bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk stratification in patients discharged for STEMI. Ejection fraction by echocardiography as the gatekeeper for a selective use of cardiac magnetic resonance
Authors: Marcos Garces V , Gavara J , Lopez-Lereu M.P , Monmeneu J.V , Rios-Navarro C , De Dios E , Merenciano-Gonzalez H , Gabaldon-Perez A , Bonanad C , Chorro F.J , Valente F , Lorenzatti D , Rodriguez-Palomares J.F , Ortiz J.T , Bodi V 
Published: November 2020

Abstract

Background
CMR permits robust risk stratification of discharged STEMI patients but an indiscriminate use in all cases is unfeasible.

Purpose
We evaluated the usefulness of left ventricular ejection fraction (LVEF) by echocardiography (Echo) as the gatekeeper for identifying those patients discharged for ST-segment elevation myocardial infarction (STEMI) who benefit most from cardiac magnetic resonance (CMR) for prognostic purposes.

Methods
Echo and CMR were performed in 1119 patients discharged for STEMI included in a multicenter registry. The prognostic power of CMR beyond Echo-LVEF was assessed using C-statistic, net reclassification index (NRI) and integrated discrimination improvement index (IDI).

Results
During a 4.8-year median follow-up, 136 (12%) first major adverse cardiac events (MACE) occurred (47 cardiovascular deaths and 89 re-admissions for acute heart failure). Lesser Echo-LVEF and CMR-LVEF associated with the occurrence of MACE but only CMR-LVEF and microvascular obstruction were independent predictors. The MACE rate significantly increased only in patients with CMR-LVEF &lt;40% (≥50%: 7%, 40–49%: 9%, &lt;40%: 27%, p&lt;0.001). The majority of patients (629, 56%) displayed Echo-LVEF ≥50% and most of them (94%) were at the “safe zone” (CMR-LVEF &gt;40%). On the other hand, 490 patients (44%) exhibited Echo-LVEF &lt;50% and 33% of them were incorrectly classified either in the “safe zone” (CMR-LVEF ≥40%) or in the “risk zone” (CMR-LVEF &lt;40%). C-statistic, NRI and IDI demonstrated potent reclassification for MACE prediction by CMR in patients with Echo-LVEF &lt;50% but not in those with Echo-LVEF ≥50%.

Conclusions
Echo-LVEF &lt;50% identifies the subset of discharged STEMI patients who may benefit most from CMR in terms of long-term risk prediction.
Figure 1. LVEF reclassification

Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was funded by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (PIE15/00013, PI17/01836, and CIBERCV16/11/00486 grants).
Three-dimensional volume-strain loops may reflect fibrosis in hypertrophic cardiomyopathy
Authors: Pagourelias E , Antoniadis A , Boulmpou A , Tsarouchas A , Mouselimis D , Bakogiannis C , Papadopoulos C.E , Vassilikos V , Voigt J.U 
Published: November 2020

Abstract

Background
Combined plotting of deformation parameters against other indices [e.g. arterial pressure, left ventricular (LV) volume] might offer additional information about different diseases. Especially in hypertrophic cardiomyopathy (HCM) this approach might offer new insights into the various phenotypic and pathophysiologic features of this entity.

Purpose
Aim of this study was i) to apply strain-volume loops in HCM based on simultaneous frame-by-frame strain and volume changes' recordings acquired by means of three-dimensional (3D) speckle tracking imaging and ii) to investigate potential correlations between these loops and phenotypic features of HCM (including thickness, obstruction and fibrosis).

Methods
We included 40 HCM patients (54.1±14.3 years, 82.5% male, maximum wall thickness 19.3±4.8mm) who have consecutively undergone 3D-speckle tracking echocardiography and cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE). Values of 3D strain were plotted vs. volume for each frame to build a strain–volume loop. Peak of radial, longitudinal, and circumferential systolic strain (Rsp, Lsp, and Csp, respectively), systolic slopes of the loops (RsSl, LsSl, CsSl), and strain to end-diastolic volume (EDV) ratio (Rs/V, Ls/V, Cs/V) were computed for the analysis (panel A). Additionally, burden of fibrosis (percentage of LV mass) was defined by LGE extent (&gt;5 standard deviations compared to nulled myocardium) in CMR slices.

Results
All HCM patients had preserved EF (60.5±5,7%), while 16 (40%) had LV outflow tract obstruction (LVOTO&gt;30 mm Hg at rest). Mean LV mass index was 78.9±14.5 g (evaluated by 3D echocardiography). LGE was observed in 23 patients (57.5%) occupying 5.2±4.5% of LV mass. Concerning strain-volume loops the following values were recorded for radial (Rsp 30.8±9.8%, RsSl 0.4±0.13 and Rs/V 0.25±0.09), longitudinal (Lsp −9.4±3.7%, LsSl 0.12±0.06 and Ls/V 0.08±0.04) and circumferential deformation (Csp −14.2±3.5%, CsSl 0.18±0.05 and Cs/V 0.11±0.03). Among typical HCM characteristics tested (LV mass, LVOTO and LGE), only LV mass presented significant correlations with LsSl (r=−0.41, p&lt;0.01). Interestingly, HCM patients with smaller LVMI and without LGE presented steeper and narrower (difference between systolic and diastolic strain for the same volume) longitudinal strain-volume loops compared to patients with larger LVMIs and fibrosis (panel B).

Conclusions
Strain-volume loop is an innovative application of 3D deformation imaging in HCM. According to this new non-invasive method, increase of LVMI in HCM is accompanied by less longitudinal contribution to stroke volume, whereas better systolic-diastolic coupling may exclude the presence of underlying fibrosis.

Funding Acknowledgement
Type of funding source: None
Gen-editing to model Short QT syndrome type 5 using human-induced pluripotent stem cell-derived cardiomyocytes
Authors: El-Battrawy I , Maywald L , Cyganek L , Zhong R , Zhang F , Kleinsorge M , Dinkel H , Lan H , Li X , Huang M , Liao Z , Moscu-Gregor A , Borggrefe M , Zhou X , Akin I 
Published: November 2020

Abstract

Aims
Short QT syndrome (SQTS), a disorder associated with characteristic electrocardiogram QT-segment abbreviation, predisposes afflicted patients to sudden cardiac death. Despite some progress in assessing the organ level pathophysiology and genetic changes of the disorder, the understanding of the human cellular phenotype and discovering of an optimal therapy has lagged due to a lack of appropriate human cellular models of the disorder. The aim of this study was to establish a cellular model of SQTS type 5 using human-induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CMs) and gene-edited cell line using CRISPR/CAS9.

Methods and results
This study recruited one patient with short QT syndrome type 5 carrying a mutation in CACNb2 gene as well as one healthy control subject. We generated hiPSCs from their skin fibroblasts, and differentiated hiPSCs into cardiomyocytes (hiPSC-CMs) for physiological. Isogenic control hiPSC-CMs generated by the CRISPR/CAS9 technique were also used for the study.
The hiPSC-CMs from the patient showed a reduced calcium current (ICa-L) density and shortened action potential duration (APD) compared with healthy control hiPSC-CMs and isogenic hiPSC-CMs. Furthermore, they demonstrated abnormal rhythmic activities. Carbachol increased the arrhythmic events in SQTS significantly but not in healthy and isogenic control cells. Gene and protein expression profiling showed a decreased CACNb2 expression in SQTS cells. Quinidine prolonged the APD and abolished arrhythmic activity.

Conclusions
Patient-specific hiPSC-CMs are able to recapitulate single-cell phenotype features of SQTS type 5 and provide novel opportunities to further elucidate the cellular disease mechanism and test drug effects.

Funding Acknowledgement
Type of funding source: None
Inducibility of atrial fibrillation is associated with disturbed activation pattern in bachmanns bundle
Authors: Van Staveren L , Van Der Does W.F.B , Heida A , De Groot N.M.S 
Published: November 2020

Abstract

Background
Electrophysiological differences in Bachmann's bundle (BB) between patients with a history of atrial fibrillation (AF) and patients without prior tachyarrhythmias have been demonstrated, including a higher proportion of conduction block (CB) and longer lines of CB. However, whether conduction abnormalities in BB influence inducibility of AF is yet unknown.

Purpose
To investigate which electrophysiological characteristics of BB during sinus rhythm increase susceptibility to AF in patients undergoing elective cardiac surgery, using intraoperative high density epicardial mapping data.

Methods
Fifty-four patients without a history of AF, admitted for correction of structural cardiac disease (coronary artery disease, heart valve regurgitation or stenosis or congenital heart disease), were examined. Epicardial mapping of Bachmann's bundle during sinus rhythm was performed using a rectangle-shaped electrode array (192 electrodes, interelectrode distance: 2mm). AF was induced using bursts of fixed rate pacing. Patients in whom sustained AF was induced (lasting throughout the mapping procedure, N=34) and patients in whom AF was non-inducible (N=20) were compared with respect to lines of conduction block (CB, defined as interelectrode conduction time &gt;12ms), total activation time of Bachmann's bundle and patterns of activation.

Results
AF inducibility was not related to patient characteristics. Patients in whom AF was induced showed a higher proportion of CB (3.23 (0.0–23.9)% vs 1.82 (0.048- 4.6)%, p&lt;0.05), longer maximum lines of CB (12 (0–78)mm vs 9 (2–24)mm, p&lt;0.05) and a longer total activation time (55.0 (24.0–154.5)ms vs 41.8 (23.0–73.0)ms, p&lt;0.01) compared to patients in the non-inducibility group. In addition, BB was activated by more separate waves entering the mapping area from different directions in the induced AF group; more than 1 wave entered BB in 22 (65%) of the induced AF patients versus 7 (40%) of non-inducibility patients, p&lt;0.05.

Conclusion
Inducibility of AF is associated with an increased proportion of CB, longer maximum continuous lines of CB, a longer total activation time of BB and more than 1 wave entering the mapping area from different directions during sinus rhythm.

Funding Acknowledgement
Type of funding source: Foundation. Main funding source(s): Dutch Heart Foundation
QRS dispersion using 252-leads Body Surface Mapping (BSM) – an explorative study of a novel diagnostic tool for Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
Authors: Kommata V , Elshafie M.I , Perez M , Augustine R , Blomstrom-Lundquist C 
Published: November 2020

Abstract

Background
The diagnosis of ARVC is complex and challenging requiring multiple investigational tools, most of which include the demonstration of depolarization/conduction abnormalities, described in recent HRS consensus documents 2019. A simple and user friendly diagnostic tool is warranted.

Purpose
The purpose of our study was therefore to explore whether the analysis of QRS dispersion obtained from 252-leads recorded by a Body Surface Mapping (BSM) system can be used to identify ARVC patients as compared to the traditional ECG criteria including QRS dispersion measured by conventional 12 lead surface ECG.

Methods
12 definite ARVC patients (10/12 with known pathogenic mutation) (Group 1) and 8 healthy family members tested negative for the family mutation served as controls (Group 0), were included. All patients underwent 12-lead ECG (50mm/sec), Signal-averaged ECG for late potentials and 252 lead BSM recordings. The QRS duration was measured in each of the 12 ECG leads manually with digital caliper. The QRS duration from the BSM leads were manually analyzed in Matlab by two observers unaware of the diagnosis. For each lead, the mean value of three randomly chosen beats was calculated. The QRS dispersion was calculated as the difference between the minimum and maximum value for both the 12 lead ECG and the BSM recordings.

Results
The mean age was 49,6 and 38,8 years in ARVC patients and controls, respectively. The number of males in the two groups were 8/12 and 5/8, respectively. Epsilon waves and Terminal Activation Duration (TAD) &gt;55msec were detected in 6/12 and 8/12 ARVC patients, respectively, but in no controls. Late potentials were detected in 11/12 ARVC patients and in 2 controls. The QRS duration and QTc duration was not statistically different in the two Groups.
The ECG-QRS dispersion was significantly more pronounced in Group 1 (42 ms ± 15, range 20–70 ms) than in Group 0 (26 ms ± 8, range 16–36 ms) (p=0.013). The BSM-QRS dispersion was significantly longer in Group 1 (68 ms ± 17, range 29–90ms) than in Group 0 (30 ms ± 7, range 22–41ms) (p=0.001). Only one ARVC patient had a BSM-QRS dispersion &lt;50 msec, whereas none of the controls had a QRS dispersion over 50 msec (Fig. 1).

Conclusion
BSM-QRS dispersion, specifically using the cut off &lt;50 ms, can potentially be a more sensitive and specific method than other ECG related techniques for diagnosing ARVC patients versus non-ARVC patients. Larger patient cohorts and further studies are required to confirm our findings.
Figure 1. ECG and BSM-QRS dispersion

Funding Acknowledgement
Type of funding source: Foundation. Main funding source(s): Selanders Stiftelse
A nationwide 16 year analysis of trends and impact of arrythmias in transplant recipients
Authors: Isath A , Perembeti S , Rao S , Sherif A , Correa A , Chahal A , Padmanabhan D , Garg V , Contreras J , Mehta D 
Published: November 2020

Abstract

Background
Orthotopic heart transplantation is the most effective long-term therapy for end-stage heart disease. Denervation of transplanted heart with the loss of autonomic modulation, vasculopathy, utilization of immunosuppressant drugs, and risk of allograft rejection may result in change in the prevalence of arrhythmias in transplanted hearts.

Purpose
To describe the trends, distribution and the clinical impact of arrhythmias in transplanted hearts in a large nationwide population.

Methods
We queried the National Inpatient Sample with administrative codes. Cardiac transplant patients were identified using procedure ICD-9-CM codes 37.5 and 33.6. Common arrhythmias were extracted using appropriate validated ICD-9-CM codes. Statistical Analysis System (SAS) version 9.4 was used for analysis of data.

Results
There was a total of 30,020 hospitalizations of heart transplant recipients between 1999 and 2014 in the United States and 16342 (54.4%) of these had arrhythmias. The prevalence of total arrhythmias increased from 53.6% (n=1,158) in 1999 to 67.3% (n=1,575) in 2014. The most common arrhythmia was atrial fibrillation (26.83%) followed by ventricular tachycardia (22.86%) and the prevalence of individual arrhythmias is as shown in Figure 1.
Cardiogenic shock was higher in transplanted hearts with arrhythmias when compared with patients without arrhythmias (25.96% vs 18.18%; p&lt;0.001). Transplant recipients with arrhythmias were also associated with an increased use of mechanical circulatory device (18.22% vs 12.67%, p&lt;0.001). The use of implantable cardiac defibrillators and permanent pacemaker was also higher in the arrhythmia group (2.19% vs 0.63% and 40.43% vs 30.24% respectively, p&lt;0.0001). However, there was no significant difference in inpatient mortality between transplant recipients with arrhythmias and without arrhythmias (7.72% vs 6.90%, p=0.225). Further, there was no significant difference in frequency of strokes between the groups (4.98% vs 5.08%; p=0.857).
The total hospital cost when adjusted for inflation was significantly higher in the arrhythmic patients, with an average cost of about $570,415±9,590 vs $439,707±8362 in patients without arrhythmias (p&lt;0.0001). The mean length of hospitalization was 44.2±0.8 days in patients with arrhythmias compared to 33.9±0.8 days in patients without arrhythmias (p&lt;0.0001).

Conclusion
A significant proportion of patients with heart transplant have cardiac arrhythmias and are associated with worse in-hospital outcomes of cardiogenic shock, increased length of stay, and cost of hospitalization. However, they are not associated with worse inpatient mortality.

Funding Acknowledgement
Type of funding source: None
Frequency of cardiac arrhythmias in older adults: findings from the subclinical atrial fibrillation and risk of ischemic stroke (SAFARIS) study
Authors: Mannina C , Jin Z , Matsumoto K , Ito K , Biviano A , Elkind M , Rundek T , Homma S , Sacco R , Di Tullio M 
Published: November 2020

Abstract

Background
Prolonged monitoring of cardiac rhythm has been used in patients with symptomatic arrhythmias and to assess for atrial fibrillation (AF) after cryptogenic stroke, but not in the general population and especially in older adults.

Purpose
To evaluate the frequency of arrhythmias in a community-based cohort of older adults through 14-days continuous cardiac monitoring using a patch-based device.

Methods
Cardiac rhythm was analyzed in 533 participants free of AF and congestive heart failure (CHF) from the tri-ethnic (white, black, Hispanic) Subclinical Atrial Fibrillation and Risk of Ischemic Stroke (SAFARIS) study. AF, supraventricular tachycardia (SVT, defined as 4 beats or more), premature atrial (PACs) and ventricular (PVCs) contractions, ventricular tachycardia (VT, defined as 4 beats or more), sinus pauses (SP) and atrio-ventricular blocks (AVB) were analyzed. Gender, age and race-ethnic differences were examined.

Results
Mean age was 77.2±6.8 years (198 men, 335 women). Recording duration was over 10 days in 91%, and over 13 days in 84%. AF was present in 10 participants (1.9%), atrial flutter in 1 (0.2%). Other arrhythmias are reported in the Table. SP (1.9%) and high-degree AVB (Mobitz II: 0.6%; 3rd degree: 0.9%) were rare. No significant race-ethnic differences were observed.

Conclusion
In older adults without history of stroke or CHF, prolonged rhythm monitoring revealed moderate frequency of AF, but higher than expected frequencies of AF-predisposing conditions such as SVT and frequent PACs. VT episodes were relatively frequent, whereas SP and AVB were less frequent than commonly believed. Most arrhythmias were more frequent in the oldest; ventricular arrhythmias were more common in men than in women.

Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): NINDS R01 NS083874
Provocation testing is irreplaceable to uncover or refute Brugada syndrome – an electrocardiographic validation study during ajmaline provocation
Authors: Van Der Ree M.H , Vendrik J , Kors J.A , Wilde A.A.M , Tan H.L , Postema P.G 
Published: November 2020

Abstract

Background
A Brugada syndrome (BrS) diagnosis is made upon documenting its characteristic type-1 ECG abnormality, being either spontaneously present or provoked by drug challenge, in the absence of co-morbidities resulting in similar ECG characteristics. In patients without type-1 ECG but in whom a suspicion of BrS exists, several ECG characteristics have been proposed that could aid in distinguishing BrS from non-BrS, particularly in individuals with incomplete right bundle branch block.

Purpose
To validate the diagnostic value of ECG characteristics that were previously proposed.

Methods
For this retrospective study, ECGs were evaluated from consecutive patients suspected of BrS who underwent ajmaline testing (n=1392). Baseline ECG and peak-effect ECG were analyzed with the MEANS software. Parameters considered were P, PR, QRS, S, JT, QT and QTc durations (all in ms), J and S amplitudes (both in mV), and QRS and T axes (both in °). ECG evaluations also included b-angles (in °) and duration of the base of a triangle (DBT) at 0.5 mV from the r' (in ms) in right precordial leads (V1, V2, V1ic3, V2ic3).

Results
Diagnostic type-1 ECGs were uncovered in 345 subjects and 1047 subjects had a negative test. Patients with BrS had significantly more atrial and ventricular conduction abnormalities (P, PR, QRS, and S duration) at baseline; these differences, except in PR duration, were aggravated upon ajmaline administration. In particular, the b-angle (e.g., V1: 28° [20; 46.5] versus 18° [12; 24], p&lt;0.01) and DBT (e.g., V1: 130 ms [89; 214] versus 65 ms [42; 92.3], p&lt;0.01) were significantly larger at baseline in patients with BrS, however, only with modest diagnostic value (area-under-the-curve 0.67–0.80). The optimal b-angle cut-off value based on the ROC curves to rule out BrS was determined at an angle of &gt;15°, negative predictive values ranged from 78.6–95.5 and sensitivities ranged from 80–98.1% among different leads.

Conclusions
Patients with BrS show more baseline ECG abnormalities and display more conduction slowing upon ajmaline infusion. The b-angle and DBT do not demonstrate strong enough diagnostic characteristics to serve as a stand-alone diagnostic tool. Drug provocation tests remain necessary for diagnosing BrS in patients without a spontaneous type-1 ECG.

Funding Acknowledgement
Type of funding source: None
Competency differences in ECG interpretations between medical students, interns, and family residents
Authors: Alanazi H , Ahmed A , Alsadi M , Almousa S , Homoud E , Almutairi R , Alkhalifah B 
Published: November 2020

Abstract

Background
The 12-lead electrocardiogram (ECG) is an indispensable screening and diagnostic tool used to identify cardiovascular abnormalities as well as fatal cardiac emergencies. Our aim was to identify whether a competency difference in interpreting ECG strips between medical students, interns, and family residents exists.

Methods
A cross-sectional, single-center study conducted at tertiary health care facility and its academic institution. Participants were given a self-administered questionnaire which consisted of a demographic sheet and 10-ECGs each with 9 multiple choice questions about the basic ECG parameters. Correct answer was given a 1-point score, with the minimum and maximum scores being 0 and 90, respectively.

Results
The total participants were 93; 54 (58.1%) medical students, 27 (29.0%) interns, and 12 (12.9%) family Medicine residents. Medical students had a statistically significant higher mean score 84.7±9.5 when compared to the medical interns 73.4±12.9 (p&lt;0.001) and family medicine residents 58.2±18.0 (p&lt;0.001). There were no differences in the mean scores between male and female medical students and interns. However, female family medicine residents had a higher mean score when compared to their male colleagues (p-value=0.04). Medical students performed better in detection of more than 65% of all ECG parameters when compared to the interns and residents. Fifty-seven (61.3%) reported that ECGs exposure during their medical program was not sufficient. Lectures were reported as the most effective modality of ECG teaching among 38 medical students (70.4%) and 9 residents (75.0%). However, 9 medical interns reported self-teaching (33.3%) as effective as standard lectures (33.3%) in teaching ECG.

Conclusion
Among our study cohort, medical students had higher ECGs-related skills, interpretation skill and more reading competency than medical interns and family residents. Most used method of learning ECG in all levels was lectures. Although Study generalizability is limited, refining ECG reading skills is required.

Funding Acknowledgement
Type of funding source: None