Optimal Level of Transducer for Measuring Atrial and Pulmonary Arterial Pressure in Patients with Functional Single Ventricle

Abstract

ABSTRACT

Introduction: Obtaining accurate hemodynamic data is the first step in making a correct decision for the hemodynamic management of patients with congenital heart disease. This study was conducted to investigate the optimal transducer position for atrial and pulmonary arterial pressure monitoring in the supine and sitting position in patients with functional single ventricle.

Methods: Contrast enhanced chest computed tomographic data of 108 patients who underwent either bicaval pulmonary shunt (BCPS) placement or the Fontan procedure were retrospectively reviewed. From the transverse-section images, vertical distances between the skin of the back and the uppermost fluid levels of the single atrium and pulmonary artery, and their ratios to the largest anteroposterior (AP) diameter of the thoracic cage were calculated for the supine position. For the sitting position, distances between the mid-sternoclavicular joint and the most cephalad fluid levels of the atrium and the pulmonary artery and their ratios to the sternal length were calculated. Each level was determined with regard to the corresponding rib or intercostal space.

Results: The ratios of the uppermost blood level of the atrium and pulmonary artery to the largest AP diameter of the thorax in the patient who underwent BCPS placement in the supine position were 76.0 ± 8.1%, and 56.3 ± 5.5 %, respectively. These values were 79.3 ± 10.0% and 58.3 ± 5.8% respectively, in the patients who underwent the Fontan procedure. In the sitting position, the ratios of the most cephalad blood level of the atrium and pulmonary artery to the sternal length in the patients who underwent BCPS placement were 51.4±11.2%, and 42.2±8.1% respectively, whereas those in the patients who underwent the Fontan procedure was 52.7 ± 8.6% and 41.4 ± 7.1% respectively. The external land mark corresponding to the most cephalad atrium and pulmonary artery was the second intercostal space for both the patients who underwent BCPS placement and those who underwent the Fontan procedure.

Conclusions: Taken together, the optimal transducer levels for measuring atrial and pulmonary arterial pressures in the supine position were at 75-80% and 55-60% of the AP diameter of the thorax respectively for patients with functional single ventricle. For the sitting position, the optimal transducer level for measuring atrial and pulmonary arterial pressures was approximately the second intercostal space.

------------------------------------ Keywords: Central venous pressure

supine position

sitting position

congenital heart disease