Cardiac events monitoring.

Cardiac events recorders have been developed in order to record the heart rhythm during symptoms such as palpitations or presyncope, to first make a diagnosis, and subsequently drive the treatment strategy. In other circumstances, they can be also used in asymptomatic patients (to record silent atrial fibrillation for instance). Because they are non-invasive, potentially cost-saving and relatively easy to use, the external rhythm recording devices have shown some great advances in the last years, spreading from photoplethysmographic technique to real ECG reconstruction. Technological advances in the field of microelectronics, as well as in the field of data transmission have contributed to their widespread use in cardiology. The trend for miniaturization was also expanded to the implantable recorders. This paper will review will review advantages and limitations of the different existing available well-established recording devices, as well as the last technological developments in terms of ECG recordings.

[Organization and management of acute complete atrioventricular block: Results from a Multicenter National Survey]. / Organisation et gestion aiguë du bloc atrioventriculaire complet : résultats d'une enquête multicentrique nationale.

BACKGROUND: Complete atrioventricular block (AVB3) may be an urgent potentially lifethreatening situation. Our objective was to describe the routine management of AVB 3, with emphasis on the organizational aspects. METHODS: From September 2019 to November 2019, a prospective national survey including 28 questions was electronically sent to 100 physicians (Google Form). RESULTS: The answers were collected from 93 physicians (response rate 93%). Permanent pacemaker implantation during weekends and nights (after 8PM) is possible for 49% of the operators (<5 times a year), for 15% (>5 times a year), impossible for 36% of the operators. For AVB3 nonresponsive to isoproterenol occurring during the night, a temporary pacing lead (TPL) is implanted by: the on-site medical staff on-duty (27%), the on-call interventional cardiologist (21%), the on-call electrophysiologist (19%), a permanent pacemaker is implanted by the electrophysiologist (12%), the strategy is not standardized (15%). An externalized active fixation lead (AFL) for AVB3 has already been implanted by 50% of the operators. 80 (86%) have already observed a dislocation of the TPL, a cardiac perforation already occurred in 57 (61%), a groin hematoma in 35 (38%), and this technique was proscribed for 4% of the operators. CONCLUSION: Our survey shows important disparities in terms of management of AVB3 among the different centers. An externalized AFL with a reusable generator was used by half of the centers.

[Evaluation of an "Emergency Thrombosis" care system in a university-hospital department of general emergencies]. / Évaluation de la mise en place d'une filière de soins « Urgence Thrombose ¼ dans un service hospitalo-universitaire d'Urgences générales.

GOAL: Describe the use of diagnostic, prognostic and therapeutic algorithms for venous thromboembolism (VTE), derived from the 2014 European guidelines, in a teaching hospital's emergencies department and compare two groups: the 2015 group "without a care path" and the 2017 group "with a care path". METHOD: Comparative and retrospective study of the characteristics of emergencies department patients admitted for VTE from January to June 2015 for the 2015 group and from January to June 2017 for the 2017 group. RESULTS: Seventy-nine patients were included in the 2015 group and 62 patients in the 2017 group. In 24% of cases a clinical probability rule was calculated in the 2017 group (vs. no score in 2015, P<0.05). In the 2015 group, 10% of patients did not have a D-Dimer measurement in case of low clinical probability (vs. 0% in 2017, P<0.05). For both groups, the severity score sPESI was not noted in the medical record. All patients with pulmonary embolism were hospitalized in both groups. A total of 36% of patients with deep vein thrombosis (DVT) were hospitalized in the 2015 group (vs. none in 2017, P<0.05). A total of 52.5% of patients were treated with direct oral anticoagulants (DOAS) in the 2017 group vs. 32.5% in the 2015 group (P<0.05). In 18% of cases DOAS were prescribed by emergency physicians in the 2017 group vs. 2.5% in the 2015 group (P<0.05). Mean hospital stay was 7.4 days in the 2017 group and 9.4 days in the 2015 group (P<0.05). CONCLUSION: We observed a change in clinical practices and prescriptions after the establishment of an "Emergency Thrombosis" care system. Indeed, improvement in the calculation of the clinical probability score, increase in the outpatient management of DVT, increase in prescribing DOAS and reducing the length of hospital stay were the main revisions. The implementation of standardized digitally calculated clinical and prognostic probability scores would optimize this care path, as well as allow a better distribution of the post-emergency consultations created for outpatients.

A2A adenosine receptor function in patients with vasovagal syncope.

AIMS: Adenosine is a possible mediator in vasovagal syncope (VVS) via the activation of its receptors. High expression of adenosine A2A receptors (A2AR) has been reported in VVS. The function of these over-expressed receptors in this population has never been evaluated. METHODS AND RESULTS: We used Adonis, a specific-made antibody with A2AR agonist properties, to evaluate binding parameters (i.e. dissociation constant KD) and cAMP production (i.e. EC50) by peripheral blood mononuclear cells of 16 VVS patients. Eight healthy volunteers served as controls. A2AR expression was higher in patients than controls; mean: 11.5 ± 1.2 vs. 7.7 ± 0.8 AU, P = 0.04. Also, KD values were higher in patients than controls: 2.1 ± 0.02 × 10(-7) vs. 5 ± 1 × 10(-8) M, P < 0.01 In controls, KD values were lower than EC50 (5 ± 1.7 × 10(-8) vs. 2.8 ± 0.4 10(-7) M, P < 0.01), but in patients, KD values did not differ from EC50: 2. ± 0.2 × 10(-7) vs. 2.5 ± 0.4 × 10(-7) M, P > 0.05. However, four patients had lower EC50 (3.5 ± 0.3 × 10(-8) M) than KD (2.9 ± 1.2 × 10(-7) M; KD/EC50 = 9.6), suggesting the presence of spare receptors. CONCLUSION: The function of A2AR of patients with VVS was preserved since their stimulation by Adonis led to cAMP production with an EC50 comparable with those in controls. However, their affinity was lower than those of controls. Our results suggest that A2AR are implicated in the physiopathology of VVS.

Peripheral plasma adenosine release in patients with chronic heart failure.

OBJECTIVE: Chronic heart failure (CHF) is accompanied by increased adenosine plasma levels (APLs). It is unknown whether adenosine release occurs at the peripheral level or whether the myocardium itself is the source of adenosine release. To answer this question, we evaluated APLs in the coronary sinus of CHF patients during a resynchronisation procedure and compared the values with those at the peripheral level. We also investigated a possible correlation between APLs and ischaemia-modified albumin (IMA) levels, a useful marker of tissue ischaemia. METHODS: 19 men and seven women were prospectively included. Blood samples for APLs were collected simultaneously from a brachial vein (peripheral) and from the coronary sinus. Blood samples for brain natriutretic peptide (BNP) and IMA were collected from a brachial vein. RESULTS: APLs from the brachial vein were higher than those from the coronary sinus (1.69 vs 0.75 muM p<0.01). IMA levels were correlated with APLs from the brachial vein (r = 0.59, p<0.01). BNP concentrations were correlated with APLs from the brachial vein (r = 0.73, p<0.001) but not with APLs from the coronary sinus (r = 0.38, p>0.05). BNP concentrations and IMA levels were correlated (r = 0.71, p<0.001). CONCLUSIONS: In CHF patients, adenosine release occurs at a peripheral level and not at the myocardium level.

[Role of non antiarrhythmic medications in the prevention of atrial fribrillation]. / Le rôle des médicaments non anti-arythmiques dans la prévention de la fibrillation auriculaire.

After cardioversion of atrial fibrillation, structural and electrophysiologic remodelling of the atria is implicated in the arrhythmia recurrences despite antiarrhythmic drug treatment. Strategies targeting this substrate have therefore been proposed. In this view, Renin angiotensin system inhibition and drugs targeting inflammation and oxidative injury are the most promising strategies up to now. We discuss here the rationale and evidence which are behind these therapeutic approaches.

[Clinical and electrophysiological study of asymptomatic Wolff-Parkinson-White syndrome]. / Etude clinique et électrophysiologique du syndrome de Wolff-Parkinson-White asymptomatique.

AIM: This study was designed to describe clinical characteristics and electrophysiologic in patients with asymptomatic Wolff-Parkinson-White syndrome. METHODS: From December 2000 to August 2005, a total of 154 patients with accessory pathway-mediated reentry mechanism underwent electrophysiologic studies at Sainte-Marguerite and Timone hospitals in Marseille. Ninety-six patients had WPW syndrome, out of which 78 were symptomatic patients and 18 were asymptomatic. The mean age was 26 years. Sex (masculine) 17. RESULTS: The incidence of intermittent arrhythmia associated with Wolff-Parkinson-White syndrome was lower in 2 patients (11%). There was a higher occurrence of rapid induced tachycardia in 9 patients (50%). However, atrial fibrillation occurred more commonly in 6 (33%) patients. The anterograde accessory pathway effective refractory period (APRP) in patients was much shorter (less than 250 ms [N=16]) 13 patients with accessory pathways were managed by ablation. CONCLUSION: This study demonstrated the difference in the electrophysiologic characteristics of anterograde accessory pathway and the atrioventricular node in asymptomatic WPW patients, and thus concluded that radiofrequency (RF) catheter ablation is a safe and effective method to manage patients with asymptomatic WPW syndrome.

Anti-arrhythmic effects of I (Na), I (Kr), and combined I (Kr)-I (CaL) blockade in an experimental model of acute stretch-related atrial fibrillation.

INTRODUCTION: Atrial dilatation is commonly associated with atrial fibrillation (AF), but the electrophysiological mechanisms and the implications for anti-arrhythmic therapy are poorly understood. In a model of acute stretch-related AF in isolated rabbit hearts, we evaluated the electrophysiological effects of three different anti-arrhythmic drugs: dofetilide, flecainide and BRL-32872 (associating I (Kr) and I (CaL) blocking properties). METHODS: After 30 min of sustained stretch-related AF, we perfused BRL 10-7 M, BRL 3.10-7 M, BRL 10-6 M, flecainide 2.4 10-6 M and dofetilide 10-7 M and iteratively measured atrial effective refractory periods (ERPs), AF inducibility and AF cycle length (AFCL) 15, 30 and 60 min after drug perfusion, respectively. RESULTS: After a significant shortening of the ERPs by acute atrial stretch in the five groups individually (p < 0.001, stretch vs baseline for each group individually), drug perfusion led to a strong lengthening of AFCL, a very significant prolongation of ERPs (p < 0.001 vs stretch) and a reduction of AF inducibility (p < 0.01 vs control group) for each of the five experimental groups. The relative ERP increase was comparable in all groups, whereas a significantly lower AF inducibility was observed in the BRL 10-6 M group (p < 0.05 vs other BRL concentrations). CONCLUSION: In a model of acute stretch-related AF, dofetilide, flecainide and BRL-32872 terminated AF and prevented its immediate reinduction after having comparatively prolonged AFCL and ERPs. These comparative results suggest that those drugs are equally efficacious, albeit with different mechanisms, in the setting of acute atrial stretch.

Home Monitoring: what can we expect in the future?

The Home Monitoring of implanted cardiac rhythm management devices developed by Biotronik (Berlin, Germany) is a new useful tool for monitoring patients. Home Monitoring provides access to technical and clinical data, allowing almost continuous patient surveillance. The implanted defibrillators and pacemakers transmit encrypted messages, which are automatically analyzed in the Home Monitoring Service Center and sent to the physician. The expected benefit of this kind of data transmission is an improvement in patient follow-up and early detection of changes in the rhythmologic state of the patient. However, these new tools raise several questions, which will require an answer in the nearest future. These questions focus on safety and economic aspects, and on the liability of the physician and the manufacturer. Technological improvement is also expected.

[Role of antiarrhythmic drugs in reducing the number of defibrillation shocks]. / Place des anti-arythmiques dans la réduction du nombre de chocs des défibrillateurs.

There is a logical basis for the prescription of antiarrhythmic therapy (AAT) in patients with an implanted automatic defibrillator (IAD): the prevention of supraventricular and ventricular arrhythmias, slowing the rate of a ventricular arrhythmia to improve the haemodynamic tolerance and better efficacy of anti-tachycardia stimulation. Adjuvant therapy of this kind is used in 49 to 69% of cases. Forty six per cent of patients in the MADIT I trial had AAT at the last follow-up. In the AVID trial, despite recommendations to avoid the association of AAT and [AD, 18% of patients had this combination because of the large number of shocks in 64% of cases; AAT was associated with both a reduction in the number of shocks (p < 0.05) and in the delay to a recurrence of the arrhythmia (p < 0.0001). In the CASCADE trial, carried out in survivors of cardiac arrest, the prescription of amiodarone in patients with IAD significantly reduced the number of defibrillation shocks. Finally, almost 40% of patients with IAD have an "arrhythmia storm", sometimes during follow-up, usually requiring the association of AAT. Despite the frequent association of AAT and IAD, the results of this combination have rarely been studied systematically. Only one randomised trial has been published comparing D,L-sotalol and placebo in patients with IAD. The treatment reduced the probability of a first defibrillation shock, whether appropriate or not. Amiodarone has often been proposed in association with IAD in isolated cases. The OPTIC trial (Optimal Pharmacological Therapy in Implantable Cardioverter), currently under way, has three sub-groups of IAD (betablocker, amiodarone and betablocker, sotalol), with the aim of determining the preventive value of each AAT with respect to the IAD performance. In addition to the results of combined treatment, the interaction with the threshold of defibrillation is an important factor which is not clearly understood at present. Class I AAT increases the threshold of defibrillation whereas Sotalol reduced it. Amiodarone has a variable effect, neutral or deleterious. The OPTIC trial should provide valuable information via the sub-analysis of the effects of drugs on the threshold of defibrillation in each of the three arms of the trial.

[Pacemaker longevity. Replacement of the device]. / Longévité des stimulateurs cardiaques. Remplacement du boîtier de stimulateur.

Life expectancy of patients implanted with cardiac pacemakers has largely increased, so that generator replacement is becoming an important part of the activity in most of the implanting centers. In more than 70% of the cases, the indication for pacemaker replacement is normal battery depletion. Since the new devices are more and more sophisticated and smaller, longevity optimization becomes a real challenge. The main determinant of pacemaker longevity is the output programmed for the pulse generator. It mainly depends on the output voltage and duration settings. The pacing impedance and the percentage of time with pacing are other major determinants of pacemaker longevity. Each manufacturer provides specific policy but the battery voltage and internal impedance are the more accurate and easy-to-obtain battery depletion parameters. The magnet rate is still frequently used but is less valuable since it can drop abruptly at the end of battery life. The complication rate of pacemaker replacement is three-fold higher than the one of first implant. Infections, skin erosions and lead related complications are not uncommon. The replacement should be systematically preceded by the checking of several points including the patient's pacemaker dependency, the necessity to replace or extract one or several leads, the venous system status, the compatibility between the new generator and the leads and the necessity to upgrade the pacing system or to change the pacemaker pocket.

[Implantable defibrillator and ventricular resynchronisation]. / Défibrillateur implantable et resynchronisation ventriculaire.

Ventricular resynchronisation by pacing, introduced at the end of the 1990s, has revolutionised the management of advanced chronic cardiac failure. Its value in the reduction of haemodynamic mortality has been demonstrated in the latest studies. However, despite these decisive advances, patients with cardiac failure continue to have a high incidence of sudden death which, classically, according to its stage of progression, represents 28 to 68% of deaths in this condition. The implantable automatic defibrillator (IAD) has been shown to be effective in preventing sudden death, mainly in patients with severe left ventricular dysfunction. Based on these data, and in a context of rapid technological progress, devices capable of both defibrillating and resylchronising the heart have been introduced. The problems experienced at the beginning of their utilisation, mainly related to "double-counting" of left and right ventricular electrical activation have been resolved and the method is now technically feasible. A complication rate >10%, mainly due to the implantation of the left heart catheter, continues to bear witness to the difficulties of this technique and to the severity of the condition of patients referred for the treatment. The COMPANION trial has shown a greater reduction in mortality of patients treated by resynchronisation associated with IAD compared with resynchronisation alone or medical therapy in > or = Stage III cardiac failure. The SCD-HeFT trial has recently demonstrated that the primary prevention of global mortality by the IAD is effective in cardiac failure irrespective of the underlying cardiac pathology, especially in functional Stage II. These results should lead to significant increase in the indications for implantation of devices capable of both resynchronisation and defibrillation. However, the obvious problems of cost associated with the difficulty of the technique mean that a systematic attitude cannot be recommended. A case-by-case discussion has its place but the causal cardiac disease, ischaemic or not, does not seem to be a determining factor.

Global myocardial index in patients with multisite pacing.

UNLABELLED: Global myocardial index (GMI) is a sensitive echocardiographic indicator of overall cardiac function. The aim of this study was to compare the GMI changes induced by Bi-V pacing to the variations in clinical, electrocardiographic and echocardiographic parameters currently used for evaluation of ventricular resynchronization in order to test the potential marker of positive clinical response. PATIENTS AND METHODS: This study included 35 consecutive patients (pts), aged 65.7+/-7.5 years, implanted with an endocavitary Bi-V pacemaker for drug refractory severe heart failure. NYHA class was evaluated before implantation and at day 30. QRS duration (QRSd), echocardiographic interventricular delay (IVD), and GMI were determined in the paced and non-paced situation at day 1, 7 and 30 after implantation. RESULTS: NYHA class improved from 3.5+/-0.3 to 2.4+/-0.4 (p<0.01). GMI improved significantly (p<0.0001) after Bi-V in all pts from 1.25 +/- 0.5 to 0.77 +/- 0.34 and remained stable all along the study. GMI decrease (dGMI) in pts with NYHA functional class improvement > 0.5 was 0.52 +/- 0.16while dGMI in pts with NYHA functional class improvement < or = 0.5 was 0.21+/- 0.19. dGMI was statistically correlated with IVD shortening (r=0.67, p<0.0001) but not with QRSd shortening. CONCLUSION: The GMI improves during Bi-V pacing, mostly in responders pts and the improvement remains unchanged after the implant. The GMI decrease induced by Bi-V pacing is correlated with the IVD shortening and NYHA functional class improvement.

[The best of arrhythmias in 2002]. / L'essentiel de 2002 en rythmologie.

In the era of evidence based medicine the year 2002 will be remembered principally for having brought the results of two large trials in areas of daily preoccupation for rhythmologists: those of atrial fibrillation and of prevention of rhythmic sudden death. The Atrial Fibrillation Following Investigation of Rhythm Management (AFFIRM) study compared strategies for controlling frequency and rhythm in atrial fibrillation for subjects aged over 65 years or having at least one risk factor for cerebral vascular accident. In an unexpected fashion, although in accordance with other recent results, the two strategies are equivalent in terms of mortality. It also underlined the necessity of continuing anticoagulation with an INR > 2. even when it is proposed to maintain the rhythm. In the matter of primary prevention of sudden coronary death, the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) had the originality of evaluating patients with no other risk factor than a severe alteration in left ventricular ejection fraction (30% Pounds). This "simple" selection of patients at risk allowed a mortality reduction of 30% to be demonstrated by the placement of a ventricular defibrillator, in addition to that brought about by optimal conventional treatment. In the chapter on syncope, the Framingham study delivers information in terms of incidence and long term prognosis, in a non selected population. Even if these results are difficult to compare with those recent studies using notably the inclination test, they remind us of the poor prognosis of cardiac origin syncope and the absence of excess mortality in patients affected by vagal syncope. The significance of these very wide series does not preclude drawing the greatest attention to the work by the Bordeaux team who have been able to provide evidence, in 27 patients with relapsing idiopathic ventricular fibrillation, of the initiator role of extra-systoles originating from the distal Purkinje network. A medium term cure was obtainable by ablation of these extra-systoles. This work of course allows the prospect of application to other types of malign ventricular arrhythmias.

The effects of antimalarial drugs on ventricular repolarization.

Cardiotoxicity has become a major concern during treatment with antimalarial drugs. Lengthening of the QTc and severe cardiac arrhythmia have been observed, particularly after treatment with halofantrine for chloroquine-resistant Plasmodium falciparum malaria. The purpose of this prospective study was to evaluate whether antimalarial agents alter dispersion of the QTc and ventricular repolarization dynamicity. Sixty patients with uncomplicated falciparum malaria were randomly allocated in four groups of 15 patients and treated with quinine, mefloquine, artemether, or halofantrine at recommended doses. Patients in treatment groups were compared with a group including 15 healthy controls with no history of malaria and/or febrile illness within the last month. QTc dispersion was measured on surface electrocardiograms. Repolarization dynamicity was analyzed from Holter recordings, which allow automatic beat-to-beat measurement of QT and RR intervals. Plasma drug concentration was determined by reversed-phase high-performance liquid chromatography. No change in QTc dispersion was observed after treatment with quinine, mefloquine, or artemether. Treatment with halofantrine was followed by a significant increase in QTc dispersion at 9 hours (P < 0.0001) and 24 hours (P < 0.01). Assessment of QT heart rate variability by QT/RR nychtohemeral regression slope demonstrated no significant difference between the artemether (mean +/- SEM = 0.170 +/- 0.048), mefloquine (0.145 +/- 0.044), and the control groups (0.172 +/- 0.039). A significant decrease in the Q-eT/RR slope was observed in the quinine group compared with the control and artemether groups (0.135 +/- 0.057; P < 0.04). With halofantrine, a significant increase in the QT/RR regression slope (0.289 +/- 0.118) was observed (P < 0.0002). QTc interval, QT dispersion, and QT regression slope were significantly correlated with halofantrine and quinine plasma concentration. Mefloquine and artemether did not alter ventricular repolarization. Quinine induced a significant decrease in QT/RR slope of the same order of magnitude as those previously observed with quinidine. Both QTc dispersion and QT/RR slope were significantly modified by halofantrine. These repolarization changes were related to a class-III antiarrhythmic drug effect and may explain the occurrence of ventricular arrhythmia and/or sudden deaths reported after halofantrine intake.

[Hospital management of atrial fibrillation. Epidemiologic data and therapeutic strategy. Report of 100 consecutive patients]. / Prise en charge hospitalière de la fibrillation auriculaire. Données épidémiologiques et stratégie thérapeutique. A propos de 100 patients consécutifs.

Despite recent large scale trials, the management of atrial fibrillation remains very variable. The authors report the results of a prospective study of the management of atrial fibrillation in their department. One hundred consecutive patients admitted for atrial fibrillation were included in the study. The epidemiological and clinical data and the results of the therapeutic strategy were recorded prospectively. Three embolic complications occurred before hospital admission. The hospital stay was marked by spontaneous reduction of atrial fibrillation in 14 cases in the 6 hours following admission. The therapeutic strategy was the following: 40 arrhythmias were respected (well tolerated, > 1 year or with a left atrium 60 mm). Oral amiodarone (30 mg/Kg and 15 mg/Kg the next day) was given to 22 patients. Only 9 patients (41%) were converted (average delay of 12 hours). Four patients received intravenous amiodarone, reducing two arrhythmias. Twenty patients were treated by external electrical cardioversion of first intent and 14 after failure of pharmacological reduction. All of these procedures, early (after 48 hours anticoagulation and transoesophageal echocardiography), or late (after 1 month of anticoagulation), restored sinus rhythm without complications, especially embolic. This register showed a relatively low efficacy of oral amiodarone in the reduction of atrial fibrillation and underlines the efficacy and safety of external electrical cardioversion, even when performed early.