Ramon Castello

Atrial septal aneurysm and stroke: a transesophageal echocardiographic study.

The prevalence and morphologic characteristics of atrial septal aneurysms identified by transesophageal echocardiography in 410 consecutive patients are described. Two groups of patients were compared: Group I consisted of 133 patients referred for evaluation of the potential source of an embolus and Group II consisted of 277 patients referred for other reasons. An atrial septal aneurysm was diagnosed by transesophageal echocardiography in 32 (8%) of the 410 patients. Surface echocardiography identified only 12 of these aneurysms. Atrial septal aneurysm was significantly more common in patients with stroke (20 [15%] of 133 vs. 12 [4%] of 277) (p less than 0.05); right to left shunting at the atrial level was demonstrated in 70% of patients in Group I and 75% of patients in Group II by saline contrast echocardiography. Four patients in Group I had an atrial septal defect with additional left to right flow. There was no difference between the two groups in aneurysm base width, total excursion or left atrial or right atrial excursion. However, Group I patients had a thinner atrial septal aneurysm than did Group II patients. It is concluded that an atrial septal aneurysm occurs commonly in patients with unexplained stroke, is more frequently detected by transesophageal echocardiography than by surface echocardiography and is usually associated with right to left atrial shunting. Treatment (anticoagulant therapy vs. surgery) of atrial septal aneurysm identified in stroke patients can be determined only by long-term follow-up studies.

American Society of Echocardiography Consensus Statement on the Clinical Applications of Ultrasonic Contrast Agents in Echocardiography

UNLABELLED ACCREDITATION STATEMENT: The American Society of Echocardiography (ASE) is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The ASE designates this educational activity for a maximum of 1 AMA PRA Category 1 Credit.trade mark Physicians should only claim credit commensurate with the extent of their participation in the activity. The American Registry of Diagnostic Medical Sonographers and Cardiovascular Credentialing International recognize the ASEs certificates and have agreed to honor the credit hours toward their registry requirements for sonographers. The ASE is committed to resolving all conflict-of-interest issues, and its mandate is to retain only those speakers with financial interests that can be reconciled with the goals and educational integrity of the educational program. Disclosure of faculty and commercial support sponsor relationships, if any, have been indicated. TARGET AUDIENCE This activity is designed for all cardiovascular physicians, cardiac sonographers, and nurses with a primary interest and knowledge base in the field of echocardiography; in addition, residents, researchers, clinicians, sonographers, and other medical professionals having a specific interest in contrast echocardiography may be included. OBJECTIVES Upon completing this activity, participants will be able to: 1. Demonstrate an increased knowledge of the applications for contrast echocardiography and their impact on cardiac diagnosis. 2. Differentiate the available ultrasound contrast agents and ultrasound equipment imaging features to optimize their use. 3. Recognize the indications, benefits, and safety of ultrasound contrast agents, acknowledging the recent labeling changes by the US Food and Drug Administration (FDA) regarding contrast agent use and safety information. 4. Identify specific patient populations that represent potential candidates for the use of contrast agents, to enable cost-effective clinical diagnosis. 5. Incorporate effective teamwork strategies for the implementation of contrast agents in the echocardiography laboratory and establish guidelines for contrast use. 6. Use contrast enhancement for endocardial border delineation and left ventricular opacification in rest and stress echocardiography and unique patient care environments in which echocardiographic image acquisition is frequently challenging, including intensive care units (ICUs) and emergency departments. 7. Effectively use contrast echocardiography for the diagnosis of intracardiac and extracardiac abnormalities, including the identification of complications of acute myocardial infarction. 8. Assess the common pitfalls in contrast imaging and use stepwise, guideline-based contrast equipment setup and contrast agent administration techniques to optimize image acquisition.

Analysis of coronary blood flow velocity dynamics in angiographicaily normal and stenosed arteries before and after endolumen enlargement by angioplasty

OBJECTIVES This study was designed to assess whether the spectral waveform of coronary velocity on Doppler study is characteristically altered in the presence of significant stenosis with normalization of the spectral waveform after relief of endolumen obstruction. BACKGROUND Although coronary flow reserve determinations have provided physiologic information complementary to the angiographic percent diameter narrowing, flow velocity measurements have been limited to proximal arteries with inconsistent results after angioplasty. A 12-MHz Doppler guide wire permits flow velocity determination in the proximal and distal coronary artery with fast Fourier spectral analysis. METHODS With the Doppler guide wire, proximal arterial flow velocity and flow reserve measurements in 17 angiographically normal arteries were compared with measurements in 29 significantly stenosed arteries. Proximal and distal flow velocity measurements were also obtained before and after angioplasty of the 29 abnormal arteries. Velocity spectrum was digitized to compute peak diastolic velocity, peak systolic velocity, mean velocity, diastolic/systolic velocity ratio and first third and first half flow fraction. RESULTS Compared with proximal stenosed arteries, proximal normal arteries had significantly higher peak diastolic velocity (64 +/- 26 cm/s vs. 41 +/- 26 cm/s) and higher coronary vasodilator reserve (2.3 +/- 0.8 vs. 1.6 +/- 0.7). Normal arteries had higher flows in the first third and first half of the coronary cycle (46 +/- 3% vs. 39 +/- 7% and 65 +/- 2% vs. 56 +/- 10%, respectively). Before angioplasty, coronary velocity variables were significantly lower distal than proximal to the stenosis. After angioplasty, there was a greater mean increase in distal velocities (200% vs. 90% for the proximal arteries) that resulted in near equalization of proximal and distal mean velocity and a significant reduction in proximal/distal mean velocity ratio (2.4 +/- 1.7 vs. 1.2 +/- 0.4). CONCLUSIONS Before angioplasty, abnormal coronary flow velocity dynamics are more marked distal than proximal to the stenosis. Greater increase in coronary flow velocities in the distal circulation after relief of endolumen obstruction results in a significant reduction in the proximal/distal flow velocity ratio. Thus, normalization of Doppler-derived flow velocity variables with marked reduction of the proximal/distal flow velocity ratios parallels angiographic success and may prove useful as an additional end point measurement in interventional cases with questionable angiographic findings.

Mobile aortic atheroma and systemic emboli: efficacy of anticoagulation and influence of plaque morphology on recurrent stroke.

OBJECTIVES We sought to determine the influence of plaque morphology and warfarin anticoagulation on the risk of recurrent emboli in patients with mobile aortic atheroma. BACKGROUND An epidemiologic link between aortic atheroma and systemic emboli has been described both in pathologic and transesophageal studies. Likewise, a few studies have found an increased incidence of recurrent emboli in these patients. The therapeutic implications of these findings has not been studied. METHODS Thirty-one patients presenting with a systemic embolic event and found to have mobile aortic atheroma were studied. The height, width and area of both immobile and mobile portions of atheroma were quantitated. The dimensions of the mobile component was used to define three groups: small, intermediate and large mobile atheroma. The patients were followed up by means of telephone interview and clinical records, with emphasis on anticoagulant use and recurrent embolic or vascular events. RESULTS Patients not receiving warfarin had a higher incidence of vascular events (45% vs. 5%, p = 0.006). Stroke occurred in 27% of these patients and in none of those treated with warfarin. The annual incidence of stroke in patients not taking warfarin was 0.32. Myocardial infarction occurred in 18% of patients also in this group. Taken together, the risk of myocardial infarction or stroke was significantly increased in this group (p = 0.001). Forty-seven percent of patients with small, mobile atheroma did not receive warfarin. Recurrent stroke occurred in 38% of these patients, representing an annual incidence of 0.61. There were no strokes in patients with small, mobile atheroma treated with warfarin (p = 0.04). Likewise, none of the patients with intermediate or large mobile atheroma had a stroke during follow-up. Only three of these patients had not been taking warfarin. CONCLUSIONS Patients presenting with systemic emboli and found to have mobile aortic atheroma on transesophageal echocardiography have a high incidence of recurrent vascular events. Warfarin is efficacious in preventing stroke in this population. The dimension of the mobile component of atheroma should not be used to determine the need for anticoagulation.

Prevalence and clinical implications of atrial spontaneous contrast in patients undergoing transesophageal echocardiography

The prevalence of atrial spontaneous contrast was evaluated in 150 consecutive patients undergoing transesophageal echocardiography. Spontaneous contrast was observed in 29 patients (19%). It was seen in the left atrium in 24 patients, in the right atrium in 4 patients and in both atria in 1 patient. Spontaneous atrial contrast was not seen in the absence of an associated cardiac abnormality. Univariate analysis showed a significant relation between the presence of spontaneous contrast and significant mitral regurgitation (p less than 0.05), the presence of mitral valve prostheses (p less than 0.001), atrial fibrillation (p less than 0.0001) and left atrial size (p less than 0.001). Multivariate analysis showed that the presence of atrial fibrillation, prosthetic mitral valve and atrial size were independent factors for the presence of spontaneous contrast. However, of the 29 patients with spontaneous contrast, 13 (45%) were in sinus rhythm and in only 4 (16%) was the left atrial size greater than 60 mm. Left atrial thrombus was detected in 9 of the 150 patients. Although spontaneous contrast was noted in 5 (55%) patients with left atrial thrombus and in only 20 (14%) patients without left atrial thrombus (p less than 0.001), none of the 3 patients who had right atrial thrombus had spontaneous contrast in that chamber. Overall, 7 (58%) of the 12 patients with right or left atrial thrombi had no evidence of spontaneous contrast. Multivariate analysis showed that atrial fibrillation was the only independent clinical predictor of left atrial thrombus. Thus, spontaneous echocardiographic contrast is a common phenomenon observed in approximately 20% of the patients undergoing transesophageal echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of pulmonary venous flow by transesophageal echocardiography in subjects with a normal heart: Comparison with transthoracic echocardiography

Nineteen normal subjects and five patients with atrial fibrillation underwent transesophageal and transthoracic echocardiographic studies to evaluate the normal pulmonary venous flow pattern, compare right and left pulmonary venous flow and assess the effect of sample volume location on pulmonary venous flow velocities. Best quality tracings were obtained by transesophageal echocardiography. Anterograde flow during systole and diastole was observed in all patients by both techniques. Reversed flow during atrial contraction was observed with transesophageal echocardiography in 18 of the 19 subjects in normal sinus rhythm, but in only 7 subjects with transthoracic echocardiography. Two forward peaks during ventricular systole were clearly identified in 14 subjects (73%) with transesophageal echocardiography, but in none with the transthoracic technique. The early systolic wave immediately followed the reversed flow during atrial contraction and was strongly related to the timing of atrial contraction (r = 0.78; p less than 0.001), but not to the timing of ventricular contraction, and appeared to be secondary to atrial relaxation. Conversely, the late systolic wave was temporally related to ventricular ejection (r = 0.66; p less than 0.001), peaking 100 ms before the end of the aortic valve closure and was unrelated to atrial contraction time. Quantitatively, significantly higher peak systolic flow velocities were obtained in the left upper pulmonary vein compared with the right upper pulmonary vein (60 +/- 17 vs. 52 +/- 15 cm/s; p less than 0.05) and by transesophageal echocardiography compared with transthoracic studies (60 +/- 17 vs. 50 +/- 14 cm/s; p less than 0.05). Increasing depth of interrogation beyond 1 cm from the vein orifice resulted in a significant decrease in the number of interpretable tracings.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and utility of transesophageal echocardiography in the critically ill patient

We studied the safety and utility of transesophageal echocardiography in the evaluation of critically ill patients in the intensive care unit setting. Sixty-two studies were performed in four different intensive care units on 61 patients with a mean age of 58 +/- 14 years (range 25 to 78 years). Indications for the study included suspected aortic pathologic conditions (18 patients), cardiac source of embolus (16 patients), postmyocardial infarction complications (6 patients), and suspected infective endocarditis (5 patients). Studies were performed at bedside with the use of small amounts of intravenous sedatives. The probe was passed successfully in 61 of 62 attempts. Diagnoses that were missed by surface echocardiography, including aortic dissection, left atrial thrombus, ruptured papillary muscle, and prosthetic valve vegetation were clearly identified by transesophageal echocardiography, which facilitated appropriate management in these cases. In cases in which no pathologic condition was identified, transesophageal echocardiography was useful in ruling out intracardiac shunt, in assessing left ventricular function, and in excluding significant valvular pathologic conditions. No serious complications were recorded, and the procedure was, in general, very well tolerated.

Effect of mitral regurgitation on pulmonary venous velocities derived from transesophageal echocardiography color-guided pulsed doppler imaging

The effect of mitral regurgitation on pulmonary venous flow velocity was studied in 66 patients undergoing transesophageal echocardiography. Nine patients were studied intraoperatively before and after surgery, so that 75 pulmonary venous flow tracings were analyzed. Fifty-four patients had no significant (0 to 1+) mitral regurgitation and 21 had significant (2 to 3+) mitral regurgitation. Comparison of both groups revealed significant differences in the pulmonary venous flow pattern. In patients with no significant mitral regurgitation, the peak systolic velocity was higher (55 +/- 16 vs. -4 +/- 16 cm/s; p less than 0.0001) and the peak diastolic velocity was lower (43 +/- 13 vs. 59 +/- 17 cm/s; p less than 0.01) when compared with values in patients with significant mitral regurgitation. Consequently, the peak systolic/diastolic velocity ratio was significantly higher in the patients without significant mitral regurgitation (1.4 +/- 0.5 vs. 0.4 +/- 1.3; p less than 0.0001). The same trend was noted with respect to the systolic and diastolic velocity integrals. As the degree of mitral regurgitation increased, the peak diastolic velocity and diastolic velocity integral increased, whereas the peak systolic velocity and systolic velocity integral decreased. In patients with severe mitral regurgitation, the systolic flow became reversed (retrograde). The sensitivity of reversed systolic flow for severe mitral regurgitation was 90% (9 of 10), the specificity was 100% (65 of 65), the positive predictive value was 100% (9 of 9), the negative predictive value was 98% (65 of 66) and the predictive accuracy was 99% (74 of 75).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitation of mitral regurgitation by transesophageal echocardiography with Doppler color flow mapping: Correlation with cardiac catheterization

Eighty consecutive patients who underwent both left ventriculography and single-plane transesophageal echocardiography with Doppler color flow mapping were studied to compare the two techniques in the assessment of mitral regurgitation. Only the mosaic aspect of the regurgitant jet was included in the measurements. Values for inter- and intraobserver variability for the maximal regurgitant area measurements were 10 +/- 9% and 9 +/- 8%, respectively. The best correlation between angiography and Doppler color flow imaging was obtained with the maximal regurgitant area (r = 0.90). A maximal regurgitant area less than 3 cm2 predicted mild mitral regurgitation with a sensitivity of 96%, specificity of 100% and a predictive accuracy of 98%, whereas a maximal regurgitant area greater than 6 cm2 predicted severe mitral regurgitation with a sensitivity of 91%, a specificity of 100% and a predictive accuracy of 98%. A strong, although inferior, correlation was found for the maximal regurgitant area/left atrial area ratio (r = 0.81). A ratio less than 20% predicted mild mitral regurgitation with 94% accuracy, whereas a ratio greater than 35% predicted severe mitral regurgitation with 85% accuracy. Thus, single-plane transesophageal echocardiography with Doppler color flow mapping is an exquisitely sensitive technique for the diagnosis of mitral regurgitation. Minimal degrees of mitral regurgitation can be detected in approximately 62% of patients in whom no mitral regurgitation is detected by angiography. The mosaic maximal regurgitant area is a simple and easily obtainable Doppler echocardiographic index that provides an accurate estimation of mitral regurgitation severity.

Differential characterization of blood flow, velocity, and vascular resistance between proximal and distal normal epicardial human coronary arteries : analysis by intracoronary Doppler spectral flow velocity

To characterize coronary blood flow velocity parameters and to determine the relation among velocity, volumetric flow, and vascular resistance in awake human beings, we performed paired proximal and distal velocity measurements in 28 angiographically normal coronary arteries. Mean velocity, peak velocity, diastolic-to-systolic velocity ratio, and diameter and cross-sectional area of proximal and distal arteries were determined and coronary flow and vascular resistance computed. Mean velocity and coronary vasodilator reserve were similar for all three native arteries and were preserved from proximal to distal segments. Volumetric flow decreased from proximal to distal segments. The demonstrated inverse and curvilinear (polynomial) relation between volumetric flow and vascular resistance agrees with theoretical and animal models of coronary physiologic characteristics and suggests a nadir of coronary vascular resistance below which coronary flow no longer increases.