QRS Complex Research Articles

Correlation of serum zinc and magnesium with reduced heart rate variability in male Parkinson’s disease patients

Background: Parkinson’s disease (PD) is a neurological disorder associated with altered cardiac autonomic function. Heart rate variability (HRV) analysis is a tool to assess the cardiac autonomic status. Altered serum zinc (Zn) and magnesium (Mg) levels are observed in PD. The serum Zn and Mg alteration is associated with nerve function impairment. Objective: To evaluate the relationship between serum zinc, magnesium, and time domain measures of HRV in male patients with PD. Methods: This observational analytical cross-sectional study was conducted in 2023on 30 newly diagnosed male PD patients aged 50-60 years. In this study, 30 healthy volunteers were the control. The 30 patients were divided into different categories based on serum mineral levels. The HRV was recorded by Power Lab 8/35, AD Instruments, Australia and the time domain measures of HRV were used in data analysis. The serum Zn and Mg levels were measured by atomic absorption spectrophotometry. Independent sample ‘t’ test and Pearson’s correlation coefficient test were used for statistical analysis and p<0.05 was considered statistical significance. Results: Significantly higher mean HR (Heart rate) (p<0.01) and significantly lower mean RR (Normal to normal QRS complex) interval,CVRR (Coefficient variation of RR interval) (p<0.01), SDRR (Standard deviation of the RR intervals), SDSD (Standard deviation of the difference between successive RR intervals), RMSSD (Square root of mean squared differences of successive RR intervals), pRR50% (Proportion of RR interval with duration >50 ms) (p<0.001)were observed in PD patients compared to control. In PD patients, significantly lower (p<0.001) serum Zn and significantly higher (p<0.01) serum Mg were observed compared to control. In addition,significant decrement was observed in SDRR, CVRR (p<0.05), SDSD, RMSSD, and pRR50% (p<0.01) in hypozincemic PD patients compared to normozincemic patients. On correlation analysis, significant positive correlations of serum Zn were observed with SDRR (p<0.05),SDSD (p<0.001), RMSSD (p<0.001) and pRR50% (p<0.01). Moreover,serum Mg was positively correlated with SDRR (p<0.05) in PD patients. Conclusion: Hypozincemia and magnesium were directly related to reduced HRV in male PD patients. J Bangladesh Soc Physiol 2023;18(2): 63-71

ELECTRICAL CARDIAC REMODELING IN MEN WITH ARTERIAL HYPERTENSION AFFECTED BY PSORIASIS VULGARIS

Psoriasis and arterial hypertension are often observed in men of working age. Biologically active molecules such as insulin-like growth factor, vascular endothelial growth factor (VEGF), etc. play a significant role in the pathogenesis of these diseases. These factors contribute to cardiac remodeling, which is one of the arrhythmogenic substrates. The aim of the study was a comprehensive assessment of electrical cardiac parameters in male patients suffering from arterial hypertension affected by psoriasis vulgaris. Materials and Methods. The study was conducted in 2021–2023. It involved 110 male patients undergoing outpatient treatment for stage 2 arterial hypertension. Their average age was 52.4±6.9 years. The patients were divided into 2 groups: Group 1 (comparison) – 50 patients with arterial hypertension; Group 2 (control) – 60 patients with hypertension and psoriasis vulgaris in the progressive moderate severity stage (PASI index between 10 and 20). Results. In males with arterial hypertension affected by psoriasis vulgaris, late ventricular potentials were statistically significantly more common (33 %) compared to those with arterial hypertension without psoriasis (16 %) (χ²=4.32; p=0.048). In patients with both arterial hypertension and psoriasis, a greater number of local peaks in the ventricular complex along all Frank orthogonal leads were registered in spectral-temporal mapping of the QRS complex. Conclusion. The concomitant psoriasis vulgaris in males with arterial hypertension negatively effects the parameters of cardiac electrical remodeling.

Comparison of pathological electrocardiographic changes between long-term kidney transplant recipients and hemodialysis patients

Aims: We aimed to reveal electrocardiographic changes in kidney transplant recipients (KTRs) compared with hemodialysis patients. Methods: We included 70 KTRs who had underwent a kidney transplantation for more than one year and 84 patients who had been on hemodialysis for more than one year. We recorded age, sex, body-mass index (BMI) (kg/m2), primary disease (makes chronic kidney disease) and duration of hemodialysis treatment. Standard measurements such as heart rate (HR), P wave, PR interval, P axis, QRS complex, QRS axis, T axis, QT interval and QTc interval were performed for all electrocardiography (ECG). Results: KTRs were younger than the hemodialysis patients group (HPG) (31.5 vs. 54.5, p

Electrocardiographic Patterns and Arrhythmias in Cardiac Amyloidosis: From Diagnosis to Therapeutic Management-A Narrative Review.

Electrophysiological aspects of cardiac amyloidosis (CA) are still poorly explored compared to other aspects of the disease. However, electrocardiogram (ECG) abnormalities play an important role in CA diagnosis and prognosis and the management of arrhythmias is a crucial part of CA treatment. Low voltages and a pseudonecrosis pattern with poor R-wave progression in precordial leads are especially common findings. These are useful for CA diagnosis and risk stratification, especially when combined with clinical or echocardiographic findings. Both ventricular and supraventricular arrhythmias are common in CA, especially in transthyretin amyloidosis (ATTR), and their prevalence is related to disease progression. Sustained and non-sustained ventricular tachycardias' prognostic role is still debated, and, to date, there is a lack of specific indications for implantable cardiac defibrillator (ICD). On the other hand, atrial fibrillation (AF) is the most common supraventricular arrhythmia with a prevalence of up to 88% of ATTR patients. Anticoagulation should be considered irrespective of CHADsVA score. Furthermore, even if AF seems to not be an independent prognostic factor in CA, its treatment for symptom control is still crucial. Finally, conduction disturbances and bradyarrhythmias are also common, requiring pacemaker implantation in up to 40% of patients.

Analyzing the impact of transfer learning on explanation accuracy in deep learning-based ECG recognition systems

Abstract Electrocardiogram (ECG) recognition systems now play a leading role in the early detection of cardiovascular diseases. However, the explanation of judgments made by deep learning models in these systems is prominent for clinical acceptance. This article reveals the effect of transfer learning in ECG recognition systems on decision precision. This article investigated the role of transfer learning in ECG image classification using a customized convolutional neural network (CNN) with and without a VGG16 architecture. The customized CNN model with the VGG16 achieved a good test accuracy of 98.40%. Gradient-weighted class activation mapping (Grad-CAM), for this model, gave the wrong information because it focused on parts of the ECG that were not important for making decisions instead of features necessary for clinical diagnosis, like the P wave, QRS complex, and T wave. A proposed model that only used customized CNN layers and did not use transfer learning performed 99.08% on tests gave correct Grad-CAM explanations and correctly identified the influencing areas of decision-making in the ECG image. Because of these results, it seems that transfer learning might provide good performance metrics, but it might also make things harder to understand, which could make it harder for deep learning models that use ECG recognition to be reliable for diagnosis. This article concludes with a call for careful consideration when using transfer learning in the medical field, as model explanations resulting from such learning may not be appropriate when it comes to domain-specific interpretations.

ECG Biometric Verification Incorporating Different Physiological Conditions

The liveness detection criteria of biological signals have become one of the reasons it has been introduced as an ideal biometric recognition system. Electrocardiogram (ECG) is one of the biological signals that records the rhythms of human’s heart in the form of PQRST waves proves the uniqueness of the ECG itself making it suitable to be applied as biometric mechanisms. Previous research had shown the success of proving ECG as a biometric modality however most experimentations were done in normal conditions. Thus, to improve the current research, this work proposed a robust biometric identification by introducing ECG signals incorporating various physiological conditions. After the data collection of cycling, walking, climbing stairs, and jogging, the signals are pre-processed by using MODWT to remove unwanted noises produced during data collection process. Then, Pan Tompkins algorithm is used to segment the QRS complexes. The segmented signals are overlapped and align with each other to observe its pattern. Next, the QRS waveform is classified by using various class of SVM by considering two factors which are same physiological conditions and different physiological conditions. The subjects are compared between same and different physiological condition to validate the proposed method. The results show that the precision achieved up to 100%. In average, Gaussian SVM gives highest precision when compared to other type of SVM classifiers suggesting that Gaussian SVM is the most appropriate to be applied for person identification. Thus, the proposed method proves that biometric recognition can be performed regardless of different physiological conditions and can be applied in real life scenarios.

Causal relationship between Brugada syndrome and electrocardiogram traits: A bidirectional Mendelian randomization study

IntroductionObservational studies have suggested associations between Brugada syndrome (BrS) and electrocardiograms traits. Nonetheless, the causal relationships remains uncertain in observational studies. This study aims to investigate the causal relationships between BrS phenotypic risk and electrocardiogram traits using Mendelian randomization (MR) analysis and colocalization analysis. MethodsMR analysis was performed to investigate the causal relationships between BrS phenotype risk and electrocardiogram traits (P wave duration, PR interval, QRS wave duration, ST segment duration, T wave duration, QT interval, heart rate (HR) and heart rate variability). The genetic instruments for BrS (number of cases = 12,821) were obtained from the latest GWAS. GWAS summary data of electrocardiogram traits were obtained from the MRC-IEU and GWAS catalog databases. The causal relationships were obtained through MR methods, and sensitivity analyses (e.g. Cochran's Q test, MR-PRESSO). Furthermore, the causal relationships were evaluated whether they were driven by one linkage disequilibrium using colocalization analysis. ResultsWe found that there are positive causal relationships between BrS phenotypic risk and P wave duration, PR interval, QRS wave duration and QT interval, respectively (IVWP: β = 1.238, 95 % CI = 0.857–1.619, P<0.001; IVWPR: β = 2.199, 95 % CI = 1.358–3.039, P<0.001; IVWQRS: β = 0.157, 95 % CI = 0.115–0.198, P<0.001; IVWQT: β = 0.593, 95 % CI = 0.391–0.796, P<0.001), and there is a negative causal relationship between BrS phenotypic risk and heart rate (IVWHR: β = −0.023, 95 % CI = −0.03 ∼ −0.015, P<0.001). Additionally, there are bidirectional causal relationships between BrS phenotypic risk and P wave duration and PR interval, respectively (IVWP: OR = 1.217, 95 % CI = 1.118–1.325, P<0.001; IVWPR: OR = 1.02, 95 % CI = 1.008–1.032, P = 0.001). Furthermore, colocalization analysis identified that the causal relationships between BrS phenotype risk and P wave duration, PR interval and QRS wave duration were driven by rs6790396, rs6801957 and rs6801957, respectively. ConclusionsBidirectional causal relationships were identified between BrS phenotypic risk and P wave duration and PR interval, respectively. There were positive causal relationships between BrS phenotypic risk and QRS wave duration and QT interval, respectively, and there is a negative causal relationship between BrS phenotypic risk and heart rate.

A case of “regularly irregular” tachycardia with wide and narrow QRS complexes

A case of “regularly irregular” tachycardia with wide and narrow QRS complexes

Patient Health Monitoring Using Fibrillation Detection in Electrocardiogram Signal

Fibrillation (Fib) is the most well-known sort of sporadic heartbeat. The sporadic termination of electrical impulses causes the atria (the top chambers in the heart) to tremble (or fibrillate). Cardiovascular arrhythmias happen in older people with coronary disease. Now and again, individuals with Fib have no manifestations, and their condition is just recognizable upon actual assessment. The issues include inconsistent heartbeats when the heart is reliably in a sporadic mood, as anticipated through the patient well-being observation framework (PHMS). The PHMS proposed calculation is ready to anticipate the inconsistent pulses by the location of the R top in electrocardiogram signals (ECG) and the unpredictable beat anticipated by utilizing the P wave along with the QRS complex with the T wave for one heart cycle. Hence, this paper proposes a hybrid Convolutional Neural Network (CNN) and Recurrent Neural Networks (RNN), termed hybrid C-RNN, to proceed with the characterization and determination of the arrhythmic beats. This work also analyzes the QRS peak variations, followed by classification. The practicability of the heartbeat characterization utilizing hybrid C-RNN is completed by metrics like accuracy, sensitivity, and specificity. The proposed model achieved an accuracy of 98.57%, sensitivity of 1%, and specificity of 9.565217e-01%. This is compared best with some existing approaches in the result section.

Risk Factors for PVC Induced Cardiomyopathy and Post-Ablation Left Ventricular Systolic Dysfunction Reversibility: A Systematic Review and Meta-Analysis of Observational Studies.

Premature ventricular complex (PVC) induced cardiomyopathy (PVC-CMP) and exacerbated left ventricular systolic dysfunction (LVSD) are common in clinical scenarios. However, their precise risk factors are currently unclear. We performed a systematic review of PubMed, EMBASE, Web of Science, and Chinese-based literature database (CBM) to identify observational studies describing the factors associated with PVC-CMP and post-ablation LVSD reversibility. A total of 25 and 12 studies, involving 4863 and 884 subjects, respectively, were eligible. We calculated pooled multifactorial odds ratios (OR) and 95% confidence intervals (CI) for each parameter using random-effects and fixed-effects models. The results showed that 3 independent risk factors were associated with PVC-CMP: being asymptomatic (OR and 95% CI: 3.04 [2.13, 4.34]), interpolation (OR and 95% CI: 2.47 [1.25, 4.92]), and epicardial origin (epi-origin) (OR and 95% CI: 3.04 [2.13, 4.34]). Additionally, 2 factors were significantly correlated with post-ablation LVSD reversibility: sinus QRS wave duration (QRSd) (OR and 95% CI: 0.95 [0.93, 0.97]) and PVC burden (OR and 95% CI: 1.09 [0.97, 1.23]). the relatively consistent independent risk factors for PVC-CMP and post-ablation LVSD reversibility are asymptomatic status, interpolation, epicardial origin, PVC burden, and sinus QRS duration, respectively.

Electro‐anatomically confirmed sites of origin of ventricular tachycardia and premature ventricular contractions and occurrence of R wave in lead aVR: A proof of concept study

AbstractBackgroundThe R wave in lead aVR, during the wide QRS complex tachycardia, is commonly observed in a ventricular tachycardia (VT) arising from certain locations in the ventricles.ObjectivesThis was a retrospective and a proof of concept study to correlate the sites of origin of VT and premature ventricular contractions (PVCs) with the occurrence of R wave in lead aVR.MethodsPatients with VT or high density of PVCs were included. Surface and intracardiac electrograms were recorded during the arrhythmia. VTs and PVCs arising from the inferior, inferolateral, or apical region of the ventricles were grouped into Zone 2. Those arising from the other areas of the ventricles were grouped into Zone 1.ResultsSixty‐four patients were included in the study. The mean age was 57 years. There were 47 males. Among 64 patients with VT or PVCs, 28 patients had an R wave in aVR (43.7%), In 26 of 28 patients with an R wave in aVR, the site of origin of the arrhythmia was in Zone 2. The R wave in aVR was absent in 36 patients, 34 of whom had the origin of arrhythmia focus in Zone 1. The presence of an R wave in aVR correctly identified Zone 2 as a site of origin of the arrhythmia with high sensitivity (93%) and specificity (94%).ConclusionsThe presence of an R wave in aVR during wide QRS complex tachycardia or PVC is a valuable observation for identifying the site of origin of the arrhythmia and hence in distinguishing supraventricular tachycardia with aberrancy from VT.

Review of Atrioventricular Node Ablation Combined with Permanent His-Purkinje Conduction System Pacing in Patients with Atrial Fibrillation with Heart Failure.

With the advancement of pacing technologies, His-Purkinje conduction system pacing (HPCSP) has been increasingly recognized as superior to conventional right ventricular pacing (RVP) and biventricular pacing (BVP). This method is characterized by a series of strategies that either strengthen the native cardiac conduction system or fully preserve physical atrioventricular activation, ensuring optimal clinical outcomes. Treatment with HPCSP is divided into two pacing categories, His bundle pacing (HBP) and left bundle branch pacing (LBBP), and when combined with atrioventricular node ablation (AVNA), can significantly improve left ventricular (LV) function. It effectively prevents tachycardia and regulates ventricular rates, demonstrating its efficacy and safety across different QRS wave complex durations. Therefore, HPCSP combined with AVNA can alleviate symptoms and improve the quality of life in patients with persistent atrial fibrillation (AF) who are unresponsive to multiple radiofrequency ablation, particularly those with concomitant heart failure (HF) who are at risk of further deterioration. As a result, this "pace and ablate" strategy could become a first-line treatment for refractory AF. As a pacing modality, HBP faces challenges in achieving precise localization and tends to increase the pacing threshold. Thus, LBBP has emerged as a novel approach within HPCSP, offering lower thresholds, higher sensing amplitudes, and improved success rates, potentially making it a preferable alternative to HBP. Future large-scale, prospective, and randomized controlled studies are needed to evaluate patient selection and implantation technology, aiming to clarify the differential clinical outcomes between pacing modalities.

Exploring the interplay between extracellular pH and Dronedarone's pharmacological effects on cardiac function

Dronedarone (DRN) is a clinically used drug to mitigate arrhythmias with multichannel block properties, including the sodium channel Nav1.5. Extracellular acidification is known to change the pharmacological properties of several antiarrhythmic drugs. Here, we explore how modification in extracellular pH (pHe) shapes the pharmacological profile of DRN upon Nav1.5 sodium current (INa) and in the ex vivo heart preparation. Embryonic human kidney cells (HEK293T/17) were used to transiently express the human isoform of Nav1.5 α-subunit. Patch-Clamp technique was employed to study INa. Neurotoxin-II (ATX-II) was used to induce the late sodium current (INaLate). Additionally, ex vivo Wistar male rat preparations in the Langendorff system were utilized to study electrocardiogram (ECG) waves. DRN preferentially binds to the closed state inactivation mode of Nav1.5 at pHe 7.0. The recovery from INa inactivation was delayed in the presence of DRN in both pHe 7.0 and 7.4, and the use-dependent properties were distinct at pHe 7.0 and 7.4. However, the potency of DRN upon the peak INa, the voltage dependence for activation, and the steady-state inactivation curves were not altered in both pHe tested. Also, the pHe did not change the ability of DRN to block INaLate. Lastly, DRN in a concentration and pH dependent manner modulated the QRS complex, QT and RR interval in clinically relevant concentration. Thus, the pharmacological properties of DRN upon Nav1.5 and ex vivo heart preparation partially depend on the pHe. The pHe changed the biological effect of DRN in the heart electrical function in relevant clinical concentration.

Integrating Contrastive Learning and Cycle Generative Adversarial Networks for Non-invasive Fetal ECG Extraction.

Fetal electrocardiogram (FECG) contains crucial information about the fetus during pregnancy, making the extraction of FECG signal essential for monitoring fetal health. However, extracting FECG signal from abdominal electrocardiogram (AECG) poses several challenges: (1) FECG signal is often contaminated by noise, and (2) FECG signal is frequently overshadowed by high-amplitude maternal electrocardiogram (MECG). To address these issues and enhance the accuracy of signal extraction, this paper proposes an improved Cycle Generative Adversarial Networks (CycleGAN) with integrated contrastive learning for FECG signal extraction. The model introduces a dual-attention mechanism in the generator of the generative adversarial network, incorporating amulti-head self-attention(MSA) module and achannel-wise self-attention (CSA) module to enhance the quality of generated signals. Additionally, a contrastive triplet loss is integrated into the CycleGAN loss function, optimizing training to increase the similarity between the extracted FECG signal and the scalp fetal electrocardiogram. The proposed method is evaluated using the ADFECG dataset and the PCDB dataset both from the Physionet. In terms of signal extraction quality, Mean Squared Error is reduced to 0.036, Mean Absolute Error (MAE) to 0.009, and Pearson Correlation Coefficient reaches 0.924. When validating the model performance, Structural Similarity Index achieves 95.54%, Peak Signal-to-Noise Ratio (PSNR) reaches 38.87dB, and R-squared (R2) attains 95.12%. Furthermore, the positive predictive value (PPV), sensitivity (SEN) and F1-score for QRS wave cluster detection on the ADFECG dataset also reached 99.56%, 99.43% and 99.50%, respectively. On the PCDB dataset, the positive predictive value (PPV), sensitivity (SEN) and F1-score for QRS wave cluster detection also reached 98.24%, 98.60% and 98.42%, respectively. All of them are higher than other methods. Therefore, the proposed model has important applications in effective monitoring of fetal health during pregnancy.

Relationship of different left bundle branch pacing sites and clinical outcomes in patients with heart failure

BackgroundLeft bundle branch pacing (LBBP) is a novel physiological pacing modality. However, whether it delivers comparable efficacy with different capture sites in patients with heart failure remains unclear. ObjectiveThis study aimed to assess the association between different pacing sites and the response of LBBP. MethodsForty-three consecutive patients with heart failure, referred for successful LBBP implantation, were prospectively recruited in this study. Patients were assigned to 3 subgroups according to the paced QRS complex morphology (left bundle branch trunk pacing [LBTP], left posterior fascicular pacing, or left anterior fascicular pacing groups). Echocardiograms and electrocardiograms were recorded and analyzed at baseline and 6-month follow-up. ResultsThe response rate was 95.0%, 88.2%, and 83.3% in LBTP, left posterior fascicular pacing, and left anterior fascicular pacing groups, respectively. All subgroups were efficient in narrowing the QRS complex (QRS complex narrowing: 38.1 ± 10.8 ms, 36.4 ± 12.6 ms, and 40.8 ± 10.8 ms) and improving cardiac function (LVEF improvement： 25.7% ± 8.1%, 15.3% ± 8.1%, and 18.8% ± 4.4%). Compared with left fascicular pacing, LBTP resulted in longer peak left ventricular activation time (76.5 ± 10.2 ms vs 82.3 ± 6.5 ms; P = .037) and shorter duration from intrinsicoid deflection in V1 or V2 to QRS end (128.0 ± 6.0 ms vs 113.3 ± 5.2 ms; P＜.0001), along with better improvement in septal systolic longitudinal strain (P = .007) and lateral-septal myocardial loading inhomogeneity (P = .036). Linear regression analysis further revealed that left bundle branch capture sites were strongly associated with the improvement in peak strain dispersion (model R2 = 0.586; P = .042) and LVEF (model R2 = 0.425; P < .0001). ConclusionDifferent left bundle branch capture sites led to a subtle difference in mechanical synchrony, which may, in turn, affect LVEF improvement in patients with heart failure.

Rate-Dependent Pacemap Matching in Scar-Related Ventricular Tachycardia: Impact of “TR Fusion” Phenomenon

BackgroundThe impact of varying rates of pacemapping (PM) rates on QRS morphology and PM score matching in patients with scar-related ventricular tachycardia (VT) has not been systematically assessed. ObjectivesIn this study, the authors sought to assess the variability in PM score matching at different pacing rates. MethodsDuring substrate mapping for VT ablation, PM was performed at cycle lengths (CLs) of 600 ms, 500 ms, 400 ms, 300 ms, and VT CL. PM scores were compared for the entire QRS, the first half (H1) of QRS, and the second half (H2) of QRS to examine the influence of the preceding T-wave superimposed into the onset of paced QRS complex (TR fusion). ResultsA total of 269 PMs in 40 patients undergoing scar-related VT ablation were systematically analyzed. The PM score improved at rates closer to VT with a median difference of 6% (Q1-Q3: 4%-10%; range: 0%-33%) between the lowest and the highest PM scores at a given site. Greater slurring of the QRS onset was observed at faster-paced CL, corresponding to a superimposition of the preceding T-wave into QRS onset, with significant differences in H1 but not H2 of the QRS complex. At faster PM rates, 32% of overall sites developed pseudo delta wave and 69% of endocardial pacing sites fulfilled epicardial criteria. ConclusionsThe rate of pacemapping can significantly alter morphologic score matching, with the most optimal match observed closest to VT CL. The onset of QRS complex morphology is influenced by superimposition of the preceding T-wave at faster rates, resulting in an underrecognized TR fusion phenomenon that may confound epicardial electrocardiographic criteria predicated upon the initial QRS slope and vector.

Design of ECG Circuit and Patient Remote Monitoring System Using MQTT Protocol for ECG Signals

In the healthcare sector, leveraging the Internet of Things (IoT) brings significant advantages, especially in remote monitoring of patients' health using electrocardiogram (ECG) signals. This study employs IoT technology to enable remote ECG monitoring, utilizing the MQTT (Message Queuing Telemetry Transport) protocol to establish a web server. The dedicated measuring device integrates the ADAS1000-3 IC with ESP32 for real-time ECG signal acquisition. In this study, we utilize the Pan-Tompkins algorithm to extract QRS complexes from electrocardiographic signals, count heartbeats, and early detect cardiovascular abnormalities. This solution was tested on a sample dataset from the MIT-BIH (Massachusetts Institute of Technology - Beth Israel Deaconess Medical Center) database. Finally, the article proposes to design and develop a device using advanced IC technologies such as IC ADAS1000-3 combined with ESP32. This device will be designed to meet the requirements of real-time processing and data transmission via webserver.

Association of QRS Duration with Echocardiographic Left Ventricular Dimensions

Background: QRS duration (QRSd) is used to diagnose left bundle branch block (LBBB) and is important for determining cardiac resynchronization therapy eligibility. Others have reported associations of left bundle branch block (LBBB) and interventricular conduction delay with left ventricular (LV) systolic and diastolic dysfunction in patients without clinical HF. Individualized QRSd thresholds may improve diagnosis and intervention strategies. The goal of this study was to assess the relations of QRS duration to echocardiographic left ventricular (LV) dimensions in individuals. Methods: This was a hospital-based cross-sectional analytical study. A total of 134 purposively selected respondents were included in the study from the patients attending the outpatient or inpatient department of cardiology, Dhaka Medical College Hospital, advised for an echocardiogram. They were divided into two groups depending on their QRS complex duration (Group I≤100 ms and Group II&gt;100 ms). After taking informed written consent, a case record form was filled and Echo measurements were taken following standard procedure with confidentiality. Results: Among the respondents, the mean age was found 52.68 ± 14.24 years. The majority were male (68%), and around 1/3rd of the respondents were overweight or obese. Males were found to have less QRS duration than females (p&lt;0.001) but there was no difference in age (p=0.814) between the groups. All the risk factors considering obesity, diabetes mellitus, hypertension, family history, smoking status, and dyslipidemia were found in similar proportions in both groups (p&gt;0.05). The study found that the interventricular septum thickness and inferolateral wall thickness were higher among those having a QRS duration of more than 100 ms (Group II), but this difference was not significant (p &gt; 0.05). On the other hand, left ventricular diastolic dimension, systolic dimension, and left ventricular mass were found to be increased significantly (p&lt;0.05) with a reduction in ejection fraction in Group II (p&lt;0.05). Conclusion: Left ventricular diastolic and systolic dimensions along with left ventricular mass significantly increase according to QRS duration among the patients. Meanwhile, a reduction in ejection fraction was also evident. (Bangladesh Heart Journal 2024; 39(2): 144-150

Association of Fragmented QRS Complex with Short Term Outcome in Patients with Acute ST-Elevation Myocardial Infarction

Background: Acute ST-elevated myocardial infarction is a life-threatening condition. Presence of fragmented QRS (fQRS) after acute STEMI is associated with alteration of myocardial activation due to myocardial scar and myocardial fibrosis. Previous studies have suggested that fQRS in acute STEMI is associated with increased mortality, morbidity, sudden cardiac death and recurrent adverse cardiovascular events. The study was designed to assess the association of fQRS complex with short-term outcome (in hospital and 30 days follow up) in patients with acute ST elevation myocardial infarction. Methods: This prospective cohort study was conducted in the Department of Cardiology, Dhaka Medical College Hospital among the STEMI patients who were thrombolysed. All patients underwent serial ECG at admission, within first 12 hours, at 24 hours and at 48 hours for detecting the presence of fQRS complex. Patients showing fQRS involving infarct territory within 48 h of admission were included in the “fQRS group” and those who did not develop fQRS within 48 h of admission were included in the “without fQRS” group. 114 patients had fQRS complex and 104 patients were without fQRS in their ECG. In-hospital outcomes such as: death, heart failure, significant arrhythmias (VT, VF AF, SVT, 20 AV block, CHB), cardiogenic shock were recorded. Among the study patients, sixteen patients were lost to follow up in 30 days of index hospitalization. Finally, 202 patients were tracked for follow up regarding death or re hospitalization information by personal contact or over telephone. Statistical analysis was performed using the statistical package for social science (SPSS) 21.0 software for windows. Results: Appearance of fQRS complex occurred at admission, within first 12 hours, 24 hours and 48 hours in 53.5%, 23.7%, 14.9% and 7.9% cases respectively. During index hospitalization, development of cardiogenic shock (27.19% vs 11.54%), heart failure (23.68% vs 9.62%) and significant arrhythmias were significantly higher in fQRS group (42.10% vs 11.53%, p&lt;0.05). Although mean duration of hospitalization was similar in both groups (p&gt;0.05), but in-hospital mortality was higher in fQRS group (11.40% vs 3.85%, p&lt;0.05). Rate of re-hospitalization was significantly higher in patients with fQRS complex (21.69% vs 7.29% p&lt;0.05). Overall mortality within 30 days of index hospitalization follow-up also differs significantly in presence of fQRS complex (19.81% vs 5.2%; p =0.006). Conclusion: Presence of fQRS complex is associated with adverse short-term outcome in patients with acute ST elevation myocardial infarction. Hence, these patients need more aggressive and early invasive treatment to reduce morbidity and mortality. Bangladesh Heart Journal 2024; 39(2); 93-101

The Significance of Right-Sided Precordial ECG Leads (V3R and V4R) in Assessing Right Ventricular Dysfunction: ASingle Center Cross-Sectional Study.

Right ventricular systolic dysfunction is associated with poor prognosis and increased mortality rates. Our objective was to investigate ECG changes in patients with this condition, focusing on the right-sided precordial leads. In this cross-sectional study, 60 patients with right ventricular dysfunction were included from April 2020 to April 2021. Cardiac structure and function were assessed using 2D transthoracic echocardiography. Standard 12-lead electrocardiograms and right-sided precordial ECGs (V3R-V4R) were obtained and analyzed for QRS complex configuration, ST-segment elevation, and T-wave morphology. In our study, the majority were male (70.0%) with a mean age of 58.76 years. The most common initial diagnoses were pulmonary thromboembolism (43.3%), chronic obstructive pulmonary disease (26.7%), and pulmonary hypertension (25.0%). The predominant ECG finding in the right-sided precordial leads (V3R, V4R) was a deep negative T wave (90.0%). Patients with severe right ventricular systolic dysfunction often exhibited a qR pattern (41.2%), whereas those with nonsevere dysfunction showed rS and QS patterns (55.8%). Approximately 41.0% of severe RV dysfunction cases had ST segment depression in the right-sided precordial leads, and 28.0% of patients displayed signs of right atrial abnormality. The study found that qR, rS, and QS patterns were more prevalent in V3R and V4R leads among patients with severe and nonsevere right ventricular systolic dysfunction. The most common ECG feature observed was deep T-wave inversion in these leads. The study recommends using right-sided precordial leads in all patients with RV systolic dysfunction for early detection and risk stratification.