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M Zabalgoitia

Publications and source records attributed to M Zabalgoitia.

47 records · Page 3Linked to original sources
PubMed1993

Pitfalls in the echo-Doppler diagnosis of prosthetic valve disorders.

Assessment of artificial heart valves is a classic example of pitfalls in Doppler and color flow echocardiography. These limitations should be analyzed in the context of the most common clinical conditions associated with prosthetic valve dysfunction, that is, assessment of stenosis, regurgitation, endocarditis, and source of emboli. Estimation of the mean transvalvular gradient in addition to valve areas may avoid potential problems of over- or underestimation of stenotic lesions. The combination of acoustic attenuation, acoustic shadowing, and jet(s) eccentricity makes accurate grading of prosthetic regurgitation difficult and often frustrating. Reverberations and side lobe are frequent artifacts that decrease the ability of two-dimensional echocardiography to identify endocarditis-induced lesions such as vegetations and abscesses, as well as potential sources of emboli such as thrombus and atrial septal abnormalities. Transesophageal echocardiography has provided a new window in the evaluation of prosthetic cardiac valve function. With this approach, high frequency, high resolution transducers greatly improve the quality of ultrasound and color flow Doppler images that result in a higher diagnostic yield. In patients with suspected mitral prosthesis malfunction, transesophageal echocardiography is the method of choice. Contrast study during the transesophageal examination increases the sensitivity to detect potential sources of emboli such as patent foramen ovale. The improvement in diagnostic accuracy may allow one to avoid further diagnostic tests and, in selected patients, it may facilitate optimal timing of a surgical intervention.

Echocardiography, Doppler↗
PubMed1993

Improvement in the diagnosis of bioprosthetic valve dysfunction by transesophageal echocardiography.

Transthoracic two-dimensional echocardiography has been considered the method of choice for the non-invasive assessment of bioprosthetic valves. Recently, transesophageal echocardiography has provided a better imaging window for detecting valve abnormalities not identified otherwise, but pathologic confirmation is essential to establish the role of new diagnostic techniques in clinical practice. Therefore, the purpose of this study was to evaluate the usefulness of transesophageal echocardiography in determining the etiology of bioprosthetic valve dysfunction. Transthoracic and transesophageal two-dimensional and color-flow Doppler echocardiography were performed on 44 consecutive patients with suspected bioprosthetic dysfunction who underwent surgical intervention. At surgery a total of 63 abnormalities in 44 bioprostheses were identified: 31 (49.2%) flail cusps, 14 (22.2%) vegetations, four (6.3%) abscesses, four (6.3%) dehiscences, and 10 (15.9%) stenoses. Transesophageal echocardiography was superior to its transthoracic counterpart for the detection of flail cusps (96.7% vs. 54.8%, p < 0.01), vegetations (85.7% vs. 42.8%, p < 0.01), abscesses (100% vs. 25.0%, p < 0.05), and dehiscences (100% vs. 25.0%, p < 0.05). All patients with flail cusps had severe regurgitation as evaluated by color-flow Doppler. In bioprosthetic mitral stenosis, both methods provided accurate estimates of valve area, while in bioprosthetic aortic stenosis, transthoracic Doppler velocity measurements allowed calculation of valve area in four of six patients. In two patients with high flow velocities, the valve area was not estimated because of an inability to measure the left ventricular outflow tract dimension. Conversely, the transesophageal approach provided measurement of the outflow tract in all six patients, but Doppler velocities were not obtained in any of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1992

Systolic anterior motion of the chordal apparatus after mitral ring insertion.

To describe the Doppler and two-dimensional echocardiographic characteristics of systolic anterior motion of the chordal apparatus after mitral annuloplasty, 24 consecutive patients (19 men and 5 women; mean age, 55 years) were studied with the use of serial Doppler and two-dimensional echocardiography, which included preoperative transthoracic, intraoperative epicardial, and postoperative transthoracic examinations at 1 week after annuloplasty and every 3 months thereafter for up to 12 months. Systolic anterior leaflet motion of the mitral valve was not seen in this series; however, chordal systolic anterior motion was seen in three patients during surgery and in one additional patient at the time of the 1-week transthoracic examination. During subsequent studies at 3-month intervals, chordal systolic anterior motion was not present. The left ventricular outflow tract velocities were normal in all patients with and without chordal systolic anterior motion. In conclusion, chordal systolic anterior motion should be differentiated from leaflet systolic anterior motion after mitral annuloplasty because the former is a transient, benign, and relatively common finding.

Adult↗
PubMed1992

Feasibility and safety of transesophageal stress echocardiography.

To determine the feasibility and safety of transesophageal stress echocardiography (TSE), 86 patients with chest pain syndrome were studied. The TSE test consists of transesophageal atrial pacing during simultaneous monitoring of left ventricular contractility by the use of transesophageal echocardiography. An octapolar pacing catheter attached to the transesophageal echoscope was used in conjunction with a cardiac stimulator to induce pacing-tachycardia. The optimal pair of electrodes was chosen from 13 possible combinations of the 8-electrode catheter. The pacing rate was increased until greater than or equal to 90% maximal age-predicted heart rate was reached or significant wall motion abnormalities were developed. The test was also stopped if ischemic electrocardiographic changes or progressive chest pain occurred. A successful TSE test was performed on 77 patients (90%). Twenty-one patients (24%) developed Wenckebach AV block during pacing that was resolved by intravenous atropine sulfate in all but one of them. The TSE test could not be completed in nine patients (10%) because we were unable to capture in four patients (5%), there were suboptimal images in three patients (3%), and two patients suffered intolerable epigastric discomfort (2%). Pacing-induced wall motion abnormalities were identified in 53 patients (69%). No serious complications were noted. We conclude that TSE is a feasible nonexercise stress test that can be performed safely in patients with suspected coronary artery disease.

Adult↗
PubMed1991

Pathologic and angiographic correlations of transesophageal echocardiography in prosthetic heart valve dysfunction.

To determine the diagnostic accuracy of transesophageal echocardiography (TEE) in prosthetic valve dysfunction, the pathologic and/or angiographic data from 37 valves were compared with that obtained by transesophageal and transthoracic echocardiography. Of the 21 prostheses with severe regurgitation, TEE identified all 14 mitral, the five aortic, and one of the two tricuspid valves; on the other hand transthoracic echocardiography identified 2 of the 14 mitral, the five aortic, and one of the two tricuspid valves. Of the 10 prostheses with flail cusp(s), nine (90%) were correctly identified by TEE and four (40%) were correctly identified by transthoracic echocardiography. All five prostheses with paravalvular regurgitation were detected through the esophageal window and one detected through the precordial window. TEE was unable to document the two prosthetic aortic stenoses, whereas the transthoracic examination correctly quantified the gradient in one but underestimated it in the other case. Seven patients underwent valve replacement on the basis of the clinical and TEE information alone. In assessing cause, origin, and severity of prosthetic mitral regurgitation, TEE is the method of choice. In selected cases, TEE can avoid angiography and facilitate optimal timing of reoperation. In selected aortic and tricuspid dysfunction, TEE may provide additional morphologic, but limited hemodynamic information.

Adult↗
PubMed1991

Transesophageal stress echocardiography: detection of coronary artery disease in patients with normal resting left ventricular contractility.

A new nonexercise test to detect significant coronary disease was prospectively evaluated in 36 patients with chest pain syndrome and normal left ventricular contractility. Transesophageal atrial pacing was used to provoke ischemia during monitoring of left ventricular contractility by transesophageal echocardiography. A 12-lead ECG was recorded. A TSE was abnormal if new segmental wall motion abnormalities developed. On the basis of the TSE results, patients were separated into normal (group 1, n = 16) and abnormal response (group 2, n = 20). Arteriography revealed significant disease in 21 patients, 19 from group 2 and two from group 1. Sensitivity and specificity of TSE were 90% and 93%, respectively, and those for pacing ECG were 43% and 100%, respectively. In addition, TSE accurately predicted the coronary artery perfusion bed involved. In 10 patients, Wenckebach AV block developed during pacing and resolved immediately by the administration of atropine sulfate. No serious complications were seen. Thus TSE is a highly sensitive and specific novel technique to detect significant coronary disease in patients with chest pain syndrome and normal resting left ventricular contractility.

Aged↗
PubMed1990

Transesophageal echocardiography in the awake elderly patient: its role in the clinical decision-making process.

To assess the impact on the management and safety of transesophageal echocardiography (TEE) in the elderly population, the results and limitations of this technique were retrospectively analyzed in 88 patients. TEE was indicated whenever the transthoracic approach was not diagnostic or was inconsistent with the clinical setting. The most frequent clinical indications were to investigate the source of emboli, assess valvular regurgitation, and identify valvular vegetations. In 72 patients (82%) TEE significantly influenced management decisions. In selected patients TEE avoided the use of more invasive diagnostic procedures. Adverse effects included occasional premature atrial or ventricular beats (11 patients), sinus bradycardia (six patients), and protracted nausea (one patient). We conclude that in elderly patients with cardiovascular diseases, TEE plays a significant role in the decision-making process without adding a significant risk.

Aged↗
PubMedDate not supplied

Evidence of hibernating myocardium by a new transesophageal echocardiographic technique.

Reversal of resting wall motion abnormalities after successful coronary angioplasty were documented in a patient with the use of a novel approach to stress testing. Transesophageal stress echocardiography utilizes transesophageal atrial pacing to provoke myocardial ischemia while the left ventricular contractility is being monitored by means of transesophageal echocardiography. The potential use of this technique is illustrated in this report.

Adult↗