Rest and exercise hemodynamics after the Ross procedure: an echocardiographic study

Area of Science:

• Cardiology
• Cardiac Surgery
• Echocardiography

Background:

• Superior hemodynamic performance of aortic prosthetic valves aids left ventricular hypertrophy regression and function.
• Pulmonary autografts demonstrate good resting function, but exercise hemodynamics are less understood.
• Assessing autograft and homograft performance under stress is vital for surgical outcomes.

Purpose of the Study:

• To evaluate the hemodynamic performance of pulmonary autografts in the aortic position during high cardiac output.
• To assess the hemodynamic performance of homografts used in right ventricular outflow tract reconstruction during stress.
• To investigate the impact of dobutamine stress echocardiography on these valve replacements.

Main Methods:

• The study included 20 patients who underwent the Ross operation, with a mean follow-up of 15.7 months.
• Dobutamine stress echocardiography was used to evaluate hemodynamics at rest and during exercise.
• Dobutamine infusion ranged from 5 to 40 microg/kg, monitoring heart rate, cardiac output, and valve gradients.

Main Results:

• Cardiac output significantly increased from 6.3 L/min at rest to 16.8 L/min during dobutamine stress.
• Left ventricular function remained satisfactory in all patients throughout the study.
• Autograft mean gradient increased from 1.03 mmHg to 4.03 mmHg; homograft mean gradient increased from 9.06 mmHg to 17.55 mmHg.

Conclusions:

• Pulmonary autografts maintain normal hemodynamic function at rest and during exercise post-Ross operation.
• Mild-to-moderate gradients across the right ventricular outflow tract homografts are common and require monitoring.
• Dobutamine stress echocardiography is effective in evaluating valve performance under simulated high-output conditions.