Combination of ECG and Echocardiography for Identification of Arrhythmic Events in Early ARVC

OBJECTIVES: The aim of this study was to investigate early markers of arrhythmic events (AEs) and improve risk stratification in early arrhythmogenic right ventricular cardiomyopathy (ARVC). BACKGROUND: AEs are frequent in patients with ARVC, but risk stratification in subjects with early ARVC is challenging. METHODS: Early ARVC disease was defined as possible or borderline ARVC diagnosis according to the ARVC Task Force Criteria 2010. We performed resting and signal averaged electrocardiogram (ECG). Using echocardiography, we assessed right ventricular (RV) outflow tract diameter and right ventricular basal diameter (RV diameter). Global longitudinal strain and mechanical dispersion (MD) from strain echocardiography were assessed in both the right and left ventricle. AEs were defined as documented ventricular tachycardia, cardiac syncope, or aborted cardiac arrest. RESULTS: Of 162 included subjects with ARVC (41 ± 16 years of age, 47% female), 73 had early ARVC, including mutation positive family members not fulfilling definite ARVC diagnosis. AEs occurred in 15 (21%) subjects with early ARVC. Those with AEs in early disease had larger RV diameter (40 ± 4 mm vs. 37 ± 5 mm), more pronounced RVMD (39 ± 15 ms vs. 26 ± 11 ms), and more pathological signal averaged ECGs compared with those without AEs (all p ≤ 0.05). Adding measurements of RV diameter and RVMD to electrical parameters improved identification of subjects with AEs compared with electrical parameters alone (p = 0.05). CONCLUSIONS: ECG parameters, RV diameter, and RVMD were markers of previous arrhythmic events in patients with early ARVC. A combination of electrical and echocardiographic parameters improved identification of subjects with AEs in early ARVC disease. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved. KEYWORDS: arrhythmic risk; arrhythmogenic right ventricular cardiomyopathy; echocardiography; signal averaged ECG; ventricular arrhythmia

Echocardiographic comparison between left ventricular non-compaction and hypertrophic cardiomyopathy

Background: Modern imaging technology has improved detection of left ventricular non-compaction cardiomyopathy (LVNC). Hypertrophic cardiomyopathy (HCM) shares morphological features with LVNC, but prognosis and treatment strategies differ between LVNC and HCM. Methods and results: Weaimed to compare global and regional LV myocardial function in LVNC and HCM.We hypothesized that apical function is reduced in LVNC due to the embryonic reduced compaction of the apex. We studied 25 patients with LVNC (47 ± 14 years) according to current criteria, 50 with HCM (47 ± 14 years) and 50 healthy individuals (49 ± 19 years). By echocardiography, we assessed maximal wall thickness (MWT) and LV ejection fraction (EF). Numbers of trabeculations were counted from 3 apical views. Global longitudinal strain by speckle tracking echocardiography was calculated froma 16 LV segments model. LV basal (6 segments) and apical (4 segments) longitudinal strainswere averaged.MWTwas thinner, EF lower and trabeculationswere more pronounced in LVNC compared to HCM(all p b 0.001) butwith no significantly differences in LV global longitudinal strain (−15.1± 6.1 vs.−16.8±3.7, p=0.14). Function by longitudinal strain increased significantly frombase to apex in HCM(−14.9±4.3% vs.−19.5±4.7%, p b 0.001) and in healthy controls (−20.0±1.9% vs. −21.8 ± 2.9%, p b 0.001), but not in LVNC (−14.7 ± 6.4% vs. −15.7 ± 7.2%, p = 0.35). Conclusions: Increased number of trabeculations, thinnerMWT and lower EF were characteristics of LVNC. Myocardial function was homogeneously reduced in LVNC,while an apical to basal gradient with relatively preserved apical function was present in HCM. These characteristics may help to discriminate between LVNC and HCM

Comparison of patients with early phase arrhythmogenic right ventricular cardiomyopathy and right ventricular outflow tract ventricular tachycardia

Aims: Differentiation between early-phase arrhythmogenic right ventricular cardiomyopathy (ARVC) and right ventricular outflow tract (RVOT)-ventricular tachycardia (VT) can be challenging, and correct diagnosis is important. We compared electrocardiogram (ECG) parameters and morphological right ventricular (RV) abnormalities and investigated if ECG and cardiac imaging can help to discriminate early-phase ARVC from RVOT-VT patients. Methods and results: We included 44 consecutive RVOT-VT (47+14 years) and 121 ARVC patients (42+17 years). Of the ARVC patients, 77 had definite ARVC and 44 had early-phase ARVC disease. All underwent clinical examination, ECG, and Holter monitoring. Frequency of premature ventricular complexes (PVC) was expressed as percent per total beats/24 h (%PVC), and PVC configuration was recorded. By echocardiography, we assessed indexed RV basal diameter (RVD), indexed RVOT diameter, and RV and left ventricular (LV) function. RV mechanical dispersion (RVMD), reflecting RV contraction heterogeneity, was assessed by speckle-tracking strain echocardiography. RV ejection fraction (RVEF) was assessed by cardiac magnetic resonance imaging (CMR). Patients with early-phase ARVC had lower %PVC by Holter and PVC more frequently originated from the RV lateral free wall (both P , 0.001). RVD was larger (21+3 vs. 19+2 mm, P , 0.01), RVMD was more pronounced (22+15 vs. 15+13 ms, P ¼ 0.03), and RVEF by CMR was decreased (41+8 vs. 49+4%, P , 0.001) in early-phase ARVC vs. RVOT-VT patients. Conclusion: Patients with early-phase ARVC had structural abnormalities with lower RVEF, increased RVD, and pronounced RVMD in addition to lower %PVC by Holter compared with RVOT-VT patients. These parameters can help correct diagnosis in patients with unclear phenotypes

Lamin A/C cardiomyopathy: Young onset, high penetrance, and frequent need for heart transplantation

Aims: Lamin A/C (LMNA) mutations cause familial dilated cardiomyopathy (DCM) with frequent conduction blocks and arrhythmias. We explored the prevalence, cardiac penetrance, and expressivity of LMNA mutations among familial DCM in Norway. Furthermore, we explored the risk factors and the outcomes in LMNA patients. Methods and results: During 2003–15, genetic testing was performed in patients referred for familial DCM. LMNA genotype-positive subjects were examined by electrocardiography, Holter monitoring, cardiac magnetic resonance imaging, and echocardiography. A positive cardiac phenotype was defined as the presence of atrioventricular (AV) block, atrial fibrillation/flutter (AF), ventricular tachycardia (VT), and/or echocardiographic DCM. Heart transplantation was recorded and compared with non-ischaemic DCM of other origin. Of 561 unrelated familial DCM probands, 35 (6.2%) had an LMNA mutation. Family screening diagnosed an additional 93 LMNA genotype-positive family members. We clinically followed up 79 LMNA genotype-positive [age 42 ± 16 years, ejection fraction (EF) 45 ± 13%], including 44 (56%) with VT. Asymptomatic LMNA genotype-positive family members (age 31 ± 15 years) had a 9% annual incidence of a newly documented cardiac phenotype and 61% (19/31) of cardiac penetrance during 4.4 ± 2.9 years of follow-up. Ten (32%) had AV block, 7 (23%) AF, and 12 (39%) non-sustained VT. Heart transplantation was performed in 15 of 79 (19%) LMNA patients during 7.8 ± 6.3 years of follow-up. Conclusion: LMNA mutation prevalence was 6.2% of familial DCM in Norway. Cardiac penetrance was high in young asymptomatic LMNA genotype-positive family members with frequent AV block and VT, highlighting the importance of early family screening and cardiological follow-up. Nearly 20% of the LMNA patients required heart transplantation

In vivo estimation of elastic heterogeneity in an infarcted human heart

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Vigorous exercise in patients with hypertrophic cardiomyopathy

Background: We aimed to investigate if history of vigorous exercise was associated with changes in left ventricular morphology, left ventricular function and ventricular arrhythmias (VAs) in hypertrophic cardiomyopathy genotype positive, phenotype negative (Genotype+ LVH−) and in phenotype positive (HCM LVH+). Methods: In this cross sectional study we included 187 subjects (age 49 ± 16 years, 89(48%) female, 121(65%) HCM LVH+ and 66 (35%) Genotype+ LVH-) who answered a questionnaire on physical activity history. Exercise ≥6 metabolic equivalents was defined as vigorous. Subjects with a history of vigorous exercise ≥4 h/week during ≥6 years were defined as athletes. All underwent echocardiography and Holter monitoring. VAs were defined as aborted cardiac arrest, sustained or non-sustained ventricular tachycardia. Results: In both Genotype+ LVH− and HCM LVH+, lifetime vigorous exercise correlated with larger left ventricular end-diastolic volume (rho 0.44 and 0.38 respectively, both p b 0.001). Lifetime vigorous exercise correlated with increased left ventricular mass in Genotype+ LVH− (rho 0.28, p = 0.03), but not in HCM LVH+ (p = 0.53). Left ventricular systolic function was similar between athletes and non-athletes in Genotype+ LVH− and HCM LVH+. HCM LVH+ athletes had lower E/e' (p = 0.03) and higher e' (p = 0.02) compared to non-athletes, while this difference was not observed in Genotype+ LVH−. Lifetime vigorous exercise was similar among HCM LVH+ with and without VAs (p = 0.89). Conclusions: Increased lifetime vigorous exercise was associated with larger left ventricular volumes in hypertrophic cardiomyopathy, but correlated to left ventricular mass only in Genotype+ LVH−. Vigorous exercise was associated with favorable diastolic function in HCM LVH+, and was not associated with VAs

Contractility surrogates derived from three-dimensional lead motion analysis and prediction of acute haemodynamic response to CRT

Patient-specific left ventricular (LV) lead optimisation strategies with immediate feedback on cardiac resynchronisation therapy (CRT) effectiveness are needed. The purpose of this study was to compare contractility surrogates derived from biventricular lead motion analysis to the peak positive time derivative of LV pressure (dP/dtmax) in patients undergoing CRT implantation.Twenty-seven patients underwent CRT implantation with continuous haemodynamic monitoring. The right ventricular (RV) lead was placed in apex and a quadripolar LV lead was placed laterally. Biplane fluoroscopy cine films facilitated construction of three-dimensional RV–LV interlead distance waveforms at baseline and under biventricular pacing (BIVP) from which the following contractility surrogates were derived; fractional shortening (FS), time to peak systolic contraction and peak shortening of the interlead distance (negative slope). Acute haemodynamic CRT response was defined as LV ∆dP/dtmax ≥ 10 %.We observed a mean increase in dP/dtmax under BIVP (899±205 mm Hg/s vs 777±180 mm Hg/s, p<0.001). Based on ΔdP/dtmax, 18 patients were classified as acute CRT responders and nine as non-responders (23.3%±10.6% vs 1.9±5.3%, p<0.001). The baseline RV–LV interlead distance was associated with echocardiographic LV dimensions (end diastole: R=0.61, p=0.001 and end systole: R=0.54, p=0.004). However, none of the contractility surrogates could discriminate between the acute CRT responders and non-responders (ΔFS: −2.5±2.6% vs − 2.0±3.1%, p=0.50; Δtime to peak systolic contraction: −9.7±18.1% vs −10.8±15.1%, p=0.43 and Δpeak negative slope: −8.7±45.9% vs 12.5±54.8 %, p=0.09).The baseline RV–LV interlead distance was associated with echocardiographic LV dimensions. In CRT recipients, contractility surrogates derived from the RV–LV interlead distance waveform could not discriminate between acute haemodynamic responders and non-responders