Time course of the hemodynamic response during exercise right heart catheterization in patients with HFrEF

Background

Exercise right heart catheterization (ERHC) is an elegant invasive tool for the diagnosis of patients with heart failure with preserved ejection fraction, pulmonary hypertension and valvular heart disease. The hemodynamic response during ERHC can also provide valuable information to risk stratify patients with HFrEF.

Purpose

To characterize the timeline of the hemodynamic changes encountered during ERHC in patients with HFrEF.

Methods

Symptomatic patients with HFrEF scheduled for ERHC were assigned in our study. ERHC was performed via the right jugular vein with a 7F Swan-Ganz catheter which was left in the pulmonary artery (PA) during exercise. A controlled 6 minute exercise protocol with a supine cycle ergometer was implemented. Hemodynamics and venous blood from the PA for gas analysis before and during every minute of exercise were obtained The cardiac output (CO) at rest was calculated using the Fick formula whereas during exercise by the following formula:

CO= VO2/CaO2-CvO2

(CaO2= Arterial oxygen content, CvO2= Venous oxygen content)

VO2 (oxygen consumption) was derived from the following formula:

VO2= 0.9x{[(10.8xWatts)/Body weight]+7}

Results

Thirty three patients with HFrEF (mean age: 69y, NYHA:2.8±0.8, mean ejection fraction: 29±10%) were included. In total, 55 ERHC were successfully completed. Significant increase of the systolic, diastolic and mean PA pressures was observed during the first two minutes of exercise with no further significant changes thereafter (Figure). A significant increase of the pulmonary capillary wedge pressure was also recorded (from 12±7 to 24±5 mmHg, p=0.01) and a borderline elevation of the ratio PCWP/CO (from 2,3±0,8 to 2,6±0,7 mmHg/lt/min, p=0.05). On the contrary, a significant drop of the venous oxygen saturation of the pulmonary artery (SvO2) (from 69±16 to 42±17%, p=0.01) was found. A multivariate linear regression analysis model was used to identify changes of the PCWP based on the changes of PA pressures and SVO2 (Table).

Conclusions

Significant hemodynamic changes were recorded in the ERHC during the first 2 minutes of exercise. The hemodynamic response during ERHC may add prognostic value and predict exercise capacity in patients with HFrEF.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.