Introduction:
Ischemic stroke is associated with electrocardiographic and cardiac enzyme changes indicative of stunned myocardium. It is unknown if acute pulmonary edema occurs independent of cardiac dysfunction in ischemic stroke or in association with particular vascular distributions.
Hypothesis:
Ischemic strokes in the posterior fossa are associated with acute pulmonary edema independent of stroke related cardiac dysfunction.
Methods:
This is a retrospective study of ischemic stroke patients treated over two years at a tertiary medical center, including patients with basilar artery stroke (N=18), RMCA (N=31) and LMCA (N=27) distribution strokes involving the insula, and TIA controls (N=67). Of the 143 patients, 53% were female, 45% were black, 40% had a history of stroke or TIA, and 73% had hypertension. Discharge diagnosis, brain imaging, and review of chest x-rays (by two blinded reviewers) were used to determine the proportion of patients within each group with evidence of pulmonary edema. Cardiac variables including ejection fraction, serum troponin levels (>0.06 ng/mL), non-specific ST segment changes and QTc prolongation (>460ms) were compared between groups.
Results:
Patients with basilar artery occlusions and associated ischemic stroke developed pulmonary edema during their hospitalization more frequently than control patients (0.67 vs. 0.01, P<0.0001). There were no signs of stunned myocardium or CHF as indicated by elevated troponin, altered echocardiography, or QTc prolongation for the basilar group. None of the patients in the basilar group with pulmonary edema had altered echocardiography. Patients with RMCA and LMCA distribution strokes were noted to have a higher frequency of pulmonary edema compared to the controls (0.23, P=0.0012; 0.41, P=0.002), at a proportion less than the basilar group (for RMCA, P=0.005; LMCA, P=0.13,). The proportions of patients with elevated serum troponin and QTc prolongation were significantly greater for RMCA (0.41 vs. 0.05, P=0.0008; 0.40 vs.0.16, P=0.017) and LMCA (0.33 vs. 0.05, P=0.008; 0.36 vs. 0.16, P=0.046) patients relative to controls.
Conclusion:
Pulmonary edema occurs independently of cardiac stunning or dysfunction in patients with basilar artery occlusions.