1,329 calculators and references across 60 specialties, with formula confidence shown up front.
PDA Severity Score (PDAsc) — Explanation and Clinical Context The PDA Severity Score (PDAsc) is a multivariable echocardiography-based prognostic index developed to quantify early hemodynamic significance of a patent ductus arteriosus in very preterm infants and predict the composite outcome of chronic lung disease or death before discharge. The score combines gestational age, echocardiographic PDA diameter (pulmonar
CRISP Pediatric Cardiac Catheterization Risk Score: Explanation and Clinical Context The CRISP (Catheterization RISk Score for Pediatrics) model is a validated risk tool to predict serious adverse events (SAEs) in pediatric patients undergoing cardiac catheterization. } It incorporates multiple pre‑procedural variables (age, procedure risk level, hemodynamic vulnerability, use of inotropes or mechanical support, emer
Pediatric Cardiomyopathy Mortality Score: Explanation and Clinical Context The Pediatric Cardiomyopathy Mortality Score is a clinical tool designed to estimate the 1-year mortality risk in children diagnosed with primary cardiomyopathy. It integrates patient age, left ventricular systolic function (fractional shortening), left ventricular size (LVEDD z-score), serum BNP levels, and the presence of arrhythmias. Lower
Pediatric Heart Failure Severity Index (Ross Classification): Explanation and Clinical Context The Ross Classification is a widely used clinical scoring system to assess the severity of heart failure in infants and young children. It evaluates symptoms such as feeding difficulty, tachypnea, diaphoresis, hepatomegaly, and growth. Class I represents asymptomatic patients, Class II indicates mild symptoms with exertion
Pediatric LV Mass (LVM) and Z-score: Explanation and Clinical Context Left ventricular mass (LVM) estimated from M-mode echocardiography is commonly calculated using the Devereux formula (implemented above). Because children vary widely in body size, LVM must be normalized for body size; common approaches include indexing to height (allometric index, e.g., height^2.7), indexing to body surface area (BSA), or using ce
Pediatric Myocarditis Severity Index: Explanation and Clinical Context The Pediatric Myocarditis Severity Index (PMSI) is a clinical tool designed to stratify the risk and predict outcomes in children with acute myocarditis. It incorporates key variables including age, heart rate, left ventricular ejection fraction (LVEF), serum troponin I levels, and BNP levels to provide an integrated risk score. A higher PMSI scor
Pulmonary Valve Annulus (PVA) Z-score — explanation and clinical context This calculator implements the regression equations published by Pettersen et al. (J Am Soc Echocardiogr 2008) to compute a z-score for the pulmonary valve annulus relative to body size. Pettersen and colleagues derived nonlinear polynomial regression models on the natural-log transformed echocardiographic measurements against body surface area
Pulmonary Vascular Resistance Calculator Explanation and Clinical Context Pulmonary vascular resistance describes the afterload that the right ventricle must overcome to eject blood into the pulmonary circulation. It is derived from a hemodynamic relationship that integrates pressure gradients across the pulmonary vasculature and the magnitude of pulmonary blood flow. PVR reflects the degree of vasoconstriction, remo
Pulmonary-to-Systemic Flow Ratio (Qp/Qs): Explanation and Clinical Context The Pulmonary-to-Systemic Flow Ratio (Qp/Qs) is a hemodynamic index derived from the Fick principle that quantifies the relative blood flow between the pulmonary and systemic circulations. It is essential for the assessment of cardiac shunts such as atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA)