Introduction: Delayed identification of hemodynamic deterioration remains a persistent issue for in-hospital patient care. Unfortunately, no continuously measured non-invasive method of detecting hemodynamic deterioration currently exists. Clinicians rely on vital signs associated with tachycardia and hypotension to identify hemodynamically unstable patients. However, the collection of non-invasive vital signs remains labor-intensive, inconsistent, and error-prone in practice. In contrast, the Analytic for Hemodynamic Instability (AHI) depends only on the continuous ECG signal from a typical bedside monitor. Hypothesis: Continuous real-time hemodynamic status obtained from the analysis of existing ECG monitor data can accurately detect the combination of hypotension and tachycardia without the need for continuous direct measurement of blood pressure. Methods: 28,348 5-minute windows of the analytic output were analyzed from 222 consecutive adult patients receiving continuous ECG and arterial line monitoring at an academic medical center. AHI outputs were compared to vital sign indication of tachycardia and hypotension in the same window. Results: The observed sensitivity and specificity of AHI compared to vital signs measurement were 95.6% and 84.9%, respectively, with an area under the curve (AUC) of 0.90 and an accuracy of 85.6%. The false-negative rate was 4.4%. The false-positive rate was 15.1%. Conclusions: The AHI derived hemodynamic status correlated well with vital sign derived hemodynamic status for both invasive and non-invasive methods. In patients who had their blood pressure monitored non-invasively, AHI provided continuous hemodynamic monitoring in patients who usually have vitals measured only every few hours. Footnote: The Analytic for Hemodynamic Instability is currently pending US FDA review and is not yet for sale in the US.