Intraoperative two-dimensional Doppler echocardiography. A preliminary study for congenital heart disease

Intraoperative two-dimensional echocardiograms were performed in 30 patients (group I) and two-dimensional Doppler color flow imaging was performed in 30 additional patients (group II) with various forms of congenital heart disease. A comparative complete two-dimensional Doppler and color flow examination was performed in group II patients 10 to 14 days postoperatively. Standard intraoperative two-dimensional echocardiograms demonstrated excellent correlation with preoperative findings and allowed assessment of valvular regurgitation or shunt when combined with echocardiographic contrast injections. However, intraoperative and postoperative two-dimensional color flow imaging was obtained more easily and rapidly and allowed recognition of more postoperative residual defects. Color flow imaging appears to be a useful method for intraoperative assessment of surgical repair of congenital cardiac defects. Twenty-one residual lesions were correctly diagnosed intraoperatively, whereas seven residual lesions were demonstrated only during later postoperative examination. This preliminary experience has also demonstrated several areas for future development and improvement of these techniques. Combined two-dimensional Doppler and contrast echocardiographic studies may allow better disclosure of residual defects.     

Diagnosis and classification of atrial septal aneurysm by two-dimensional echocardiography: report of 80 consecutive cases

Atrial septal aneurysms have been related (either by association or as potential causes) to systolic clicks, atrial arrhythmias, systemic and pulmonary embolism, atrioventricular valve prolapse and atrial septal defect. To study these associations and the incidence of atrial septal aneurysm, we reviewed 80 consecutive patients (female to male ratio 1.9:1, mean age 47 years, range 1 day to 89 years) who had been identified prospectively as having an atrial septal aneurysm. These were found in 36,200 two-dimensional echocardiographic studies (incidence: 0.22% overall; 0.29% in the last year of the study done between 1978 and 1984). Three types of fossa ovalis aneurysm and one type of aneurysm involving the entire atrial septum were observed; a fossa ovalis aneurysm with leftward projection and excursion of less than 5 mm or an aneurysm involving the entire atrial septum with rightward projection was not observed. Atrial septal aneurysm occurred more often as an isolated abnormality than in association with other cardiac malformations, although all patients with an aneurysm involving the entire atrial septum had complex congenital cardiac anomalies of the hypoplastic right heart type. The reported associations between atrial septal aneurysms and atrial septal defect, atrioventricular valve prolapse, midsystolic clicks, atrial arrhythmias and cerebral ischemic events were examined. A hypothesis based on interatrial pressure gradients is proposed to explain the different motions and configurational characteristics of fossa ovalis aneurysms observed in these patients. All patients in whom atrial septal aneurysm is demonstrated should undergo examination for atrial septal defect. Atrial septal aneurysm should be specifically looked for in patients who have these associations and who undergo two-dimensional echocardiography, especially if these abnormalities are unexplained.     

Dynamic intraventricular obstruction during dobutamine stress echocardiography. A new observation.

BACKGROUND. The implications of hypotension occurring during dobutamine stress echocardiography have not been elucidated. We observed in some patients that hyperdynamic left ventricular function developed during dobutamine stress echocardiography and hypothesized that intracavitary obstruction was occurring and might account for hypotension in some patients. METHODS AND RESULTS. Fifty-seven consecutive patients undergoing dobutamine stress echocardiography underwent pulsed-wave and continuous-wave Doppler examination of the left ventricular cavity at rest and at peak dobutamine infusion. The development of an intraventricular gradient with dobutamine stress was defined as a late-peaking left ventricular Doppler velocity profile that exceeded basal velocity by at least 1 m/sec. During dobutamine stress testing, left ventricular outflow velocity or intracavitary velocity increased in all patients. Obstruction occurred in 12 patients (21%, group 1). Group 2 was the remaining 45 patients. Peak velocities in group 1 ranged from 2.0 to 5.0 m/sec (mean, 3.5 m/sec), and the mean increase from velocity at rest was 2.3 m/sec. The mean change in systolic blood pressure was significantly lower in patients in group 1 (-15 versus 4 mm Hg, p = 0.02). When the 18 patients with an ischemic response to stress testing (evidenced by new or worsening wall motion abnormalities) were excluded from analysis, systolic blood pressure response was still significantly different for the two groups (-19 versus 2 mm Hg, p = 0.03). CONCLUSIONS. Dynamic left ventricular obstruction is a new observation; it may develop frequently in patients undergoing dobutamine stress echocardiography. Obstruction rather than ischemia may explain a decrease in blood pressure during dobutamine stress echocardiography.     

Relation of tissue displacement and strain to invasively determined right ventricular stroke volume

The role of echocardiography in the clinical assessment of right ventricular (RV) systolic function remains limited. Limited data exist on the potential use of newer techniques for RV function assessment. Conventional echocardiography and tissue Doppler echocardiography (TDE) were performed during right-sided cardiac catheterization in 46 patients. Thermodilution or the Fick-derived RV stroke volume indexed (RVSVI) indexed to body surface area was used as the reference standard. Univariate and multivariate regression analyses were used to test correlations between RVSVI and various echocardiographic and TDE-derived parameters. In a subset of 12 subjects, changes in echocardiographic and TDE variables to reduced afterload from intravenous epoprostenol were measured. TDE-derived RV tissue displacement and systolic strain best predicted the RVSVI (r = 0.63, p = 0.001; r = 0.48, p = 0.002, respectively). The prediction improved after adjustment for tricuspid regurgitation jet vena contracta width (r = 0.74, p < 0.0001; r = 0.60, p < 0.001, respectively). Assuming a RVSVI of > or =30 ml/m(2) as normal, a RV displacement cutoff of 15 mm yielded a sensitivity of 100% and a specificity of 41% for RV dysfunction, and an RV systolic strain cutoff of 20% yielded a sensitivity of 91% and a specificity of 63%. The percentage change of RV systolic displacement correlated well with the percentage change of RVSVI after epoprostenol infusion (r = 0.75, p < 0.001). In conclusion, TDE-derived RV displacement and strain closely correlate with RVSVI and appropriately track load-related changes in RV function. These new parameters may help provide the noninvasive, quantitative assessment of RV function.     

The effects of freeze/thawing process on cryopreserved equine umbilical cord blood-derived mesenchymal stem cells

The use of mesenchymal stem cells (MSCs)-derived equine umbilical cord blood in cell grafts transplantation is advantageous; therefore, preservation of these cells is of utmost importance in repair therapies. To evaluate the viability ratio of the MSCs obtained from equine umbilical cord blood after cryopreservation, umbilical cord blood obtained from nine 46–48-week-old foals were purified for harvesting MCs. The purified cells were frozen from the first to tenth passages and stored in liquid nitrogen. After thawing, the cell viability was assessed through trypan blue staining procedure. The highest viability (>80%) ratio was observed with the cells derived from the first passage in 1 and 8?weeks after cryopreservation. However, the viability of cells was dependent on the passage used for cryopreservation. Results in this study demonstrated that equine umbilical cord blood stem cells could successfully be frozen and stored in liquid nitrogen for 8?weeks without significant change in the characterization of the cells cryopreserved as regards their viability, growth ability, and differentiation potential.     

Dynamic left ventricular outflow tract obstruction in acute coronary syndromes: an important cause of new systolic murmur and cardiogenic shock.

Dynamic left ventricular outflow tract (LVOT) obstruction has traditionally been associated with hypertrophic obstructive cardiomyopathy. Recently, acute dynamic LVOT obstruction has been described as a complication of myocardial infarction (MI). Herein the cases of 3 patients are described, all of whom presented with a systolic murmur and electrocardiographic evidence of MI. All 3 patients developed cardiogenic shock and were subsequently found by echocardiography to manifest an acute dynamic LVOT obstruction. Cardiogenic shock persisted until therapy was directed toward decreasing the degree of the dynamic LVOT obstruction. The treatment of acute coronary syndromes in the presence of a dynamic LVOT obstruction differs from the traditional treatment of acute coronary syndromes and includes the use of beta-blockers and alpha1-agonists, as well as the avoidance of therapies that aggravate the magnitude of the LVOT obstructive gradient, including nitrates, inotropic agents, and afterload reduction. The development of a systolic murmur in the setting of acute MI complicated by cardiogenic shock with only a small elevation in creatine kinase suggests the presence of a dynamic LVOT obstruction, as well as the classical mechanical complications of MI, namely, ventricular septal rupture and papillary muscle rupture. The presence of a dynamic LVOT obstruction is reliably detected by transthoracic echocardiography or by transesophageal echocardiography if transthoracic image quality is suboptimal.