Synchronization of the acoustic evidence in the assassination of President Kennedy.

We have revisited the acoustic evidence in the Kennedy assassination--recordings of the two Dallas police radio channels upon which our original NRC report (Ramsey NF et al., Report of the Committee on Ballistic Acoustics. National Research Council (US). Washington: National Academy Press, 1982. Posted at http://www.nap.edu/catalog/10264.html) was based--in response to the assertion by DB Thomas (Echo correlation analysis and the acoustic evidence in the Kennedy assassination revisited. Science and Justice 2001; 41: 21-32) that alleged gunshot sounds (on Channel 1), apparently recorded from a motorcycle officer's stuck-open microphone, occur at the exact time of the assassination (as established by emergency communications on Channel 2). We have critically reviewed these two publications, and have performed additional analyses. In particular we have used recorded 60 Hz hum and correlation methods to obtain accurate speed calibrations for recordings made on both channels, cepstral analysis to seek instances of repeated segments during playback of Channel 2 (which could result from groove jumping), and spectrographic and correlation methods to analyze instances of putative crosstalk used to synchronize the two channels. This paper identifies serious errors in the Thomas paper and corrects errors in the NRC report. We reaffirm the earlier conclusion of the NRC report that the alleged "shot" sounds were recorded approximately one minute after the assassination.

Cor triatriatum associated with partial anomalous pulmonary venous connection to the coronary sinus: echocardiographic and angiocardiographic features.

An infant girl is described who had cor triatriatum and partial anomalous pulmonary venous connection of the left pulmonary veins to the coronary sinus, the first report of this combination of lesions. The infant also had a Dandy-Walker malformation and multiple facial and intrathoracic hemangiomas. The cardiac diagnosis was made by two-dimensional echocardiography. Cardiac catheterization and angiography confirmed the findings and also demonstrated a persistent left superior vena cava draining to the coronary sinus. The infant underwent successful surgical repair. Partial anomalous pulmonary venous connection and left superior vena cava not infrequently are associated with cor triatriatum. Although two-dimensional echocardiography is sensitive for the detection of cor triatriatum, preoperative cardiac catheterization is necessary to identify unequivocally systemic and pulmonary venous connections.

Digital subtraction angiography in patients with transposition of the great arteries after surgical repair.

Digital subtraction angiography was used for postoperative evaluation of seven patients who underwent the Senning procedure for repair of d-transposition of the great arteries. Their ages ranged from 2.5 to 3 years. The patients were premedicated with methohexital (25 mg/kg rectally), and 0.3 to 0.4 ml/kg of diatrizoate was injected into a peripheral vein through a plastic needle. Images were obtained on a Technicare DR-960 or Diasonics DA 100 digital angiographic unit at four frames per second using 256 X 256 matrix and a 6 inch (15.24 cm) field size. In all patients, the venous systems, cardiac chambers and great arteries were well visualized. Two patients had obstruction of the superior vena cava with a dilated azygos vein draining into the inferior vena cava. One patient had severe obstruction of the left pulmonary artery. Digital subtraction angiography is safe and easy to perform and appears to be a valuable alternative method for evaluating patients after surgical repair of transposition of the great arteries. The small amount of contrast material required and the low radiation dose make it attractive for use in children.

Transfemoral snaring of broken catheters from the right heart in small infants.

Successful retrieval of embolized central venous catheter fragments from the right heart was accomplished in two small infants weighing 2100 and 4050 Gm respectively. The catheters had been broken off at the site of entry into the vein and migrated to right atrium. A 5F end-hole Cook catheter with 0.018 inch diameter, 125 cm long Curry snaring wire with flexible mid-segment was successfully utilized through the femoral vein percutaneously to remove the foreign body without complication.

Apnea recordings of healthy infants at 40, 44, and 52 weeks postconception.

A total of 129 recordings of the respiratory activity of 46 normal full-term infants were obtained continuously for 24 hours in the hospital nursery at 3 days of life and in the home environment at 4 weeks and 12 weeks after birth. The pediatric pneumogram (PPG) technique, an impedance method, was used. Pneumogram data over longer than 16 hours was obtained on 77% of infants monitored. No infants experienced apnea longer than 15 seconds in duration at 40 and 44 weeks postconception, or greater than 11 seconds at 52 weeks postconception. Twenty-four hour plots of hourly apnea frequency revealed a marked variability, with evidence of clustering of apneic episodes during periods of reported sleep. Longest apnea time and hourly frequency of apneic episodes were highly correlated.