Sildenafil and Ventriculo-Arterial Coupling in Fontan-Palliated Patients: A Noninvasive Echocardiographic Assessment

Abstract

The fundamental role of pulmonary vascular resistance in the Fontan circulation is obvious. Medications decreasing this resistance may have an impact on the fate of this population. Hence, we assessed noninvasively the effect of oral sildenafil on the ventriculo-arterial coupling in patients with Fontan circulation. In a single-center, prospective case series study, 23 patients with fenestrated extracardiac total cavopulmonary connection age 12-31 years were enrolled in this study. Clinical characteristics and echocardiographic examination were performed before and after a 1 week course of sildenafil at 0.5 mg/kg every 8 h. Sildenafil had no effect on heart rate and blood pressure. However, oxygen saturation was significantly increased with sildenafil (87.6 ± 4.3 vs. 90.1 ± 3.6; P < 0.0001). The calculated noninvasive ventricular end-systolic elastance (Ees) was greater after sildenafil compared with the pre-sildenafil values (1.59 ± 0.17 vs. 1.72 ± 0.27 mm Hg/ml; P = 0.001). Moreover, significant decreases in arterial elastance (Ea) (1.62 ± 0.53 vs. 1.36 ± 0.43 mm Hg/ml; P < 0.0001), ventricular end-diastolic elastance (Eed) (0.05 ± 0.021 vs. 0.04 ± 0.013; P = 0.002), and, finally, ventriculo-arterial coupling index (0.99 ± 0.26 vs. 0.76 ± 0.15; P < 0.0001) were found after sildenafil administration. The intolerable side effects that led to stopping the sildenafil occurred only in one (4 %) patient. Sildenafil has increased ventricular systolic elastance and improved ventriculo-arterial coupling in patients palliated with Fontan circulation. Short-term sildenafil was well tolerated in most of the patients with only minor side effects.

Ventricular‐Arterial Function and Coupling in the Adult Fontan Circulation

“…The other coupling studies in Fontan patients used similar methods as ours or even much simplified, less‐rigorous methods, but did not include similarly studied non‐Fontan patients to determine whether VA parameters were abnormal relative to persons without Fontan circulation 30, 31. A mathematical simulation study and an animal study of acute Fontan physiology indicated that immediately after creation of a Fontan circulation, Ees is mildly reduced whereas Ea is increased 24, 32.…”

Inhaled iloprost for the treatment of patient with Fontan circulation

“…Most studies were based on high level of endothelin-1 in Fontan patients9,10), the endothelin receptor antagonist induced improvement of clinical, hemodynamic parameters and exercise capacity. Experiences with sildenafil therapy on Fontan patients have also been reported11,12). In a recent study, Rhodes et al15) reported on the effect of inhaled iloprost on exercise function of Fontan patients.…”

“…Several studies8,9,10,11,12) reported the pulmonary vasodilating therapy had an effective influence on Fontan patients so we want to determine whether inhaled iloprost as a pulmonary vasodilator might have a role in the clinical symptoms, hemodynamics and exercise capacity of Fontan patients.…”

Preoperative echocardiographic measures of left ventricular mechanics are associated with postoperative vasoactive support in preterm infants undergoing patent ductus arteriosus ligation

“…12 To use these measures more routinely, single beat estimations of echocardiographic Ees and Ea (ie, estimates of Ees and Ea that do not require load alteration to be measured) have been developed and validated in children. 4,13 Ea was calculated as (0.9 × systolic blood pressure/stroke volume). Ees was calculated as (0.9 × systolic blood pressure/end-systolic volume).…”