivariate analysis using clinical parameters that reached statistical significance in univariate analysis (Figure 1B), higher PIP was found as an independent predictor of AF occurrence (HR=2.1, 95% CI: 1.1–3.9, p=0.02), as well as male gender (HR=2.1, 95% CI: 1.1–3.9, p=0.02), and non-sustained supraventricular tachycardia (HR=2.1, 95% CI: 1.1–3.9, p=0.02).

Conclusion

(see Figure 2) Elevated PIP, a marker of heart rate fragmentation secondary to impaired ANS activity, is an independent predictor of the onset of AF in the healthy general population. Therefore, high HRV associated to AF occurrence could be the consequence of general ANS impairment rather than increased parasympathetic activity.

Funding Acknowledgement

Type of funding sources: None.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Comparison of clockwise and counterclockwise right atrial flutter using high-resolution mapping

Background

To the best of our knowledge, few studies have been performed that explore the electrophysiological differences between clockwise (CW) and counterclockwise (CCW) right atrial (RA) cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) using the high-resolution Rhythmia mapping system. Objectives. Accordingly, our prospective cohort study, sought to compare CW and CCW CTI-dependent AFL in preselected pure right AFL patients (pts) using the ultra-high-definition (ultra-HD) Rhythmia mapping system. The study also aimed to mathematically develop a cartography model based on automatic velocity RA measurements to identify electrophysiological AFL specificities.

Methods and results

Between October 2019 and July 2020, 33 patients were recruited. The mean age was 71±13 years old. No difference was found concerning clinical variables between CCW AFL and CW AFL or regarding left ventricular ejection fraction (LVEF) (55.5±10 vs. 56.6±12; p=0.76). The AFL cycle length was very similar (248±20 vs. 252±28 ms; p=0.6). The sinus venosus (SV) block line was present in 32/33 of cases (97%) and no significant difference was found between CCW and CW CTI AFL (100% vs. 91%; p=0.7). No line was localized in the region of the crista terminalis (CT). A superior gap was present in the posterior line in 14/31 (45.2%) but this was similarly present in CCW AFL, when compared to CW AFL (10/22 [45.5%] vs. (4/10 [40%]); p=0.9). When present, the extension of the posterior line of block was observed in 18/31 pts (58%) without significant differences between CCW and CW CI AFL (12/22 [54.5%] vs. (6/10 [60%]) (p=.9) The Eustachian ridge line of block was similarly present in both groups (82% [18/22] vs. 45.5% [5/11]; p=0.2). The absence of the Eustachian ridge line of block led to significantly slowed velocity in this area (28±10cm/s; n=8),and the velocities were similarly altered between both groups (26±10 [4/22] vs. 29.8±11cm/s [4/11]; p=0.6). We created mathematical, three-dimensional RA reconstruction-velocity model measurements. In each block localization, when the block line was absent, velocity was significantly slowed (≤20cm/s). A systematic slowdown in conduction velocity was observed at the entrance and exit of the CTI in 100% of cases. This alteration to the conduction entrance was localized at the lateral side of the CTI for the CCW AFL and at the septal side of the CTI for CW AFL. The exit-conduction alteration was localized at the CTI septal side for the CCW AFL and at the CTI lateral side for the CW AFL. The only differences between CW and CCW AFL concerned activation patterns.

Conclusions

The ultra-HD Rhythmia mapping system confirmed the absence of significant electrophysiological differences between CCW and CW AFL. The mechanistic posterior SV and Eustachian ridge block lines were confirmed in each arrhythmia. A systematic slowing down at the entrance and exit of the CTI was demonstrated in both CCW and CW AFL, but in reverse positions.

Funding Acknowledgement

Type of funding sources: None.

Is transesophageal echocardiogram mandatory for patients undergoing ablation for right atrial flutter with uninterrupted anticoagulants? A prospective single registry

Funding Acknowledgements

Type of funding sources: None.

Background. Limited data exist regarding the prevalence of left atrial appendage (LAA) thrombi and spontaneous echocardiographic contrast (SEC) in patients with atrial flutter (AFL). Objectives. Our prospective single-center observational study sought to evaluate the prevalence of LAA thrombi in patients referred for AFL ablation, compared to those requiring atrial fibrillation (AFib) ablation during the same time period, as well as to determine the predictive factors of LAA thrombi in terms of arrhythmia etiology. Methods and Results. From July 2019 to August 2020, 321 consecutive patients who were referred for either AFib ablation (n = 229) or AFL ablation (n = 92) were included in the study, with a thrombus detected by transesophageal echocardiography (TEE) in 3.22% (12/321). Prior to ablation under anticoagulants, the percentage of thrombi was similar between patients referred for AFL ablation and those referred for AFib ablation (5.4% [n = 5/92] vs. 3.1% [n = 7/229]; p = 0.3). In the overall population, patients with LAA thrombi had a higher CHA²DS²-VASc score (3 ± 2 vs. 2 ± 1.5; p = 0.048) and a higher presence of valvular prothesis (25% vs. 4.9%; p = 0.003), with relevant left atrial remodeling  more often observed, such as demonstrated by a higher left atrium (LA) volume (57 ± 19 vs. 46 ± 17 ml/m²; p = 0.04), a lower LAA velocity (0.41 ± 0.3 vs. 0.55 ± 0.2; p = 0.04) and a more severe LAA echo contrast (83.3% vs. 3.2%; p <0.0001). In the subset of patients with right AFL, patients with LAA thrombi had a higher CHA²DS²-VASc score (4.4 ± 1 vs. 2.5 ± 1.5; p = 0.008), had more often hypertension (100% vs. 53%; p = 0.04) and more often diabetes mellitus (60% vs. 18.4%; p = 0.03), and a more severe LAA echo contrast (80% vs. 5.7%; p <0.0001). Predictive factors of atrial thrombi evaluated by crude odds ratios were the presence of valvular prosthesis (OR = 6.53; [1.60, 26.65] ; p = 0.009), the CHA²DS²-VASc score (OR = 1.41 [0.99, 2.01] ; p = 0.05), the LAA velocity (cm/s) (OR = 0.03; [0.001, 0.79]; p = 0.04) and presence of severe LAA contrast (OR = 188 ; [35.32, 1002.02] ; <0.0001) rather than the atrial arrhythmia itself. Conclusions. Patients referred for ablation with right AFL have a similar risk of LAA thrombi, compared to those with AFib. The risk of LAA thrombi is better related to the presence of valvular prosthesis, CHA²DS²-VASc score and LA remodelling than the atrial arrhythmia itself. Accordingly, TEE should be recommended before right AFL ablation, especially in case of a valvular prosthesis, high CHA²DS²-VASc score or LA alteration.

5205Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

Background

The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in patients with tetralogy of Fallot. QRS duration has been consistently associated with outcomes, with a lack of specificity for sudden mortality and a relatively low predictive value. New markers such as QRS fragmentation and vectocardiographic parameters have been recently suggested.

Purpose

To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD).

Methods

The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies.

Results

A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively (p=0.058). Overall, QRSd ≥180ms (p=0.073), QRS fragmentation (p=0.052), and QRS vector magnitude (vm, p=0.327) were not significantly associated with appropriate ICD therapies, whereas QRS fragmentation in right leads (HR=1.7, 95% CI: 1.1–2.9, p=0.039) and the association of QRSd ≥180ms and overall QRS fragmentation (HR=1.9, 95% CI: 1.1–3.4, p=0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), 53.8% had QRS fragmentation, 48.6% had decreased QRS vm, and 41.0% had QRSd ≥180ms. In this group, while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with ventricular events during follow-up (p=0.069), respective combinations with QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.011), QRS fragmentation (HR=3.8, 95% CI: 1.2–12.4, p=0.025), or decreased QRS vm (HR=3.6, 95% CI: 1.1–12.1, p=0.042) were all associated with a higher incidence of appropriate ICD therapies. Positive predictive value and negative predictive value were 0.33 and 0.85, 0.58 and 0.74, and 0.36 and 0.84 in patients with NSVT and QRS ≥180ms, NSVT and QRS fragmentation, and NSVT and decreased QRS vm, respectively.

Conclusions

Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

P1899Heparin and low-molecular-weight heparin switch associated with an increase in bleeding complications in patients on apixaban undergoing catheter ablation: The AMPER ABLATION study

Background

The aim of this study was to identify the factors associated with bleeding complications in patients taking apixaban and undergoing a catheter ablation in everyday clinical practice.

Methods

AMPER ABLATION is a multicenter, observational, prospective study of patients with non valvular atrial fibrillation (AF) undergoing a catheter ablation. Eligible patients had been taking apixaban (2.5 or 5 mg twice daily) for ≥3 weeks before the procedure, and were followed for 30 days afterwards.

Results

A total of 595 patients (65 [interquartile range 59, 72] years, 67% male, mean CHA2DS2-VASc score 1.85±1.37) were enrolled at 25 academic/nonacademic centers in France; 524 patients (88%) were receiving apixaban 10 mg/day and 71 (12%) 5 mg/day. 323 patients (54%) underwent an AF ablation, and 272 (46%) an atrial flutter (AFL) ablation. The most prevalent concomitant disorders were hypertension (51% of patients), diabetes (15%) and vascular disease (10%). Mean creatinine concentration was 1.06±0.28 mg/dL, median weight was 83±18 kg and mean creatinine clearance (Cockcroft-Gault) was 82±34 mL/min. The management of apixaban in the periprocedural period was left to the investigator's preference. Overall, 264 patients were switched to unfractionated heparin or enoxaparin (238 for AF ablations and 26 for AFL ablations). The median duration of switch was 29 hours. Complications were reported at 30 days, and included 12 bleeding events (1 tamponade needing drainage, 1 pericardial effusion without drainage, 7 International Society on Thrombosis and Haemostasis [ISTH] non major bleedings for AF ablations and 1 pericardial effusion without drainage, and 2 ISTH non major bleedings for AFL ablations) and 1 embolic event (non disabling stroke for an AF ablation). Comparing patients with and without a bleeding event revealed a higher rate of heparin or low-molecular-weight heparin (LMWH) switching in patients with a bleeding event (60% vs 35%; p=0.02). A switch to heparin or LMWH was the only factor associated with an increase rate of bleeding (odds ratio 2.5; [CI 95%; 1.1, 7.1]; p=0.01).

Conclusion

Heparin or LMWH switch in the periprocedural AF and AFL-ablation period is associated with an increased rate of bleeding complications at 30 days.

Acknowledgement/Funding

Financial support from BMS

Review of lignocellulolytic enzyme activity analyses and scale-down to microplate-based assays

With the increasing use of enzymes in environmental applications, there is a need for analytical methods adapted to large factorial experiments. Existing reference methods are chemical and labor intensive and unsuitable to analyze in parallel a large number of samples. Based on an extensive literature review and on experimental results, this work compares reference and microplate adapted methods to define the most adequate filter paper, carboxymethylcellulase, β-glucosidase and xylanase activity tests. In the adapted methods, the total reaction volume was reduced from 2.2-24.5 mL to 0.21-0.24 mL. Statistical analysis of the activities measured on enzyme mixtures by applying the 96-well plate reduced methods showed that they were not significantly different to the activities obtained with reference tests.

Effects of ZNF804A on auditory P300 response in schizophrenia

The common variant rs1344706 within the zinc-finger protein gene ZNF804A has been strongly implicated in schizophrenia (SZ) susceptibility by a series of recent genetic association studies. Although associated with a pattern of altered neural connectivity, evidence that increased risk is mediated by an effect on cognitive deficits associated with the disorder has been equivocal. This study investigated whether the same ZNF804A risk allele was associated with variation in the P300 auditory-evoked response, a cognitively relevant putative endophenotype for SZ. We compared P300 responses in carriers and noncarriers of the ZNF804A risk allele genotype groups in Irish patients and controls (n=97). P300 response was observed to vary according to genotype in this sample, such that risk allele carriers showed relatively higher P300 response compared with noncarriers. This finding accords with behavioural data reported by our group and others. It is also consistent with the idea that ZNF804A may have an impact on cortical efficiency, reflected in the higher levels of activations required to achieve comparable behavioural accuracy on the task used.

[Pacemaker, implanted cardiac defibrillator and irradiation: Management proposal in 2010 depending on the type of cardiac stimulator and prognosis and location of cancer]

Ionizing radiation may interfere with electric components of pacemakers or implantable cardioverter-defibrillators. The type, severity and extent of radiation damage to pacemakers, have previously been shown to depend on the total dose and dose rate. Over 300,000 new cancer cases are treated yearly in France, among which 60% are irradiated in the course of their disease. One among 400 of these patients has an implanted pacemaker or defibrillator. The incidence of pacemaker and implanted cardioverter defribillator increases in an ageing population. The oncologic prognosis must be weighted against the cardiologic prognosis in a multidisciplinary and transversal setting. Innovative irradiation techniques and technological sophistications of pacemakers and implantable cardioverter-defibrillators (with the introduction of more radiosensitive complementary metal-oxide-semiconductors since 1970) have potentially changed the tolerance profiles. This review of the literature studied the geometric, dosimetric and radiobiological characteristics of the radiation beams for high energy photons, stereotactic irradiation, protontherapy. Standardized protocols and radiotherapy optimization (particle, treatment fields, energy) are advisable in order to improve patient management during radiotherapy and prolonged monitoring is necessary following radiation therapy. The dose received at the pacemaker/heart should be calculated. The threshold for the cumulated dose to the pacemaker/implantable cardioverter-defibrillator (2 to 5 Gy depending on the brand), the necessity to remove/displace the device based on the dose-volume histogram on dosimetry, as well as the use of lead shielding and magnet are discussed.

Coping Strategies Used By Patients With Chronic and/or Complex Wounds 

Objective. The aim of this study was to investigate coping strategies used by patients with chronic and/or complex wounds treated in an outpatient wound clinic.

METHODS

Coping strategies were assessed using the Utrecht Coping List (UCL). The Mini-Mental State Examination (MMSE) was used to assess the patient's cognitive functioning. Fifty patients were selected for this study. The wound etiologies studied were: diabetic foot ulcers, lower extremity ulcers, surgical wounds, trauma wounds, and pressure ulcers.

RESULTS

Scores on the coping measure for men and women differed significantly from the control groups. It was also found that each wound etiology showed a preference toward different coping strategies. Furthermore, 28% of the studied group had a lowered score on the MMSE, indicating possible cognitive impairments.

CONCLUSION

There might be an association between wound etiology and the coping strategy that is preferred; this knowledge could be used to guide treatment strategies used by clinicians. Further research could focus on the effects of coping strategies on wound healing rates .

[Atrial fibrillation: epidemiologic stakes, definition, and economic aspects]

Atrial Fibrillation (AFib) is the most common sustained cardiac arrhythmia and a major contributor to cardiovascular morbidity and mortality in the general population. Morbidity and mortality are essentially related to stroke and heart failure. Despite a long history of medical exploration of AFib, many aspects deserve to be considered including AFib definitions, epidemiologic stakes and economic burden posed by AFib. Such aspects are integral part of the evaluation, and accordingly both clinical and therapeutic AFib patients approach. Through this article these various aspects were raised in order to help the clinician to better understand this arrhythmia which is generally easy to identify but often delicate and complex to treat.

Diversity in VIM-2-encoding class 1 integrons and occasional blaSHV2a carriage in isolates of a persistent, multidrug-resistant Pseudomonas aeruginosa clone from Tunis

From 2002 to 2006, 35 of 73 multidrug-resistant Pseudomonas aeruginosa isolates from different wards at Charles Nicolle hospital of Tunis were positive for class B carbapenemase (using the imipenem-EDTA test), owing to a bla(VIM-2) gene cassette in a class 1 integron. Twenty-three isolates additionally produced the extended-spectrum beta-lactamase SHV2a. DNA sequences immediately surrounding bla(SHV2a) shared extensive identity with a Klebsiella pneumoniae plasmid sequence. Despite belonging to the same chromosomal type, as shown by pulsed-field gel electrophoresis (PFGE), the VIM-2 producing P. aeruginosa isolates prevalent at Charles Nicolle hospital displayed a diversity of VIM-2-carrying integrons.

Polysaccharide Lyases: Recent Developments as Biotechnological Tools

Polysaccharide lyases, which are polysaccharide cleavage enzymes, act mainly on anionic polysaccharides. Produced by prokaryote and eukaryote organisms, these enzymes degrade (1,4) glycosidic bond by a beta elimination mechanism and have unsaturated oligosaccharides as major products. New polysaccharides are cleaved only by their specific polysaccharide lyases. From anionic polysaccharides controlled degradations, various biotechnological applications were investigated. This review catalogues the degradation of bacterial, plant and animal polysaccharides (neutral and anionic) by this family of carbohydrate acting enzymes.

Spectrum of pathogenic mutations and associated polymorphisms in a cohort of 44 unrelated patients with long QT syndrome

Long QT syndrome (LQTS) is a rare and clinically heterogeneous inherited disorder characterized by a long QT interval on the electrocardiogram, increased risk of syncope and sudden death caused by arrhythmias. This syndrome is mostly caused by mutations in genes encoding various cardiac ion channels. The clinical heterogeneity is usually attributed to variable penetrance. One of the reasons for this variability in expression could be the coexistence of common single nucleotide polymorphisms (SNPs) on LQTS-causing genes and/or unknown genes. Some synonymous and nonsynonymous exonic SNPs identified in LQTS-causing genes may have an effect on the cardiac repolarization process and modulate the clinical expression of a latent LQTS pathogenic mutation. We report the molecular pattern of 44 unrelated patients with LQTS using denaturing high-performance liquid chromatography analysis of the KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 genes. Forty-five disease-causing mutations (including 24 novel ones) were identified in this cohort. Most of our patients (84%) showed complex molecular pattern with one mutation (and even two for four patients) associated with several SNPs located in several LQTS genes.

[Evaluation and surveillance of patients with an implantable defibrillator]

The implantable cardioverter-defibrillator became in some years the reference treatment of ventricular arrhythmias in association with heart disease. Recently, this technique showed its efficiency in primary prevention for patients at high risk of sudden death. The follow-up of patients with automatic defibrillator requires a detailed knowledge of both electrophysiology and stimulation. This training is based on a practical and theoretical formation. In France, a specific diploma validation is necessary and centres organisation is required. The purpose of this general review is to supply a set of updated data necessary for the coverage and the follow-up of patients with an implantable cardioverter-defibrillator.

Factors associated with early atrial fibrillation after ablation of common atrial flutter. A single centre prospective study

BACKGROUND

The occurrence of early atrial fibrillation (< or = 6 months) after ablation of common atrial flutter is of clinical significance. Variables predicting this evolution in ablated patients without a previous atrial fibrillation history have not been fully investigated.

OBJECTIVES

The aim of the present study was: (1) to identify predictive factors of early atrial fibrillation (< or = 6 months) in the overall population following atrial flutter catheter ablation; (2) to identify predictive variables of early atrial fibrillation following (< or = 6 months) atrial flutter catheter ablation within a subgroup of patients without documented prior atrial fibrillation.

METHODS

This study prospectively included 96 consecutive patients (age 65 +/- 13 years; 18 women) over a 12-month period. Their counterclockwise flutter was ablated by radiofrequency, by the same operator, with an 8-mm-tip catheter. Clinical, electrophysiological and echocardiographic data were collected and 27 variables were retained for analysis: age; gender; type of atrial flutter (permanent vs paroxysmal); symptom duration (months +/- SD); pre-ablation history of atrial fibrillation; structural heart disease; left ventricular ejection fraction (%); left atrial size (mm); cava--tricuspid isthmus dimension; septal isthmus dimension; systolic pulmonary pressure > or < or = 30 mmHg; right atrial area; left atrial area; isthmus block; number of radiofrequency applications (+/- SD); antiarrhythmic drugs at discharge; left ventricular diastolic diameter; left ventricular systolic diameter; left ventricular telediastolic volume; left ventricular telesystolic volume; A-wave velocity (cm . s(-1)); E-wave velocity (cm . s(-1)); E/A; isovolumetric relaxation time; E-wave deceleration time; significant mitral regurgitation and flutter cycle length (ms).

RESULTS

Of the 96 consecutive ablated patients, early atrial fibrillation was documented in 16 patients (17%). Atrial fibrillation occurred 30 +/- 46 days (range 1 to 171 days) after ablation. Univariate analysis associated an early occurrence of atrial fibrillation with: atrial fibrillation history, left ventricular ejection fraction, left atrial size, left ventricular telesystolic volume, A-wave velocity, significant mitral regurgitation and flutter cycle length. Multivariate analysis using a Cox model found that the only independent predictors of early atrial fibrillation were left ventricular ejection fraction and pre-ablation history of atrial fibrillation. In the subgroup without prior atrial fibrillation history (n=63; 66%), the only independent predictor of early atrial fibrillation was the presence of a significant mitral regurgitation.

CONCLUSIONS

In a subgroup of patients without atrial fibrillation history, 8% of patients revealed an early atrial fibrillation. Mitral regurgitation is a strong predictive factor of early atrial fibrillation occurrence with 80% sensitivity, 78% specificity and 98% negative predictive value. These data should be considered in post-ablation management.