DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN

DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN Milad El-Segaier, MD Division of Paediatric Cardiology, Department of Paediatrics, Lund University Hospital, Lund, Sweden SUMMARY Despite tremendous development in cardiac imaging, use of the stethoscope and cardiac auscultation remains the primary diagnostic tool in evaluation of cardiac pathology. With the advent of miniaturized and powerful technology for data acquisition, display and digital signal processing, the possibilities for detecting cardiac pathology by signal analysis have increased. The objective of this study was to develop a simple, cost-effective diagnostic tool for analysis of cardiac acoustic signals. Heart sounds and murmurs were recorded in 360 children with a single-channel device and in 15 children with a multiple-channel device. Time intervals between acoustic signals were measured. Short-time Fourier transform (STFT) analysis was used to present the acoustic signals to a digital algorithm for detection of heart sounds, define systole and diastole and analyse the spectrum of a cardiac murmur. A statistical model for distinguishing physiological murmurs from pathological findings was developed using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to evaluate the discriminating ability of the developed model. The sensitivities and specificities of the model were calculated at different cut-off points. Signal deconvolution using blind source separation (BSS) analysis was performed for separation of signals from different sources. The first and second heart sounds (S1 and S2) were detected with high accuracy (100% for the S1 and 97% for the S2) independently of heart rates and presence of a murmur. The systole and diastole were defined, but only systolic murmur was analysed in this work. The developed statistical model showed excellent prediction ability (area under the curve, AUC = 0.995) in distinguishing a physiological murmur from a pathological one with high sensitivity and specificity (98%). In further analyses deconvolution of the signals was successfully performed using blind separation analysis. This yielded two spatially independent sources, heart sounds (S1 and S2) in one component, and a murmur in another. The study supports the view that a cost-effective diagnostic device would be useful in primary health care. It would diminish the need for referring children with cardiac murmur to cardiac specialists and the load on the health care system. Likewise, it would help to minimize the psychological stress experienced by the children and their parents at an early stage of the medical care

Complete atrio-ventricular septal defect and Wolf-Parkinson-White syndrome

A full term female infant was born after 41 weeks of gestation, with a birth weight of 3815g and normal Apgar scores (9-10-10). Immediately after birth tachycardia was noted. An electrocardiogram (ECG) showed a heart rate of 300 beats per minute (bpm) and narrow QRS complexes. The newborn was clinically stable. She was admitted to the neonatal intensive care unite and an intravenous line was inserted for treatment with Adenosine. While preparing for Adenosine infusion her heart rate spontaneously decreased. Her ECG at presentation with normal heart rate is shown in figure1a. On auscultation, a soft systolic murmur was heard

Cardiac rhabdomyoma mimicking haemodynamics of hypoplastic left heart syndrome

Cardiac rhabdonnyomas are rare and often regress spontaneously. However, the management of rhabdomyoma with severe inflow and outflow obstructions is a challenge. An infant with a massive left ventricular rhabdomyoma mimicking the haemodynamics of hypoplastic left heart syndrome is reported. Surgery could not be contemplated because the mitral valve leaflets and chordae were imbedded in the tumour mass. The arterial duct (AD) was kept open to perfuse the systemic circulation and palliations with pulmonary artery branch banding and AD stenting were planned. However; while waiting for spontaneous regression of the tumour, the child died of circulatory collapse when 4 weeks old

60. A three years old girl with atrial septal defect associated with multiple coronary artery micro-fistulas to the left ventricle

Congenital coronary artery fistulas are rare anomalies. Most of these fistulas drain to the right side of the heart. They seldom connect to either left atrium or left ventricle. We report a three years old girl in whom an atrial septal defect (ASD) was diagnosed. Echocardiography suggested a possible additional coronary artery fistula to the left ventricle (LV). Before closing the ASD, coronary angiography identified multiple coronary artery fistulas to the left ventricle. Transcatheter closure of the ASD was done successfully. The hemodynamic effect of coronary artery fistula to LV after ASD closure is discussed along with literature review of this extremely rare association

Recanalization of arterial duct is feasible, effective and its potential risks are treatable

Background Recanalization of arterial duct (AD) is rarely needed. Objective The aim of this study is to report our experience regarding the feasibility and effectiveness of arterial duct recanalization in three infants and review the relevant literature. Methods and results We report on three patients with decreased pulmonary blood flow after initial palliation. The first patient had pulmonary atresia (PA) and an intact ventricular septum. He needed recanalization of the AD after pulmonary valve perforation and dilatation. The second patient had PA and ventricular septal defect (VSD). His AD originated from the left subclavian artery. He required AD recanalization after palliation with a central shunt and clipping of the duct. During intervention he developed a thrombus in the stent, which was treated successfully using thrombolytic treatment. The third patient had PA and VSD. The arterial duct originated from the left subclavian artery and was recanalized after spontaneous closure despite prostaglandin infusion. During the procedure the patient had severe desaturation and bradycardia requiring resuscitation for two minutes. All infants had successful arterial duct recanalization and stenting. Additionally, they were clinically stable during follow-up. Conclusion Arterial duct recanalization and stenting is a feasible and effective procedure in selected cases, and its risks are treatable. Long-term studies are required