Definition of inseparably fused ventricular myocardium in thoracopagus: Fetal echocardiographic utility and pathologic refinement

Summary Correlative echocardiographic and pathological findings in a thoracopagus with conjoined hearts are reported. One twin had tricuspid atresia with discordant atrioventricular connections and concordant ventriculoarterial connections. The morphologic right ventricle was hypoplastic and there was a large muscular ventricular septal defect. The other twin had hypoplasia of the mitral valve anulus and left ventricle with double-outlet right ventricle and pulmonary valve atresia. The tricuspid valve was severely insufficient in part because of a large orifice and redundant, elongated leaflets with abnormal chordal attachments. The left ventricles of these two twins shared a perforated common free wall with at least two large defects allowing mixing of the circulations at that level. Not all anatomic details were established conclusively by fetal echocardiography; however, sufficient diagnostic information was obtained to support a decision not to aggressively resuscitate these twins after elective cesarean delivery at 31 weeks' gestation.     

Left atrial thrombi in non-rheumatic atrial fibrillation: assessment of prevalence by transesophageal echocardiography

To determine the prevalence of left atrial thrombus in hospitalized patients with non-rheumatic atrial fibrillation, 48 patients were consecutively studied with single-plane transesophageal echocardiography. There were 23 males (48%) and 25 females (52%). The mean age was 66±11 years (range 43–87). Thrombus was detected in 13 patients (27%) 11 were confined to the left atrial appendage, 1 to the atrial body and appendage, and 1 to the left upper pulmonary vein. Prevalence of atrial thrombus was not different among those patients with or without previous stroke [4/16 (25%) vs 9/32 (28%), p=NS] or between patients > 65 years and patients 65 years old (p=NS). Atrial thrombus was detected more frequently in patients with reduced left ventricular global systolic function than in those with normal function [7/14 (50%) vs 6/34 (17%), p<0.05]. In patients with spontaneous contrast echoes in the left atrium, thrombi were visualized more often than in those without spontaneous echoes [10/24 (41%) vs 3/24 (12%), p<0.05]. The finding of the atrial spontaneous contrast echoes was more frequent among patients with reduced left ventricular global systolic function [11/14 (78%) vs 13/34 (37%), p<0.02].We conclude that in hospitalized patients with non-rheumatic atrial fibrillation the prevalence of left atrial thrombus is high. Reduced left ventricular global systolic function identifies a subset of patients at high risk for formation of thrombus in the left atrium.     

Enhanced sensitivity for detection of coronary artery disease by addition of atropine to dipyridamole echocardiography

Dipyridamole echocardiography test (DET) has gained acceptancedue to its safety, feasibility, diagnostic accuracy and prognosticpower. The main limitation of the test is a less than idealsensitivity in some patient subsets, such as those with limitedcoronary artery disease. Atropine with dipyridamole might theoreticallycombine to become a synergistic ischaemic stress test, by increasingmyocardial oxygen demand through chronotropic stress and byreducing flow supply through a shortening of the diastolic intervalunder maximal coronary vasodilation. The aim of this study wasto assess the effects of the addition of atropine to DET. Threehundred and twenty-one patients (age=58±9 years), referredfor testing in the echo lab, were initially studied by DET.Of these, 151 were stopped during or within the 2 min followingdipyridamole infusion because of achievement of a predeterminedend-point: obvious echocardiographic positivity (n = 137), severechest pain (n = 3), diagnostic ST segment changes (n = 7) orlimited side effects (n = 4). In another three cases, atropinewas not given due to a history of glaucoma or severe prostatichypertrophy. In the remaining 167 patients with a negative DETtest, atropine (0.25 mg intravenously, repeated every min upto a maximum of 1 mg, if necessary) was added, starting 3 minafter the end of the dipyridamole infusion. The dipyridamole-atropineecho test (DETA) was positive in 32 and negative in 135 patients,and no major side effects occurred in any patient. The peakheart rate was significantly higher during DETA than with DETalone (108±16 vs 86±14 beats . min^–1; P<0.0001).In the subset of 178 patients who were studied while not takingantianginal therapy, who had no prior myocardial infarctionor revascularization procedure and who underwent coronary catheterization,independently of the test results, coronary angiography showednormal coronary arteries in 48 patients and significant coronaryartery disease (CAD) ( 50% luminal reduction in at least onemajor coronary vessel by quantitative coronary arteriography)in 130 patients—with single-, double- and triple-vesseldisease in 56, 47 and 27 patients, respectively. The sensitivitywas 96/130 for DET and 110/130 for DETA (72 vs 85%, P<0.01)while the specflcity was 96% and 92% (P=ns), respectively. Theaddition of atropine to dipyridamole, which causes further chronotropicstress to the myocardium already challenged by flow maldistribution,is well tolerated and safe, and increases the sensitivity ofthe test for the detection of coronary artery disease with noloss in specificity.     

Reference ranges of echocardiographic measurements in the Dutch population

Reference ranges for echocardiographic measurements were determinedin 609 healthy Dutch subjects, using height, weight, age, sex,RR-interval and blood pressure (in adults only) as determinants.Endsystolic as well as end-diastolic measurements of the aorticroot as well as left ventricular inner diameter, posterior andseptal thickness were taken, as was the left atrial end-systolicdiameter. Multiple linear regression was performed of the form: =A.(age)^B.(height)^C.(weight)^D.(RR-interval)^E.(sex)^F. The residuals were calculated in order to determine the percentilelimits by means of linear interpolation. Sex and weight weresignificant determinants in all the echocardiographic parametersstudied. The results were presented twofold, with a simple versionfor males and females separately, using only weight as a determinantand allowing graphical presentation, and secondly a complexversion taking into account all determinants, which can onlybe solved with help of a calculator.     

Transoesophageal echocardiogram may fail to diagnose peri-operative myocardial infarction

We report a case in which a 55-yr-old man undergoing aortocoronary bypass was monitored with electrocardiogram and transoesophageal echocardiogram. Intraoperative electrocardiogram and simultaneous ECG recordings using the Holter monitor showed an ST elevation of greater than 2 mm and new Q wave formation in leads AVF and V5 during skin closure. However, the transoesophageal echocardiogram showed no wall motion abnormalities. No significant haemodynamic abnormalities were observed during the period of intraoperative ECG changes. He was treated with nitroglycerin infusion. Confirmation of a perioperative myocardial infarct was documented by postoperative 12-lead ECG and CPK-MB. A post-operative transthoracic echocardiogram showed a hypokinetic left ventricle with an anteroapical infarct. Thus transoesophageal echocardiography failed to detect an apical wall motion abnormality when the probe was placed at the midpapillary level. This limitation can be overcome by periodically obtaining apical views or by using probes with more than one imaging plane.     

Measurement of cardiac output-transtracheal Doppler versus thermodilution

The ABCOM 1 transtracheal Doppler (TTD) has been developed as a non-invasive cardiac output monitor. With this device, cardiac output is continuously calculated from ascending aortic blood flow velocity and aortic diameter obtained via an ultrasound transducer incorporated into the tip of an endotracheal tube. We evaluated the clinical use of the ABCOM 1 monitor and compared cardiac outputs obtained using the TTD system with simultaneous thermodilution (TD) measurements. We found the operation of the ABCOM 1 monitor to be difficult and time-consuming. In our operating rooms, acceptable Doppler signal quality was difficult to obtain. There was no correlation between 36 simultaneously obtained TTD and TD cardiac output measurements. The average difference between measurement techniques and the limits of agreement were unacceptably large (mean difference = 3.04 L.min-1, mean +/- 2 SD = -6.04 to 12.48 L.min-1). Separately analyzing only those measurements during which Doppler signal quality was adequate did not improve agreement between TTD and TD measurements. On the basis of these findings, TTD cannot be recommended as a clinical cardiac output measurement technique.     

Diagnostic value of two-dimensional echocardiography in cardiac hydatid disease

Echinococcal infection of the heart is rare. The preoperativefindings, with special attention to two-dimensional echocardiography(2DE), of six patients with cardiac echinococcosis and theirsurgical and pathological correlations are reported. Cardiachydatid cysts (HCs) were located in the cardiac apex in threepatients, in the upper part of the interventricular septum extendingtowards the anterior aspect of the heart in one and in the postero-superiorright atrial wall in another patient. The remaining patienthad multiple intrapericardial cysts. In three patients the cystspresented as well defined, rounded, echolucent masses withinthe myocardial wall bulging into the cardiac chambers. In twopatients, the cysts had ruptured into a cardiac chamber withloss of the characteristic ‘cystic’ appearance;these cysts presented as an echogenic or solid mass protrudinginto a cardiac chamber. Finally, another patient had one HCwith echolucent appearance and another HC in a different locationwith echogenic appearance; this last cyst corresponded to adegenerated HC. In two cases the cyst showed a loculated internalaspect. In one patient the myocardial segment involved by thecyst had a dyskinetic movement. In all six patients, 2DE accuratelydemonstrated the location and morphological details of the cardiaccysts, permitted recognition of the ruptured and/or degeneratedcysts and was superior to thoracic computed tomography and angiographyin the preoperative assessment of these patients. Nuclear magneticresonance imaging (one patient) gave no further informationto that obtained by 2DE. We conclude that 2DE is the techniqueof choice for an early diagnosis of this rare entity.     

Role of prenatal echocardiography in the study of hypertrophic cardiomyopathy in the fetus

The increased incidence of hypertrophic cardiomyopathy in children of diabetic mothers has already been demonstrated, but its prenatal diagnosis has not yet been extensively studied. The purpose of this prospective study was to evaluate the frequency, severity, and echocardiographic features of fetal hypertrophic cardiomyopathy in a population with several indications for prenatal echocardiography. From March 1987 to April 1991, 283 fetuses were submitted to comprehensive prenatal echocardiography, including M-mode measurements, cross-sectional imaging, Doppler studies, and color flow mapping. One hundred seventy-six were pregnancies complicated by previous or gestational diabetes. The diagnosis of disproportionate septal hypertrophy was made in 39 fetuses (mean septal thickness 7.12 +/- 1.6 mm), at a mean gestational age of 32 weeks. Diabetes mellitus was present in 36 of these pregnancies (92.3%). In four cases, nonimmune hydrops was detected. A systolic anterior motion of the mitral valve was present in three fetuses, but only one showed a gradient across the left ventricular outflow tract. Postnatal echocardiographic examination in 27 babies did not show false positivity. In ten cases, spontaneous regression of the septal hypertrophy was shown. There were three neonatal deaths, unrelated to the myocardial disease. We concluded that transient hypertrophic cardiomyopathy is a frequent entity, especially when associated with diabetes during gestation, being a potential cause for nonimmune hydrops. Fetal echocardiography is the method of choice for its prenatal diagnosis and should always be indicated in diabetic mothers.     

Echocardiographic and color flow Doppler assessment of systemic and pulmonary venous connection and drainage in the neonate with congenital heart disease

Systemic and pulmonary venous anomalies are frequently encountered either as isolated lesions or as a significant component of a more complex lesion in the newborn infant with congenital heart disease. Two-dimensional echocardiography and Doppler techniques (conventional and color flow) have become the primary diagnostic imaging modality in this setting. Precise pre-operative definition of these variable venous connection and drainage patterns is critical as the required surgical procedure may solely be based on exact understanding of the veins' anatomy and physiology. On the systemic venous site, anomalies of superior and inferior venae cavae, innominate vein, and coronary sinus can be equally well imaged with either echocardiography or angiography. However, on the pulmonary venous site, echocardiography and Doppler techniques including color flow mapping are superior to angiography for precise definition of the connection and drainage sites of the individual pulmonary veins.     

Intraoperative color Doppler assessment in valve repair surgery

Intraoperative color Doppler recordings, obtained either from the epicardial or transesophageal approach, offer real-time information about the presence and severity of mitral regurgitation at the time of surgery. The technique allows instantaneous evaluation of mitral and tricuspid repair and may offer important information about the postoperative outcome.