Electroanatomical voltage mapping with contact force sensing for diagnosis of arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Three-dimensional electroanatomical mapping (EAM) can be helpful to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC). Yet, previous studies utilizing EAM have not systematically used contact-force sensing catheters (CFSC) to characterize the substrate in ARVC, which is the current gold standard to assure adequate tissue contact. OBJECTIVE: To investigate reference values for endocardial right ventricular (RV) EAM as well as substrate characterization in patients with ARVC by using CFSC. METHODS: Endocardial RV EAM during sinus rhythm was performed with CFSC in 12 patients with definite ARVC and 5 matched controls without structural heart disease. A subanalysis for the RV outflow tract (RVOT), septum, free-wall, subtricuspid region, and apex was performed. Endocardial bipolar and unipolar voltage amplitudes (BVA, UVA), signal characteristics and duration as well as the impact of catheter orientation on endocardial signals were also investigated. RESULTS: ARVC patients showed lower BVA vs. controls (p = 0.018), particularly in the subtricuspid region (1.4, IQR:0.5-3.1 vs. 3.8, IQR:2.5-5 mV, p = 0.037) and RV apex (2.5, IQR:1.5-4 vs. 4.3,IQR:2.9-6.1 mV, p = 0.019). BVA in all RV regions yielded a high sensitivity and specificity for ARVC diagnosis (AUC 59-78%, p < 0.05 for all), with the highest performance for the subtricuspid region (AUC 78%, 95% CI:0.75-0.81, p < 0.001, negative predictive value 100%). A positive correlation between BVA and an orthogonal catheter orientation (46°-90°:r = 0.106, p < 0.001), and a negative correlation between BVA and EGM duration (r = -0.370, p < 0.001) was found. CONCLUSIONS: EAM using CFSC validates previous bipolar cut-off values for normal endocardial RV voltage amplitudes. RV voltages are generally lower in ARVC as compared to controls, with the subtricuspid area being commonly affected and having the highest discriminatory power to differentiate between ARVC and healthy controls. Therefore, EAM using CFSC constitutes a promising tool for diagnosis of ARVC.

Multiple clinical profiles of families with the short QT syndrome.

Aims: Short QT syndrome (SQTS) is a rare cardiac channelopathy characterized by a shortened corrected QT (QTc)-interval that can lead to ventricular arrhythmias and sudden cardiac death. The aim of this study was to investigate the clinical phenotypes and long-term outcomes of three families harbouring genetic mutations associated with the SQTS. Methods and results: Clinical data included medical history, physical examination, 12-lead ECG, 24-h Holter-ECG, and transthoracic echocardiography from three index patients and their first-degree relatives. Next generation clinical exome sequencing and genetic cascade screening were performed in index patients and their relatives, respectively. Two index patients experienced malignant ventricular arrhythmias and one patient suffered from arrhythmogenic syncope during a median follow-up period of 8 years. They all had genetic mutations associated with the SQTS. Two mutations were found in the KCNH2 gene, and one in the CACNA2D gene. One patient had an additional SCN10A variant. Alive and mutation-positive family members had short QTc-intervals, but no further phenotypic manifestations. None of the mutation-negative family members had an abnormal ECG or any symptoms. In all patients with shortened QTc-intervals, the QTc-interval had a low long-term variability and QTc shortening always remained detectable by 12-lead ECG. Conclusion: This study shows the variety of phenotypic manifestations in different families with SQTS. It further emphasizes the importance of a 12-lead ECG for early diagnosis, and the utility of next generation sequencing for the identification of mutations associated with the SQTS.

Renal insufficiency is independently associated with a distal distribution pattern of symptomatic lower-limb atherosclerosis.

OBJECTIVES: The purpose of this study was to assess the impact of renal insufficiency (RI) on the distribution pattern of peripheral arterial disease (PAD). We hypothesised that RI is associated with a distally accentuated involvement of the peripheral arterial tree. DESIGN: This is a retrospective analysis. MATERIALS AND METHODS: Analysis was based on a consecutive series of 2709 patients with chronic PAD of atherosclerotic origin undergoing primary endovascular treatment of lower-extremity arteries. Atherosclerotic pattern was grouped into femoropopliteal (n=2085) and infragenicular (n=892) disease according to target lesions treated while using iliac disease (n=1133) as reference. Univariable and multivariable multinomial regression analyses were performed to assess relation with RI. Results are shown as relative risk ratio (RRRs) with 95% confidence intervals (95% CIs). A p<0.05 was considered statistically significant. RI was defined as glomerular filtration rate (GFR)<60 ml min(-1) 1.73 m(-2). RESULTS: Presence of RI was an independent risk factor for a centrifugal lesion pattern (RRR 1.48, 95% CI: 1.17-1.86, p=0.001). Moreover, a decrease in GFR by 10 ml min(-1) 1.73 m(-2) was associated with an RRR of 1.08 for below-the-knee arterial disease (95% CI: 1.03-1.13, p=0.003). CONCLUSION: Presence and severity of RI are independent predictors of a distal obstructive pattern in patients with symptomatic PAD.