Electrocardiographic Criteria Research Articles

Abstract 4136394: Elucidation of a novel genetic substrate responsible for genetically elusive ring-like arrhythmogenic cardiomyopathy

Background: Arrhythmogenic cardiomyopathy (ACM) is a genetic heart disease characterized by fibrofatty replacement of ventricular myocardium. Arrhythmogenic left ventricular (LV) cardiomyopathy (ALVC) is a phenotypic variant of ACM predominantly involving the LV. Mutations in genes encoding for desmosome proteins and filamin C have been implicated in ALVC, especially in the setting of a ring-like late gadolinium enhancement (LGE) imaging pattern. Objective: To identify the underlying genetic substrate responsible for genetically elusive ring-like ALVC in a patient with seemingly sporadic/recessive disease. Methods: A 38-year-old male was referred for genetic investigation to determine the underlying genetic substrate responsible for his ALVC phenotype. The patient fulfilled both electrocardiographic (low voltage in the limb leads and anterolateral T-wave inversions) and imaging (>1 segment of subepicardial LGE) criteria for ALVC. Additionally, the patient experienced unexplained episodes of tachycardia, shakiness, sweating, and nausea prompting concern for an underlying neuromuscular disease. Genome sequencing (GS) was performed on DNA isolated from the affected patient and both of his unaffected parents. Variants were filtered assuming either a sporadic de novo occurrence or an autosomal recessive inheritance pattern. Results: GS identified compound heterozygous GNPTAB variants in the affected patient. A previously reported maternally derived p.Leu257Leu (c.771G>A) variant involving the last nucleotide of exon 7 of the GNPTAB gene and a novel paternally inherited Lys834fs*5 frame-shift variant were identified. The p.Leu257Leu variant has been reported to cause aberrant splicing and exon skipping of the GNPTAB mRNA transcript. Pathogenic variants in the GNPTAB encoded N-acetylglucosamine-1 (GlcNAc)-phosphotransferase subunits alpha/beta cause mucolipidosis type III, a rare recessive lysosomal storage disease characterized by coarse facial features, developmental delay, short stature, skeletal deformities, and cardiac involvement including valvular thickening and cardiomyopathy. Conclusions: Here, using a genome sequencing trio analysis we identified a compound heterozygous GNPTAB pathogenic variants as the underlying genetic substrate in a patient with ring-like ALVC and concomitant neuromuscular disease manifestation. Genome sequencing may identify the genetic etiology responsible for an otherwise undifferentiated diagnosis of cardiomyopathy.

Verification of intra- and inter-atrial conduction during Bachmann's bundle pacing using longitudinal bi-atrial strain

Abstract Introduction Although atrial septal pacing has been reported to reduce atrial fibrillation (AF) burden, there is less evidence regarding its effect on the prevention of permanent AF and the improvement of long-term clinical outcomes. However, Bachmann's bundle pacing (BBp), which features P-wave morphology similar to sinus rhythm and shortened P-wave duration (PWD), was reported to significantly reduce permanent AF recurrences and occurrences compared with right atrial appendage pacing (RAAp) and non-specific right septal pacing. Purpose Possible mechanisms for AF suppression with BBp are that fast inter-atrial conduction through BB decreases global atrial activation time and the dispersion of the overall atrial refractoriness, and it prevents the decrease in left ventricular filling and increase in left atrial pressure associated with delayed left atrial contraction. Intra-and inter-atrial conduction during BBp was evaluated using longitudinal bi-atrial strain. Methods In patients with successful BBp implantation defined by electrocardiographic criteria using SelectSecure pacing lead and C315 delivery catheter (Medtronic, Inc), both left atrium (LA) and right atrium (RA) global longitudinal strain (GLS) in simultaneous phases were measured using Philips Ultrasound Workspace 2D Strain in apical 4-chamber view during atrial pacing to assess intra- and inter-atrial conduction delay. The atrial GLS were measured semi-automatically, and the strain rate was analyzed in the three segments of septal wall, lateral wall, and roof and their average. The negative peak of strain rate during atrial systole was the starting point of atrial contraction, and time to peak (TTP) was measured. The difference in TTP between septal and lateral walls in each atrium was measured as intra-atrial conduction delay and the difference in average TTP between LA and RA as inter-atrial conduction delay. Results Ten patients who underwent successful BBp were enrolled (Sick sinus syndrome: 3, advanced atrioventricular block: 2, complete atrioventricular block: 5). At implantation, bipolar atrial electrogram amplitude was 2.03±0.93 mV, atrial lead impedance was 632.7±157.6 Ω, and atrial pacing threshold was 0.7±0.2 V at 0.4 ms. The PWD during sinus rhythm on the 12-lead ECG was 132.8±10.6 ms, while during BBp it was 108.0±11.9 ms, which was significantly shorter in the BBp group (p<0.001). The intra-atrial conduction delay in RA and LA was 10.9 ± 12.1 ms and 12.1 ± 17.3 ms, respectively, and the inter-atrial conduction delay was 6.6 ± 8.6 ms. On the other hand, for the 10 RAAp and 10 sinus rhythm patients as control groups, the inter-atrial conduction delay was 29.7±13.8 ms and 8.5±9.5 ms, respectively. BBp had significantly less inter-atrial conduction delay than RAAp (p=0.005) and was comparable to sinus rhythm (p=0.719). Conclusion Longitudinal bi-atrial strain suggested that BBp significantly reduced inter-atrial delay and it might be effective in AF suppression.Longitudinal bi-atrial strain

Electrocardiographic criteria for the diagnosis of left ventricular hypertrophy in patients with severe aortic stenosis

Abstract Introduction There is a lack of data regarding the performance of current electrocardiographic (EKG) criteria for left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). Purpose To test the performance of the current EKG scores to diagnosis LVH in AS patients, and also to compare the performance of a new proposed score. Methods The present study evaluated 80 patients with severe AS that underwent cardiac magnetic resonance to diagnose LVH, defined as left ventricular indexed mass of 95 g/m² for female and 115 g/m² for male patients. The EKG criteria used for left ventricular hypertrophy were Sokolow-Lyon criteria, Romhilt-Estes point score system, Cornell voltage criteria and Peguero-Lo Presti criteria. Results Among the 80 patients included in analysis, 58.7% were male and the mean age was 64±8 years. There was a high prevalence of comorbidities, highlighting diabetes (32.5%), hypertension (67.5%), atrial fibrillation (5.0%) and coronary artery disease (11.3%). Regarding echocardiogram, the median left ventricle ejection fraction was 64 (56-68)% and the median indexed aortic valve area was 0.43 (0.35-0.49) cm²/m². Cardiac magnetic resonance analysis demonstrated a mean left ventricle mass of 168±55g, and the LVH incidence was 26.3%. Regarding EKG, Strain pattern was found in 49.1% of the patients, Cornell voltage criteria was positive in 51.3%, Sokolow-Lyon criteria in 51.3%, Romhilt-Estes point score system in 42.5% and Peguero-Lo Presti criteria in 61.3%. Discriminative capacity of electrocardiographic criteria for LVH is shown in Figure 1. Peguero-Lo Presti score had the best diagnostic accuracy in the overall population and in male sex (AUC 0.776), while Cornell voltage criteria had the best diagnostic accuracy in female patients (AUC 0.776). Based on linear regression model, the proposed score was created to predict LVH at cardiac magnetic resonance: 48 + (1.3 x Deepest S wave) + (0.5 x S wave in V1 or V2 plus R wave in V5). The proposed score cutoff value of 90.5 mm had a sensitivity of 0.765 and specificity of 0.707 (for male sex: 0.769 and 0.655, respectively; for female sex: 0.750 and 0.759, respectively). Compared to the scores described in the literature, the proposed score had the best area AUC for the overall population (Figure 1), for female and male patients (AUC 0.796, 0.819 and 0.780, respectively). Conclusion In patients with severe AS, the proposed score had the best diagnostic accuracy compared to the scores described in the literature for LVH identification, followed by Peguero-Lo Presti score, even when analyzed based on gender. Besides, the proposed score had also acceptable sensitivity and specificity for LVH detection.AUC of electrocardiographic scores.

Comparative study of the surface and endocavitary signals of cardiac pacing system analyzers with respect to the conventional polygraphy systems signals during implantation of conduction system pacing

Abstract Introduction and objectives Left bundle branch area pacing (LBBAP), is a novel modality of physiologic pacing that requires an adequate assessment of the endocardium as well as the body-surface electrocardiographic signals for a successful pacing-lead implantation. We aimed to assess if LBBAP criteria(1), specifically left ventricular septal pacing (LVSP) and left bundle branch pacing (LBBP) criteria, can be satisfactory measured using the signals resulting from different cardiac pacing analyzers (PSAs) by comparing them to the ‘conventional’ signals obtained from multichannel polygraph systems (MPSs) during the implantation procedure. Methods Comparative observational, prospective, multicenter study of consecutive patients who underwent a LBBAP strategy as first intention. LBBP was defined in the presence of a paced QRS with right bundle branch morphology in V1 (initial r wave in lead V1) and at least one of the following criteria: 1. V6-R-Wave Peak Time (RWPT) < 80 ms. 2. V1–V6 interpeak interval > 33 ms. 3. QRS transition from non-selective left bundle branch pacing to selective left bundle branch pacing or NS-LBBP to left ventricular septal pacing during pacing threshold. 4. Sudden increase of V6-RWPT > 15 ms because of reducing pacing output. 5. Left bundle potential-V6RWPT = stim-V6RWPT (±10 ms). For patients without initial r wave in V1, LBBP was considered in the presence of QRS transition during pacing. LVSP was defined by a paced QRS showing a typical terminal R-wave in V1, anatomical position of the lead in the left ventricular septum documented by fluoroscopy and not fulfilling the additional criteria previously described for LBBP. Results 63 patients were included. The basal characteristics of the patients are shown in Figure I. No significant differences (p<0.96) were observed in the basal QRS between the MPSs (129±29ms) and the PSAs (129±28ms). Initial "W" morphology in V1 during initial pacing was obtained in 90% of patients, without differences between both measurement systems. There were no significant differences between the MPSs and the PSAs in the paced QRS in V1 (140±10ms vs 141±12ms, p<0.746) nor in V6 (127.4±13ms vs 128.2±14.6ms, p<0.96). The measurement of the R wave peak time (RWPT) in V6 was 78.3±15ms vs 77±14 ms (p<0.72), and the V1-V6 inter-peak was 41.1±16ms in the MPSs vs 39±16 ms the PSAs (p<0.6), respectively, the Pearson correlation coefficients for these last two measurements being 0.91 (p <0.0001) and 0.91 (p <0.0001) (Figure II). Finally, according to electrocardiographic criteria measured by the MPSs, LBBP was achieved in 69% of patients, accomplishing 31% of the patients LVSP criteria, being the same proportions observed when PSAs measures where applied. Conclusions The signals resulting from the different PSAs can be useful to assess septal as well as LBBP criteria as an alternative to the ‘conventional’ signals obtained from MPSs.

IN-HOSPITAL OUTCOMES AMONG PATIENTS PRESENTED WITH ST-ELEVATION MYOCARDIAL INFARCTION TREATED WITH PRIMARY PERCUTANEOUS CORONARY INTERVENTION

Primary Percutaneous Coronary Intervention (PCI) is considered the gold standard treatment for patients with ST-elevation myocardial Infarction (STEMI). Prompt intervention, aimed at restoring blood flow, plays a critical role in improving survival and minimizing complications in these patients. Objective: The objective of this study was to evaluate in-hospital outcomes among patients diagnosed with STEMI and treated with Primary PCI. Methods: This cross-sectional study was conducted in the Cardiology Department over one year. The study included patients aged 50 years and older who were diagnosed with STEMI based on electrocardiographic criteria and presented within 12 hours of symptom onset. Demographic information, clinical characteristics, comorbidities, and in-hospital outcomes were recorded. Statistical analyses were performed using relevant descriptive measures. Results: A total of 150 patients were included in the study. The mean age of patients was 60.89 ± 5.65 years, with 64.4% being male. The average door-to-balloon time was 89.93 ± 18.12 minutes. Successful reperfusion, defined as achieving a TIMI grade 3 flow, was observed in 87.8% of the patients. In-hospital mortality was recorded at 4.4%, while 3.3% of patients developed infections during their hospital stay. Conclusion: The study demonstrated favourable in-hospital outcomes for STEMI patients treated with Primary PCI, with a high success rate in achieving TIMI grade 3 flow and a relatively low in-hospital mortality rate. These findings underscore the efficacy of timely PCI in improving survival and procedural outcomes in STEMI patients, particularly when door-to-balloon time is minimized.

Revolutionizing LVH detection using artificial intelligence: the AI heartbeat project.

Many studies have shown the utility and promise of artificial intelligence (AI), for the diagnosis of left ventricular hypertrophy (LVH). The aim of the present study was to conduct a meta-analysis to compare the accuracy of AI tools to electrocardiographic criteria, including Sokolow-Lyon and the Cornell, most commonly used for the detection of LVH in clinical practice. Nine studies meeting the inclusion criteria were selected, comprising a sample size of 31 657 patients in the testing and 100 271 in the training datasets. Meta-analysis was performed using a hierarchal model, calculating the pooled sensitivity, specificity, accuracy, along with the 95% confidence intervals (95% CIs). To ensure that the results were not skewed by one particular study, a sensitivity analysis using the 'leave-out-one approach' was adopted for all three outcomes. AI was associated with greater pooled estimates; accuracy, 80.50 (95% CI: 80.4-80.60), sensitivity, 89.29 (95% CI: 89.25-89.33) and specificity, 93.32 (95% CI: 93.26-93.38). Adjusting for weightage of individual studies on the outcomes, the results showed that while accuracy and specificity were unchanged, the adjusted pooled sensitivity was 53.16 (95% CI: 52.92-53.40). AI demonstrates higher diagnostic accuracy and sensitivity compared with conventional ECG criteria for LVH detection. AI holds promise as a reliable and efficient tool for the accurate detection of LVH in diverse populations. Further studies are needed to test AI models in hypertensive populations, particularly in low resource settings.

Electrocardiographic Criteria for the Diagnosis of Acute Myocardial Infarction in Patients with Left Bundle Branch Block

During normal conduction system, the first segment depolarized is interventricular septum, normal ventricular depolarization begins with the septal fascicle of the left bundle branch followed by a simultaneous depolarization of the remaining ventricular walls from endocardium to pericardium via the right and left bundle branches. In left bundle branch block (LBBB) condition, the left ventricular activation is delayed, and the initial septal activation is from right to left, secondary ST segment and T wave abnormalities occur, and septal Q waves indicative of an MI are absent. About 0.5 percent of patients with acute myocardial infarction had left bundle-branch block Patients with left bundle branch block (LBBB) and suspected of acute myocardial infarction (MI) is challenge to the clinician. A diagnosis of MI with electrocardiogram (ECG) is especially difficult in the setting of LBBB because of the characteristic ECG changes caused by altered septal and left free wall ventricular depolarization. Here we review the pathophysiology of LBBB in MI, highlight evolving paradigms for the diagnosis of suspected MI in patients with LBBB.

Performance of electrocardiographic criteria for detecting LVH in hypertensive Africans.

To evaluate the performance of the currently accepted LVH electrocardiographic (ECG) criteria from ethnic-specific normal values. We included 309 hypertensive subjects with both ECG (12‑leads device) and echocardiographic analysis. The diagnosis of LVH was established by echocardiography from specific norms. Current ECG criteria for the diagnosis of LVH have low performances. Area Under Curve of Sokolow-Lyon, Peguero-Lo Presti, Cornell voltage and Cornell Product were respectively 0.61, 0.65, 0.72 and 0.71. In hypertensive African, the most accurate criterion for diagnosing LVH is Cornell voltage.

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.

Electrocardiographic Diagnosis of Right Ventricular Hypertrophy: a Literature Review

The development of right ventricular hypertrophy (RVH) is a consequence of a large group of diseases that lead to increased pressure or volume load on the right ventricle. Electrocardiography (ECG) is a commonly used diagnostic method in clinical practice. This method allows for the identification of RVH signs in the early stages of examination. During the 20th century, more than 30 diagnostic criteria were developed. Several of these criteria are associated with worse prognosis, including increased mortality. Authors of international guidelines recommend the verification of criteria in local populations. Such studies have not been published in Russia, but according to data obtained from foreign researchers, the diagnostic properties of ECG criteria can vary significantly. In most cases, the criteria are characterized by low sensitivity and high specificity, which complicates early diagnosis of conditions leading to RVH development. It is proposed to increase the sensitivity of the method by using all the developed criteria or sets that include some of them. However, this approach may reduce the specificity of ECG diagnosis of RVH, and the selection of criteria for inclusion in diagnostic algorithms is not always based on scientific research data. This article analyzes the history of the development of RVH criteria, research data on their diagnostic capabilities, and ways to improve diagnostic algorithms.

Evaluation of electrocardiographic criteria for predicting left ventricular hypertrophy and dilation in presence of left bundle branch block

BackgroundThe utility of standard published electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH) in patients with left bundle branch block (LBBB) is not established. We have previously shown that in ECGs demonstrating LBBB, QRS duration outperforms vectorcardiographic X, Y, Z lead and root-mean-squared (3D) amplitudes and voltage-time-integrals in diagnosing LVH and dilation. We sought to evaluate diagnostic yields of published LVH criteria versus QRS duration for ECG based diagnosis of LVH and dilation in presence of LBBB. MethodsWe included adult patients with typical LBBB having ECG and transthoracic echocardiogram performed within 3 months of each other in 2010–2020. We obtained area under receiver-operator characteristic curve (AUC) for QRS duration and each of the published ECG LVH criteria to predict increased LV mass indexed (↑LVMi, women >95 g/m2, men >115 g/m2) and LV end diastolic volume indexed (↑LVEDVi, women >61 mL/m2, men >74 mL/m2). ResultsAmong 413 adults (53 % women, age 73 ± 12 yr) with LBBB, the traditional LVH criteria performed poorly to detect ↑LVMi or ↑LVEDVi. Cornell voltage-duration product had the highest AUCs (↑LVMi 0.634, ↑LVEDVi 0.580). QRS duration had a higher AUC for diagnosing ↑LVMi (women 0.657, men 0.703) and ↑LVEDVi (women 0.668, men 0.699) compared to any other criteria. ConclusionsIn patients with LBBB, prolonged QRS duration (women ≥150 ms, men ≥160 ms) is a superior predictor of LVH and dilation than traditional ECG-based LVH criteria.

Artificial intelligence applied to the diagnostic accuracy of left ventricular hypertrophy using electrocardiographic criteria

Artificial intelligence applied to the diagnostic accuracy of left ventricular hypertrophy using electrocardiographic criteria

Factors that Determined a Positive Response to Resynchronization Therapy in Patients With Chronic Heart Failure and Cardiac Dyssynchrony. One Center Experience.

To evaluate the efficacy of cardiac resynchronization therapy (CRT) in patients with chronic heart failure (CHF) associated with cardiac dyssynchrony and to identify the factors that influence the CRT efficacy. This retrospective study included 155 patients after implantation of CRT devices. The CRT devices with a built-in cardioverter-defibrillator (CRT-D) and without it (CRT-P) were implanted in 139 (89.7%) and 16 (10.3%) patients, respectively. The follow-up period was 52.37±35.94 months. Based on the study results, two groups of patients were formed depending on the presence of a clinical response to CRT, responders and non-responders. The factors that influenced the clinical response to CRT were studied. The effect of the baseline state of patients on the effect of therapy was assessed. The need for CRT optimization and a possibility of using electrocardiographic criteria for that purpose were studied. Modern devices and leads for CRT, their functional capabilities and their influence on the CRT efficacy were characterized. Statistical analysis was performed with an IBM SPSS Statistics 21.0 (Chicago, USA) package. CRT implantation with the left ventricular lead placement according to the traditional technique, through the coronary sinus, was successful in 130 (87.9%) patients. Difficulties with the left ventricular lead placement were noted in 13 (8.3%) patients when other techniques were used. After 6 months, a hemodynamic and clinical response was observed in 112 (72.2%) patients, and no positive response in 43 (27.8%). The increase in left ventricular ejection fraction in the responder group was more than 21.8±3.7%, which was associated with an improvement of the 6-minute walk test results. Th clinical response was significantly influenced by the possibility of stimulation from the basal parts of the heart; the use of more modern devices for CRT and quadripolar left ventricular leads; timely CRT optimization; and persistent dyssynchrony in non-responders. During the follow-up period, 34 (21.9%) patients died. The death rate in the non-responder group was significantly higher than in the responder group, 18 (41.3%) vs. 16 (14.3%), p=0.001. The main cause of death in the group of non-responders was CHF. Heart transplantation was performed in 3 (1.9%) patients. CRT increases the life span and improves the quality of life in patients with CHF and cardiac dyssynchrony. There was a group of patients with no benefit from CRT in this study. Modern devices allow increasing the number of patients who benefit from CRT. Periodic optimization of CRT is necessary. When optimizing CRT, it is possible to use electrocardiographic criteria of effectiveness: duration of the QRS complex and changes in the position of the electrical axis of the heart.

Electrocardiographic criteria for occlusive and prognostically unfavorable coronary artery disease

Since patients with occlusive coronary artery thrombosis benefit more from emergency reperfusion, after the widespread introduction of thrombolytic therapy, the concept of Q-wave and non-Q-wave myocardial infarction was replaced by the concept of ST-segment elevation (STE) and non-STE (NSTE) acute coronary syndrome (ACS). But at present, due to the spread of mechanical reperfusion, this concept does not seem to be fully perfect. The electrocardiographic (ECG) diagnostic method allows, among patients with NSTE-ACS, to identify a group of patients with occlusive and/or prognostically unfavorable hemodynamically significant coronary lesions, as well as to provide them with timely percutaneous coronary intervention as early as possible and to improve outcomes. This article rationales changing approaches to the management of patients with NSTE-ACS and analyzes in detail the currently known ECG criteria for occlusive and/or prognostically unfavorable coronary lesions.

Electrocardiographic Criteria for Diagnosis of Acute Myocardial Infarction in Patients with Left Bundle Branch Block

In patients with normal heart and normal conduction system, the initial depolarized segment in ventricle is interventricular septum which begins with septal fascicle of the left bundle branch from left side and direction to right side followed by a simultaneous depolarization of the remaining ventricular free walls from endocardium to pericardium via the right and left bundle branches. But among patients with left bundle branch block (LBBB), the initial septal activation is changing direction and become from right to left then the left ventricular activation is delayed, ST segment and T wave abnormalities occur, and septal Q waves indicative of an MI are absent in this condition. About 0.5 percent of patients with acute myocardial infarction had left bundle-branch block. Because this changes the patients with left bundle branch block (LBBB) and acute myocardial infarction (MI) is challenge to the clinician. The diagnosis of MI with electrocardiogram (ECG) is so difficult in the setting of LBBB because of the characteristic ECG changes caused by altered interventricular septal and left ventricle free wall depolarization. Here we review the ECG diagnostic criteria included all criteria until now and short summary of patient with acute MI and LBBB condition.

Accuracy of Electrocardiography Criteria for Left Ventricular Hypertrophy in Hypertensive Patients at Shahid Gangalal National Heart Centre

Accuracy of Electrocardiography Criteria for Left Ventricular Hypertrophy in Hypertensive Patients at Shahid Gangalal National Heart Centre

Comprehensive approach and real-life patient registry: exploring management and patient outcomes in dealing with septal complications during left bundle branch area pacing

Abstract Background Left bundle branch area pacing (LBBAP) aims to capture the left bundle branch (LBB) through a transventricular septal approach. Pacing this left-sided conduction system requires deep septal lead positioning due to the subendocardial course of the LBB at the left-sided septum. Such deep septal lead deployment might cause iatrogenic septal complications and collateral damage to septal vasculature. Purpose This study aims to explore both the immediate and medium-term clinical results of septal complications during LBBAP in a large single-center patient cohort, while also entailing the management strategies employed to address these issues. Methods The LBBAP implant procedure was conducted using a lumen-less (LLL) or a stylet-driven pacing lead (SDL) and a dedicated delivery sheath. Septal complications encompassed septal perforations into the left ventricular cavity, septal coronary artery or venous fistulas (SCAF/SCVF) and septal hematomas, which were identified using fluoroscopy, echocardiography and electrocardiographic criteria. Enrollment included adult patients who required permanent pacing for bradycardia or heart failure indications in whom LBBAP was attempted between November 2019 and October 2023. Results The study enrolled 508 patients, with a mean age of 71±16 years and 60% male. Successful LBBAP was achieved in 471 (93%) patients. Septal complications during implant occurred in 24/508 patients (5%), including 19 cases of septal perforation (4%), 4 cases of SCAF (0.8%) and 1 case of SCVF (0.2%). All cases of septal perforation were identified during the implantation procedure and were effectively managed by lead retraction and septal repositioning, eventually resulting in successful LBBAP. With regard to SCAF and SCVF, all but one were detected via septography during implantation and were addressed by lead repositioning. One case of SCAF was detected the day after implant on post-procedural echocardiography and was conservatively managed without lead repositioning. No ventricular septal defects were observed on echocardiography, either immediately or during follow-up (mean follow-up period of 25±12 months). Septal kinetics remained unaffected on follow-up echocardiography (mean follow-up 23±9 months), and all SCAF cases healed spontaneously. Additionally, no septal hematomas were observed. Importantly, no late septal perforations occurred during the follow-up period. Furthermore, no cardiac ischemia or thoracic discomfort were reported among any of these patients. Conclusions The findings of this study underscore the safety of deep septal lead deployment in LBBAP, and highlight that LBBAP provides near physiologic pacing with a high success rate and a low incidence of septal complications. The majority of these complications are promptly detected during the implant procedure and often remain asymptomatic. Furthermore, they exhibit spontaneous healing without enduring persistent septal harm throughout the follow-up period.

An incremental energy stimulation test to predict success in left bundle branch capture

Abstract Introduction Left bundle branch (LBB) stimulation is guided by fluoroscopic projections and electrocardiographic criteria limited by positional variations. Purpose To evaluate an incremental energy stimulation test (IEST) to optimize success. Methods Prospective, non-randomized experimental study for proof-of-concept analysis (N=23), consisting on: (i) stimulation at three locations at the high, middle and low right mid-ventricular septum (right oblique 30o); and (ii) continuous unipolar stimulation (lumenless fixed helix electrode) at each location with increasing outputs (2 volt x 0.5 ms up to 10 vol x 1.5 ms). The final position for lead penetration was made by the operator blinded to the results of the IEST. Results IEST shortened the S-LVAT (δ-S-LVAT) up to 6.4±5 ms (range 0 to 18 ms), 8±8 ms (range 0 to 36 ms) and 5.5±5 ms (range 0 to 20 ms) respectively for high, mid, and low sites (Figure, panel A and B). There was not observed any paired correlation between the magnitude of the δ-S-LVAT at the three different positions (Pearson 0.36, 0.12 and 0.22; p= 0.1, 0.6 and 0.4 respectively), suggesting that the δ-S-LVAT is site specific. The final position for lead penetration was medium in 17 cases vs low in 6 cases. The low-output S-LVAT interval at the final position before lead penetration was positively correlated with the final S-LVAT achieved after lead penetration (Pearson 0.44; p=0.04), but the magnitude of the correlation increased with the high-output S-LVAT interval (Pearson 0.57; p=0.006) suggesting a better prediction performance (Figure, panel C). A complex relationship was observed where higher δ-S-LVAT values were associated with shorter S-LVAT after penetration and final position of the lead. In fact, for cases with low-output S-LVAT interval > 100 ms, the δ-S-LVAT significantly correlated with S-LVAT after penetration and final position of the lead (Pearson -0.61; p=0.026). Conclusions IEST lead to a site-specific shortening of the S-LVAT, pointing to optimized positions for LBB pacing. The technique provides with additional diagnostic criteria to determine the better site for lead penetration.

DEVELOPMENT OF AN APPLICATION AS AN AUXILIARY TOOL FOR VERIFICATION OF AN ELECTROCARDIOGRAM CONCLUSION

Objective: Electrocardiography (ECG) is a key step in the diagnosis of cardiovascular pathology. Interpretation of the ECG is carried out by the doctor in the first minutes of severe patient admission and often determines further tactics of management. However, such an important diagnostic method is quite subjective, since it is highly dependent on the knowledge, and experience of the doctor and even on his attention to detail. The objective is to develop an application for automatic verification of various ECG criteria (exceptionally as an addition to the subjective interpretation of the doctor). Design and method: The desktop application was developed in Python (v3.10.5) by implementing its object-oriented programming concepts. Tkinter was chosen as a Graphical User Interface framework. The set of standard libraries has been supplemented by OpenCV (v4.6.0.66) for recognizing and digitizing ECG images, Pillow (v9.3.0) for manipulating the image and its metadata, NumPy (v1.23.5) for further analysis, and others. The initial version of the program includes STEMI recognition. Real ECGs printed on graph paper were used for debugging and testing. Results: When launching the application, the user is prompted to select a file containing an ECG image (a). After the required image has opened, the user should indicate the requested ECG-leads in the picture, following the simplest instructions (b). Then processing of the leads automatically starts. This phase is hidden from the user, and only a progress bar is displayed on the screen (c). Meanwhile, a number of manipulations are performed, such as converting the picture to a binary state, recognizing the ECG-line, and storing the coordinates of each pixel in the database. Objects of such classes as Isoline, and Cardiac Cycle with R wave, ST segment, etc. are created for each of the objects of the Lead class (d). Further geometric study of the pixel base and checking for the pathological ECG-signs on the backend form the final conclusion for the user (e). Conclusions: The developed application is relevant for use as an additional tool in the work and training of doctors. It can be expanded to cover a wide range of pathologies.

Rate of Change of Initial Intrinsicoid Deflection Predicts Endocardial Versus Epicardial Ventricular Tachycardia

BackgroundAssessment of origin of ventricular tachycardias (VTs) arising from epicardial vs endocardial sites are largely challenged by the available criteria and etiology of cardiomyopathy. Current electrocardiographic (ECG) criteria based on 12-lead ECG have varying sensitivity and specificity based on site of origin and etiology of cardiomyopathy. ObjectivesThis study sought to test the hypothesis that epicardial VT has a slower initial rate of depolarization than endocardial VT. MethodsWe developed a method that takes advantage of the fact that electrical conduction is faster through the cardiac conduction system than the myocardium, and that the conduction system is primarily an endocardial structure. The technique calculated the rate of change in the initial VT depolarization from a signal-averaged 12-lead ECG. We hypothesized that the rate of change of depolarization in endocardial VT would be faster than epicardial. We assessed by applying this technique among 26 patients with VT in nonischemic cardiomyopathy patients. ResultsWhen comparing patients with VTs ablated using epicardial and endocardial approaches, the rate of change of depolarization was found to be significantly slower in epicardial (6.3 ± 3.1 mV/s vs 11.4 ± 3.7 mV/s; P < 0.05). Statistical significance was found when averaging all 12 ECG leads and the limb leads, but not the precordial leads. Follow up analysis by calculation of a receiver-operating characteristic curve demonstrated that this analysis provides a strong prediction if a VT is epicardial in origin (AUC range 0.72-0.88). Slower rate of change of depolarization had high sensitivity and specificity for prediction of epicardial VT. ConclusionsThis study demonstrates that depolarization rate analysis is a potential technique to predict if a VT is epicardial in nature.