Persistent compromised hemodynamic function, due to single ventricular epicardial pacing, after aortic valve replacement surgery: A case report

We report the case of a 69-year old woman, who was admitted to the cardiac surgery intensive care unit (ICU) of a tertiary hospital, after surgical aortic valve replacement, due to severe aortic stenosis. During the early postoperative period, the patient was hemodynamically stable and her cardiac rhythm was supported by temporary epicardial ventricular pacing. One hour after her ICU admission, the woman presented compromised hemodynamics, characterized by severe hypotension with poor response to aggressive inotropic, vasopressor and fluid therapy. After 15 minutes of her significant clinical worsening, the change of the pacing mode from single ventricular to single atrial effected immediate hemodynamic stabilization, improved arterial blood pressure and optimum patient cardiovascular function. This could be explained by the significantly reduced cardiac output in the absence of atrial contraction to assist ventricular preloading, which characterized some patients with impaired ventricular function, as those with severe aortic stenosis.