1,329 calculators and references across 60 specialties, with formula confidence shown up front.
P-wave Axis Deviation Index: Explanation and Clinical Context The P-wave axis is calculated using the frontal plane ECG leads I and aVF to estimate atrial depolarization direction. A normal P-wave axis ranges from 30° to 75° in adults. Values outside this range indicate potential right or left atrial enlargement, atrial conduction abnormalities, or underlying structural heart disease. Abnormal P-wave axis has been as
P-wave Dispersion (PWD): Explanation and Clinical Context P-wave Dispersion is defined as the difference between the maximum and minimum P-wave durations measured on a standard 12-lead ECG. It reflects the heterogeneity of atrial conduction and has been widely studied as a predictor of atrial fibrillation (AF) in both structural heart disease and healthy populations. Increased PWD indicates inhomogeneous and disconti
PVC Burden Percentage: Explanation and Clinical Context PVC Burden Percentage represents the proportion of premature ventricular contractions (PVCs) relative to the total number of heartbeats over a 24-hour period as recorded by Holter monitoring or similar continuous ECG monitoring. A low PVC burden (<1%) is generally considered clinically insignificant, moderate burden (1–10%) may warrant follow-up in symptomatic p