Dobutamine echocardiography and resting-redistribution thallium-201 scintigraphy predicts recovery of hibernating myocardium after coronary revascularization.

The value of dobutamine echocardiography and resting thallium-201 scintigraphy to predict reversal of regional left ventricular wall motion dysfunction after revascularization in patients with chronic coronary artery disease was assessed. Improvement in wall motion during dobutamine echocardiography and normal or mildly decreased uptake on thallium-201 scanning are strong predictors of reversible left ventricular dysfunction. Dobutamine echocardiography and resting thallium-201 scanning are simple and safe methods of assessing hibernating myocardium.

Transcutaneous cardiac pacing during thoracic surgery. Feasibility and hemodynamic evaluation by transesophageal echocardiography.

BACKGROUND: Occasionally, emergency perioperative pacing is necessary. Transcutaneous cardiac pacing is noninvasive, safe, and readily available. Its feasibility and hemodynamic effects during thoracic surgery and one-lung ventilation have not been established. METHODS: Twenty anesthetized patients (aged 25-70 yr) without cardiac disease undergoing elective pulmonary resection (right n = 10, left n = 10) were studied in normal sinus rhythm and during transcutaneous cardiac pacing. Patients were paced in supine and lateral decubitus positions (with closed and opened chest) at the minimal current necessary to produce ventricular capture. Invasive arterial monitoring permitted calculation of mean arterial pressure, and transesophageal echocardiography was used to assess atrial and ventricular wall motion and the evaluation of transmitral flow. Twelve patients underwent Doppler analysis of pulmonary venous flow. RESULTS: Pacing was achieved in all patients, with a mean threshold of 86.9 +/- 20.6 mA for the right thoracotomy group, and 106.7 +/- 16.2 mA for the left thoracotomy group. The mean paced heart rates for the right and left thoracotomy groups were 101.6 +/- 18.2 and 105.4 +/- 11.5 beats/min, respectively. During pacing, all patients sustained reversible transient decrements in mean arterial pressure (9-19%) from baseline, the loss of AV synchrony, and the development of paradoxical ventricular septal wall motion. No patient had significant mitral regurgitation during sinus or paced rhythms. Decreased systolic pulmonary venous flow velocity and abnormal systolic flow reversal were seen during pacing in 11 of the 12 patients studied. CONCLUSIONS: Transcutaneous cardiac pacing is effective in patients undergoing thoracotomy and one-lung ventilation. Its use in patients in normal sinus rhythm induces reversible decrements in mean arterial pressure because of the effects of altered atrioventricular association, ventricular wall motion, and pulmonary venous return.

Left ventricular outflow tract obstruction following repair of pneumococcal mitral annular abscess.

An unusual case of a mitral annular abscess caused by Streptococcus pneumoniae was diagnosed by transesophageal echocardiography. The patient underwent surgical resection of the abscess and developed outflow tract obstruction. This is an unusual complication of the surgical procedure. The outflow tract obstruction may have been due to anterior displacement of the mitral valve by the abscess.

Using contrast material-enhanced echocardiography to identify abnormal pulmonary arteriovenous connections in patients with hypoxemia.

The phenomenon of abnormal pulmonary arteriovenous connections in patients with acquired lung disease rarely has been reported. We report three patients with acquired lung disease and hypoxia that did not respond to the administration of 100 percent oxygen. Contrast-material-enhanced echocardiography demonstrated intrapulmonary right-to-left shunting in all three patients. These cases suggest that patients with hypoxia due to acquired lung disease may be screened by contrast-enhanced echocardiography to identify the presence and the location of anatomic right-to-left shunts.

Doppler echocardiography versus cardiac catheterization in the evaluation of valvular heart disease: do we have a gold standard?

Definitive evaluation of valvular heart disease is traditionally accomplished by cardiac catheterization. Recent advances in Doppler echocardiography allow noninvasive assessment of valvular heart disease with a high degree of accuracy compared to the cardiac catheterization gold standard. Doppler echocardiography may occasionally yield erroneous results due to technical difficulties in the performance of the study. A number of patient related and echo-machine related factors may also affect the Doppler measurements independent of the severity of the lesion. Thus, a discrepancy between Doppler and catheterization data is generally considered to be a failure of Doppler methods. However, catheterization data may also be flawed due to errors in the measurement of pressure and cardiac output, as well as the known shortcomings of qualitative angiography. The Gorlin equation itself suffers from several limitations, including the substitution of pressure gradient for velocity in the basic hydrodynamic equation, and the use of a constant which may not be appropriate in all circumstances. Therefore, when Doppler echocardiography and cardiac catheterization yield discordant results, both studies should be carefully reviewed and correlated with other clinical data in order to elucidate the sources of the discrepancy and ascertain the actual severity of the valvular lesion.

Transesophageal echocardiography is superior to transthoracic echocardiography in the diagnosis of sinus venosus atrial septal defect.

The purpose of this study was to compare transthoracic and transesophageal echocardiography in the diagnosis of various types of atrial septal defects. Forty-one adult patients with the clinical diagnosis of atrial septal defect were studied by transthoracic and transesophageal echocardiography (30 women, 11 men; 18 to 81 years of age). Transthoracic echocardiography demonstrated the atrial septal defect in 33 patients (secundum type in 28, primum type in 3 and sinus venosus type in 2). Transesophageal echocardiography demonstrated the defect in all 41 patients. Thus, in 8 (20%) of 41 patients the atrial septal defect was demonstrated by transesophageal and not by transthoracic echocardiography. Six of the eight had a sinus venosus type atrial septal defect; the other two patients had a secundum atrial septal defect (one of these two had a technically poor transthoracic echocardiogram and the other had a small atrial septal defect). Transthoracic echocardiography, therefore, failed to demonstrate the sinus venosus defect in six (75%) of eight patients. An anomalous venous connection associated with the sinus venosus defect was visualized by transesophageal echocardiography in seven of the eight patients but was not seen on transthoracic echocardiography in any patient. Sinus venosus type atrial septal defects are frequently not visualized in adults by conventional transthoracic echocardiography. Transesophageal echocardiography is recommended when an atrial septal defect is clinically suspected but cannot be visualized by transthoracic echocardiography.

Clinical evaluation of high-frequency (ultrasonic) mechanical débridement in the surgical treatment of calcific aortic stenosis.

Repair of aortic valve stenosis due to calcific degeneration may lead to hemodynamic and clinical improvement without the problems inherent with prosthetic valves. We have evaluated the use of a device capable of débriding calcium, the Cavitron ultrasonic aspirator (CUSA), as an adjunct to mechanical débridement in the repair of calcific aortic stenosis. Ten patients (five women), ages 63 to 83 years, were studied by M-mode, two-dimensional, and Doppler echocardiography before and an average of 26 (range 3 to 124) days after this procedure. The degree of calcification of the valve cusps was clearly reduced. The maximal cusp excursion increased from 0.7 +/- 0.1 cm preoperatively to 1.5 +/- 0.4 cm postoperatively (p = 0.006). The peak aortic gradient fell from 80 +/- 36 mm Hg to 28 +/- 10 mm Hg (p = 0.0007). The mean aortic gradient fell from 53 +/- 20 mm Hg to 16 +/- 5 mm Hg (p less than 0.0001). Aortic valve area calculated by the continuity equation increased from 0.6 + 0.2 cm2 to 1.6 +/- 0.6 cm2 (p = 0.0009). No patient had more than mild aortic insufficiency preoperatively. Postoperatively, color Doppler flow mapping revealed severe aortic insufficiency in two patients. Seven patients had further echocardiographic evaluation 99 (range 33 to 196) days after the procedure. These studies revealed the development of severe aortic insufficiency in an additional four patients. Four patients with severe symptomatic aortic insufficiency eventually underwent aortic valve replacement. Pathology revealed scarring and retraction of the aortic cusps. Widening of the commissures was responsible for the severe aortic insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of unexpected atrial septal defect by inspired hydrogen appearance time in adult patients referred for cardiac catheterization.

Atrial septal defects may have clinical consequences regardless of their size. We evaluated the incidence of clinically unsuspected atrial septal defects in 4,411 consecutive adult patients referred for cardiac catheterization by the previously validated method of inspired hydrogen appearance time. Oximetry was performed only when an abnormally short inspired hydrogen appearance time was measured. Seventy-five patients (1.7%) were discovered to have a left-to-right shunt by this method. The shunting was at the atrial level in 65 patients. Thirty-five of these patients (0.8% of all catheterizations) were not suspected of having any form of congenital heart disease by history, physical examination, chest X-ray, EKG, or echocardiogram. In 19 cases there was no significant oxygen step-up and the diagnosis would have been missed by oximetry. The atrial septum was explored during open heart surgery in 7 patients. Atrial septal defects were detected and closed in all. Four patients had the finding confirmed by echocardiography after the catheterization. Small atrial septal defects are frequently not detected by clinical evaluation, noninvasive testing, or oximetry and are easily detected by the rapid, safe, and accurate method of inspired hydrogen appearance time.

The anatomy of the interatrial septum: a transesophageal echocardiographic study.

Transesophageal echocardiography provides a unique view of the IAS. We reviewed results of 119 transesophageal studies (1) to study the detailed anatomy of the IAS, and (2) to determine the thickness of the IAS at different times during the cardiac cycle, (3) the effect of age, and (4) the thickness of the IAS in relation to various disease states. From the transesophageal view the IAS extends from the right posteriorly toward the left and anteriorly. The more inferior aspect of the septum courses in a more direct posteroanterior direction and is more difficult to accurately visualize. The IAS is thickest peripherally and gradually narrows toward the more centrally located fossa ovalis. A region of constant thickness is frequently present between the most peripheral aspect of the IAS and the fossa ovalis. We standardized the measurement of the thickness of the septum by measuring it only at this region of constant thickness in the plane that visualized the fossa ovalis. The mean thickness at this point was 6 +/- 2 mm. The thickness correlated weakly with the age of the patient. These results agree with previously published autopsy findings. Thickness was not affected by the presence of significant disease of the atrioventricular valves, atrial fibrillation, or an atrial septal defect. However, the thickness increased to 7 +/- 2 mm with atrial contraction during sinus rhythm (p less than 0.0001). The mean thickness of the septum primum covering the fossa ovalis was 1.8 +/- 0.7 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Dynamic left ventricular outflow obstruction after aortic valve replacement: a Doppler echocardiographic study.

An 81-year-old woman with severe symptomatic aortic stenosis underwent aortic valve replacement. The postoperative course was complicated by new subvalvular left ventricular outflow tract obstruction created by systolic anterior motion of the anterior mitral leaflet. The condition was recognized by echocardiography and was successfully treated medically.

Echocardiographic and hemodynamic characteristics of atrial septal defects created by percutaneous valvuloplasty.

Twenty-nine patients were studied by pulsed, continuous wave, and color Doppler before and after percutaneous transseptal valvuloplasty. New atrial septal defects were detected in 14 patients, and the patients were monitored for up to 320 days after the procedure. The diameter of the defect, best evaluated by the transesophageal approach, was 3 to 15 mm. A narrow, high velocity (1.4 to 3.1 meters per second) left-to-right shunt jet was detected in 13 of 14 patients. The shunt jet was continuous in nine of 14 patients, late systolic-holodiastolic in four patients, and bidirectional in one patient. Cardiac catheterization in nine patients confirmed the Doppler findings and demonstrated a peak pressure gradient of 10 to 32 mm Hg between the left and right atria. Oximetry revealed a calculated pulmonary to systemic flow ratio ranging from 2.3:1 in the patient with the largest atrial septal defect by echocardiography to 1:1 (no oxygen saturation step-up) in the patient with the smallest atrial septal defect. In the three patients who underwent cardiac surgery, the operative findings confirmed those of echocardiography. We concluded that atrial septal defects are common after transseptal valvuloplasty. Usually, their relatively small size and the underlying valvular disease that produces high left atrial pressure are responsible for the high pressure gradient between the left and right atria. This results in the high velocity and continuous shunt jet detected by Doppler echocardiography.

Transesophageal echocardiography during percutaneous mitral valvuloplasty.

Transesophageal echocardiography was performed during mitral balloon valvuloplasty. It provided valuable information about the position of the transseptal needle, wires, and balloon catheter throughout the procedure, and it helped in the immediate evaluation of its results. Transesophageal echocardiography was well tolerated and there were no complications.