The Development of Color Doppler Echocardiography: Innovation and Collaboration.

Conception, development, innovation, introduction, and validation are some of the steps in the introduction of new technologies and their clinical applications. More than 50 years ago, Doppler techniques and applications were introduced into echocardiography. An important further addition was the introduction of color as a medium for the display of Doppler information. The amplitude of the returning ultrasound signal has been used to generate a black and white image of structure. The phase shift between the transmitted and returning Doppler signal has been used to display Doppler shift information in color. This review focuses on some of the resources critical to this new development, the challenges imposed by the introduction of a new color display, and some of the early clinical validation and applications of color Doppler echocardiography.

Intraoperative echocardiography for atrioventricular canal: decision-making for surgeons.

Intraoperative echocardiography has become a standard patient management tool in the assessment of the patient undergoing surgical repair of a congenital cardiac defect. Over the past 15 years transesophageal echocardiography has emerged as an integral part of the intraoperative assessment of the congenital cardiac surgery patient. The important role of intraoperative echocardiography is largely because of its ability to define complex anatomy, identify functional abnormalities, and recognize flow disturbances at the time of surgical repair. Intracardiac defects are particularly suited to the strengths of intraoperative transesophageal echocardiography because of the unobstructed windows that can be obtained. This article focuses on how intraoperative echocardiography can guide surgical decision-making in the patient undergoing repair of an atrioventricular canal defect.

Direct microvascular repair of an infant's transected coronary artery: case report.

The authors report the direct, microvascular repair of a right coronary artery transected during reoperation fOr complications of arterial switch operation (ASO) in a 3 month-old child. This is the first documented use of direct microsurgical anastamosis in the repair of an infant's transected coronary artery. Deviation from standard coronary bypass graft repair was permitted by vessel characteristics, as well as close collaboration between plastic surgery and cardiac surgery services. Patency of repair was confirmed intraoperatively with Doppler ultrasound and through postoperative echocardiograms documenting stable right ventricular function. This case highlights the benefit of a multidisciplinary approach to an emergent clinical problem using microsurgical techniques.

Cause of normal pulmonic velocity in fetal tetralogy of Fallot.

In 10 fetuses with tetralogy of Fallot, 9 lacked high velocity across the obstructed right ventricular outflow tract, which we conclude was due to the parallel flow circulations created by the combination of ventricular septal defect and arterial duct. The normally high resistance in the fetal pulmonary vascular system substantially exceeds the resistance of the systemic vasculature, resulting in the maintenance of right-to-left ductal flow in all 10 fetuses who had only moderate pulmonary obstruction.

Utilization of intraoperative transesophageal echocardiography during repair of congenital cardiac defects: a survey of North American centers.

BACKGROUND: Intraoperative transesophageal echocardiography (TEE) has been increasingly utilized during repair of congenital cardiac defects. HYPOTHESIS: The aim of this study was to assess the practice of TEE in this setting. METHODS: A survey was sent to 70 centers in the United States and Canada; replies were obtained from 65 centers (93%). Responses were grouped into four categories: (1) Performance of intraoperative echocardiography, (2) performance practices, (3) equipment and probe issues, (4) billing and reimbursement. Data were available from all responding centers unless specified below. RESULTS: All responding centers employed intraoperative echocardiography, with 98% employing TEE. All responding centers employed intraoperative echocardiography. The majority of centers (72%) utilized intraoperative echocardiography in all cases or all open cases except atrial septal defects, while the remainder employed it selectively. The average duration of TEE experience at responding centers was 6.1 years. Transesophageal echocardiography was primarily the responsibility of cardiologists, with most centers having individuals meeting published TEE training guidelines. The large majority of centers performed both pre- and postbypass TEE studies. Equipment and probes were widely available. All centers disinfected the TEE probe between studies, but for longer times than recommended. CONCLUSION: Utilization of intraoperative TEE during surgery for congenital heart disease is widespread; the results of this survey may be useful to individual institutions as they evaluate their utilization of intraoperative echocardiography.

What is the feasibility of imaging coronary arteries during routine echocardiograms in children?

BACKGROUND: Abnormalities of coronary artery (CA) origins may be associated with sudden death. No data exist regarding the feasibility of routine echocardiographic imaging of CA in pediatrics. OBJECTIVE: Our aim was to determine the feasibility of imaging CA origins during routine echocardiograms. METHODS: One hundred randomly selected children without clinical evidence of heart disease were studied. The mean age was 13.8 +/- 6.4 years. Location of CA origins were tallied with clock-face reference. RESULTS: The left CA origin was imaged in 98% with the origin most commonly at 3:30 o'clock. The right CA origin was imaged in 95% with the origin most commonly at 11 o'clock. Four abnormalities of CA were discovered: right CA origin from the left coronary sinus n = 2, circumflex from right CA origin n = 1, and small left CA origin to pulmonary artery fistula n = 1. CONCLUSION: We conclude that imaging of CA origins during routine pediatric echocardiograms is feasible with a potentially life-saving result.

Effect of unilateral diaphragm paralysis on branch pulmonary artery flow.

BACKGROUND: Respiration is known to be a significant contributor to pulmonary flow in patients who have had Glenn or Fontan procedures. OBJECTIVE: The purpose of this study was to evaluate the effect of respiration on branch pulmonary artery flow in normal participants, in those with uncomplicated Glenn or Fontan procedures, and in those with uncomplicated biventricular (2V) repairs, and to compare them with similar groups of postoperative patients who had unilateral diaphragm paralysis. METHODS: Twenty-one normal infants and children were studied, along with 10 who had undergone uncomplicated bidirectional Glenn or Fontan palliation. Also studied were 10 patients with uncomplicated 2V repairs and 17 patients having ultrasound demonstration of diaphragm paralysis. Nine had undergone Glenn or Fontan procedures and 8 had undergone 2V repair. With the use of conventional pulsed Doppler, branch right and left pulmonary artery waveforms were recorded during spontaneous respiration. The velocity time integral (VTI); heart rate (HR); and systolic, diastolic, and mean velocities were measured at end-expiration and during inspiration. The pulsatility index (PI) (PI = systolic velocity - diastolic velocity/mean velocity) was calculated for each condition. RESULTS: In normal participants PI was 1.69 with a 4.7% increase with inspiration; VTI x HR was 1859. In patients who had undergone uncomplicated Glenn/Fontan procedures PI was 1.06 with a 27.5% increase with inspiration; VTI x HR was 1303, all P =.001 versus normal participants. In patients with 2V repairs PI was 1.7 with a 5.6% increase with inspiration; VTI x HR was 1850, all P = ns versus normal participants. Patients with Glenn/Fontan connections and diaphragm paralysis had lower PI (0.81), inspiratory increase (7.9%), and VTI x HR (610) on the affected side, all P =.001 versus the normal side, and versus patients who had undergone uncomplicated Glenn/Fontan procedures. Patients with 2V repair with a pulsatile source of pulmonary flow had a smaller significant difference in the measured indices. Three patients underwent diaphragm plication with improvement in PI, inspiratory increase in PI, and VTI x HR postplication. CONCLUSION: In normal participants and patients with uncomplicated 2V repair, inspiration has little effect on PI in branch pulmonary arteries. In patients who have undergone uncomplicated Glenn/Fontan procedures, PI is less than that of normal participants and the effect of inspiration is approximately 5-fold greater. This significant effect of inspiration on pulmonary flow is lost on the affected side in patients with Glenn/Fontan connections and diaphragm paralysis, and is blunted on the affected side in patients with 2V repair and diaphragm paralysis. Loss of diaphragm function is associated with redistribution of pulmonary flow away from the affected side.

The use of transesophageal echocardiography to facilitate removal of a thoracic nail.

IMPLICATIONS: Transesophageal echocardiography may be useful in guiding detection and removal of thorax penetrating objects and for the monitoring of complications after removal of such objects.