Akemi Ono

Early combined treatment with steroid and immunoglobulin is effective for serious Kawasaki disease complicated by myocarditis and encephalopathy

Severe-type Kawasaki disease (KD) complicated by serious myocarditis and encephalopathy can be successfully treated without abnormality of the coronary arteries by steroid pulse treatment and intravenous immunoglobulin (IVIg). A 4-year-old Japanese girl was diagnosed with KD due to a 6-day history of fever, rash, flushed lips, conjunctival hyperemia, palmar edema, and cervical lymphadenopathy. The day after initiation of IVIg and aspirin, cardiac gallop rhythm was identified. Cardiac ultrasonography revealed severe left ventricular dysfunction. Disturbance of consciousness, hallucinations, and slurred speech were also observed. Magnetic resonance imaging showed no abnormalities, but electroencephalography revealed high-voltage slow waves. Despite this serious disease, cardiac function and neurological abnormalities showed complete recovery without dilatation of the coronary arteries by steroid pulse treatment and additional IVIg. Follow-up at 15 months revealed no abnormality of the coronary arteries. In conclusion, we suggest that early combined treatment with steroid and IVIg is effective for serious KD complicated by myocarditis and encephalopathy.

Analysis of Right Ventricular Myocardial Stiffness and Relaxation Components in Children and Adolescents With Pulmonary Arterial Hypertension

Background The rate of left ventricular pressure decrease during isovolumic relaxation is traditionally assessed algebraically via 2 empirical indices: the monoexponential and logistic time constants (τE and τL). Since the pattern of right ventricular (RV) pressure decrease is quite different from that of the left ventricular, we hypothesized that novel kinematic model parameters are more appropriate and useful to evaluate RV diastolic dysfunction. Methods and Results Eight patients with pulmonary arterial hypertension (age 12.5±4.8 years) and 20 normal subjects (control group; age 12.3±4.4 years) were enrolled. The kinematic model was parametrized by stiffness/restoring Ek and damping/relaxation μ. The model predicts isovolumic relaxation pressure as a function of time as the solution of d2P/dt2+(1/μ)dP/dt+EkP=0, based on the theory that the pressure decay is determined by the interplay of inertial, stiffness/restoring, and damping/relaxation forces. In the assessment of RV diastolic function, τE and τL did not show significant differences between the pulmonary arterial hypertension and control groups (46.8±15.5 ms versus 32.5±14.6 ms, and 19.6±5.9 ms versus 14.5±7.2 ms, respectively). The pulmonary arterial hypertension group had a significantly higher Ek than the control group (915.9±84.2 s−2 versus 487.0±99.6 s−2, P<0.0001) and a significantly lower μ than the control group (16.5±4.3 ms versus 41.1±10.4 ms, P<0.0001). These results show that the RV has higher stiffness/elastic recoil and lower cross‐bridge relaxation in pulmonary arterial hypertension. Conclusions The present findings indicate the feasibility and utility of kinematic model parameters for assessing RV diastolic function.

Long-term Results After Open Mitral Commissurotomy for a One-Month-Old Infant With Mitral Stenosis

The strategy for an infant with congenital mitral stenosis should be determined by three important factors: left ventricular volume, the degree of the systemic outflow tract obstruction, and the type of mitral valve dysfunction. A successful staged biventricular repair in early infancy for a patient who had congenital mitral stenosis with short chordae, hypoplastic left ventricle and coarctation of the aorta, and the long-term results are described. There were the following important hemodynamic factors that led to the successful biventricular repair in the patient. Total systemic output was barely supplied through the hypoplastic left ventricle after closure of the ductus arteriosus on admission. The neonate underwent repair of coarctation of the aorta alone as the initial stage at 9 days after birth. Also, spontaneous closure of the foramen ovale following repair of coarctation of the aorta accelerated the progressive left ventricular growth. Open mitral commissurotomy with an interatrial fenestration using the modified Brawleys approach was performed for a 40-day-old infant. Good left ventricular growth and good mitral valve function have been observed for 18 years after open mitral commissurotomy. Appropriate early augmentation of left ventricular inflow through the mitral valve might be effective for growth of a hypoplastic left ventricle. J. Med. Invest. 64: 187-191, February, 2017.

Assessment of pulmonary arterial compliance evaluated using harmonic oscillator kinematics

We hypothesized that KPA, a harmonic oscillator kinematics-derived spring constant parameter of the pulmonary artery pressure (PAP) profile, reflects PA compliance in pediatric patients. In this prospective study of 33 children (age range = 0.5–20 years) with various cardiac diseases, we assessed the novel parameter designated as KPA calculated using the pressure phase plane and the equation KPA = (dP/dt_max)2/([Pmax – Pmin])/2)2, where dP/dt_max is the peak derivative of PAP, and Pmax – Pmin is the difference between the minimum and maximum PAP. PA compliance was also calculated using two conventional methods: systolic PA compliance (sPAC) was expressed as the stroke volume/Pmax – Pmin; and diastolic PA compliance (dPAC) was determined according to a two-element Windkessel model of PA diastolic pressure decay. In addition, data were recorded during abdominal compression to determine the influence of preload on KPA. A significant correlation was observed between KPA and sPAC (r = 0.52, P = 0.0018), but not dPAC. Significant correlations were also seen with the time constant (τ) of diastolic PAP (r = −0.51, P = 0.0026) and the pulmonary vascular resistance index (r = −0.39, P = 0.0242). No significant difference in KPA was seen between before and after abdominal compression. KPA had a higher intraclass correlation coefficient than other compliance and resistance parameters for both intra-observer and inter-observer variability (0.998 and 0.997, respectively). These results suggest that KPA can provide insight into the underlying mechanisms and facilitate the quantification of PA compliance.

Coil occlusion of aberrant arteries to pulmonary sequestration in a case with pulmonary atresia with intact ventricular septum: successful treatment of repetitive myocardial ischaemic attacks.

In this study, we describe an infant case of pulmonary atresia with intact ventricular septum associated with ventriculo-coronary arterial communication for which a modified Blalock-Taussig shunt operation was performed. He experienced repeated myocardial ischaemic attacks. Further examination revealed pulmonary sequestration in the right lower lobe. He therefore underwent a bidirectional Glenn operation and coil occlusion of the feeding arteries. His myocardial ischaemic attacks subsequently improved.