Low-voltage Electrocardiogram Research Articles

Improving pericardial effusion detection: evaluating sensitivity and specificity of traditional and novel ECG criteria

Abstract Funding Acknowledgements None. Introduction Historical studies have demonstrated that conventional low voltage criteria on ECG have high specificity but limited sensitivity in detecting pericardial effusion (PE). Indeed, an ECG showing low voltage can be indicative of several conditions, including PE. Purpose This study aimed to introduce new ECG criteria organized into a score called ARENA, to improve ECG diagnostic performance in detecting PE. Furthermore, we compared the sensitivity and specificity of traditional low voltage ECG criteria with the ARENA score using a test cohort. Methods This retrospective case-control study was conducted at our public University hospital from January 2022 to May 2023. Inclusion criteria were: age ≥18 years old, an available 12 lead ECG and an echocardiogram performed within 5 days from the recorded ECG. Exclusion criteria were: ventricular paced rhythm, heart transplantation, poor subcostal echocardiographic window. In the cohort of patients were selected: patients with ≥1.0 cm of PE on echocardiography and patients without effusion on echocardiography. ECG parameters were evaluated by two cardiologists blinded for the presence or absence of PE. Echocardiographic images were reviewed by an expert echocardiographer. Optimal ECG criteria with the highest ROC curve area were selected from the test cohort to develop the ARENA score. Patients were assessed using both traditional low voltage ECG criteria and the novel ARENA score. Statistical analysis showed that with 96 patients in the test cohort, there would be >90% power to detect a significant area under the curve (AUC) of 0.7 (vs. the null hypothesis of AUC of 0.5) to detect a moderate effect size. We used the AUC analysis to estimate the predicted performance of the proposed criteria. The McNemar test was used to assess the lack of agreement between the ECG criteria and the gold standard (echocardiography), and the results were reported as percentages with their respective 95% confidence intervals (CI). A p-value < 0.05 was considered statistically significant. Results The patient population consisted of 97 patients: 50 patients with PE, and 47 patients without it. The ARENA score showed a sensitivity of 52.0% (95% CI: 39.2% to 64.8%), compared to 14.0% (95% CI: 6.2% to 21.8%) of the traditional criteria. Specificity was 94% (95% CI: 84.1% to 100%) for ARENA Score and 100% (95% CI: 96.3% to 100%) for traditional criteria. Accuracy of the ARENA score was 70.0%, compared to 57% of the traditional criteria. The McNemar test indicated a p-value of <0.001 in the performance comparison. The AUC for the ARENA score was 0.781. Conclusion The novel ARENA score demonstrated an improved sensitivity while maintaining high specificity in detecting PE. This new score could become a valuable diagnostic tool for detecting PE by ECG in daily practice.ROC Curve ARENA ScoreECG criteria for pericardial effusion

ECG-only explainable deep learning algorithm predicts the risk for malignant ventricular arrhythmia in phospholamban cardiomyopathy

BackgroundPhospholamban (PLN) p.(Arg14del) variant carriers are at risk for development of malignant ventricular arrhythmia (MVA). Accurate risk stratification allows timely implantation of intracardiac defibrillators and is currently performed with a multimodality prediction model. ObjectiveThis study aimed to investigate whether an explainable deep learning–based approach allows risk prediction with only electrocardiogram (ECG) data. MethodsA total of 679 PLN p.(Arg14del) carriers without MVA at baseline were identified. A deep learning–based variational auto-encoder, trained on 1.1 million ECGs, was used to convert the 12-lead baseline ECG into its FactorECG, a compressed version of the ECG that summarizes it into 32 explainable factors. Prediction models were developed by Cox regression. ResultsThe deep learning–based ECG-only approach was able to predict MVA with a C statistic of 0.79 (95% CI, 0.76–0.83), comparable to the current prediction model (C statistic, 0.83 [95% CI, 0.79–0.88]; P = .054) and outperforming a model based on conventional ECG parameters (low-voltage ECG and negative T waves; C statistic, 0.65 [95% CI, 0.58–0.73]; P < .001). Clinical simulations showed that a 2-step approach, with ECG-only screening followed by a full workup, resulted in 60% less additional diagnostics while outperforming the multimodal prediction model in all patients. A visualization tool was created to provide interactive visualizations (https://pln.ecgx.ai). ConclusionOur deep learning–based algorithm based on ECG data only accurately predicts the occurrence of MVA in PLN p.(Arg14del) carriers, enabling more efficient stratification of patients who need additional diagnostic testing and follow-up.

Clinical profile of patients admitted with pericardial effusion in Shahid Gangalal National Heart Centre, Kathmandu, Nepal

Background and Aims: Pericardial effusion is a common finding in every day clinical practice. It is caused by a range of local and systemic disorders, many of which could be idiopathic. Pericardial effusions can be acute or chronic. The etiology of pericardial effusion varies in different parts of the world and is related to the relative prevalence of different diseases.&#x0D; Methods: This is a retrospective study where data from all the cases admitted with pericardial effusion in the SGNHC from January 2021 to December 2022 were included. Altogether 218 cases diagnosed with pericardial effusion established by Echocardiograpy were included. Evaluation for the cause of pericardial effusion was done. Iatrogenic (cardiac surgery, catheterization) and post-traumatic cases and age &lt;15 years were excluded. Demographic profile, common causes, the presentation and the clinical outcome of the patients were documented.&#x0D; Results: Majority of patients were aged between 56-75 years. Most common etiology of pericardial effusion was tuberculosis (56%) followed by heart failure (11%), Hypothyroidism (6.4%) and malignancy (5.6%). Tachycardia was the most common ECG finding in 152 (69.7%) followed by Low voltage ECG in 96 (44%). The most common clinical feature was breathlessness in 85% followed by tachycardia in 56% of the patient.&#x0D; Conclusion: Tuberculosis, Heart Failure and Hypothyroidism were the common causes of Pericardial effusion with male predominance. Breathlessness was the most common presenting symptom.

The phospholamban (PLN) p.Arg14del risk model; Longitudinal validation and reevaluation of predictors regarding sudden cardiac death (SCD)

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): PSIDER (ZOn-MW) PREDICT2 (Hartstichting) Background The PLN p.Arg14del risk model is a mutation-specific risk model developed to predict individual malignant ventricular arrhythmia (VA) risk to inform decision-making for primary prevention implantable cardioverter defibrillator (ICD) implantation. While the risk model has proven to be valid, two main points of criticisms remain to be discussed: first, the risk model is only validated at baseline and second, appropriate ICD therapy and sustained ventricular tachycardia (VT) &amp;lt;250 bpm is an imperfect surrogate outcome for SCD. Purpose To evaluate the diagnostic performance of the PLN p.Arg14del risk model longitudinal at 3 year follow-up and to reevaluate the predictors regarding SCD. Methods Clinical data of 278 PLN p.Arg14del mutation carriers with no history of malignant VA at both baseline and 3 year follow-up were collected. During a median follow-up of 4 years (Interquartile range (IQR) 1.8-6.5), 31 (11%) carriers experienced malignant VA, defined as sustained VA, appropriate ICD intervention, or (aborted) SCD. The reevaluation of the predictors with the 3 year follow up data revealed hazard ratio’s (HR) that were similar to the baseline PLN p.Arg14del risk model for left ventricular ejection fraction (HR 1.10 [95% CI, 1.06-1.12], p&amp;lt;0.001), low-voltage ECG (HR 12.24 [95% CI, 5.21-28.8], p&amp;lt;0.001) and the PVC count per 24h (HR 1.51 [1.15-1.98], p=0.003). The 5-year malignant VA risk was divided into tertiles of predicted risk. The tertiles clearly demonstrated good discrimination between risk group as shown in figure 1 and this resulted in an C-statistic of 0.85 (95% CI 0.78-0.92). To reevaluate the predictive performance of the PLN p.Arg14del risk model for a more strict surrogate of SCD we redefined the outcome as VT &amp;gt;250 beats per minute sustained (lasting ≥30 seconds) or terminated by ICD, ventricular fibrillation, aborted SCD and SCD. We included 669 PLN p.Arg14del carriers with no presentation or history of sustained VA or (aborted) SCD. During a median follow-up of 4.75 years (IQR 1.9-7.9), 33 (5%) carriers experienced the outcome. Results of the univariable analysis are shown in table 1. The PLN p.Arg14del risk model yielded a C-statistic of 0.75 (95% CI 0.70-0.80). Adding risk factors sex, age and sustained VT &amp;lt;250 bpm did not change its performance. Conclusion The PLN p.Arg14del risk model was validated longitudinal at 3 year follow-up and it held its performance with a more strict definition of SCD.

PO-05-202 FIRST DRAFT OF A NOVEL PLN P.ARG14DEL HEART FAILURE RISK MODEL TO POTENTIALLY AID PATIENT SELECTION FOR FUTURE GENE THERAPY.

Gene therapy is a rapidly developing treatment option that will alleviate heart disease by directly targeting pathophysiological mechanisms underlying hereditary heart disease. As it stands today, patient selection is focused on the early-stage, young patients with severe and lethal cardiomyopathies for whom other treatment options are lacking. Many severely affected PLN p.Arg14del carriers precisely fit in this characterization, but risk stratification is needed to select patients as this genetic cardiomyopathy is characterized by incomplete penetrance. To develop a prediction model for heart failure in PLN p.Arg14del carriers to help future patient selection for gene therapy. Data were collected of PLN p.Arg14del mutation carriers with no history or presentation of left ventricular ejection fraction (LVEF) <30%, heart failure hospitalization, left ventricular assist device (LVAD), heart transplantation (HTX) or heart failure (HF) death. The composite endpoint of HF included a LVEF <30%, hospitalization, LVAD, HTX or HF death. Cox regression was performed with lasso penalty for selection of covariates. Cross validation was used to select the penalty and predictors were chosen based on the number of events in a 10:1 ratio. Model performace was estimated using C-statistic. This study included 500 PLN p.Arg14del carriers, aged 39.7 ± 16 years and 42.8% male. During a median follow-up of 6 years (Interquartile range 2.9-9.2) after first MRI, 43 (8.6%) carriers experienced a composite endpoint of HF. We included atrial fibrillation (HR 2.31 [95% CI, 1.57-3.04]; p=0.064), NYHA class ≥2 at presentation (HR 2.74 [95% CI, 1.83-3.65], p=0.037), low-voltage ECG (HR 1.70 [95% CI, 0.99-2.41], p=0.15) and late gadolinium enhancement on MRI (HR 2.18 [95% CI, 1.40-2.97], p=0.064) in the final multivariable Cox regression model. The 5-year risk for HF was calculated for each carrier, after which the cohort was divided into two risk groups. Carriers in the high risk group had one or more risk factors and experienced most events and carriers in the low risk group experienced the least events. This resulted in a C-statistic of 0.76 (95% CI, 0.67-0.85). It should be noted, however, that the number needed to treat at 5 year is still 20 and only after 9 years its declines towards 6 in the high risk group. This is the first outline of a novel PLN p.Arg14del risk prediction model for heart failure to potentially aid patient selection for gene therapy in the future when validated.

Global Longitudinal Strain Is Associated with Mortality in Patients with Multiple Myeloma.

Patients with multiple myeloma (MM) are at a high risk for developing cardiovascular complications. Global longitudinal strain (GLS) can detect early functional impairment before structural abnormalities develop. It remains unknown if reduced GLS is associated with reduced survival in patients with MM. We conducted a retrospective cohort analysis of patients diagnosed with MM between 1 January 2000 and 31 December 2017 at our institution. Patients with a 2D transthoracic echocardiogram completed within 1 year of MM diagnosis, left ventricular ejection fraction (LVEF) greater than 40%, and no history of myocardial infarction prior to MM diagnosis were included. GLS was measured using an artificial-intelligence-powered software (EchoGo Core), with reduced GLS defined as an absolute value of <18%. The primary outcome of interest was overall survival since myeloma diagnosis. Our cohort included 242 patients with a median follow up of 4.28 years. Fifty-two (21.5%) patients had reduced average GLS. Patients with reduced GLS were more likely to have an IVSd ≥ 1.2cm, E/E' > 9.6, LVEF/GLS > 4.1, higher LV mass index, and low-voltage ECG. A Total of 126 (52.1%) deaths occurred during follow-up. Overall survival was lower among patients with reduced GLS (adjusted HR: 1.81, CI: 1.07-3.05).

Abstract 9814: Clinical Characteristics and Outcomes in Patients With Congestive Heart Failure and Low Voltage 12-Lead Ecg

Background: Low voltage ECG (LowV-ECG) pattern is defined as a peak-to-peak QRS amplitude of less than 5mm in the limb leads and/or less than 10mm in the pericardial leads. It can occur in many cardiac conditions associated with congestive heart failure (CHF), such as ischemic cardiomyopathy (ICM), cardiac amyloidosis (CA), hemochromatosis (HC), and hypothyroidism (HT). The clinical significance of LowV-ECG abnormalities in CHF patients has not been well investigated. Methods: Clinical, echocardiographic, and ECG data was collected in 460 consecutive CHF patients with non-V-paced rhythms enrolled over 2 years in the Get With the Guidelines Heart Failure (GWG-HF) registry at a single academic tertiary center. ECGs were reviewed for the presence of low QRS voltage and additional ECG features classically reported in ICM, CA, HC, and HT. Results: LowV-ECG was noted in 8.5% patients (39/460) of the study cohort, and was more common in females, 11.6% (25/216) vs. 5.7% (14/244) in males, p=0.025. LowV-ECG patients had increased BMI (34.9+/-12.8 vs. 31.1+/-9 kg/m2, p=0.016) and more commonly had a history of DM (12.2% vs.5.5%, p=0.01). There were no significant differences in age, GFR, or presence of CAD, hypertension or Afib. Prevalence of HFrEF, HFmrEF, and HFpEF in patients with LowV-ECG was 6.8, 10, and 9.8%, respectively, p=0.506. With regards to the ECG features typically associated with cardiac amyloidosis, poor R-wave progression was more common in LowV-ECG patients, 41% (16/39) vs.13.5% (57/421) in the rest of the cohort, p&lt;0.001, but there was no significant difference in prevalence of pseudo-infarct pattern, 15.4% (6/39) vs. 10.5% (44/421), p=0.344, or in prevalence of LBBB or incomplete LBBB or non-specific IVCD, 15.4% (6/39) vs. 17.3% (73/421), p=0.164. After 70.7+/-25.2 months follow-up, Low-V ECG was not associated with increased mortality (12.8% vs. 20.4%, p=0.253). Rates of 30, 60, and 90-day readmissions were not increased. Conclusions: Among patients admitted with a CHF diagnosis, low voltage ECG pattern was more commonly seen in females, overweight patients, and in patients with diabetes. Low voltage ECG patients did not display additional ECG features typical of cardiac amyloidosis and did not experience adverse short- or long-term outcomes.

Abstract 12434: ECG-Only Deep Learning Algorithm Predicts Risk of Arrhythmia in Phospholamban Cardiomyopathy

Introduction Phospholamban (PLN) p.Arg14del mutation carriers are at risk of developing arrhythmogenic cardiomyopathy, but phenotypic penetrance is incomplete and much interpatient variability exists in the risk of malignant ventricular arrhythmias (MVA). Accurate risk stratification allows for timely device implantation which may prevent sudden cardiac death (SCD). The current prediction model is multimodal and uses data from ECG, echocardiography, MRI and 24-hour Holter monitoring. Hypothesis We hypothesized that a deep learning-based approach may allow for accurate risk prediction using only 12-lead ECG data. Methods A total of 679 PLN p.Arg14del mutation carriers without MVA at baseline were identified. MVA was defined as sustained VA, appropriate ICD intervention or (aborted) SCD. Prediction models were developed using Cox regression and validated using a bootstrap-based optimism corrected area under the receiver operating curve (AUC). A deep learning-based variational auto-encoder, trained on 1.1 million ECGs, was used to convert the median beat baseline ECG into its FactorECG. The FactorECG is a compressed version of the ECG which summarizes it into 21 explainable factors. Seven ECG factors that were previously shown to be associated with reduced ejection fraction were included in the model. A comparison to conventional ECG parameters and the current prediction model was performed. Results The deep learning-based ECG-only approach was able to predict MVA in PLN mutation carriers with an AUC of 0.82 [95% CI 0.78 - 0.86], comparable to the current multimodal prediction model (AUC 0.84 [95% CI 0.80 - 0.88]) and outperforming a model based on conventional ECG parameters (low voltage ECG and negative T waves; AUC 0.66 [95% CI 0.59 - 0.73]). Conclusions In conclusion, our deep learning-based algorithm uses only ECG data to accurately predict the occurrence of MVA in PLN mutation carriers, which could allow for easier stratification of patients at risk.

Relative apical sparing in severe aortic stenosis: does it mean concomitant amyloid cardiomyopathy?

Abstract Background Relative apical sparing (RAS) of left ventricular (LV) longitudinal strain (LS) is a red flag marker for the suspicion of amyloid cardiomyopathy. However, it has also been described in patients with severe aortic stenosis (AS). Aim To assess the prevalence of RAS in patients with severe symptomatic AS referred for surgical aortic valve replacement (AVR), to evaluate its clinical significance and assess its presence after surgery. Methods We prospectively studied 135 consecutive patients (age: 73 y [IQR 68–77 y], 49% men) with severe symptomatic AS – mean transaortic pressure gradient (AVmean): 60.9±17.7 mmHg; mean aortic valve area: 0.7±0.2 cm2, referred for surgical AVR with no previous history of ischemic cardiomyopathy or other. Beyond 12 lead-ECG and transthoracic echocardiography (TTE), all patients underwent cardiac magnetic resonance (CMR) before surgery. RAS was defined by the ratio &amp;gt;1 of average LS at apical segments/sum of the average basal and mid LS at speckle tracking analysis. AVR with septal myocardial biopsy, for investigational purposes, was performed in 80 patients. AS severity indexes, LV remodeling and tissue characterization parameters were compared in both groups of patients, with and without RAS. LS deformation pattern was reassessed at 3–6 months after AVR. Results RAS was present in 24 patients (18%). In the whole cohort there were neither pseudoinfarct pattern or low voltage ECG criteria, nor infiltration suspicion from CMR (native T1 value 1053 ms [IQR 1025–1071 ms] for institutional reference values: 972–1070 ms; ECV 24% [IQR 21–27%]). None of the patients had amyloid deposition at histopathology. Overall, mean CMR LV ejection fraction (LVEF) was 59.6±10.5% and 98 patients (74%) had non-ischemic delayed enhancement, with a median fibrosis fraction of 4.1% [IQR 1.6–7.8%]. RAS cohort had a significantly higher AVmean gradient, relative wall thickness, maximum septal thickness, peak systolic dispersion, with lower global LS at TTE, as well as higher LV mass and lower LVEF at CMR. RAS group has also higher NT-proBNP ambulatory values (Table 1). Follow-up evaluation after AVR revealed RAS disappearance in 19 patients (79.2%). Conclusions RAS occurs in almost one-fifth of the patients in this cohort despite the absence of signs of myocardial infiltration. This deformation pattern elapses with worse indexes of LV remodeling consistent with a more advanced stage of the disease, being reversible after AVR, which stands for the absence of concomitant myocardial infiltration. Funding Acknowledgement Type of funding sources: None.

Longitudinal validation of the phospholamban (PLN) p.Arg14del risk model

Abstract Background/Introduction Recently, a variant-specific prediction model for PLN p.Arg14del variant carriers was developed to predict individual malignant ventricular arrhythmia (VA) risk to inform decision-making for primary prevention implantable cardioverter defibrillator (ICD) implantation. This model predicts malignant VA risk from data at diagnosis, but iterative evaluation of malignant VA risk may be warranted considering that the risk factors for malignant VA are progressive. Purpose To evaluate the diagnostic performance of the PLN p.Arg14del risk model. Methods/Results Date were collected of 278 PLN p.Arg14del variant carriers at 3 year follow-up. This was considered the new baseline for the survival analysis. Patients with history of malignant VA at both baseline and during the first 3 years after baseline were excluded. At 3 year patients were aged 40.1±18.0 year and 40.7% was male. Median left ventricular ejection fraction (LVEF) was 53% and percentage with microvoltages was 10.3. During a median follow-up of 4 years (Interquartile range 1.8–6.5) 31 (11%) carriers experienced malignant VA, defined as sustained VA, appropriate ICD intervention, or (aborted) sudden cardiac death. Reevaluation of the predictors with the 3 year follow-up data revealed hazard rates that were similar to those in the original PLN p.Arg14del risk model; LVEF per 1% decrease (hazard ratio (HR) 1.10 [95% confidence interval (CI), 1.06–1.12]; p&amp;lt;0.001), premature ventricular contraction count/24h (HR 1.51 [95% CI, 1.15–1.98]; p=0.003) and the presence of low-voltage electrocardiogram (HR 12.24 [95% CI, 5.21–28.8); p&amp;lt;0.001). Negative T waves did not remain significant as a predictor. The 5-year malignant VA risk was calculated for each variant carrier, after multiple imputation for dealing with incomplete cases, by applying the PLN p.Arg14del risk model to the 3 year follow-up data. Afterwards the cohort was divided into tertiles of predicted risk. This clearly demonstrated the lowest risk tertile having a low malignant VA rate and the highest risk tertile having a high malignant VA rate, which resulted in an optimism-corrected C-statistic of 0.85 (95% CI 0.78–0.92). Conclusion The PLN p.Arg14del risk model is valid at 3 year follow-up in PLN p.Arg14del variant carriers with no history of malignant VA and can therefore be used to inform decision-making for primary prevention ICD implantation not merely at diagnosis, but also during follow-up and can be seen as a type of validation in a cohort where no other large cohort is present to perform external validation. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): 1. PSIDER: From pluripotent stem cells to prime editing gene therapy for inheritedcardiomyopathies. ZOn-MW.2. PREDICT2: Predicting sudden cardiac arrest. The Dutch Heart Foundation.

Clinical Presentation, Complications and Early Predictors for Poor Outcomes in Pediatric Myocarditis in a Tertiary Care Hospital

Objective: To evaluate common clinical presentation, complications and poor prognostic outcomes in children with acute myocarditis.&#x0D; Study Design: Prospective longitudinal study.&#x0D; Place and Duration of Study: Pediatric Cardiology Department, National Institute of Cardiovascular Disease Karachi Pakistan, from Feb to Aug 2020.&#x0D; Methodology: The children aged one month to 16 years were included in the study. Clinical, demographic features, Electrocardiogram, Echocardiography, management, complications, and immediate outcomes were recorded.&#x0D; Results: The total number of patients enrolled was 161. The median age was 5.01 ± 3.38 years for 66.4% of males and 33.5% females, mean Duration of symptoms was 8.35 ± 3.49 days. Upper respiratory tract infection was present in 84 (52.2%) and diarrhea in 8 (5%) in the preceding illness. Symptoms and signs include loss of appetite in 153 (96.27%), irritability in 148 (91.9%), vomiting in 132 (82%) and abdominal pain in 112 (69.6%), tachycardia in 148 (91.9%) and pallor in 143 (88.8%). Low voltage ECG was present in 125 (77.6%), arrhythmias in 12 (7.45%) and heart block in 6 (3.7%). Left ventricle end-diastolic dimensions (LVIDD)&gt;4SD were present in 30.2% and LV end-systolic dimensions (LVIDS)&gt;4SD in 19.5%, Left ventricular ejection fraction (LVEF)mean was 21.13 ± 5.07 vs 23.45 ± 3.31 at discharge. 9.21% of patients expired, out of which 78.5% had Left bundle branch block (LBBB), mean LVEF was 16.24 ± 3.16, LVID d&gt;4SD in 78%, and LVIDs&gt;4SD in 30%.&#x0D; Conclusion: The most frequent presentations were loss of appetite, difficulty breathing, irritability and abdominal pain. Tachycardia and pallor were......

Sex-specific aspects of phospholamban cardiomyopathy: The importance and prognostic value of low-voltage electrocardiograms.

A pathogenic variant in the gene encoding phospholamban (PLN), a protein that regulates calcium homeostasis of cardiomyocytes, causes PLN cardiomyopathy. It is characterized by a high arrhythmic burden and can progress to severe cardiomyopathy. Risk assessment guides implantable cardioverter-defibrillator therapy and benefits from personalization. Whether sex-specific differences in PLN cardiomyopathy exist is unknown. The purpose of this study was to improve the accuracy of PLN cardiomyopathy diagnosis and risk assessment by investigating sex-specific aspects. We analyzed a multicenter cohort of 933 patients (412 male, 521 female) with the PLN p.(Arg14del) pathogenic variant following up on a recently developed PLN risk model. Sex-specific differences in the incidence of risk model components were investigated: low-voltage electrocardiogram (ECG), premature ventricular contractions, negative T waves, and left ventricular ejection fraction. Sustained ventricular arrhythmias (VAs) occurred in 77 males (18.7%) and 61 females (11.7%) (P = .004). Of the 933 cohort members, 287 (31%) had ≥1 low-voltage ECG during follow-up (180 females [63%], 107 males [37%]; P = .006). Female sex, age, age at clinical presentation, and proband status predicted low-voltage ECG during follow-up (area under the curve: 0.78). Sustained VA-free survival was lowest in males with low-voltage ECG (P <.001). Low-voltage ECGs predict sustained VA and are a component of the PLN risk model. Low-voltage ECGs are more common in females, yet prognostic value is greater in males. Future studies should determine the impact of this difference on the risk prediction of PLN cardiomyopathy and possibly other cardiomyopathies.

A descriptive report on short QT interval in Kherameh branch of the PERSIAN cohort study

Short QT-interval is a condition that bear the suspicion of short QT syndrome (SQTS). SQTS is known to increase risk of life-threatening arrythmias and sudden cardiac death (SCD). Due to the insufficient population-based studies and use of various QT cut-off values, it accounts for as an undiagnosed condition. In this study, we sought for prevalence of short QT interval in Kherameh cohort study, one of the southern branches of the Prospective Epidemiological Research Studies in Iran (PERSIAN). Data of 4363 adult subjects were analyzed from phase 1 of the cohort during 2014–2017. The corrected QT (QTc) intervals were calculated and electrocardiograms (ECGs) with QTc of less than 370 ms (msec) were reanalyzed for bradycardia, early repolarization, atrial fibrillation (AF), arrhythmias, and other electrical conduction abnormalities. Seventy-two subjects (1.65%) had a QTc of less than 370 ms (mean QTc of 360.72 ± 11.72). A male predominance and a lower mean heart rate observed in SQTS susceptible group (M/F of 1/0.26 vs. 1/1.145, p-value < 0.0001; 58.389 ± 9.787 vs. 70.899 ± 11.775; p-value < 0.0001) compare to the subjects with normal QTc. At least, 2 subjects with high-probability SQTS and 3 with intermediate-probability SQTS identified. The frequency of AF, syncope, bradycardia, early repolarization, low voltage ECG, and infantile SCD in first- and second-degree relatives were 16.67, 4.17, 33.33, 11.11, 11.11, 11.11%, respectively. The prevalence of short QT interval in our cohort was in line with previous studies. The incidence of cardiac symptoms/events, familial SCDs and ECG derived specific findings were high amongst SQTS-susceptible index persons. However, these variables could not predict the symptomatic subjects, which emphasizes gene studies and family screening.

OR47. Index of Cardiac Electrophysiological Balance (iCEB) in Patients with COVID-19

AimsWe aimed to examine whether there is abnormal value of index of cardiac electrophysiological balance (iCEB=QT/QRS) in patients with confirmed coronavirus disease 2019 (COVID-19), which can predict ventricular arrhythmias (VAs), including non-Torsades de Pointes-like ventricular tachycardia/ventricular fibrillation (non-TdPs-like VT/VF) in low iCEB and Torsades de Pointes (TdPs) in high iCEB. We also investigated low voltage ECG among COVID-19 group.Methods and ResultsThis is a cross-sectional, single center study with a total of 53 newly diagnosed COVID-19 patients (confirmed with polymerase chain reaction (PCR) test) and 63 age and sex-matched control subjects were included in the study. Electrocardiographic marker of iCEB were calculated manually from 12-lead ECG. Low voltage ECG defined as peak-to-peak QRS voltage less than 5 mm in all limb leads and less than 10 mm in all precordial leads. Patients with COVID-19 more often had low iCEB, defined as iCEB below 3.24 compared to control group (56.6% vs 11.1%), (OR = 10.435; 95%CI 4.015 – 27.123; p = 0.000). There were no significant association between COVID-19 and high iCEB, defined as iCEB above 5.24 (OR = 1.041; 95%CI 0.485 – 2.235; p = 0.917). There were no significant difference of the number of low voltage ECG between COVID-19 and control groups (15.1% vs 6.3%), (OR = 2.622; 95%CI 0.743 - 9.257, p = 0.123).ConclusionIn this study showed that patients with COVID-19 are more likely to have low iCEB, suggesting that patients with COVID-19 may be proarrhytmic (towards non-TdPs-like VT/VF event), due to the alleged myocardial involvement in SARS-CoV-2 infection.

C19. Cardiac Amyloidosis: A Great Pretender of Left Ventricular Hypertrophy with Systemic Manifestation

Abstract Background Systemic amyloidosis encompasses an underdiagnosed disorder characterized by the extracellular deposition of amyloid in one or more organs, including the heart. The therapeutic strategy depends on the characterization of amyloid protein type and the extent of the disease. When founding a pathological left ventricular hypertrophy, initial clues provided by electrocardiography and echocardiography combined with other clinical manifestations could support a suspicion of cardiac amyloidosis. Case Summary A 54-year-old male patient was repeatedly admitted to a local hospital for recurrent heart failure and refractory bilateral pleural effusions of unknown cause. There was intolerance of any heart failure medications and repeated thoracocentesis failed to control the pleural effusion. The echocardiogram revealed severely impaired left ventricular function with phenotypic overlap between hypertrophic and restrictive cardiomyopathy. In contrast, we found a low voltage electrocardiogram. After an extensive diagnostic workup, including speckle tracking echocardiography, cardiac magnetic resonance, serum immunofixation and free light chain, bone marrow biopsy, and also Congo Red staining for amyloid, the final diagnosis was light chain (AL) amyloidosis. Discussion Cardiac involvement in systemic amyloidosis is the leading cause of morbidity and mortality. Frequently, myocardial wall thickening is incorrectly referred to as hypertrophy which may potentially lead to the wrong diagnosis and therapy. However, a need remains for improved awareness and expertise, while a multidisciplinary approach is important in making the correct diagnosis and management of this debilitating disease.

C19. Cardiac Amyloidosis: A Great Pretender of Left Ventricular Hypertrophy with Systemic Manifestation

Abstract Background Systemic amyloidosis encompasses an underdiagnosed disorder characterized by the extracellular deposition of amyloid in one or more organs, including the heart. The therapeutic strategy depends on the characterization of amyloid protein type and the extent of the disease. When founding a pathological left ventricular hypertrophy, initial clues provided by electrocardiography and echocardiography combined with other clinical manifestations could support a suspicion of cardiac amyloidosis. Case Summary A 54-year-old male patient was repeatedly admitted to a local hospital for recurrent heart failure and refractory bilateral pleural effusions of unknown cause. There was intolerance of any heart failure medications and repeated thoracocentesis failed to control the pleural effusion. The echocardiogram revealed severely impaired left ventricular function with phenotypic overlap between hypertrophic and restrictive cardiomyopathy. In contrast, we found a low voltage electrocardiogram. After an extensive diagnostic workup, including speckle tracking echocardiography, cardiac magnetic resonance, serum immunofixation and free light chain, bone marrow biopsy, and also Congo Red staining for amyloid, the final diagnosis was light chain (AL) amyloidosis. Discussion Cardiac involvement in systemic amyloidosis is the leading cause of morbidity and mortality. Frequently, myocardial wall thickening is incorrectly referred to as hypertrophy which may potentially lead to the wrong diagnosis and therapy. However, a need remains for improved awareness and expertise, while a multidisciplinary approach is important in making the correct diagnosis and management of this debilitating disease.

Breast Implants in A Woman Associated With Low-Voltage Electrocardiogram (ECG)

Breast Implants (BIs) in women are associated with several Electrocardiogram (ECG) modifications. However, the association between BIs and low-voltage ECG has not been reported yet. A 44-year-old woman with a history of breast implant surgery visited our outpatient cardiology clinic complaining of atypical chest pain. A standard ECG showed low voltage in all precordial and most of the limb leads. Physical examination and echocardiography showed no pathology. Nothing other than BIs was found as a cause of low-voltage ECG in the woman. Breast implant-induced ECG modification can mislead clinicians resulting in diagnostic challenges and unnecessary tests. Low-voltage ECG is one of the modifications associated with BIs, which has not been reported before. A large prospective study is required to investigate the impacts of BIs on ECG thoroughly.

Prediction of ventricular arrhythmia in phospholamban p.Arg14del mutation carriers-reaching the frontiers of individual risk prediction.

AimsThis study aims to improve risk stratification for primary prevention implantable cardioverter defibrillator (ICD) implantation by developing a new mutation-specific prediction model for malignant ventricular arrhythmia (VA) in phospholamban (PLN) p.Arg14del mutation carriers. The proposed model is compared to an existing PLN risk model.Methods and resultsData were collected from PLN p.Arg14del mutation carriers with no history of malignant VA at baseline, identified between 2009 and 2020. Malignant VA was defined as sustained VA, appropriate ICD intervention, or (aborted) sudden cardiac death. A prediction model was developed using Cox regression. The study cohort consisted of 679 PLN p.Arg14del mutation carriers, with a minority of index patients (17%) and male sex (43%), and a median age of 42 years [interquartile range (IQR) 27–55]. During a median follow-up of 4.3 years (IQR 1.7–7.4), 72 (10.6%) carriers experienced malignant VA. Significant predictors were left ventricular ejection fraction, premature ventricular contraction count/24 h, amount of negative T waves, and presence of low-voltage electrocardiogram. The multivariable model had an excellent discriminative ability {C-statistic 0.83 [95% confidence interval (CI) 0.78–0.88]}. Applying the existing PLN risk model to the complete cohort yielded a C-statistic of 0.68 (95% CI 0.61–0.75).ConclusionThis new mutation-specific prediction model for individual VA risk in PLN p.Arg14del mutation carriers is superior to the existing PLN risk model, suggesting that risk prediction using mutation-specific phenotypic features can improve accuracy compared to a more generic approach.

Low voltage ECG as a diagnostic criterion of postcanulation pneumothorax after pacemaker implantation

A case of post-puncture pneumothorax is presented, which complicated the pacemaker implantation, proceeding with an unclear clinical picture that was revealed solely due to a decrease in the voltage of the postoperative electrocardiogram.

A novel electrocardiogram characteristic in patients with myocardial injury due to COVID-19

Background: Coronavirus disease of 2019 (COVID-19) is a respiratory disease which can lead to cardiovascular complications including myocarditis, myocardial infarction, and heart failure. Electrocardiogram (ECG) may change in patients with COVID-19 with or without heart involvement. In this study, the ECG changes were evaluated in myocardial injuries due to COVID-19. Methods: This study was done on 22 COVID-19 patients with ST segment elevation in ECG and high troponin level. COVID-19 was confirmed using reverse-transcription polymerase chain reaction test. The ECG variables were evaluated by an expert cardiologist. Statistical analyses were carried out on ECG variables where the significance level of 0.05 was assigned. Results: Of 22 patients, 17 cases (77.3%) were male and 6 cases (27.3%) had a history of coronary artery disease. The most common myocardial involvement was extensive anterior type (31.8%), followed by anterior type (22.7%). Sinus rhythm was observed in 95.5% of patients and 54.5% had low voltage ECG in limb leads. No significant correlation was found between low voltage ECG and demonstrable etiologies of low voltage. Conclusion: The prevalence of low voltage ECG was significantly high in limb leads of patients with myocardial injury due to COVID-19 which was considerably greater than that of myocarditis or myocardial infarction patients.