Arrhythmic Episodes Research Articles

Validation of Adhesive Single-Lead ECG Device Compared with Holter Monitoring among Non-Atrial Fibrillation Patients.

There are few reports on head-to-head comparisons of electrocardiogram (ECG) monitoring between adhesive single-lead and Holter devices for arrhythmias other than atrial fibrillation (AF). This study aimed to compare 24 h ECG monitoring between the two devices in patients with general arrhythmia. Twenty-nine non-AF patients with a workup of pre-diagnosed arrhythmias or suspicious arrhythmic episodes were evaluated. Each participant wore both devices simultaneously, and the cardiac rhythm was monitored for 24 h. Selective ECG parameters were compared between the two devices. Two cardiologists independently compared the diagnoses of each device. The two most frequent monitoring indications were workup of premature atrial contractions (41.4%) and suspicious arrhythmia-related symptoms (37.9%). The single-lead device had a higher noise burden than the Holter device (0.04 ± 0.05% vs. 0.01 ± 0.01%, p = 0.024). The number of total QRS complexes, ventricular ectopic beats, and supraventricular ectopic beats showed an excellent degree of agreement between the two devices (intraclass correlation coefficients = 0.991, 1.000, and 0.987, respectively). In addition, the minimum/average/maximum heart rates showed an excellent degree of agreement. The two cardiologists made coherent diagnoses for all 29 participants using both monitoring methods. In conclusion, the single-lead adhesive device could be an acceptable alternative for ambulatory ECG monitoring in patients with general arrhythmia.

Degree of coronary occlusions links to the patient clinical outcome: four cases of double culprits acute ST-segment elevation myocardial infarction

Background: Double coronary culprit lesions in ST-segment elevation myocardial infarction (STEMI) is uncommon. Despite successful primary percutaneous coronary intervention (PPCI) in all culprit lesions, the clinical outcome remains unfavorable and the possible factors for the outcome are not fully understood.Cases Presentation: We reported four cases of double culprit lesions STEMI underwent PPCI. Patient A, a 62 y.o. male with extensive anterior-inferior STEMI, had total occlusion (TO) at both proximal left anterior descending (LAD) and mid right coronary artery (RCA). Patient B, a 42 y.o. male with extensive anterior-inferior STEMI, had subtotal occlusion (STO) at proximal RCA and TO at proximal LAD. Both of them had RBBB ECG pattern. Patient C, a 67 y.o. male with inferior STEMI had 90% thrombus occlusion at proximal–mid LAD and TO at proximal RCA. Patient D, a 65 y.o. male with anteroseptal STEMI, had STO at proximal LAD and 80% thrombus occlusion at mid left circumflex. The cardiomyocyte infarction biomarkers increased in all patients. Although all of them underwent successful PPCI in all of culprit lesions, they suffered from acute heart failure and two of them experienced recurrent ventricular arrhythmia episodes. One of them (patient A) died two days post PPCI. He was only patient who suffering from total occlusion in LAD and RCA with TIMI thrombus 5 and experienced a total atrioventricular block post-PPCI.Conclusion: STEMI with coronary double culprits have severe clinical outcome, regardless of the successful PCI. The degree of coronary occlusions might be linked to the patient clinical outcome.

Pregnancy-related cardiac non-elective hospitalizations and pregnancy outcomes. A tertiary referral cardiac center experience.

Pregnant women with cardiovascular diseases (CVD) and their offspring are at higher risk of morbidity and mortality. To provide data on pregnancy outcomes among women with different types of CVD requiring non-elective cardiac hospitalization in a tertiary referral cardiac center. We identified all records of non-elective hospitalizations of pregnant women hospitalized between January 2009 through March 2018, at our institution - a tertiary referral cardiac center. The incidence and types of cardiac complications during pregnancy, as well as the pregnancy and offspring outcomes, were determined. One hundred and sixty-one out of 328 pregnancy-related hospitalizations in 140 pregnancies were non-elective. Cardiac complications occurred in 62 (44%) pregnancies, with the most frequent being episodes of arrhythmia (22.1% pregnancies), followed by heart failure exacerbations (6.4% pregnancies). Maternal mortality reached 2.1% and affected only women with primary cardiomyopathies (CMP). Offspring mortality was 2.8%. Newborns of mothers with cardiac complications had significantly lower Apgar scores and gestational age at delivery, compared to mothers without cardiac complications. In our series mortality and morbidity among pregnant women with CVD hospitalizations were high. An unfavorable maternal outcome mainly affected women with CMP. Offspring of mothers with cardiovascular complications are prone to have a lower gestational age and Apgar score.

Cardiac arrhythmias in patients with COVID-19: Lessons from 2300 telemetric monitoring days on the intensive care unit

BackgroundPatients with COVID-19 seem to be prone to the development of arrhythmias. The objective of this trial was to determine the characteristics, clinical significance and therapeutic consequences of these arrhythmias in COVID-19 patients requiring intensive care unit (ICU) treatment. Methods and resultsA total of 113 consecutive patients (mean age 64.1 ± 14.3 years, 30 (26.5%) female) with positive PCR testing for SARS-CoV2 as well as radiographically confirmed pulmonary involvement admitted to the ICU from March to May 2020 were included and observed for a cumulative time of 2321 days. Fifty episodes of sustained atrial tachycardias, five episodes of sustained ventricular arrhythmias and thirty bradycardic events were documented.Sustained new onset atrial arrhythmias were associated with hemodynamic deterioration in 13 cases (35.1%). Patients with new onset atrial arrhythmias were older, showed higher levels of Hs-Troponin and NT-proBNP, and a more severe course of disease.The 5 ventricular arrhythmias (two ventricular tachycardias, two episodes of ventricular fibrillation, and one torsade de pointes tachycardia) were observed in 4 patients. All episodes could be terminated by immediate defibrillation/cardioversion. Five bradycardic events were associated with hemodynamic deterioration. Precipitating factors could be identified in 19 of 30 episodes (63.3%), no patient required cardiac pacing. Baseline characteristics were not significantly different between patients with or without bradycardic events. ConclusionRelevant arrhythmias are common in severely ill ICU patients with COVID-19. They are associated with worse courses of disease and require specific treatment. This makes daily close monitoring of telemetric data mandatory in this patient group.

Assessment of cardiac arrhythmias using long-term continuous monitoring in patients with pulmonary hypertension

BackgroundCardiac arrhythmias are considered a prominent phenomenon in patients with pulmonary hypertension (PH). Older studies reported that 8% to 35% of patients with PH had supraventricular tachycardia (SVT), associated with adverse outcomes. Still, these arrhythmias have only been investigated via short-term monitoring or limited electrocardiogram recordings. MethodsPatients without previous arrhythmias diagnosed with PH at a tertiary facility received an insertable cardiac monitor as part of a prospective cohort study. Baseline assessments included World Health Organization functional class, six-minute walk test, echocardiography, and cardiac magnetic resonance imaging. ResultsThirty-four patients with PH were included. Twenty-four patients had pulmonary arterial hypertension (PAH) and 10 had chronic thromboembolic PH (CTEPH). During 46 patient-years of continuous monitoring (median: 594 (range: 334–654) days per patient), 70 arrhythmia episodes were recorded in 13 patients (38%), with a median of two (range: 1–3) episodes and an arrhythmic burden median of 1.6 (range: 0.1–228) minutes per patient. SVTs were the most common arrhythmias, with 16% of episodes being atrial fibrillation and 84% being other types of SVTs. Additionally, three patients experienced bradycardias, including one resulting in syncope and subsequent pacemaker implantation. None of the patients had sustained ventricular arrhythmias. ConclusionsArrhythmias were seen in 38% of contemporary patients with PH during long-term continuous monitoring; however, the vast majority of episodes were short and self-limiting. Modern therapy may alleviate the development of arrhythmias in stable patients with PH. This study is the first study to deploy long-term continuous monitoring in patients with PH.

Ureteroscopic lithotripsy combined with paravertebral block anesthesia or general anesthesia: A propensity matched case–control study

BackgroundTo evaluate the safety, efficacy and cost of paravertebral block anesthesia for ureteral stones patients undergoing ureteroscopic lithotripsy. MethodsFour hundred and eighty-two patients who underwent ureteroscopy for unilateral ureteral stones were incorporated into our retrospective study. A propensity-matched comparison in patients with paravertebral nerve block anesthesia (PVB) group and general anesthesia (GA) group was performed. Intraoperative hemodynamic parameters, operative time, visual analog scale for pain, stone-free rate, anesthetic cost and postoperative hospital stay were compared between the two groups. ResultsSixty-one GA cases were propensity matched to 61 PVB cases. In the PVB group, all the procedures were completed successfully without anesthesia conversion. Significantly less intraoperative severe hypotensive (P = 0.002) and arrhythmia (P < 0.001) episodes in PVB group. There were no significant differences in operative time (p = 0.702), initial stone-free rate (p = 0.686), and total stone-free rate (p = 0.794) between the two groups. The PVB group had lower postoperative pain and prolonged analgesia (p = 0.007). The postoperative hospital stay in the PVB group was significantly shorter (3.20 ± 0.73 vs 3.84 ± 1.32 d, p = 0.001). And the cost of anesthesia was lower in the PVB group (195.47 ± 13.01 vs 396.31 ± 36.45 US dollars, p < 0.001). ConclusionUnder PVB anesthesia, URS can be successfully completed without anesthetic transformation, and its efficacy and safety have been demonstrated. When economic aspects are taken into consideration, PVB seems to be a more economical and effective anesthetic method of URS.

Increased Incidence of Supraventricular and Ventricular Arrhythmias in Patients with Pulmonary Hypertension Awaiting for Heart Transplantation

Purpose Estimation of the risk for supraventricular and ventricular arrhythmias in patients awaiting for heart transplantation with concomitant secondary pulmonary hypertension was the aim of the study. Methods There were 50 patients (40 men and 10 women) in mean age of 48 +/- 12 years enrolled into the study . During the observational period the paroxysmal atrial fibrillation (AF) was diagnosed in 7 (4%) patients, permanent AF in 25 (50%). The electrocardiographic history included 24 (48%) non-sustained ventricle tachycardia's and 11 (22%) of ventricular tachycardia (VT). During the observational time repetitive evaluations were recorded including echocardiographic imaging and right catheterisation. Results There was neither preoperative nor intraoperative deaths in presented group. During the follow up time, the episodes of supraventricular and ventricular arrhythmias were noticed including supraventricular arrhythmias in 31 patients, persistent atrial fibrillation was diagnosed in 16 patients, atrial flutter was found in 3 patients, non-sustained ventricular tachycardia episodes were detected in 29 patients and ventricular fibrillation requiring ICD intervention in 3 cases. Logistic regression analysis revealed that left atrium diameter and pulmonary hypertension secondary to congestive heart failure were linked to the risk for atrial fibrillation OR=8.34 95%CI [1.66 - 41.84] (p = 0.010). The patients suffering from pulmonary hypertension (above 3 Units of Wood) awaiting on transplant list, were characterised by significantly higher risk for VTs episodes (46% vs 10%, p=0.0051). Conclusion The main finding of the presented study is relation between pulmonary hypertension and arrhytmogenic episodes in patients awaiting for transplantation. The study confirm the relation between supraventricular and ventricular arrhythmias and pulmonary hypertension in congestive heart failure patients. Increased episodes of arrhythmias in HF patients should be regarded as independent indicator for heart transplantation.

Recurrent sustained atrial arrhythmias and thromboembolism in Fontan patients with total cavopulmonary connection.

BackgroundTotal cavopulmonary connection (TCPC) is associated with a lower risk of incident atrial arrhythmias as compared to atriopulmonary Fontan, but the risk of recurrent atrial arrhythmias is unknown in this population. The purpose of this study was to determine the incidence and risk factors for recurrent atrial arrhythmias and thromboembolic complications in patients with TCPC.MethodsThis is a retrospective multicenter study conducted by the Alliance for Adult Research in Congenital Cardiology (AARCC), 2000–2018. The inclusion criteria were TCPC patients (age > 15 years) with prior history of atrial arrhythmia.ResultsA total of 103 patients (age 26 ± 7 years; male 58 [56%]) met inclusion criteria. The mean age at initial arrhythmia diagnosis was 13 ± 5 years, and atrial arrhythmias were classified as atrial flutter/tachycardia in 85 (83%) and atrial fibrillation in 18 (17%). The median duration of follow-up from the first episode of atrial arrhythmia was 14.9 (12.1–17.3) years, and during this period 64 (62%) patients had recurrent atrial arrhythmias (atrial flutter/tachycardia 51 [80%] and atrial fibrillation 13 [20%]) with annual incidence of 4.4%. Older age was a risk factor for arrhythmia recurrence while the use of a class III anti-arrhythmic drug was associated with a lower risk of recurrent arrhythmias. The incidence of thromboembolic complication was 0.6% per year, and the cumulative incidence was 4% and 7% at 5 and 10 years respectively from the time of first atrial arrhythmia diagnosis. There were no identifiable risk factors for thromboembolic complications in this cohort.ConclusionsAlthough TCPC provides superior flow dynamics and lower risk of incident atrial arrhythmias, there is a significant risk of recurrent arrhythmias among TCPC patients with a prior history of atrial arrhythmias. These patients may require more intensive arrhythmia surveillance as compared to other TCPC patients.

Cardiac arrhythmias in patients presenting with COVID-19 treated in Portuguese hospitals: A national registry from the Portuguese Association of Arrhythmology, Pacing and Electrophysiology

Introduction and objectivesIn December 2019, SARS-CoV-2, was discovered as the agent of COVID-19 disease. Cardiac arrhythmias have been reported as frequent but their incidence is unknown. The aim of this research was to assess the real incidence of cardiac arrhythmias among COVID-19 patients admitted to Portuguese hospitals and to understand the underlying prognostic implications. MethodsThe Portuguese Association of Arrhythmology, Pacing and Electrophysiology (APAPE) conducted a survey in Portuguese hospitals to assess the occurrence of arrhythmias in COVID-19 patients, their clinical characteristics, the use of experimental therapies and the impact on QT interval. ResultsTwenty hospitals participated, reporting 692 hospitalized patients. An arrhythmic episode occurred in 81 (11.7%) and 64 (79%) had detailed information on these episodes. New onset arrhythmias occurred in 41 (64%) patients, 45 (70.3%) male, median age 73.5 (61-80.3) years. There were 51 (79.7%) with associated comorbidities, mainly arterial hypertension (41, 64.1%). Of 53 patients (82.3%) on experimental therapy, 7 (10.9%) had an increased QTc interval. Regarding arrhythmias, two patients (3.1%) had ventricular tachycardia, 5 (7.8%) sinus bradycardia, 17 (26.6%) paroxysmal supraventricular tachycardia and 40 (62.5%) atrial fibrillation or flutter. At the time of reporting, there had been no deaths due to arrhythmic syndrome or related complications. ConclusionsIn a population of COVID-19 patients. The incidence of cardiac arrhythmias is high but not associated with increased cardiac mortality although it does though occur frequently in extremely ill patients and with multiple organ failure. Regardless of the use of experimental drugs, the incidence of ventricular arrhythmias is low and atrial fibrillation and other supraventricular arrhythmias are the most prevalent arrythmias.

Cardiac arrhythmias in critically ill patients with coronavirus disease 2019: A retrospective population-based cohort study.

BackgroundCoronavirus disease 2019 (COVID‐19) may be associated with cardiac arrhythmias in hospitalized patients, but data from the ICU setting are limited. We aimed to describe the epidemiology of cardiac arrhythmias in ICU patients with COVID‐19.MethodsWe conducted a multicenter, retrospective cohort study including all ICU patients with an airway sample positive for severe acute respiratory syndrome corona‐virus 2 from March 1st to June 1st in the Capital Region of Denmark (1.8 million inhabitants). We registered cardiac arrhythmias in ICU, potential risk factors, interventions used in ICU and outcomes.ResultsFrom the seven ICUs we included 155 patients with COVID‐19. The incidence of cardiac arrhythmias in the ICU was 57/155 (37%, 95% confidence interval 30‐45), and 39/57 (68%) of these patients had this as new‐onset arrhythmia. Previous history of tachyarrhythmias and higher disease severity at ICU admission were associated with cardiac arrhythmias in the adjusted analysis. Fifty‐four of the 57 (95%) patients had supraventricular origin of the arrhythmia, 39/57 (68%) received at least one intervention against arrhythmia (eg amiodarone, IV fluid or magnesium) and 38/57 (67%) had recurrent episodes of arrhythmia in ICU. Patients with arrhythmias in ICU had higher 60‐day mortality (63%) as compared to those without arrhythmias (39%).ConclusionNew‐onset supraventricular arrhythmias were frequent in ICU patients with COVID‐19 and were related to previous history of tachyarrhythmias and severity of the acute disease. The mortality was high in these patients despite the frequent use of interventions against arrhythmias.

Post-operative arrhythmias in patients with hypoplastic left heart syndrome and anatomic variants: incidence, type, and course.

Arrhythmias are common in the post-operative course of patients with hypoplastic left heart syndrome. We sought to determine the types, incidence, risk factors, and impact of arrhythmias in patients with HLHS and anatomic variants. We performed a retrospective chart review of 120 consecutive patients with HLHS and anatomical variants, who had single-ventricle palliation at our institution from January, 2006 to December, 2016. A total of thirty-one patients (26%) had 37 episodes of arrhythmias over a median follow-up period of 3.5 years. Of the 37 episodes, 12 (32.4%) were ectopic atrial tachycardia, 9 (24.3%) were paroxysmal supraventricular tachycardia, 4 (10.8%) were junctional ectopic tachycardia, 5 (13.6%) were sinus node dysfunction, 3 (8.1%) were heart block, 2 (5.4%) were atrial flutter, and 2 (5.4%) were ventricular tachycardia. Twenty-four (65%) of the arrhythmias occurred at post-stage 1 surgery. Most (64.8%) of the arrhythmias were resolved. Arrhythmias that occurred at post-stage 1 surgery were more likely to resolve compared to post-stages 2 or 3 (p = 0.006). No anatomical, surgical, or clinical variables were associated with arrhythmia except for age (OR per unit decrease in age at stage 1 palliation: 1.12 (95% CI 1.003, 1.250); p = 0.0439). Arrhythmias were not associated with length of hospital stay or mortality. Arrhythmias are common in patients with HLHS and anatomic variants, with EAT and PSVT being the most common types. Arrhythmias were associated with younger age at surgery, but did not affect mortality or length of hospital stay.

Cardiomiopatia Arritmogênica do Ventrículo Direito em Maratonista: Relato de Caso

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease of the cardiac muscle characterized by right ventricular dysfunction (global or regional) with or without left ventricular (LV) involvement in the presence of histological evidence of the disease and/or electrocardiographic abnormalities according to published criteria. ARVC has age-dependent penetrance and is mainly characterized by episodes of ventricular arrhythmia that can progress to sudden cardiac death (SCD). The estimated prevalence ranges from 1:2,000 to 1:5,000, with a predominance in the Caucasian population and in people who practice strenuous exercise or competitive sports. Despite its low prevalence, ARVC represents approximately 5–20% of CSM cases in young people.

Usefulness of transesophageal echocardiography before cardioversion in atrial arrhythmias.

Although many thromboembolism risk factors are well defined, formation of thrombus or dense spontaneous contrast (sludge) in the left atrium remains enigmatic and confounding. Exclusion of the thrombus is extremely important with respect to planned reversal of sinus rhythm. Data regarding the routine transesophagal echocardiography (TEE) before cardioversion are inconclusive. The authors focused on analyzing the usefulness of TEE before cardioversion by assessment of factors influencing the risk of thrombus and/or dense spontaneous echo contrast with the intention of extending indications for TEE in the group with a high risk of thrombus or to forgo TEE in the low risk group. Two hundred sixty-nine consecutive patients with persistent (> 48 h) atrial fibrillation or atrial flutter, in whom a direct current cardioversion was planned, were undergoing TEE for the detection of the left atrial thrombus or dense spontaneous echo contrast. Additional clinical and echocardiographic data were collected. The relationship between both thrombus and dense spontaneous echo contrast and covariates was analyzed with the use of binary logistic regression. Left atrium (LA) appendage (LAA) thrombus and/or sludge were detected in 79 (29%) patients. Signs of dementia in mini-mental state examination (hazard ratio [HR]: 1.16; p = 0.005), low velocities in LAA (HR: 3.38; p = 0.032); presence of spontaneous echo contrast in LA (HR: 3.38; p = 0,003) consecutive episode of AF (HR: 2.27; p = 0,046); longer duration of atrial fibrillation (HR: 1.009; p = 0.022); were significant predictors of thrombus and/or dense spontaneous echo contrast. None of the patients with a CHA2DS2VASc score ≤ 1 had thrombus or sludge in the LAA. Among patients with a CHA2DS2VASc score > 1, the prevalence of thrombus or sludge in LAA was independent of the CHA2DS2VASc score value. Amongst many factors, including an established as risk for thromboembolism only a few of them increased the risk for the presence of thrombus in LAA: low velocities in LAA, presence of spontaneous echo contrast, longer duration of arrhythmia, consecutive (not first) arrhythmia episode and signs of dementia from a mini-mental state examination questionnaire. It was believed that there could be a need for an extension of indications of TEE in vast majority of the patients with atrial arrhythmias, due most often to an unpredictable occurrence of thrombus and potentially disastrous thromboembolism. The only exception could have been the group of the patients with a CHA2DS2VASc score ≤ 1.

The Role of the Left Septal Fascicle in Fascicular Arrhythmias: Clinical Presentation and Laboratory Evaluation.

This study describes a series of cases best explained by invoking the left septal fascicle (LSF) as a critical component of the arrhythmia circuit. Numerous anatomic studies have shown evidence of the LSF, but its precise role in the onset of arrhythmia is unclear. This paper presents 5 cases that implicated the LSF as a critical component of arrhythmogenesis. The first case had ventricular fibrillation repeatedly documented after a single premature atrial complex, produced left-sided conduction delay and simultaneous earliest activation of the left anterior fascicle (LAF) and left posterior fascicle (LPF). The LSF was ablated, resulting in an arrhythmia cure. The second case showed narrow QRS morphology during fascicular re-entrant tachycardia. The earliest mid-septal diastolic potentials had distal-to-proximal activation suggesting an LSF as a retrograde common pathway. The third case, with multiple ectopic Purkinje-related premature complexes exhibited earliest Purkinje potentials in the mid-septum, with subsequent anterograde activation of the LAF and LPF. Ablation of the LSF eliminated the premature ventricular complexes (PVCs). The fourth case demonstrated LPF and LAF PVCs. The His-left bundle activation showed earliest potentials at the proximal insertion of the left bundle during LPF PVCs, as well as a distal-to-proximal activation pattern duringLAF PVC, suggestive of LSF involvement. The fifth case had focal non-re-entrant fascicular beats successfully ablated over the LSF. Involvement of the LSF is suspected with presentation of multiform fascicular and narrow QRScomplex ventricular episodes of arrhythmia. Diagnoses and ablation require detailed mapping of the entire leftsided conduction system.

Intravenous Artesunate for the Treatment of Severe Imported Malaria: Implementation, Efficacy, and Safety in 1391 Patients.

Intravenous artesunate is the World Health Organization-recommended first-line treatment for severe malaria worldwide, but it is still not fully licensed in Europe. Observational studies documenting its safety and efficacy in imported malaria are thus essential. We prospectively collected clinical and epidemiological features of 1391 artesunate-treated patients among 110 participant centers during the first 7 years (2011-2017) of a national program implemented by the French Drug Agency. Artesunate became the most frequent treatment for severe malaria in France, rising from 9.9% in 2011 to 71.4% in 2017. Mortality was estimated at 4.1%. Treatment failure was recorded in 27 patients, but mutations in the Kelch-13 gene were not observed. Main reported adverse events (AEs) were anemia (136 cases), cardiac events (24, including 20 episodes of conduction disorders and/or arrhythmia), and liver enzyme elevation (23). Mortality and AEs were similar in the general population and in people with human immunodeficiency virus, who were overweight, or were pregnant, but the only pregnant woman treated in the first trimester experimented a hemorrhagic miscarriage. The incidence of post-artesunate-delayed hemolysis (PADH) was 42.8% when specifically assessed in a 98-patient subgroup, but was not associated with fatal outcomes or sequelae. PADH was twice as frequent in patients of European compared with African origin. Artesunate was rapidly deployed and displayed a robust clinical benefit in patients with severe imported malaria, despite a high frequency of mild to moderate PADH. Further explorations in the context of importation should assess outcomes during the first trimester of pregnancy and collect rare but potentially severe cardiac AEs.

Improving the robustness of MOLLI T1 maps with a dedicated motion correction algorithm

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Myocardial T1 mapping constitutes a reliable indicator of heart diseases related to changes of myocardial extracellular content (e.g. oedema, fibrosis) as well as fat, iron and amyloid content. T1-mapping techniques rely on fitting a model to a series of MRI measurements. Alignment between these measurements is required for accurate T1 estimation. This is limited by triggering accuracy and patient motion. Image registration is often applied to improve the alignment. In the case of MOLLI series, registration is compromised by contrast variation between the images. We present the validation of a new registration method, designed to account for the contrast properties of MOLLI data. Methods A cohort of 186 patients referred for a CMR was included in this study (115 M / 71 F; weight 75 ± 15 Kg; age 55 ± 16). Scans on a 3.0T MR included a MOLLI sequence with target parameters: 2D bSSFP, 160x148, pFOV 0.8-1.0, 1.4x1.4mm², ST 8mm, TE 1.4ms, TR 3.0ms, FA 35deg, NEX 1, BW 100kHz, 2x ASSET, 5(3)3. Cartesian 2D reconstruction followed by motion correction was applied retrospectively. A new correction algorithm was implemented, based on a similarity criterion that accounted for T1 relaxation: It consisted of an iterative approach alternating polarity estimation, T1 fitting, relaxation simulation and frame registration. The coefficient of determination (R²) was used as a quality measure. A representative subset of the results was reviewed by two experienced cardiologists. Results All reconstructions (totalling 1133 2D MOLLI series) yielded qualitatively correct T1 maps. Results with the new method were compared to conventional motion correction and no correction. The number of pixels with R²&amp;gt;0.95 was 85%±9% with standard motion correction and 90%±7% with the new dedicated method. In terms of improvement w.r.t. uncorrected data, the standard method yielded +3%±8% and the new one +9%±8%. Motion correction caused noticeable performance degradation in 12% of cases with the standard method, compared to 0.2% with the proposed method. The relative performance of the different methods can be appreciated in Figure 3. Discussion Despite T1 mapping techniques constituting a reliable diagnostic tool in cardiac imaging, they remain sensitive to patient motion and triggering inaccuracies, making them vulnerable to arrhythmia episodes. Improving the similarity criterion by accounting for T1 relaxation significantly decreased the incidence of misregistration and subsequent T1 inaccuracies. Using the R² of the voxel-wise T1 fit as a surrogate of alignment allowed to confirm the increased robustness of the new, dedicated motion correction method for MOLLI series. Conclusion We have demonstrated a new reconstruction pipeline with built-in registration, optimized for MOLLI T1-mapping. Using a large database of clinical data, the new method has been shown to improve the robustness to motion of cardiac T1 mapping. Abstract Figure.

External Cardiac Loop Recorders: Functionalities, Diagnostic Efficacy, Challenges and Opportunities.

According to the World Health Organization's (WHO) report of 2016, cardiovascular diseases (CVDs) accounted for mortality of an estimated 17.9 million people globally. Of these deaths, 85% were due to myocardial infarction and stroke. Further, the pre-dominant atrial fibrillation (AF) arrhythmia has been the most suspected underlying cause of transient ischemic attack or stroke. Thus, the etiologies of early symptoms like syncope and palpitations in patients needs to be evaluated by employing proper diagnostic tests to make early treatment decisions. The most widely referred 24 to 48 hour Holter electrocardiographic (ECG) monitoring tests have not been proved to be much effective in recognizing infrequent intermittent arrhythmic episodes. These drawbacks have led to the development of long-term ambulatory ECG (AECG) monitoring devices. This review reports the state-of-the-art existing AECG monitoring devices and their role of long-term ECG recording in patients suspected with cardiac syncope and palpitations to understand the underlying arrhythmic cause, as well as in the diagnosis and management of AF. Primarily, the utility and diagnostic yield of external cardiac recorders or event loop recorders (ELRs) in capturing the symptom-rhythm correlation which constitutes a clinically useful recordings of heart's electrical activity during infrequent arrhythmic conditions was critically reviewed. Furthermore, a brief case study on challenges involved in clinical data acquisition at a cardiac care unit using ambulatory external monitoring device has been presented. Finally, improvements in design engineering and algorithmic developments to enhance the diagnostic yield and usability of ELRs in clinical settings have been proposed.

A novel machine learning framework for automated detection of arrhythmias in ECG segments

Arrhythmias such as Atrial Fibrillation (Afib), Atrial Flutter (Afl), and Ventricular Fibrillation (Vfib) are early indicators of Stroke and Sudden Cardiac Death, which are significant causes of death globally. Therefore, it is vital to detect patients with these conditions early. Manual inspection of ECG signals is tedious, time-consuming, and is limited by inter-observer variabilities. Further, it is challenging to accurately differentiate several types of arrhythmias in complex non-linear ECG signals. Computer-aided Decision Support Systems (CDSS) could be valuable in such a scenario. The CDSS uses machine learning techniques to learn the subtle differences in these rhythms and can be used for fast, accurate, repeated, and objective classification of arrhythmias. A novel CDSS has been proposed for the discrimination of normal rhythm (Nsr) from Afib, Afl, and Vfib using machine learning techniques. Predictive models have been developed for ECG segments of two durations: 2 s and 5 s. The number of samples from each of the four classes were balanced using synthetically generated samples with the ADASYN technique. Third-order cumulant images were determined from the ECG segments. 18 non-linear features, including entropies and other texture-based features, were extracted from the cumulant images, and significant features were selected using the t-test. The selected features were used to train several classifiers.On evaluating several different classifiers with the significant features using tenfold stratified cross-validation, the Random Forest classifier consistently performed better for both two and five second ECG duration studies. An accuracy of 98.2%, sensitivity of 98.1%, and specificity of 99.4% were obtained for the 2-s dataset. For the 5-s dataset, the accuracy, sensitivity, and specificity were 98.8%, 98.8%, and 99.6%, respectively. Due to the intermittent occurrence of arrhythmia, analysis of longer duration ECG signals will help detect the onset of critical episodes of arrhythmia more accurately. Since the proposed predictive models work effectively in detecting arrhythmia in two or five second ECG segments rather than single ECG beats, they have better clinical adaptability and can be incorporated into clinical monitoring systems.

Bedaquiline for multidrug-resistant tuberculosis and QTc prolongation in California

BackgroundBedaquiline (BDQ) is recommended for the treatment of multidrug-resistant tuberculosis (MDR TB), however, it has the potential to prolong QTc interval. We assessed the frequency and severity of QTc prolongation in patients receiving BDQ in California. MethodsBased on chart review for patients receiving BDQ as part of MDR TB therapy from January 2013–May 2019, we analyzed QTc values at six pre-specified time points during BDQ therapy (baseline, 2, 4, 8, 12, and 24 weeks), as well as peak QTc, time to peak QTc, and the clinical characteristics of patients who had QTc elevation >500 milliseconds (ms) during therapy. ResultsA total of 37 patients were treated with BDQ during the analysis period, with a total of 449 QTc measurements available for analysis. Most patients (89%) received at least one QTc-prolonging drug in addition to BDQ. Median QTc values at all pre-specified time points were <450 ms. Median peak QTc was 455 ms (interquartile range [IQR]: 437–486) and median time to peak was 57 days (IQR: 19–156). Four patients (11%) had a non-transient elevation in QTc to >500 ms, including one patient with profound hypokalemia and one receiving concurrent chemotherapy, but none had cardiac arrhythmia. Less than 10% of patient in our cohort had ECGs performed at all six pre-specified time points. DiscussionBDQ was generally well-tolerated in a cohort of patients treated for MDR TB in California, with 11% of patients experiencing a non-transient QTc elevation >500 ms, and no episodes of arrhythmia. Frequent ECG monitoring during BDQ therapy presents a challenge for TB clinicians, even in well-resourced countries.

In‐Body Electromagnetic Sensor Combined with AI‐Enhanced Electrocardiography for Pacemaker Working Status Telemonitoring

This paper describes the design and implementation of an in‐body electromagnetic sensor for patients with implanted pacemakers. The sensor can either be mounted on myocardial tissue and monitor the electrocardiography (ECG) with contact electrodes or implanted under the skin and monitor the ECG with coaxial leads. A 16‐bit high‐resolution analog front‐end (AFE) and an energy‐efficient 32‐bit CPU are used for instantaneous ECG recording. Wireless data transmission between the sensor and clinician’s computer is achieved by an embedded low‐power Bluetooth transmitter. In order to automatically recognize the working status of the pacemaker and alarm the episodes of arrhythmias caused by pacemaker malfunctions, pacing mode classification and fault diagnosis on the recorded ECG were achieved based on an AI algorithm, i.e., a resource allocation network (RAN). A prototype of the sensor was implemented on a human torso, and the in vitro test results prove that the sensor can work properly for the 1‐4‐meter transmission range.