Background: Apical hypertrophic cardiomyopathy (aHCM) is thought to have a more benign clinical course compared to septal HCM (sHCM), but most data have been derived from Asian cohorts. Comparative data on clinical outcome in Caucasian aHCM cohorts are scarce, and the results are conflicting. The aim of this study was to estimate the prevalence and outcome of aHCM in French-Canadians of Caucasian descent. Methods and results: We conducted a retrospective, single-center cohort study. The primary endpoint was a composite of documented sustained ventricular arrhythmia (VA), appropriate ICD therapy, arrhythmogenic syncope, cardiac arrest, or all-cause mortality. A total of 301 HCM patients (65% males) were enrolled including 80/301 (27%) with aHCM and 221/301 (73%) with sHCM. Maximal wall thickness was similar in both groups. Left ventricular apical aneurysm was significantly more common in aHCM (10 vs. 0.5%; p < 0.001). The proportion of patients with myocardial fibrosis ≥ 15% of the left ventricular mass was similar between aHCM and sHCM (21 vs. 24%; p = 0.68). Secondary prevention ICDs were more often implanted in aHCM patients (16 vs. 7%; p = 0.02). The primary endpoint occurred in 26% of aHCM and 10.4% of sHCM patients (p = 0.001) and was driven by an increased incidence of sustained VA (10 vs. 2.3%; p = 0.01). Multivariate analysis identified apical aneurysm and a phenotype of aHCM as independent predictors of the primary endpoint and the occurrence of sustained ventricular tachycardia. Unexplained syncope and a family history of sudden cardiac death were additional predictors for sustained VA. Apical HCM was associated with an increased risk of ventricular arrhythmia even when excluding patients with apical aneurysm. Conclusions: The phenotype of apical HCM is much more common in French-Canadians (27%) of Caucasian descent compared to other Caucasian HCM populations. Apical HCM in French-Canadians is associated with an increased risk for ventricular arrhythmia.

IntroductionImplantable cardioverter-defibrillator (ICD) DF-4 connectors have been introduced to facilitate defibrillator lead connection and to reduce the size of device header. There are limited data regarding the overall performance of those leads and no comparison between different ICD DF-4 leads. MethodsThis is a cohort study of consecutive patients implanted with ICD DF-4 lead system at one University Centre between October 2010 and February 2015. A historical control group of patients with ICD DF-1 lead implantation was used for comparison. The following ICD DF-4 leads were evaluated: St. Jude Medical Durata 7122Q (St. Jude Medical, St. Paul, MN, USA), Medtronic Sprint Quattro Secure 6935M (Medtronic Inc., Minneapolis, MN, USA), Boston Scientific Endotak Reliance 4-Site 0293 (Boston Scientific, Marlborough, MA, USA), and Boston Scientific Reliance 4-Front 0693. This study evaluated the acute and mid-term performances of those leads as well as complications. ResultsA total of 812 patients (age 6312 years, 80% male, left ventricular ejection fraction 31 +/- 12%) underwent implantation of an ICD DF-4 lead. Acute and follow-up R-wave sensing and threshold were excellent. Compared to implantation, intrinsic R waves were higher at follow-up for Boston Scientific and Medtronic leads, and pacing lead impedances were lower for all leads at first follow-up (P<0.001). The number of lead dislodgement or failure was similar between all leads. The estimated lead survival rates at 3 years were 95.6% for Boston Scientific Endotak 4-Site, 97.1% for Boston Scientific 4-Front, 97.7% for Medtronic Sprint Quattro, and 97.5% for St. Jude Durata (P=0.553). ConclusionAll ICD DF-4 leads had excellent acute and mid-term electrical performances. Longer follow-up will be necessary to confirm their sustained performance.

Key Teaching Points•In cardiac resynchronization therapy (CRT), loss of biventricular pacing and a 1-on-2 biventricular pacing pattern can be caused by T-wave oversensing.•T-wave oversensing can be induced by the CRT optimization algorithm AdaptivCRT.•If usual T-wave oversensing troubleshooting is inefficient, turning this algorithm off could restore resynchronization under certain conditions. •In cardiac resynchronization therapy (CRT), loss of biventricular pacing and a 1-on-2 biventricular pacing pattern can be caused by T-wave oversensing.•T-wave oversensing can be induced by the CRT optimization algorithm AdaptivCRT.•If usual T-wave oversensing troubleshooting is inefficient, turning this algorithm off could restore resynchronization under certain conditions.

BACKGROUND:Cardiostat™ is a single lead ambulatory ECG monitor. Recording is made through 2 electrodes positioned in a lead 1-like configuration. We first validated its accuracy for atrial fibrillation detection compared to a 12-lead ECG. In the second phase of the study, arrhythmia detection accuracy was compared between Cardiostat™ ambulatory ECG and a standard 24 h Holter ECG monitoring. METHOD/RESULTS:Phase one of the study included patients undergoing cardioversion for atrial fibrillation (AF) or atrial flutter. Cardiostat™ tracings were compared with standard 12-lead ECG. In the second phase, patients undergoing 24 h ambulatory Holter ECG monitoring for control or suspicion of atrial fibrillation (AF) were included. Simultaneous Holter monitoring and Cardiostat™ ECG recordings were performed. Tracings were analysed and compared. Two hundred twelve monitoring were compared. AF was diagnosed in 73 patients. Agreement between Cardiostat™ ECG and standard Holter monitoring was 99% for AF detection with kappa = 0.99. Kappa correlation for atrial flutter detection was only moderate at 0.51. AF burden was similar in both recordings. Noise hindered analysis in a greater proportion with Cardiostat™ compared to Holter ambulatory ECG (8.5 vs 3.8%). CONCLUSION:Cardiostat™ ambulatory ECG device showed excellent correlation with the standard Holter ECG monitoring for AF detection. Holter monitoring was however superior to discriminate premature atrial and ventricular beats and to qualify the morphology of PVCs since it has more vectors for analysis. Added value of Cardiostat™ includes longer monitoring duration, less cumbersome installation and water resistance.

Aims Paroxysmal atrial fibrillation (PAF) is common, often silent, and can be difficult to detect. Echocardiographic parameters assessing left atrial (LA) remodelling correlated with atrial fibrosis in permanent AF, but less is known about earlier stages such as PAF. We aimed to evaluate whether 2D and 3D echocardiographic (2DE and 3DE) assessment of LA anatomy and function is able to identify patients with PAF.Methods and results This case control study included 102 patients without overt heart disease, 44 patients with PAF. Anatomical remodelling was assessed using indexed maximal, minimal, and preatrial contraction volumes. Reservoir, conduit, and pump functions were assessed by volume and strain methods. All parameters were assessed by 2DE and 3DE and were compared between the two groups. Receiver-operating characteristic curves were constructed for each parameter for PAF prediction. PAF patients had bigger LA volumes than non-PAF group. Using 3DE, all atrial functions were impaired in the PAF group, regardless of the parameters used (all P < 0.05), whereas using 2DE, conduit function did not reach significant difference. Areas under the curve (AUCs) for 3D parameters were higher than those for equivalent 2DE parameters. PAF was best predicted by LA minimal indexed volume assessed by 2DE or 3DE (AUC 0.82 and 0.86, respectively) and 3D-LA ejection fraction and area strain (AUC = 0.82 and 0.81, respectively).Conclusion Anatomical and functional LA remodelling assessed by 2DE and 3DE is independently and strongly associated with PAF, suggesting that these parameters can help identify PAF.

Hypertrophic cardiomyopathy (HCM) is among the leading causes of unexplained sudden cardiac death in younger individuals and competitive athletes. Phenotypic variants include septal-HCM (sHCM) and apical-HCM (aHCM) with the latter being labeled to have a more benign course. Most data on aHCM are derived from Asian populations and there is a lack of contemporary data in predominantly Caucasian populations. We conducted a retrospective cohort study at a single tertiary university hospital. Patients with HCM were identified from electronic medical records and implantable cardiac defibrillator (ICD)-clinic databases. Classification into aHCM and sHCM was based on cardiac imaging (echocardiogram, cardiac magnetic resonance imaging) according to current guidelines. Clinical and genetic data of consecutive HCM patients were collected and correlated with the occurrence of ventricular arrhythmias. The primary endpoint was a composite of appropriate ICD-therapy (ATP or shock) and/or documentation of sustained ventricular arrhythmias. A total of 128 individuals with HCM were included (mean age at diagnosis, 50±17 years; male sex, 70% [89/128]; Caucasians, 98% [125/128]). Apical-HCM was diagnosed in 27% (35/128) and sHCM in 73% (93/128) individuals. Left ventricular mass index was similar (84±25 g/m2 vs. 91±32 g/m2;p=0.40), but maximal wall thickness was less pronounced in aHCM compared to sHCM (18±4 mm vs. 21±6 mm;p=0.02). Presence of late gadolinium enhancement was found in 70% of aHCM and 76% of sHCM individuals (p=0.77). Left ventricular apical aneurysm was significantly more common in aHCM compared to sHCM (17% vs. 0%;p=0.004). Familial HCM was present in 21% in both groups. Overall, 73% (94/128) of individuals were ICD carriers (76% primary and 24% secondary prevention) with similar proportions in both groups. Median follow-up duration was similar for aHCM and sHCM (58 months [IQR 75] vs. 88 months [IQR 125];p=0.34). The primary endpoint occurred twice as often in aHCM individuals (26% vs 12%;p=0.06), mainly driven by the occurrence of sustained ventricular arrhythmias, predominantly monomorphic ventricular tachycardia (23% vs. 9%;p=0.04). Presence of apical aneurysm was an independent predictor of the primary outcome (hazard ratio, 3.2; 95% confidence interval, 0.35-6.08;p=0.03). Genetic test results were available in 38% (49/128) of all individuals. There was a trend towards a higher yield of pathogenic variants in sHCM (21% vs. 0%;p=0.08). Apical-HCM is relatively common in the French-Canadian population, accounting for 27% of cases, and is associated with more frequent ventricular arrhythmias compared to sHCM. Apical aneurysm is an independent predictor of ventricular tachycardia.

Background Laminopathies are associated with a broad spectrum of clinical manifestations, from lipodystrophy to cardiac diseases. The purpose of this study was to assess genotype-phenotype correlations in a lipodystrophic laminopathy caused by the Lamin A (LMNA) mutation T655fsX49. This mutation leads to synthesis of nonfarnesylated-mutated prelamin A that does not undergo the physiologic lamin A maturation process.Methods and results We studied 35 patients originating from Reunion Island who carried the LMNA T655fsX49 mutation. Comparisons of cardiac and endocrinologic features were made between homozygous and heterozygous patients. Homozygous patients presented more overlapping syndromes with severe cardiac phenotypes, defined by cardiolaminopathy, early atheroma with coronary heart disease (CHD) and high-degree conduction disorder compared with heterozygous (40% vs4%; P = .016). Moreover, homozygous patients had earlier onset (49.6 vs 66 years old; P = .0002). Left ventricle lowered ejection fraction associated with heart failure was more frequent in homozygous than in heterozygous patients (40% vs 0%, respectively). Lipodystrophic traits were more marked in the homozygous group but only reached statistical significance for L4 subcutaneous fat measurement (2.8 +/- 2.16 vs 18.7 +/- 8.9 mm; P = .008) and leptin levels (2.45 +/- 1.6 vs 11.26 +/- 7.2 ng/mL; P = .0001).Conclusions Our results suggest that there is a relationship between mutated prelamin-A accumulation and the severity of the phenotypes in homozygous familial partial lipodystrophy type 2 patients who harbor the LMNA T655fsX49 mutation. A dose-dependent effect seems likely.