Right Ventricular Pump Efficiency in Secundum-Type Atrial Septal Defect.

Area of Science:

• Cardiology
• Medical Engineering
• Physiology

Background:

• The cardiopulmonary system requires adequate stroke volume with minimal stroke work.
• A new metric, right ventricular (RV) pump efficiency (η), is proposed: left ventricular stroke volume / right ventricular stroke work.
• This metric is designed for populations with volume overload, specifically secundum-type atrial septal defect (ASD).

Purpose of the Study:

• To investigate the relationship between right-sided volume overload and RV pump efficiency in patients with secundum-type ASD.
• To evaluate the impact of ASD closure on RV pump efficiency.

Main Methods:

• Fifty patients with secundum-type ASD were enrolled.
• Sixteen patients with a pulmonary to systemic flow ratio (Qp/Qs) > 1.5 underwent occluder implantation.
• A paired t test compared RV pump efficiency before and after ASD closure.

Main Results:

• RV pump efficiency showed an inverse correlation with Qp/Qs.
• RV pump efficiency was 60 ± 20‰ · mmHg⁻¹ at Qp/Qs = 1.
• After ASD closure, RV pump efficiency significantly increased from 27.4 ± 13.6 to 63.9 ± 20.4‰ · mmHg⁻¹.

Conclusions:

• RV pump efficiency is a superior indicator of the chronicity and severity of secundum-type ASD.
• The study demonstrates the effectiveness of RV pump efficiency as a clinical parameter.