Accuracy of Electrocardiographic Criteria in the Diagnosis of Left Ventricular Hypertrophy in Complete Left Bundle Branch Block: A Systematic Review with Meta-analysis

Introduction: Left Ventricular Hypertrophy (LVH) is commonly present in patients with complete Left Bundle Branch Block (LBBB) and has significant prognostic implications. The LBBB fundamentally alters ventricular depolarisation and repolarisation patterns, complicating the Electrocardiography (ECG) diagnosis of LVH. Despite decades of research, accurate diagnostic criteria remain unclear. Aim: A systematic review and meta-analysis was conducted to evaluate the accuracy and clinical utility of various electrocardiographic criteria in diagnosing LVH in patients with complete LBBB. Materials and Methods: A search was performed using PubMed and institutional databases from 1969 to August 2024 for studies evaluating ECG criteria for LVH diagnosis in LBBB patients, using echocardiography, Cardiac Magnetic Resonance Imaging (CMRI), or autopsy as reference standards. Sixty-four ECG criteria were analysed across 15 studies comprising 1,595 patients. Two reviewers independently selected studies, extracted data, and assessed methodological quality using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A random-effects meta-analysis was conducted to calculate pooled sensitivity, specificity, likelihood ratios, and Diagnostic Odds Ratios (DOR). Studies were stratified by cumulative sample size, and heterogeneity was assessed using the I² statistic. Results: Among the parameters evaluated in studies with sample sizes exceeding 400 patients, Left Atrial Enlargement (LAE) criteria demonstrated the highest DOR and predictive accuracy. However, decision-curve analysis could not demonstrate the clinical utility of any ECG criteria for adequately diagnosing LVH in the study population. Conclusion: No ECG criteria demonstrated significant diagnostic accuracy for LVH in patients with LBBB. Therefore, multimodal diagnostic approaches incorporating clinical assessment, risk stratification, and confirmatory imaging are essential for accurate LVH diagnosis in patients with complete LBBB in clinical practice, in addition to ECG.