Stroke Volume Index (SVi) for RV Failure Prediction Calculator

Stroke Volume Index (SVi) for RV Failure Prediction: Explanation and Clinical Context Stroke Volume Index (SVi) is a hemodynamic parameter that represents the stroke volume normalized to body surface area. It is calculated as cardiac output divided by heart rate and then indexed to BSA, providing a load-adjusted measure of cardiac performance. In the context of right ventricular (RV) failure prediction, SVi has been shown to be a strong indicator of RV function, especially in patients undergoing left ventricular assist device (LVAD) implantation, cardiac surgery, or advanced heart failure management.

A low SVi reflects compromised forward flow and poor RV contractility. Typical Reference Values: • Normal SVi: ≥ 35 mL/m²/beat • Borderline: 25–35 mL/m²/beat • High Risk (Severe RV Dysfunction): < 25 mL/m²/beat Clinical Significance: A reduced SVi indicates decreased right ventricular stroke work and correlates with increased central venous pressure and poor pulmonary artery coupling. In perioperative and critical care settings, SVi < 25 mL/m²/beat is a marker for poor prognosis and impending RV failure, especially after cardiac surgery or LVAD implantation.

Clinical Interpretation Summary: • SVi < 25 mL/m²/beat → High risk of RV failure; requires optimization of preload, afterload reduction, and inotropic support. • 25 ≤ SVi ≤ 35 → Intermediate risk; monitor closely with echocardiography and hemodynamic trends. • SVi > 35 → Low risk; suggests preserved RV performance.