Katsuro Igarashi

Elucidation on sudden death in children with the mucocutaneous lymph node syndrome.

Atrial pacing was carried out in six children aged one year to eleven years with the mucocutaneous lymph node syndrome (MCLS) during cardiac catheterization. The cardiac index (CI) was measured before pacing and at pacing rates of 150 and 180/min. The CI increased in cases which did not show any pathological findings on the coronary artery angiograms. Conversely, CI decreased at a pacing rate of 150/min, in the case which showed arterial stenosis. Atrial pacing with measurement of CI may be a good method for detecting and evaluating coronary artery lesions in children with MCLS.

A Study on Sudden Death from Kawasaki Disease as Viewed from Myocardial Metabolism

Mucocutaneous lymph node syndrome (Kawasaki disease) is an acute febrile disease. Mainly infants contract the disease, the cause of which is yet to be elucidated. The criteria (1978) for diagnosis of this disease are as shown in Table 1 . Since this disease was reported for the first time by Kawasaki in 1967, about 29,000 people have contracted it in Japan and of them, about 270 died suddenly [ 61. The cause of this sudden death is said to be vascular lesions pathologically. That is, rupture of coronary aneurysm, coronary insufficiency caused by stenosis or obstruction due to thrombogenesis in coronary aneurysm and myocarditis in the acute stage may be mentioned as the possible causes [61.

Effect of the Thiamylal Sodium on the Cardiac Function

Twelve adult rabbits weighing from 4 to 5 kg were anesthetized intravenously with thiamylal sodium and their cardiac function was investigated. As the parameter of the cardiac function, heart rate, arrhythmia and stroke volume were studied by noninvasive methods. The depth of anesthesia was determined by simultaneous recording of the electroencephalogram and the respiration movement curve. The depth of anesthesia was divided into 6 stages simply: 1) stage of nonanesthesia, 2) stage of light anesthesia, 3) stage, of moderate anesthesia, 4) stage of slightly deep anesthesia, 5) stage of deep anesthesia, 6 ) stage of very deep anesthesia. Heart rate decreased about 10% in the stage of moderate anesthesia comparing with the stage of non-anesthesia. The conduction disturbances were seen in the stage of deep and very deep anesthesia. Stroke volume decreased according to the depth of anesthesia. At the ventricular extrasystole in the stage of deep anesthesia, stroke volume more decreased. Furthermore blood was little ejected at the ventricular extrasystole in the stage of very deep anesthesia. As mentioned above, it is necessary to consider enough what stage of anesthesia is the subject.

Fundamental Properties of Precordial Vibration

The apex beat named precordial vibration (PV) was caused by the transmission of cardiac forces to the chest wall. The fundamental properties of PV were studied. Twenty subjects without heart diseases ranging from 3 to 13 years of age were studied. They were kept at rest with eyes closed in the supine position. The MT-3T pick up equipped with an accelerative piezoelectric element (Nihon Kohden Kohgyo Co., Tokyo) was attached to the skin near the apex region by aid of a both-side adhesive tape. It was recorded simultaneously with the electrocardiogram, the plethysmogram and the respiration movement curve. Furthermore, a medical data computer (Signalprocessor, SanPi Sokki Co. , Tokyo) was equipped and the autocorrelation and the power spectram of PV were obtained. As the result, the regularity was in the wave of the PV and the dominant frequency characteristic in the spectrum density of PV was from 25 to 42 Hz.

Ballistocardiography Simplified by Recording Microvibration of the Parietal Skin Surface in Childhood

The microvibration (MV) which is invisible by naked eyes on the parietal skin furface and the ballistocardiogram (BCG) obtained by means of von Wittern’s low frequency table modified by Nihon Kohden Co., were simultaneously recorded on 120 subjects without cardiovascular diseases and ranging from ’ to 16 years of age and from 4 to 60 kg of weight. The dominant waves of the MV showed a pattern very similar to the BCG in the subjects whose weight was more than about 15 kg. The frequency components of the parietal MV were about from 4 to 8 Hz. The cross correlation function between the BCG and the parietal MV was about 0.9. The parietal MV recording was suggested to be used as a simple substitute for the conventional ballistocardiography in the subjects whose weight was more than about 15 kg. On the other hand, simultaneous recordings of the parietal MV and the BCG were not always well performed in the subjects whose weight was less than about 15 kg: among them, the frequency components of the parietal MV were suggested to be about from 8 to 10 Hz. These data show that the parietal MV will be useful as a simple substitute for the BCG in childhood.

Bedside Technics for the Evaluation of the Heart Failure in Infants and Children

The microvibration (MV) on the scalp as a substitute for the conventional ballistocardiogram and electrocardiogram (ECG) of the limb lead II were simultaneously recorded on 120 healthy subjects and 26 patients with heart failure ranging in age from newborn to school children. The duration from the Q wave of the ECG to the J deflection of the MV was measured in seconds as the Q‐J interval. The Q‐J interval might be thought to represent the duration from the ventricular depolarization to the ejection period of the ventricular mechanical systole. In other words, it was the pre‐ejection period added to mechanical ejection period. The prolongation in the Q‐J interval correlated with age in healthy subjects being related inversely to the heart rate. In patients with heart failure, the Q‐J interval prolonged. The prolongation of the Q‐J interval correlated well with the myocardial contractile abnormality. This MV recording can be used for easy procedure in the bedside evaluation of cardiac performance in infants and children.

The Study of Orthostatic Dysregulation Mechanism

In the present report, the generating mechanism of the orthostatic dysregulation (O.D.) was studied by noninvasive approaches. 1. Two groups of children, 47 healthy subjects and 28 patients with O.D., ranging from 7 to 13 years of age were selected. 2. They were examined at rest in the supine position horizontally and in the 20 head up tilt position on a tilted flat table. The microvibration (MV) on the scalp was used as a mean €or estimating cardiac output and the plethysmogram (PTG) was 3. used for estimating peripheral resistance. When changing the position, the amplitude in the dominant vibration of MV was smaller in the O.D. patients than that in the healthy children, while the primary wave of the PTG didn’t decrease in the O.D. patients. 5. From the above-mentioned results, it seems to be likely that so-called O.D. will be caused by disharmony of the cardiac output with the peripheral vascular resistance, when changing the position. 4.