Body Habitus Considerations During Right Heart Catheterization.

Area of Science:

• Cardiology
• Pulmonary Hypertension
• Hemodynamics

Background:

• Obesity is common in patients undergoing right heart catheterization.
• Previous studies focused only on severe obesity.
• This study investigates the impact of varying body habitus on hemodynamic parameters.

Purpose of the Study:

• To assess the effect of body mass index on intracardiac pressures, cardiac output, and pulmonary vascular resistance.
• To compare thermodilution cardiac output (TDCO) with indirect Fick (iFick) cardiac output (CO) across different body mass index categories.
• To evaluate the accuracy of iFick CO and pulmonary vascular resistance (PVR) estimations in overweight and obese individuals.

Main Methods:

• Retrospective analysis of 65 subjects with normal hemodynamics.
• Categorization by body mass index: normal weight, overweight, and obesity (BMI 30-39.9 kg/m²).
• Comparison of mixed venous oxygen saturations, intracardiac pressures, TDCO, iFick CO, and PVR.

Main Results:

• No significant differences in intracardiac pressures were found across body mass index groups.
• Mixed venous oxygen saturations were lower in the obese group.
• Indirect Fick CO underestimated TDCO, with the largest discrepancies observed in the obese group, leading to an overestimation of pulmonary vascular resistance.

Conclusions:

• In individuals without severe obesity, intracardiac pressures remain normal, but mixed venous oxygen saturation decreases with increasing body mass index.
• Obesity complicates the accurate estimation of cardiac output and pulmonary vascular resistance using indirect Fick methods.
• These findings highlight the need for careful consideration of body habitus in hemodynamic assessments to prevent misclassification.