1,329 calculators and references across 60 specialties, with formula confidence shown up front.
Risky Mitral Valve (Echo-based risk stratification): Explanation and Clinical Context The Risky Mitral Valve concept uses echocardiographic assessment to identify mitral valve disease patients at high risk of complications during or after intervention. Key echocardiographic parameters include leaflet morphology (thickening, calcification, restricted motion), annular dilation, subvalvular apparatus abnormalities, mitr
Right and Left Heart Catheterization Calculator: Clinical explanation and context Overview Right and left heart catheterization is a procedure performed to measure intracardiac pressures and blood oxygen saturations for the purpose of calculating pulmonary and systemic blood flows and resistances. The calculations in this tool use the Fick principle to estimate pulmonary flow and systemic flow and then derive resista
Rockall Upper GI Bleeding Score Explanation and Clinical Context The Rockall score estimates risk of adverse outcome after an acute upper gastrointestinal bleeding episode. It combines three clinical variables available at admission that form the pre endoscopic score and two endoscopic variables that produce the complete score. Age contributes up to two points depending on age group. Hemodynamic status is captured by
— explanation and context This page presents an experimental composite index adapted to reflect the primary predictors and outcomes described in ROCKET-AF and its heart-failure subgroup analyses. The ROCKET-AF trial (rivaroxaban vs warfarin) enrolled a high-risk atrial fibrillation population and reported subgroup analyses examining outcomes among patients with heart failure, demonstrating that heart failure patients
Romhilt–Estes Point-Score System: Explanation and Clinical Context The Romhilt–Estes (R-E) point-score system is a composite electrocardiographic method developed to improve ECG detection of left ventricular hypertrophy by combining six ECG features (P-terminal force in V1, high QRS voltages, ST-T changes consistent with “strain”, left axis deviation, prolonged QRS duration, and delayed intrinsicoid deflection). Each
: Explanation and Clinical Context The ROPAC Registry Predictive Model, endorsed by the 2020 ESC Guidelines, provides an evidence-based estimate of 1-year mortality risk in patients with pregnancy-associated cardiovascular conditions or pre-existing heart disease. This logistic regression model incorporates patient age, NYHA functional class, left ventricular ejection fraction (LVEF), history of heart failure, presen
Explanation and Clinical Context This tool is intended for patients who have experienced out of hospital or in hospital cardiac arrest have achieved return of spontaneous circulation and subsequently are found to have an electrocardiographic pattern consistent with ST segment elevation myocardial infarction. The twenty twenty five American acute coronary syndromes guideline emphasizes that patients with return of spo
SpO2 FiO2 Percentage Respiratory Rate ROX Index Explanation and Clinical Context The ROX Index is a clinical tool used to predict the success of high flow nasal cannula therapy in patients with acute hypoxemic respiratory failure. It is calculated using the ratio of peripheral oxygen saturation to fraction of inspired oxygen divided by respiratory rate. A higher ROX Index reflects better oxygenation efficiency and lo
Rp/Rs Ratio (Pulmonary/Systemic Resistance): Explanation and Clinical Context The Rp/Rs ratio represents the relative resistance of the pulmonary circulation (PVR) to the systemic circulation (SVR). It is calculated as the pulmonary vascular resistance divided by the systemic vascular resistance, providing insight into the balance between pulmonary and systemic vascular loads. A normal Rp/Rs ratio is typically less t
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
RSBI Mechanical Ventilation Weaning Index Explanation and Clinical Context The rapid shallow breathing index known as RSBI is defined as the ratio of respiratory frequency to tidal volume in liters. It is calculated as respiratory rate divided by tidal volume in liters during spontaneous breathing conditions. RSBI measures the pattern of breathing and reflects the balance between respiratory drive and the ability of
Rutherford Classification: Explanation and Clinical Context Rutherford Classification is a widely accepted system for grading the severity of peripheral arterial disease (PAD). It stratifies patients from stage 0 (asymptomatic) to stage 6 (major tissue loss), incorporating claudication severity, presence of rest pain, and degree of tissue loss. Stage 0 represents no symptoms, stages 1-3 correspond to increasing sever
RV 2C (Right Ventricular Two-Chamber) RV 2C (Right Ventricular Two-Chamber) RA : Right atrium, RV : Right ventricle, SVC : Superior vena cava, TV : Tricuspid valve.
Right Ventricular Fractional Area Change (FAC): definition, clinical meaning and evidence-based context RV FAC quantifies global right ventricular systolic function from an RV-focused apical four-chamber view by tracing the RV endocardial border in end-diastole and end-systole and applying the equation: FAC (%) = 100 × (RV end-diastolic area − RV end-systolic area) / RV end-diastolic area. The American Society of Ech
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
Right Ventricular (RV) Involvement Index: Explanation and Clinical Context The RV Involvement Index is a composite echocardiographic score designed to quantify right ventricular dysfunction by integrating three key parameters: RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and the right ventricular myocardial performance index (RV MPI). This index provides a continuous measure of
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
The audited source currently returns an empty page. This catalog entry is retained for coverage and monitoring, but no clinical content or calculation is asserted.
Right Ventricle to Left Ventricle (RV/LV) Ratio on Echocardiography: Explanation and Clinical Context The RV/LV ratio is a measurement derived from echocardiography that compares the end-diastolic diameter of the right ventricle (RV) to the left ventricle (LV). It is widely used to assess right ventricular dilation, which can occur in conditions such as acute pulmonary embolism, pulmonary hypertension, right heart fa
RVEDd Z-score: Explanation and Clinical Context The RVEDd Z-score expresses the deviation of measured right ventricular end-diastolic dimension (in mm) from the predicted mean value, normalized by the standard deviation (SD) of the reference population. A Z-score of 0 means that the measurement equals the population mean; positive values indicate enlargement relative to body size, negative values indicate smaller dim
RVOT VTI Cardiac Output Estimation in Pulmonary Hypertension: Explanation and Clinical Context RVOT VTI (Right Ventricular Outflow Tract Velocity Time Integral) is a Doppler echocardiography parameter used to estimate stroke volume and cardiac output, particularly in patients with pulmonary hypertension (PH). The stroke volume is calculated as the product of the RVOT cross-sectional area and the VTI, then multiplied