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Signal-Averaged ECG (SAECG) Abnormality Index: Explanation and Clinical Context SAECG is a specialized electrocardiographic technique used to detect subtle abnormalities in ventricular depolarization that are not visible on standard ECG. The SAECG Abnormality Index quantifies risk for ventricular arrhythmias by scoring three primary parameters: filtered QRS duration, low amplitude signal duration, and root mean squar
Spatial Angle Index (SAI QRST): Explanation and Clinical Context SAI QRST is a quantitative ECG-derived index that measures the spatial angle between the QRS complex and T wave vectors in three-dimensional space. It reflects the degree of heterogeneity in ventricular depolarization and repolarization. Higher values of SAI QRST indicate greater electrical instability and are associated with increased risk of ventricul
SCD-HeFT Risk Model: Explanation and Clinical Context The SCD-HeFT Risk Model estimates the 5-year risk of all-cause mortality in patients with heart failure with reduced ejection fraction (HFrEF) who are candidates for implantable cardioverter-defibrillator (ICD) therapy. The model uses clinical variables available at baseline, including age, NYHA functional class, left ventricular ejection fraction (LVEF), presence
Schwartz Score for Long QT Syndrome: Explanation and Clinical Context The Schwartz Score is a validated diagnostic tool to assess the probability of congenital Long QT Syndrome (LQTS). It incorporates electrocardiographic, clinical, and family history features including QTc interval, history of syncope, congenital deafness, and family history of sudden cardiac death or LQTS. Points are assigned based on QTc duration,
Shanghai Score for Brugada Syndrome: Explanation and Clinical Context The Shanghai Score is a diagnostic scoring system developed to assess the likelihood of Brugada Syndrome based on clinical, electrocardiographic, familial, and genetic criteria. It assigns weighted points to spontaneous Type 1 ECG, fever-induced or drug-provoked Type 1 ECG, documented ventricular arrhythmias, family history of sudden cardiac death,
Signal-Averaged QRS Duration: Explanation and Clinical Context Signal-Averaged QRS (SA-QRS) duration is a specialized ECG measurement designed to detect subtle conduction abnormalities that predispose patients to ventricular arrhythmias. It is typically performed using high-resolution ECG recordings and computer averaging to reduce noise. Normal SA-QRS duration is generally less than 114 ms. Values between 114–120 ms