What are the important echocardiogram (echo) numbers to note when prepping for anesthesia, including left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), right ventricular systolic pressure (RVSP), and pulmonary artery pressure (PAP)?

Key Echocardiographic Parameters for Preoperative Anesthesia Assessment

The most critical echo parameters to document preoperatively are left ventricular ejection fraction (LVEF), left ventricular dimensions (LVEDD/LVESD), diastolic function parameters (E/e' ratio, left atrial volume index), right ventricular function (TAPSE, S' wave), and pulmonary artery systolic pressure (PASP), as these directly predict perioperative cardiac complications and guide anesthetic management. 1

Left Ventricular Systolic Function

LVEF - The Primary Metric

• LVEF <35-40% significantly increases perioperative risk of cardiac death, MI, and heart failure, with sensitivity of 50% and specificity of 91% for predicting perioperative complications 1
• Normal LVEF ranges: 53-73% by 2D methods, >54% for men and >57% for women by 3D echocardiography 2
• Critical threshold: LVEF <40% warrants heightened perioperative monitoring and may require optimization before elective surgery 1
• Note that general anesthesia itself reduces LVEF by approximately 8-9% in patients with dilated ventricles, and even patients with normal baseline function can drop into dysfunction range (28% of normal patients had LVEF <50% under anesthesia) 3

LV Dimensions and Volumes

• LVEDD >56 mm indicates ventricular dilatation and predicts greater hemodynamic instability with anesthesia 4
• LVEDD >70 mm with preserved LVEF represents severe dilatation requiring careful fluid management 5
• LVEDD ≥81 mm is associated with significantly worse outcomes even with preserved LVEF 5
• LVESD >45 mm or >25 mm/m² indicates systolic dysfunction 1
• Volumes should be indexed to body surface area: LVEDV index <80 mL/m² (men), <72 mL/m² (women) 1

Diastolic Function Assessment

E/e' Ratio - Filling Pressure Surrogate

• E/e' ratio is the single most validated parameter for estimating left ventricular filling pressures, with pooled correlation coefficient of 0.56 with invasive measurements 1
• E/e' ≥13 suggests elevated filling pressures and increased risk of perioperative pulmonary edema 1
• Each unit increase in E/e' carries a hazard ratio of 1.05 for adverse outcomes 1
• E/e' ≥2 combined with deceleration time <150 ms indicates significantly elevated LV filling pressures 1

Left Atrial Volume Index (LAVI)

• LAVI ≥34 mL/m² indicates chronic diastolic dysfunction and elevated filling pressures 1
• LAVI >40 mL/m² combined with elevated tricuspid regurgitation velocity significantly increases risk 1
• LA volume provides prognostic information independent of LVEF 1

Right Ventricular Function and Pulmonary Pressures

PASP and Pulmonary Hypertension

• Peak tricuspid regurgitation velocity >3 m/s (PASP >40 mmHg) indicates pulmonary hypertension requiring specific anesthetic considerations 1
• PASP 40-50 mmHg suggests moderate pulmonary hypertension; >60 mmHg indicates severe disease 1
• Mean pulmonary artery pressure (mPAP) <29 mmHg is a favorable prognostic indicator for perioperative outcomes 4
• Calculate pulmonary vascular resistance when PASP is elevated: PVR = (mPAP - PCWP)/cardiac output, with normal <2-3 Wood units 6

RV Function Parameters

• TAPSE <16 mm indicates RV systolic dysfunction and predicts adverse perioperative outcomes (HR 2.59) 7
• Normal TAPSE: 17-20 mm or greater 7
• S' wave velocity <10 cm/s suggests RV dysfunction, with S'/PASP ratio <0.22 indicating poor RV-pulmonary coupling 7
• TAPSE/PASP ratio <0.37-0.49 indicates RV-pulmonary uncoupling and significantly worse prognosis 7
• RV end-diastolic diameter (RVEDD) >44 mm suggests RV dilatation 7

Advanced Parameters for High-Risk Cases

Global Longitudinal Strain (GLS)

• LV GLS >-16% (less negative) indicates subclinical LV dysfunction even with preserved LVEF 2
• Normal LV GLS: >-20% (more negative than -20%) 1, 2
• General anesthesia reduces LV GLS from -19.1% to -17.3%, pushing 28% of normal patients into dysfunction range 3
• RV free wall strain >-24% (less negative) indicates RV dysfunction, with normal >-23% 2, 3

LV Mass Index

• LV mass index helps identify LV hypertrophy, which independently predicts perioperative complications 1
• Presence of LV hypertrophy carries hazard ratio of 1.59 for adverse outcomes 1

Critical Clinical Thresholds Summary

For patients with reduced LVEF (<50%):

• Focus on LVEF absolute value, TAPSE, TAPSE/PASP ratio, and IVC diameter 7
• TAPSE <16 mm and TAPSE/PASP <0.49 are strongest predictors of poor outcome 7

For patients with preserved LVEF (≥50%):

• Focus on E/e' ratio, S' wave velocity, S'/PASP ratio, and LAVI 7
• S'/PASP <0.22 is strongest predictor of adverse outcome 7

Common Pitfalls to Avoid

• Do not rely on visual estimation of LVEF alone—quantitative measurement by biplane Simpson's method or 3D echo is essential, as different methods yield different values 8
• Recognize that anesthesia and positive pressure ventilation suppress both LV and RV function by 8-9% and 9% respectively, even in patients without myocardial disease 3
• PASP estimated by echo has limited positive predictive value (25-64%) for confirming pulmonary hypertension—consider right heart catheterization for definitive assessment in borderline cases 6
• E/e' ratio can be misleading in atrial fibrillation, severe mitral regurgitation, and with pacemakers—use additional diastolic parameters for confirmation 1
• Document timing relative to dialysis in renal patients, as volume status dramatically affects all measurements 1
• Record blood pressure, heart rate, and rhythm at time of echo, as these affect interpretation of all parameters 1