Septal versus apical pacing sites in permanent right ventricular pacing: The multicentre prospective SEPTAL-PM study.

BACKGROUND: The optimal right ventricular pacing site for patients requiring pacemaker implantation for permanent atrioventricular block is a matter of debate. Long-term right ventricular apical pacing has been associated with left ventricular ejection fraction impairment and heart failure. Right ventricular septal pacing has been proposed as an alternative. AIM: The aim of this randomized prospective multicentre trial was to compare left ventricular remodelling and outcomes between right ventricular apical and septal pacing after mid-term follow-up. METHODS: Patients requiring pacemaker implantation for high-degree atrioventricular block were enrolled and randomized in a 1:1 fashion to receive a right ventricular apical or septal lead. RESULTS: A total of 141 patients were included, 69 in the septal group and 72 in the apical group. Both groups exhibited similar left ventricular ejection fractions after 18 months of follow-up (septal 57.1±11.9% vs. apical 57.4±13.4%), and left ventricular ejection fraction variation was similar in the two groups at the end of follow-up (septal -1.5±13.2% vs. apical 0.3±13.3%). Additionally, left ventricular volume, quality of life and 6-minute walk distance were similar in the two groups. However, patients in the septal group were more likely to be asymptomatic, with a significantly lower concentration of N-terminal prohormone of brain natriuretic peptide. Lastly, lead position did not impact 18-month survival. CONCLUSION: Pacing from the right ventricular apex does not have any detrimental effect on left ventricular systolic function compared with septal pacing over an 18-month period.

Factors influencing the use of leadless or transvenous pacemakers: results of the European Heart Rhythm Association Prospective Survey.

To study the proportion of leadless pacemaker (LL-PM) implants and the factors influencing the choice of LL-PM vs. transvenous pacemaker (TV-PM) across tertiary centres in Europe with routine availability of the LL-PM. A European Heart Rhythm Association (EHRA) prospective snapshot survey using electronically distributed questionnaire sent to participating centres. Participating tertiary cardiac pacing centres prospectively included consecutive patients implanted between November 2018 and January 2019. Questions covered standards of care and policies used for patient management, focusing particularly on the reasons for choosing LL-PM vs. TV-PM. Overall, 21 centres from four countries (France, Netherlands, Spain, and Italy) participated, with eventual data from 798 patients (n = 472, 59% male). With 69 implants, LL-PM represented only 9% of all implants and 36% of the single-chamber pacing group; double-chamber transvenous pacemakers were implanted in 528 patients and biventricular (cardiac resynchronization pacemaker) in 79. The two major reasons reported in favour of LL-PM implantation were an anticipated high risk of infection or low rate of ventricular pacing. Compared to TV-PM, LL-PM patients were more often male (74% vs. 54%, P = 0.009), with greater proportion of valvular heart disease (45% vs. 35%, P = 0.01) and atrial fibrillation (AF; 65% vs. 23%, P < 0.0001), with significantly more comorbidities (≥ one comorbidity, 66% vs. 52%, P = 0.02). This contemporary multicentre European survey shows that LL-PM constitutes a small proportion of all PM implants. Patients implanted with LL-PM were more likely to have AF and a high anticipated risk of infection.

Complex Brugada syndrome inheritance in a family harbouring compound SCN5A and CACNA1C mutations.

Brugada syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads and is associated with increased risk of sudden cardiac death. We have recently reported families with BrS and SCN5A mutations where some affected members do not carry the familial mutation. We evaluated the involvement of additional genetic determinants for BrS in an affected family. We identified three distinct gene variants within a family presenting BrS (5 individuals), cardiac conduction defects (CCD, 3 individuals) and shortened QT interval (4 individuals). The first mutation is nonsense, p.Q1695*, lying within the SCN5A gene, which encodes for NaV1.5, the α-subunit of the cardiac Na(+) channel. The second mutation is missense, p.N300D, and alters the CACNA1C gene, which encodes the α-subunit CaV1.2 of the L-type cardiac Ca(2+) channel. The SCN5A mutation strictly segregates with CCD. Four out of the 5 BrS patients carry the CACNA1C variant, and three of them present shortened QT interval. One of the BrS patients carries none of these mutations but a rare variant located in the ABCC9 gene as well as his asymptomatic mother. Patch-clamp studies identified a loss-of-function of the mutated CaV1.2 channel. Western-blot experiments showed a global expression defect while increased mobility of CaV1.2 channels on cell surface was revealed by FRAP experiments. Finally, computer simulations of the two mutations recapitulated patient phenotypes. We report a rare CACNA1C mutation as causing BrS and/or shortened QT interval in a family also carrying a SCN5A stop mutation, but which does not segregate with BrS. This study underlies the complexity of BrS inheritance and its pre-symptomatic genetic screening interpretation.

Cardiac remote monitoring in France.

The increase in number of implanted cardiac medical devices and the announced decrease in number of cardiologists have led to remote monitoring being considered as a pivotal tool for patient follow-up. For 10 years, remote monitoring has been the subject of multiple clinical studies. In these studies, reliability and clinical efficacy have been demonstrated, but the use of remote monitoring remains quite limited in France compared with other countries. To explain this delay in uptake, some organizational difficulties and the lack of reimbursement of remote monitoring are often mentioned. The results of medico-economic studies might provide answers about the value of remote monitoring and enable the supervisory authorities to define how its use will be financed. This review provides a global view of remote monitoring in France, and covers the principle, clinical efficacy, organizational and regulatory aspects, and medico-economic data.

Non-physiological increase of AV conduction time in sinus disease patients programmed in AAIR-based pacing mode.

PURPOSE: The EVOCAV(DS) trial aimed to quantify the paradoxal atrioventricular (AV) conduction time lengthening in sinus node (SD) patients (pts) paced in AAIR-based pacing mode. METHODS: SD pts, implanted with dual-chamber pacemaker programmed in AAIR-based pacing mode, were randomized in two arms for a 1-month period: the low atrial pacing (LAP; basic rate at 60 bpm, dual sensor with minimal slope) and the high atrial pacing (HAP; basic rate at 70 bpm, dual sensor with optimized slope, overdrive pacing) arm. At 1 month, crossover was performed for an additional 1-month period. AV conduction time, AV block occurrence and AV conduction time adaptation during exercise were ascertained from device memories at each follow-up. RESULTS: Seventy-nine pts participated to the analysis (75 ± 8 years; 32 male; PR = 184 ± 38 ms; bundle branch block n = 12; AF history n = 36; antiarrhythmic treatment n = 53; beta-blockers n = 27; class III/Ic n = 18; both n = 8). The mean AV conduction time was significantly greater during the HAP (275 ± 51 ms) vs. LAP (263 ± 49 ms) period (p < 0.0001). Class III/Ic drugs were the only predictors of this abnormal behaviour. Degree II/III AV blocks occurred in 49 % of pts in the HAP vs. 19 % in the LAP period (p < 0.0001). Fifty-two patients (66 %) presented a lengthening of AV conduction time during exercise. CONCLUSION: AAIR-based pacing in SD pts may induce a significant lengthening of pts' AV conduction time, including frequent abnormal adaptation of AV conduction time during exercise.

Identification and characterization of super-responders after cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) has been shown to induce a spectacular effect on left ventricular (LV) function in certain patients. Our aim was to analyze and characterize the super-responders (SRs) to CRT using echocardiography in 186 patients with a conventional indication according to the European Society Cardiology guidelines. The investigation took place before and 6 months after implantation. CRT-SRs were defined by an improvement of the New York Heart Association functional class and LV ejection fraction to > or = 50% in absolute values associated with a relative LV end-systolic volume reduction of > or = 15%. Of the 186 patients, 18 (9.7%) were identified as CRT-SRs and had a significantly lower prevalence of ischemic etiology (11%), lower LV dimensions, lower left atrial volume, and greater global longitudinal strain at baseline. Receiver operating characteristics curves identified global longitudinal strain as the strongest parameter for predicting CRT-SRs, with a cutoff value of -12% (area under the curve 0.87, sensitivity 71%, and specificity 85%, p <0.01). In conclusion, in the present retrospective study, only a left atrial volume <55 ml and global longitudinal strain < or = -12% were independent predictors of CRT-SRs.

Incidence of atrial fibrillation during very long-term follow-up after radiofrequency ablation of typical atrial flutter.

BACKGROUND: Radiofrequency ablation is an effective treatment for typical atrial flutter (AFL) but long-term results may be hampered by atrial fibrillation (AF). AIMS: To determine the incidence and predictors of AF during very long-term follow-up after radiofrequency ablation of typical AFL. METHODS: From November 1998 to December 2000, patients who underwent successful radiofrequency ablation for cavotricuspid isthmus-dependent AFL in our centre were followed prospectively. RESULTS: Of the 135 patients followed (mean age: 62+/-11 years), 69 (51%) had structural heart disease. Mean left ventricular ejection fraction was 52+/-11%. Patients were analysed according to preablation AF history: group 1 included patients with AFL (N=71); group 2 included patients with AFL and AF (N=64). During a median [interquartile range] follow-up of 7.8 [7.0-8.4] years, new-onset or recurrent AF was experienced by 99 (73%) patients: 44 (62%) in group 1 and 55 (86%) in group 2. Although most episodes occurred in the first 2 years postablation, AF prevalence increased continuously over time. Preablation AF history predicted AF occurrence (hazard ratio: 2.10, 95% confidence interval: 1.40-3.14; p=0.001), as did left atrial diameter (hazard ratio: 1.05 per 1 mm increase; 95% confidence interval: 1.02-1.08; p<0.001). AF evolved to become permanent in 24% of group 1 and 47% of group 2 patients (p=0.005). CONCLUSION: During long-term follow-up, most patients will experience AF after ablation of typical AFL. Preablation AF history and left atrial enlargement predict postablation AF occurrence.

A 'Regularly Irregular' tachycardia: what is the diagnosis?

We report the case of a 46-year-old female presented to the emergency room with sustained palpitations. Her ECG showed a narrow QRS regularly irregular tachycardia. This tachycardia was immediately terminated by a single dose of adenosine, and sinus rhythm was restored. Diagnosis of atrial tachycardia, orthodromic reciprocating tachycardia, and atrial nodal reentrant tachycardia (AVNRT) are discussed. An electrophysiological study was performed for further evaluation, and our final hypothesis was AVNRT with triple nodal pathways. A single application of radiofrequency energy in the posterior septum near the coronary sinus ostium effectively eliminated the tachycardia.

Are women with severely symptomatic brugada syndrome different from men?

UNLABELLED: Women with Brugada Syndrome. INTRODUCTION: Spontaneous type-1 ECG has been recognized as a risk factor for sudden cardiac death (SCD) in Brugada syndrome (BrS), but studied populations predominantly consisted of men. We sought to investigate whether a spontaneous type-1 ECG pattern was also associated in women with severely symptomatic BrS. Other known risk factors were also examined for gender specificity. METHODS: Patients with severely symptomatic BrS, defined as resuscitated SCD and/or appropriate implantable cardioverter-defibrillator (ICD) shock, were included from 11 European centers. Clinical data, investigation of family history, 12-lead ECG, and results of electrophysiological study (EPS) were collected. The average follow-up was 4 +/- 3 years. RESULTS: Fifty-eight patients fulfilled the inclusion criteria (mean age 47 +/- 11 years, 8 women). Thirty-six men (72%) but only two women (25%) had a spontaneous type-1 ECG at baseline (P = 0.02). Maximal ST elevation before or after drug challenge was 3.7 +/- 1.3 mm in men versus 2.4 +/- 0.7 mm in women (P = 0.007). The proportion of patients with a family history of SCD or an SCN5A mutation was not significantly different between both groups. Of those patients with high-risk BrS who underwent EPS, 76%(12/25) of men and 50%(2/4) of women had a positive study. CONCLUSION: In contrast to men, most women with BrS and resuscitated SCD or appropriate ICD shock do not have a spontaneous type-1 ECG pattern. In addition, the degree of ST elevation is less pronounced in women than men. While women represent a lower-risk group overall, risk factors established from a predominantly male population may not be helpful in identifying high-risk females.

Assessment of longitudinal and radial ventricular dyssynchrony in ischemic and nonischemic chronic systolic heart failure: a two-dimensional echocardiographic speckle-tracking strain study.

BACKGROUND: Current guidelines recommend a QRS greater than or equal to 120 milliseconds to select candidates for cardiac resynchronization therapy. However, ischemic and nonischemic cardiomyopathies are two different entities and they might be selected following different approaches. We sought, thus, after a validation the new 2-dimensional (2D) speckle-tracking strain (STS) against color Doppler tissue imaging (DTI)-strain (S) to compare the different correlation between electrical and mechanical dyssynchrony (DYS) in ischemic and nonischemic cardiomyopathies. METHODS: We measured: (1) QRS duration; (2) mechanical interventricular DYS (the difference between preaortic and prepulmonary ejection times); (3) left intraventricular DYS (the SD of time-to-peak of longitudinal DTI-S); and (4) longitudinal and radial 2D-STS in the basal and middle segments of lateral and septal left ventricular walls in 95 patients with chronic heart failure caused by ischemic (n = 49) or nonischemic (n = 46) heart disease. Twelve healthy control subjects were also explored. RESULTS: Mechanical interventricular DYS was correlated (DTI-S: P < .001) with QRS-duration, but not in ischemic heart disease. DTI-S and 2D-STS measurements were correlated (R = 0.6, P < .001) in the overall population. Longitudinal 2D-S DYS was correlated with QRS duration in patients with nonischemic, (P = .003) but not with ischemic heart disease, whereas radial 2D-S DYS was correlated with QRS width in both subgroups (r = 0.48, P = .003, and r = 0.43, P = .003, respectively). CONCLUSIONS: The profile of DYS is influenced by the underlying cause of heart failure. The 2D-STS is a new tool for cardiac DYS assessment. Its ability to measure both longitudinal and radial intraventricular DYS is noteworthy.

Concordance between mechanical and electrical dyssynchrony in heart failure patients: a function of the underlying cardiomyopathy?

BACKGROUND: Cardiac resynchronization therapy (CRT) improves heart failure (HF) symptoms through a reduction of cardiac mechanical dyssynchrony. Mechanical dyssynchrony is currently estimated by electrical dyssynchrony (QRS duration). It is known that electrical and mechanical dyssynchrony are not well correlated in HF patients. However, there is limited information about whether this relationship might be influenced by the underlying cardiomyopathy. METHODS: Doppler echocardiography was performed in 88 patients presenting with heart failure due to ischemic (n = 42) or nonischemic (n = 46) heart disease, left ventricular ejection fraction <40%, New York Heart Association class II-IV, regardless of their QRS duration. Interventricular dyssynchrony was assessed by the time interval between preaortic and prepulmonary ejection times. Intraventricular dyssynchrony was ascertained by (1) the delay between the earliest and the latest peak negative longitudinal strain recorded in the basal and mid-segments of the lateral and septal walls (TMinMax) and (2) the standard deviation of time-to-peak in the same segments (SDdys). RESULTS: The correlation coefficient between QRS duration and mechanical interventricular dyssynchrony was r = 0.47 (P < 0.001) in patients with nonischemic disease and nonsignificant in patients with ischemic disease. Similarly, the correlation coefficient between QRS duration and mechanical intraventricular dyssynchrony was significant in patients with nonischemic disease (r = 0.37, P = 0.01 for TMinMax; r = 0.42, P = 0.003 for SDdys) and nonsignificant in patients with ischemic disease. CONCLUSION: The concordance between electrical dyssynchrony assessed by QRS duration and mechanical dyssynchrony assessed by myocardial strain is dependent upon the underlying cardiomyopathy. This observation may improve our understanding of the various responses observed in CRT patients.