Ejection fraction (EF) is a key measure of cardiac function, expressed as the percentage of blood ejected from the left ventricle with each contraction. It provides critical insight into the heart’s ability to pump oxygen-rich blood to the body. EF is typically measured using imaging modalities such as echocardiography, magnetic resonance imaging (MRI), or nuclear stress tests. A normal EF ranges between 55% and 70%, while values below 40% indicate significant cardiac dysfunction. Ejection fraction is a vital metric in diagnosing and managing heart failure, as well as assessing perioperative risk in patients undergoing surgery and anesthesia. 

Heart failure is classified into three categories based on EF: heart failure with preserved ejection fraction (HFpEF), mildly reduced ejection fraction (HFmrEF), and reduced ejection fraction (HFrEF). HFpEF is characterized by an EF ≥50%, indicating preserved systolic function but impaired ventricular filling. HFmrEF includes patients with EF between 40% and 49%, representing a transitional group with mixed features of systolic and diastolic dysfunction. HFrEF, defined as EF <40%, reflects significant systolic impairment and is associated with higher morbidity and mortality. This classification aids clinicians in tailoring therapies and predicting outcomes for patients with heart failure. 

Reduced ejection fraction has implications for surgery and anesthesia, as it increases the risk of perioperative complications such as arrhythmias, myocardial ischemia, and hemodynamic instability. Patients with low EF are less able to tolerate fluctuations in preload, afterload, and heart rate during surgery, making them vulnerable to adverse events. Furthermore, reduced cardiac output may impair tissue perfusion, increasing the likelihood of organ dysfunction postoperatively. These risks necessitate careful preoperative assessment and planning to optimize outcomes for patients with compromised cardiac function. 

Anesthesiologists play a pivotal role in managing patients with reduced EF during surgery. They aim to maintain hemodynamic stability, avoid myocardial depression, and prevent arrhythmias. Strategies for managing reduced EF often involve the use of vasopressors to support blood pressure, inotropes to enhance contractility, and careful fluid management to optimize preload without causing volume overload. Anesthetic agents must be chosen judiciously to minimize myocardial depressant effects while ensuring adequate sedation and analgesia. Regional anesthesia techniques may be preferred in some cases to reduce systemic hemodynamic stress that may not be tolerated well in patients with reduced ejection fraction and pre-existing cardiovascular impairment. However, they require meticulous monitoring to prevent hypotension due to vasodilation. 

Perioperative management of high-risk patients with reduced EF demands additional measures to mitigate complications. Preoperative optimization includes adjusting guideline-directed medical therapies such as beta-blockers or angiotensin-converting enzyme inhibitors and addressing comorbidities like anemia or electrolyte imbalances. Intraoperatively, advanced monitoring techniques such as transesophageal echocardiography or invasive arterial pressure monitoring can provide real-time insights into cardiac function and guide therapeutic interventions. Postoperatively, close surveillance for arrhythmias or ischemic events is essential, along with aggressive management of pain and fluid balance to prevent decompensation. Referral to centers equipped with mechanical circulatory support options may be necessary for critically ill patients requiring complex surgeries. 

Despite advances in perioperative care, there are situations where surgery may be contraindicated based on EF levels. Patients with severely reduced EF (<20%) are often deemed too high-risk for elective procedures unless the surgery is life-saving or offers significant long-term benefits. In such cases, alternative therapies or palliative approaches may be considered until cardiac function improves sufficiently for surgical intervention. The decision must involve a multidisciplinary team including cardiologists, anesthesiologists, and surgeons to weigh risks against potential benefits comprehensively.

Ejection fraction is a critical determinant of cardiac function that influences surgical risk stratification and anesthesia management strategies. Reduced EF poses significant challenges for perioperative care but can often be managed effectively through meticulous planning and tailored interventions by anesthesiologists and multidisciplinary teams.

References

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