Non-invasive assessment of haemodynamic parameters in patients after Fontan procedure

Abstract

Introduction and objective Single ventricle anomaly is one of the complex congenital heart defects. A dependable non-invasive method of evaluation of Fontan circulation haemodynamics for early diagnosing unstable patients is hardly available in routine clinical practice. The aim of the study is non-invasive evaluation of the haemodynamic parameters in patients after Fontan operation. Material and methods The study involved 11 participants (age 24.4±4.3 years) with functionally univentricular hearts after Fontan operation. Evaluation of haemodynamic parameters was performed in supine and sitting positions using the impedance cardiography method. Results In comparative analysis, heart rate (70.1 vs.78.3 1/min; p=0.001), diastolic blood pressure (73.9 vs. 76.7 mm Hg; p=0.026), mean arterial blood pressure (84.5 vs. 88.0 mm Hg; p=0.013), systemic vascular resistance (1284.8 vs. 1334.9 dyn*s*cm-5; p=0.024), systemic vascular resistance index (2178.7 vs. 2272.8 dyn*s*cm-5*m2 ; p=0.018), pre-ejection period (124.2 vs. 136.2 ms; p=0.009), systolic time ratio (0.43 vs. 0.53; p=0.0001), and Zo (26.2 vs. 28.7 Ω; p<0.00001), were significantly higher in the sitting position. Stroke volume (75.4 vs. 68.5 ml; p=0.013), stroke index (42.7 vs. 39.0 ml*m-2; p=0.014), thoracic fluid content (38.5 vs. 35.4 1*kΩ-1; p=<0.00001), thoracic fluid content index (22.8 vs. 21.0 1*kΩ-1*m-2; p=<0.00001), and leftventricular ejection time 291.1 vs. 260.1 ms; p <0.00001, were significantly higher in the supine position. Conclusions In patients after Fontan procedure, impedance cardiography can be a useful tool the assessment of shortterm haemodynamic changes provoked by postural changes. Its clinical value in patients with congenital heart defects should be further investigated.

Keywords

• congenital heart disease
• fontan circulation
• impedance cardiography
• haemodynamics