The Anesthetic Challenges of Managing Patients with Aortic Stenosis for Non-cardiac Surgery

Abstract

Aortic stenosis (AS) is the most common valvular heart disease in adults over 75 years of age. The primary cause is calcification and degeneration of the valve, with the early development of stenosis in congenital bicuspid aortic valves. Obstruction of left ventricular (LV) outflow leads to pressure overload, concentric hypertrophy, and diastolic dysfunction (reduced LV compliance and increased end-diastolic pressures) that all contribute to a decreased stroke volume (SV). These changes increases myocardial oxygen demand and decreases coronary perfusion pressure (CPP). It is not uncommon for patients to present for elective or urgent non-cardiac surgery with unrecognized degrees of AS. These patients are considered to have greater risk of major cardiac complications including hypotension, myocardial ischemia or infarction, arrhythmias, heart failure, stroke, and death. Therefore, anesthesiologists must maintain a high level of suspicion when caring for elderly patients. Proper triaging is required to assess the severity of AS, and provide a safe anesthetic that avoids hemodynamic changes. Maintaining sinus rhythm, CPP, adequate preload, and systemic vascular resistance is important. Appropriate hemodynamic monitoring that allows immediate interventions. Phenylephrine is one of the agents used for treating hypotension in AS patients. The focus of this narrative review is to provide guidance on how to achieve these goals.