Fetal atrial septal aneurysm: a cause of fetal atrial arrhythmias.

Atrial arrhythmias are commonly found during fetal echocardiography performed during pregnancy to evaluate fetal arrhythmias. An association between atrial arrhythmias and an atrial septal aneurysm has been noted in children and adults. In this study, 105 fetuses were evaluated by fetal echocardiography, 39 (37%) referred to evaluate fetal arrhythmia and 66 (63%) to rule out congenital heart disease. An atrial septal aneurysm was found in 42 (40%) of the fetuses and an atrial arrhythmia in 37 (35%). An atrial septal aneurysm was found in 25 (64%) of the 39 fetuses referred to evaluate a fetal arrhythmia compared with only 17 (26%) of the 66 fetuses referred to rule out congenital heart disease. In this study, the association of an atrial septal aneurysm with an atrial arrhythmia was highly significant (p less than 0.001).

Correlates of aortic distensibility in chronic aortic regurgitation and relation to progression to surgery.

Aortic distensibility decreases with increasing age. Patients with chronic aortic regurgitation eject a large stroke volume into the proximal aorta. A decrease in distensibility of the aorta may impose a higher afterload on the left ventricule and may contribute to deterioration of left ventricular function over time. Accordingly, aortic distensibility was measured in 33 patients aged 13 to 73 years who had chronic isolated aortic regurgitation with minimal or no symptoms. Ascending aortic diameter was measured 4 cm above the aortic valve by two-dimensional echocardiography and pulse pressure was measured simultaneously by sphygmomanometry. Aortic distensibility was calculated as (Change in aortic diameter between systole and diastole/End-diastolic diameter)/Pulse pressure. Left ventricular systolic wall stress and mass were derived from standard M-mode echocardiographic measurements. Left ventricular volumes and ejection fraction were measured by radionuclide ventriculography. Aortic distensibility decreased logarithmically with increasing age (r = -0.62, p less than 0.001) and also correlated inversely with systolic wall stress, left ventricular mass and end-diastolic volume. Patients who eventually underwent aortic valve replacement for symptoms of left ventricular dysfunction had significantly lower aortic distensibility than did those who did not yet require valve replacement: 0.09 +/- 0.08 vs. 0.22 +/- 0.19 x 1/100 (1/mm Hg) (p less than 0.05). Thus, the reduced aortic distensibility that occurs with increasing age may contribute to the gradual left ventricular dilation and dysfunction seen in patients with chronic aortic regurgitation.

In utero pulmonary artery and aortic growth and potential for progression of pulmonary outflow tract obstruction in tetralogy of Fallot.

OBJECTIVES: This study was designed to define patterns of pulmonary artery and aortic growth in fetuses with tetralogy of Fallot and to determine the potential for in utero progression of right ventricular outflow tract obstruction. BACKGROUND: Despite an abundance of reports documenting the prenatal diagnosis of tetralogy of Fallot, there is little information about its course in utero. METHODS: Pulmonary artery and ascending aortic diameters were measured from prenatal and postnatal echocardiograms of 16 fetuses with tetralogy of Fallot, initially studied at 23.6 +/- 6.0 (mean +/- SD) weeks of gestation. Fetuses were classified retrospectively as having mild and severe tetralogy of Fallot according to whether the pulmonary artery circulation was (severe, n = 5) or was not (mild, n = 11) ductus arteriosus dependent at birth. RESULTS: Initial main pulmonary artery diameter was small for gestational age in 9 fetuses, large in 2 and normal in 5 compared with data from 57 gestational age-adjusted normal fetal studies; it was significantly smaller in the group with severe tetralogy of Fallot (p = 0.05). The initial main pulmonary artery/aortic diameter ratio was also smaller for the group with severe tetralogy of Fallot (0.50 +/- 0.15 vs. 0.73 +/- 0.14 in the group with mild tetralogy of Fallot, p = 0.01). Initial aortic and branch pulmonary artery diameters tended to be normal or near normal for age. In eight fetuses serially studied, main and branch pulmonary artery growth was normal or reduced during prenatal follow-up. Pulmonary artery growth was most reduced in two fetuses in the group with severe tetralogy of Fallot, resulting in pulmonary artery hypoplasia at birth. Two fetuses with valvular pulmonary atresia at birth had previously shown anterograde pulmonary outflow in midgestation, suggesting progression of pulmonary outflow obstruction. CONCLUSIONS: The postnatal spectrum of pulmonary artery size in tetralogy of Fallot can be attributed to variable patterns of growth in utero. Main pulmonary artery size, main pulmonary artery/aortic diameter ratio and pattern of pulmonary artery growth may be predictive of the severity of postnatal pulmonary outflow obstruction. Pulmonary atresia can develop in utero in some fetuses with tetralogy of Fallot.

Comparison of echocardiographic acoustic quantification with off-line manual tracing for determining left ventricular volume and ejection fraction in pediatric patients.

Echocardiographic measurement of left ventricular systolic and diastolic volume and ejection fraction in pediatric patients by acoustic quantification using automated border methods compares well with measurements done by manual trace. The time necessary for completion of measurements was similar for the two methods.

Relation of atrial size and function to Doppler indexes of diastolic function in normal human fetuses.

Fetal atrial function is compared with diastolic ventricular function indexes. The falloff of hyperfunction in fetal atrial contraction patterns matches sequentially the lessening of A wave dominance in the Doppler filling patterns for both ventricles.

The timing of spontaneous closure of the ductus arteriosus in infants with respiratory distress syndrome.

Previous studies evaluating the incidence of patent ductus arteriosus have not made a distinction between physiologic ductal patency and abnormally persistent ductus arteriosus. However, it has recently been shown that healthy premature infants without respiratory distress syndrome (RDS) undergo spontaneous closure of the ductus arteriosus in the first 4 days of life at times comparable to full-term infants. Thus, ductal patency within this time frame would appear to be physiologic. Although sick premature infants are well recognized to be at risk for ductal shunting, the purpose of this investigation was to evaluate systematically the actual impact that RDS has on duration of ductal shunting by assessing the timing of spontaneous functional closure. The presence of ductal shunting was evaluated using echocardiographic color flow Doppler techniques. Thirty-six premature infants (30 to 37 weeks gestational age) were evaluated. By the fourth day of life, only 4 of 36 (11.1%) of the infants continued to have evidence of ductal patency. The remainder of the infants underwent spontaneous functional closure of the ductus arteriosus at times comparable to healthy infants without RDS. For most infants greater than or equal to 30 weeks gestation, uncomplicated RDS does not alter the usual timing of functional ductal closure.

Effect of left ventricular wall mass on Doppler filling patterns in the developing normal human heart.

To assess gestational age- and growth-related changes in left ventricular (LV) size, LV wall, and LV transmitral flow velocity patterns, 2-dimensional (2-D) and Doppler echocardiographic studies were performed in 89 normal fetuses aged 16 to 38 weeks. Serial studies were designed in 7 fetuses. Variables measured from 4-chamber views were chamber areas and myocardial wall areas. From these measurements, area shortening fraction and ratio of myocardial wall area to end-diastolic chamber area were calculated. LV end-diastolic chamber area and myocardial wall area increased exponentially with advancing gestational age (r = 0.88 and 0.90, respectively, p < 0.001). Area shortening fraction showed no significant changes with gestational age. Ratio of myocardial wall area to LV end-diastolic chamber area decreased gradually with increasing gestational age (r = -0.77, p < 0.001). With increasing gestational age, mitral peak velocities of early diastole increased (r = 0.82, p < 0.01) with little change in peak velocity during atrial contraction. Multiple regression analysis showed that age-related increases in peak velocity of early diastole were related to advancing gestational age and also to decreases in ratio of myocardial wall area to LV end-diastolic chamber area. Low peak filling velocities during early diastole in younger fetuses may be related partly to relative increase in LV wall mass. The gestational age-related decreases in LV wall mass may be one of the important mechanisms of gestational age-related alterations in diastolic properties, especially relaxation processes.

Gestational age- and growth-related alterations in fetal right and left ventricular diastolic filling patterns.

To evaluate the effects of gestational age on left and right ventricular diastolic filling in human fetuses, we retrospectively reviewed the diastolic flow velocity patterns through mitral and tricuspid valves in 307 normal fetuses aged 17 to 39 weeks' gestation. The subjects were divided into 3 age groups; 17 to 24 weeks, 25 to 31 weeks, and 32 to 39 weeks. The variables measured were peak flow velocities of early diastole (peak E wave), of atrial contraction (peak A wave), and the velocity ratio (peak E/A ratio). As a whole, the transmitral peak E wave and peak E/A ratio correlated with age using a second-order polynomial curve fit. The strength of the linear correlation between age and transmitral peak E wave and peak E/A ratio and the slope of the relation were greater in the group aged 32 to 39 weeks than in group aged 25 to 31 weeks. Similar temporal change was observed in the relation between age, transtricuspid peak E wave, and peak E/A ratio. The peak A wave for both atrioventricular valves showed little change with gestational age. Contrary to the accepted concept that fetal peak E wave and peak E/A ratio increases linearly with aging, this study shows that early diastolic filling increases mainly after 25 weeks' gestation. We speculate that the maturational changes in ventricular properties in human fetuses accelerate after midgestation.

Doppler echocardiographic evaluation of ventricular diastolic filling in fetuses with ductal constriction.

To assess ventricular diastolic filling in fetuses with constriction of ducts arterious, 43 fetuses of pregnant women receiving indomethacin (100 to 150 mg/day) were examined with Doppler echocardiography. Ductal constriction occurred in 21 fetuses, defined as maximal systolic velocity > 140 cm/s and diastolic flow velocity > 30 cm/s. The variables measured to assess diastolic function were peak velocity during early diastole (peak E wave), peak velocity during atrial contraction (peak A wave), and the velocity ratio (peak E/A ratio); these were compared to maximal ductal flow velocity during systole and diastole. The mitral peak E wave, peak A wave, and peak E/A ratio in fetuses with ductal constriction showed no significant difference from those in fetuses without ductal constriction. In fetuses with ductal constriction, the tricuspid A wave increased significantly without changes in the peak E wave (57 +/- 9 vs 50 +/- 6 cm/s, p < 0.01) and the peak E/A ratio was significantly lower than in fetuses without ductal constriction (0.57 +/- 0.10 vs 0.65 +/- 0.08, p < 0.05). In 9 fetuses with ductal constriction, we compared the Doppler tricuspid E wave, A wave, and E/A ratio during indomethacin administration with those after withdrawal of the drug for a mean of 24 hours. Both systolic and diastolic ductal flow velocities in the fetuses returned to normal range after discontinuation of indomethacin. The tricuspid peak A wave decreased (59 +/- 9 vs 50 +/- 11 cm/s) and the E/ A ratio increased significantly (0.56 +/- 0.07 vs 0.69 +/- 0.07) (both p < 0.01) without any significant change in peak E wave after discontinuation of indomethacin. This study suggests that ductal constriction influences Doppler patterns of right ventricular diastolic filling. These changes could be related to the increased afterload presented to the right ventricle which might affect diastolic function.

Evaluation of systolic and diastolic ventricular performance of the right ventricle in fetuses with ductal constriction using the Doppler Tei index.

Fetal ductal constriction (DC) can depress right ventricular (RV) function. However, noninvasive assessment of fetal RV function remains difficult. We evaluated RV and left ventricular (LV) performance in fetuses with DC using the Doppler-derived Tei index. The Tei index measures the ratio of total time spent in isovolumic contraction and relaxation (isovolumic time) to the ejection time. Tricuspid inflow and RV outflow Doppler traces for the derivation of RV Tei indexes and mitral inflow and LV outflow traces for LV Tei indexes were measured in 78 fetuses of pregnant women who received indomethacin and 70 normal fetuses (gestational ages ranging from 20 to 39 weeks). DC occurred in 23 fetuses, defined as pulsatility index <1.9. In fetuses with DC, the RV isovolumic time was prolonged and RV ejection time was shortened, and the RV Tei index was high compared with those in fetuses that received indomethacin without DC and normal fetuses. Also, the RV Tei index clearly separated the fetuses with DC from normal and fetuses that received indomethacin without DC (0.74 +/- 0.14 vs 0.35 +/- 0.07 and 0.37 +/- 0.06, respectively; p <0.0001). The LV Tei index was not affected by DC. Serial study in 7 fetuses with DC showed that the RV Tei index decreased from 0.69 +/- 0.12 to 0.38 +/- 0.04 (p = 0.0002) after discontinuation of indomethacin coincident with ductal relaxation, although it remained elevated in 2 cases at the time of ductal relaxation. Thus, the Tei index is a useful and sensitive indicator for detecting abnormal RV performance in fetuses with DC.

New echocardiographic windows for quantitative determination of aortic regurgitation volume using color Doppler flow convergence and vena contracta.

Color Doppler images of aortic regurgitation (AR) flow acceleration, flow convergence (FC), and the vena contracta (VC) have been reported to be useful for evaluating severity of AR. However, clinical application of these methods has been limited because of the difficulty in clearly imaging the FC and VC. This study aimed to explore new windows for imaging the FC and VC to evaluate AR volumes in patients and to validate this in animals with chronic AR. Forty patients with AR and 17 hemodynamic states in 4 sheep with strictly quantified AR volumes were evaluated. A Toshiba SSH 380A with a 3.75-MHz transducer was used to image the FC and VC. After routine echo Doppler imaging, patients were repositioned in the right lateral decubitus position, and the FC and VC were imaged from high right parasternal windows. In only 15 of the 40 patients was it possible to image clearly and measure accurately the FC and VC from conventional (left decubitus) apical or parasternal views. In contrast, 31 of 40 patients had clearly imaged FC regions and VCs using the new windows. In patients, AR volumes derived from the FC and VC methods combined with continuous velocity agreed well with each other (r = 0.97, mean difference = -7.9 ml +/- 9.9 ml/beat). In chronic animal model studies, AR volumes derived from both the VC and the FC agreed well with the electromagnetically derived AR volumes (r = 0.92, mean difference = -1.3 +/- 4.0 ml/beat). By imaging from high right parasternal windows in the right decubitus position, complementary use of the FC and VC methods can provide clinically valuable information about AR volumes.

Immediate echocardiography in the management of acute respiratory exacerbations of cardiopulmonary disease. A prospective study.

This prospective study was done to determine whether immediate echocardiography, to implicate or exclude a cardiac basis for breathlessness, can improve the management of acute dyspnea. One hundred ninety-six consecutive patients admitted to the hospital with a chief complaint of dyspnea were randomized to receive or not receive an echocardiogram within 24 hours of admission. Most patients randomized to echo and control groups had cardiac or pulmonary disease and were comparable in their other clinical characteristics. Predefined study end points included the following: change in diagnosis or treatment; performance of additional diagnostic cardiopulmonary studies; and duration of hospitalization (the principal end point). Changes in diagnosis or treatment during hospitalization were as infrequent among patients randomized to echo as among control patients. Echocardiography independently confirmed the clinical diagnosis in 72 percent of echo-randomized patients. Even when echo findings conflicted with the clinical diagnosis, the diagnosis and management plan rarely changed. Additional cardiac or pulmonary studies were ordered as frequently among patients randomized to echocardiography as among those randomized to control. The mean duration of hospital stay also did not differ between the two groups, and no clinical parameter served to predict which subgroup of patients might benefit from echocardiography. Although echocardiography can be expeditiously obtained during respiratory exacerbations of cardiopulmonary disease, indiscriminate echo does not necessarily hasten or alter the treatment of such patients.

Cleft in the anterior and posterior leaflet of the mitral valve: a rare anomaly.

A rare entity that causes congenital mitral regurgitation is an isolated cleft mitral valve. The cleft in the mitral valve can be seen in either the anterior or posterior leaflet of the valve. We present a unique case of an individual with a history of congenital mitral regurgitation caused by a cleft in both the anterior and posterior leaflets of the mitral valve.

Views of physicians in training on the ethical and legal issues in preliminary reporting of echocardiographic data.

Cardiac sonographers may be pressured by physicians into giving diagnostic interpretations of echocardiographic data. This study investigated the issue of preliminary reporting of echocardiographic data. A questionnaire was sent to 292 physicians; 85 physicians (29%) responded. Seventy-two physicians (87%) thought they had more than a minimal knowledge of echocardiography, 94% wanted a written or verbal preliminary report, and 84% thought that giving a preliminary report should be part of the cardiac sonographer's job. If abnormalities were found, 80% wanted the results before a cardiologist reviewed the study, and 56% would want a diagnostic rather than a descriptive report. Fifty-four physicians (64%) would pressure the cardiac sonographer into giving a preliminary echocardiographic report and would use this information to manage the patient. The majority of the physicians thought that it is legal for the cardiac sonographer to give a preliminary echocardiogram report. Eighty percent said that the cardiac sonographer would not be "practicing medicine without a license," and 82% that the sonographer would not be "aiding and abetting the unauthorized practice of medicine." This data would indicate that physicians at Oregon Health Sciences University want the cardiac sonographer to give preliminary echocardiographic results, even though the sonographer may be breaking state statutes.

Occupational health hazards to the ultrasonographer and their possible prevention.

Occupational health hazards in ultrasonography are becoming more prevalent as the field continues to grow. Eye strain, musculoskeletal pain or injury, carpal tunnel syndrome, repetitive strain injuries, stress, burnout, and other hazards have been addressed as concerns in other studies and surveys. These topics are discussed, as well as the possible preventive measures that may be used to maximize and maintain the ultrasonographer's well-being throughout his or her career.

Echocardiographic imaging techniques with subcostal and right parasternal longitudinal views in detecting sinus venosus atrial septal defects.

Sinus venosus atrial septal defects are frequently missed and difficult to visualize with conventional two-dimensional echocardiographic views. Using modified subcostal and right parasternal longitudinal views, nine patients were found to have a sinus venosus atrial septal defect. The modified subcostal view showed a sinus venosus atrial septal defect in all nine patients; three patients had secundum atrial septal defects as well. The right parasternal view detected only six patients with sinus venosus atrial septal defect. Partial anomalous pulmonary venous return was diagnosed in seven patients using these views. The combination of subcostal and right parasternal longitudinal imaging views will improve the detection of sinus venosus atrial septal defects.

Academic physicians' opinions on preliminary reporting of echocardiographic data.

Preliminary reporting of echocardiographic data by cardiac sonographers has become a key issue in the echocardiography community. A survey on this issue was sent to 248 academic physicians and 89 (35.8%) were returned. In response to a question in the survey, 76 physicians stated that they had at least a limited amount of knowledge in echocardiography. For the group, 62% wanted a written or verbal preliminary report and 52% concluded that this report should be a part of the cardiac sonographer's position. If cardiac abnormalities are suspected, 65% wanted the results before the cardiologist reviewed the study, but only 42% of the physicians wanted a diagnostic versus a descriptive type of report. About 49% stated that if necessary they would attempt to influence the cardiac sonographer to give them a preliminary report, whereas 67% of the physicians would possibly use this information to medically manage the patient. Fifty percent believed that it was legal for a cardiac sonographer to give a preliminary report. Another 70% said that the cardiac sonographer would NOT be "practicing medicine without a license" and 66% concluded that they would NOT be "aiding and abetting the unauthorized practice of medicine" if given this information. These data have important potential ramifications for both cardiac sonographers as well as for the practice of cardiology regarding the issue of preliminary echocardiographic reports.

Contributions of color Doppler to the evaluation of cardiovascular abnormalities in the fetus.

The applications of color Doppler sonography are reviewed in this article. Color Doppler is an efficient and time-saving means of assessing normal and abnormal flow in the fetus, making it an essential part of the echocardiographic examination for fetal congenital heart disease. In survey mode, color Doppler can be used to quickly evaluate whether flow channels are normal and to detect abnormal flow patterns. These abnormal flow patterns can then be examined further by pulsed or continuous wave Doppler, if needed. Color Doppler, which is subject to less rib shadowing than other Doppler techniques, also can help in assessing the fetal heart when there is less-than-adequate gray scale imaging.