Sildenafil and ventriculo-arterial coupling in Fontan-palliated patients: a noninvasive echocardiographic assessment.

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.

Assessment of left atrial ejection force in mildly asphyxiated newborns.

OBJECTIVE: Asphyxia-induced cardiac insult is one of the major causes of mortality and morbidity in the course of perinatal asphyxia. Nowadays, a remarkable trend of interest is sensed introducing a plausible modality for early detection of cardiac insults at the beginning stages of asphyxia. In this study we aimed to evaluate diagnostic utility of transmitral Doppler-derived parameters as well as left atrial ejection force index as a marker of left atrial contractile function in these patients. METHODS: In a prospective study selected cases of 26 asphyxiated newborns with preserved systolic function underwent conventional transmitral Doppler flow echocardiographic assessment. Left atrial ejection force index was further calculated for all patients. Data was compared with normal ranges of healthy newborns in order to clarify the diagnostic utility of these parameters for determining minor cardiac insults in this age group. FINDINGS: We found that mildly asphyxiated newborns showed an increase in the values of left atrial ejection force index (5.44±2.12 kilodyne vs. 6.66±2.17 kilodyne, P= 0.02) and left atrial filling fraction (39%±10% vs. 45%±8%, P= 0.01). Furthermore, the acceleration and deceleration rate of early filling flow peak velocity were decreased in this group of asphyxiated newborns. CONCLUSION: Assessment of left atrial ejection force in mildly asphyxiated newborns reveals that newborns with even mild asphyxia, although could not be categorized in conventional grading system, suffer to some extent from a ventricular filling abnormality. This type of latent ventricular filling abnormality could simply be unmasked by calculation of atrial ejection force index.

Fast and automatic LV mass calculation from echocardiographic images via B-spline snake model and Markov random fields.

Left ventricular (LV) mass has several important diagnostic and indicative implications. In this paper, a fast and accurate technique for detection of inner and outer boundaries of LV and, consequently, calculation of LV mass from apical 4-chamber echocardiographic images is presented. For detection of the inner boundary, a modified B-spline snake is proposed, which relies merely on image intensity and obviates the need for computationally-demanding image forces. The outer boundary is then obtained using a Markov random fields model in the neighborhood of the estimated inner border. Experimental validation of the proposed technique demonstrates remarkable improvement over conventional algorithms.