OBJECTIVE Whether cardiac dysfunction contributes to morbidity and mortality after subarachnoid hemorrhage (SAH) remains controversial. The objective of this study was to test the hypothesis that cardiovascular abnormalities are independently related to in-patient mortality after SAH. METHODS This was a prospective cohort study of patients with aneurysmal SAH. Heart rate and blood pressure were measured, a blood sample was obtained, and echocardiography was performed on three study days, starting as soon after admission as possible. The cardiovascular predictor variables were heart rate, systolic blood pressure (SBP), cardiac troponin I (cTi) level, B-type natriuretic peptide (BNP) level, and left ventricular ejection fraction. The primary outcome measure was in-patient mortality. The association between each predictor variable and mortality was quantified by multivariate logistic regression, including relevant covariates and reporting odds ratios (OR) and 95% confidence intervals (CI). RESULTS The study included 300 patients. An initial BNP level greater than 600 pg/mL was markedly associated with death (OR 37.7, p < 0.001). On the third study day (9.1 +/- 4.1 days after SAH symptom onset), a cTi level greater than 0.3 mg/L (OR 7.6, p = 0.002), a heart rate of 100 bpm or greater (OR 4.9, p = 0.009), and a SBP less than 130 mmHg (OR 6.7, p = 0.007) were significantly associated with death. CONCLUSIONS Cardiovascular abnormalities are independent predictors of in-patient mortality after SAH. Though these effects may be explained by a reduction in cerebral perfusion pressure or other mechanisms, further research is required to determine whether or not they are causal in nature.