These are still-frames of the parasternal long axis view with color Doppler in our patient. On the left, red color indicates flow through the ventricular septal defect from left ventricle to right ventricle. On the right, blue color indicates flow from right ventricle into left ventricle and aorta. In the real-time study that follows, note the uniform color of each of these flows, indicating absence of turbulence, as these flows are unrestricted.
2-D parasternal short axis
This is still-frame of a 2-dimensional echocardiogram in the parasternal short axis view in our patient. Labels identify the aorta, ventricular septum, right ventricular infundibulum, pulmonary valve and right and left pulmonary arteries. The real-time color Doppler follows.
Spectral wave Doppler - RVOT
This is still-frame of a spectral wave Doppler from the same parasternal short axis view showing the velocity of flow through the right ventricular outflow tract. The maximum velocity is approximately five meters per second, indicating that the maximal systolic pressure difference is approximately 100 mmHg. This value is consistent with equal right and left ventricular systolic pressures and normal or low pulmonary artery pressure. Pressure difference equals four times the velocity squared.
Another patient
These are still-frames of the short axis view of the aorta at the level of the coronary arteries in another patient with tetralogy of Fallot. There is a single right coronary artery that gives rise to the left coronary artery. The left coronary artery then passes across the right ventricular outflow tract, not seen in this view.
Another patient - anomalous LCA
In this case, the structure seen is the entire left coronary artery system that arises anomalously from the right coronary artery. It then crosses the right ventricular infundibulum before dividing into the left anterior descending and circumflex coronary arteries. More often, only the left anterior descending coronary artery arises from the right coronary artery. These coronary artery anomalies occur in five to ten percent of patients with tetralogy of Fallot. It is a critical anomaly to identify, as it creates significant technical difficulty for surgically relieving right ventricular infundibular stenosis. Failure to identify it may result in injury to the artery during surgery, thereby increasing both mortality and morbidity of the procedure.
Another patient - 2-D & color flow Doppler
This is a still-frame of a 2-dimensional echocardiogram from the 4-chamber view in another patient with tetralogy of Fallot in which other views identify the presence of the usual large ventricular septal defect and right ventricular infundibular stenosis. Note the break in the muscular portion of the ventricular septum indicated by the arrow. This suggests the presence of an additional ventricular septal defect in this location. In the real-time color flow Doppler that follows, note the uniform red flow across the defect confirming its presence. This is another important abnormality to identify from the standpoint of surgical repair. Note that in this isolated view, only the left-to-right shunt is seen.