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

Abstract

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. Need for the investigation on cardiac performance in infants and children with congenital heart disease has been increased. Inspite of many noninvasive approaches, few useful expression of cardiac performance can be applied at the bedside in the pediatric field. Measurement of the systolic time intervals of left ventricular systole from simultaneous recordings of the electrocardiogram, the phonocardiogram and the carotid arterial pulsation determined the systolic phases of the cardiac cycle.1) These means are convenient detecting changes in cardiac performance for adults, but it is very difficult to record the carotid arterial pulsation in infants and children because of the constitutional problems. On the other hand, the systolic phases of the cardiac cycle were determined from simultaneous recordings of the electrocardiogram and the ballistocardiogram by Thompson2) in 1953. The ballistocardiogram recording had many problems to be solved. One of them was that the ballistocardiographic table was made for adults and the other was that the ballistocardiographic records were unsuitable for tachycardiac subjects such as infants. Because of the above mentioned reasons, the ballistocardiographic research did not progress in the pediatric field, 3)4)5)6) and the measurement of the wave of the ballistocardiogram was difficult at this age.