Sébastien Marchandise

Low contact force and force–time integral predict early recovery and dormant conduction revealed by adenosine after pulmonary vein isolation

Aim After pulmonary vein isolation (PVI), dormant conduction (DC) is present in at least one vein in a substantial number of patients. The present study seeks to determine whether there is a relationship between poor contact forces (CF) and the presence of DC after PVI. Methods and results This prospective, operator-blinded, non-randomized dual-centre trial enrolled 34 consecutive patients with paroxysmal atrial fibrillation who were candidates for PVI. Radiofrequency (RF) energy was delivered by using an irrigated-tip force-sensing ablation catheter (Tacticath®, St Jude Medical) at pre-defined target power. The operators were blinded to the CF data at all times. A total of 1476 RF applications were delivered in 743 pre-defined PV segments. For each application, the precise location of the catheter was registered and the following data were extracted from the Tacisys® unit: application duration, minimum contact force, maximum contact force, average contact force (CF), and force–time integral (FTI). Sixty minutes after PVI, spontaneous early recovery (ER) of the left atrium (LA) to PV conduction was evaluated. In the absence of ER, the presence of a DC was evaluated by using intravenous adenosine (ATP). In the 34 patients recruited (23 males; mean age: 62 ± 9 years), all PVs were successfully isolated. At the end of the 60 min waiting period, 22 patients demonstrated at least one spontaneous ER or DC under ATP. The mean CF and FTI per PV segment differed significantly among the different veins but the sites of ER and DC were evenly distributed. However, both the minimum, the first and the mean CF and FTI per PV segment were significantly lower in the PV segments presenting either ER or DC as compared with those without ER or DC (mean CF: 4.9 ± 4.8 vs. 12.2 ± 1.65 g and mean FTI: 297 ± 291 vs. 860 ± 81 g s, P < 0.001 for both). Using multivariate analysis, both the mean CF and the FTI per lesion remained significantly associated with the risk of ER or DC. Moreover, a CF < 5 g per PV segment predicted ER+ and DC+ with a sensitivity of 71% and specificity of 82%. In contrast, ER and DC were very unlikely if RF application was performed with a mean CF > 10 g (negative predictive value: 98.7%). Conclusion Both a low CF and a low FTI are associated with the ER of the PVI and DC after PVI.

Long-term follow-up of DDD and VDD pacing : a prospective non-randomized single-centre comparison of patients with symptomatic atrioventricular block.

AIMS This prospective non-randomized single-centre registry compared clinical outcome, pacing parameters, and long-term survival in patients receiving VDD or DDD pacemaker (PMs) for symptomatic atrioventricular (AV) block. METHODS AND RESULTS Single-lead VDD (n= 166) and DDD (n= 254) PMs were implanted in 420 successive patients with isolated AV block between January 2001 and December 2009. At the end of the follow-up period [median 25 (1-141) months], there was no difference in the incidence of atrial fibrillation [11.2% in the VDD group; 11.4% in the DDD group (P= 0.95)], myocardial infarction [31.1% in the VDD group; 25.2% in the DDD group (P= 0.20)], or dilated cardiomyopathy [9.9% in the VDD group; 8.9% in the DDD group (P= 0.74)]. At last follow-up, 65.9% of the VDD PMs and 89.3% of the DDD PMs were still programmed in their original mode with good atrial sensing. Due to permanent atrial fibrillation, 7.9% patients out of the VDD group had been switched to VVIR mode and 8.7% patients out of the DDD group to VVIR or DDIR mode. The P-wave amplitude was poor (sensed P-wave <0.5 mV) in 19.1% of the VDD PM and 1.6% of the DDD PM (P< 0.001) and 7.1% of the VDD patients and 0.4% of the DDD patients had been switched to VVIR pacing mode due to P-wave undersensing and AV dissociation (P= 0.003). Symptomatic atrial undersensing requiring upgrading was similar in both groups. The overall survival, adjusted for age, was not significantly different in the VDD and the DDD group (log rank: 0.26). Moreover, Cox survival analysis excluded the pacing mode as a significant predictor of mortality [hazard ratio (HR) = 0.79, confidence interval (CI) (0.46-1.35), P= 0.39]. CONCLUSION Comparing VDD and DDD pacing, a significantly larger number of VDD-paced patients developed poor atrial signal detection without clinical impact. However, atrial under sensing did not influence the incidence of atrial fibrillation, myocardial infarction, dilated cardiomyopathy, or mortality.

Intravenous Adenosine to Predict Conduction Recurrence in Cavotricuspid Isthmus Early After Ablation of Typical Atrial Flutter: Myth or Reality?

Adenosine and Ablation of Typical Atrial Flutter. Introduction: Early recovery of conduction (ER) after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl) occurs in approximately 10% of the patients. If not recognized, ER might lead to AFl recurrences. In this study, we hypothesized that intravenous adenosine (iADO) can be used to predict ER in the CTI immediately after RF ablation and distinguish functional block from the complete destruction of the CTI myocardium.

Evaluation of a new semiautomated external defibrillator technology: a live cases video recording study

Aim To determine the effect of a new automated external defibrillator (AED) system connected by General Packet Radio Service (GPRS) to an external call centre in assisting novices in a sudden cardiac arrest situation. Method Prospective, interventional study. Layperson volunteers were first asked to complete a survey about their knowledge and ability to give cardiopulmonary resuscitation (CPR) and use an AED. A simulated cardiac arrest scenario using a CPR manikin was then presented to volunteers. A telephone and semi-AED were available in the same room. The AED was linked to a call centre, which provided real-time information to ‘bystanders’ and emergency services via GPRS/GPS technology. The scene was videotaped to avoid any interaction with examiners. A standardised check list was used to record correct actions. Results 85 volunteers completed questionnaires and were recorded. Mean age was 44±16, and 49% were male; 38 (45%) had prior CPR training or felt comfortable intervening in a sudden cardiac arrest victim; 40% felt they could deliver a shock using an AED. During the scenarios, 56 (66%) of the participants used the AED and 53 (62%) successfully delivered an electrical shock. Mean time to defibrillation was 2 min 29 s. Only 24 (28%) participants dialled the correct emergency response number (112); the live-assisted GPRS AED allowed alerted emergency services in 38 other cases. CPR was initiated in 63 (74%) cases, 26 (31%) times without prompting and 37 (44%) times after prompting by the AED. Conclusions Although knowledge of the general population appears to be inadequate with regard to AED locations and recognition, live-assisted devices with GPS-location may improve emergency care.

Iatrogenic cardiac perforation due to pacing lead displacement: Imaging findings

PURPOSE Cardiac perforations due to pacing and implantable defibrillator lead displacement are rare and their detection may be difficult. The goal of this study was to review the clinical and imaging presentation of cardiac perforation related to pacing lead displacement. PATIENTS AND METHODS The clinical and imaging files of four patients (two men and two women) who experienced cardiac perforation related to pacing lead displacement were reviewed. The four patients were investigated in our radiology department over a 24-month-period. RESULTS Two patients had clinical symptoms at the time lead displacement was detected and the other two were free of symptoms. In all patients, lead displacement was visible on imaging examinations in retrospect but was not detected prospectively. CONCLUSION Radiologists should pay attention to the position of the tips of the leads on chest X-ray and CT, even late after the implantation and in asymptomatic patients.

Asymptomatic Late Migration of an Atrial Pacemaker Lead into the Right Lung

This report illustrates an unusual case of asymptomatic late cardiac perforation by an atrial pacemaker lead into the right lung. In the present case, the lead was explanted by simple manual traction through the device pocket without any complications.

Device Interactions and Cardiomyopathy

We read with much interest the Research Correspondence by Mehta et al. ([1][1]) of 2 cases of device interactions in patients with advanced cardiomyopathy. We experienced the same problem with a patient equipped with a St. Jude Medical (SJM) implantable cardioverter-defibrillator (Atlas II + HF,

An atypical cause of malignant syncope and sudden cardiac arrest.

Coronary spasm (CS) or Prinzmetals angina is an important cause of pectoral angina but remains difficult to diagnose. Historical descriptions presented the syndrome as a benign affection, but recent reports showed that CS could trigger ventricular arrhythmias and …

Predictive value of the heart rate reserve in patients with permanent atrial fibrillation treated according to a strict rate-control strategy

AIMS Atrial fibrillation (AF) patients treated according to a rate-control strategy seem to have excellent outcomes as long as their ventricular response is kept low. However, the stringency of the rate control to adopt with pharmacologic agents is not clearly defined. In particular, the clinical importance of preserving a heart rate (HR) reserve (HRR) during exercise has not yet been investigated. METHODS AND RESULTS We prospectively analysed the HR response profiles during exercise of 202 patients with permanent AF for whom a strict rate-control strategy was the preferred treatment option. Patients were asked to perform an exercise test on a cycle ergometer until exhaustion. The HRR was defined as the difference between the HR at peak exercise and the resting HR before exercise, divided by the resting HR. Patients were followed-up for at least 24 months or until death or hospitalization for heart failure. The mean resting HR was 80 ± 16 b.p.m. After a median follow-up period of 3 ± 1 years, 31 patients (15.3%) of our initial population (80% male, age 72 ± 12 years) presented either a hospitalization for heart failure (n = 13, 6.4%) or a death (n = 18, 8.9%). Using a univariate analysis, we found that these events correlated with a lower exercise capacity [hazard ratio, HR 0.98, 95% confidence interval, CI (0.96; 0.99), P < 0.001] and a lower HRR [HR 0.30, 95% CI (0.15; 0.60), P < 0.001]. Using a multivariate analysis, both the exercise capacity [HR 0.98, 95% CI (0.97; 0.99), P = 0.008] and the HRR [HR 0.42, 95% CI (0.20-0.87), P = 0.02] remained significantly associated with the outcome. In particular, 4-year survival free from hospitalization for heart failure was better in patients with a preserved HRR (HRR >40%, P < 0.001). No correlation was found between the treatment category (i.e. beta-blockers, calcium channel antagonist, and digoxin) and the HRR. CONCLUSION An impaired HRR in patients with permanent AF treated according to a strict rate-control strategy is associated with an increased risk of hospitalization for heart failure.

Giant right atrial thrombus associated with ICD lead externalized conductors: a case report

Abstract Introduction Narrow calibre ICD leads are prone to present insulation defects and conductor externalization. Close follow-up of these leads is recommended but as long as their electrical function is maintained, no prophyllactic replacement or extraction is advised. Although the risk of thrombus formation involving externalized conductors has been described, this risk seems considered as negligible compared with the risk of a prophylactic lead extraction. However, when an intracavitar thrombus is identified, the safest therapeutic approach remains undetermined. Case presentation In the present clinical vignette, we describe the case of a giant thrombus developed along the externalized portion of an electrically functional ICD lead. In this case, the thrombus was successfully treated with a systemic oral anticoagulation. Discussion This case report supports the concept of a prolonged anticoagulation for both the diagnosis and the long-term treatment of thrombus developed along externalized ICD leads, in particular when the patient prefers to avoid or postpone the risk of a trans-venous lead extraction.