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Biomedical subjects

Candace Keirns

Publications and source records attributed to Candace Keirns.

At least 19 recordsLinked to original sources
PubMed2006

Aortic obstruction: anatomy and echocardiography.

Echocardiography is a valuable non-invasive technique for identifying the site and type of aortic obstruction. Knowledge of the morphological details of each type of obstruction is the basis for correct interpretation of the diagnostic images and clinical decisions. This study was undertaken to correlate the echocardiographic images with anatomic specimens of equivalent valvular and supravalvular aortic obstruction. Specimens were part of the collection of the Department of Embryology. Fifty six patients were studied, and forty specimens with aortic obstruction were analyzed. Echocardiographic characteristics: Thirty one (55.3%) patients were women and twenty five (44.7%) men. Valvular aortic obstruction was found in Thirty six patients (64.3 %) and supravalvular aortic obstruction in twenty (35.7%). Anatomic characteristics: Of the forty specimens examined, twenty one (52.5%) had valvular aortic obstruction and nineteen (47.5%) supravalvular aortic obstruction. The anatomoechocardiographic correlation clearly showed that the anatomic findings of the specimen hearts and aortas corresponded to echocardiographic images of valvular and supravalvular aortic obstruction and provided solid corroboration of echocardiographic diagnoses.

Adolescent↗
PubMed2006

Non-compacted cardiomyopathy: clinical-echocardiographic study.

UNLABELLED: The aim of the present study was to describe the clinical and echocardiographic findings of ventricular noncompaction in adult patients. Fifty-three patients underwent complete clinical history, electrocardiogram, Holter and transthoracic echocardiogram. Forty patients (75%) were in class I/II of the New York Heart Association, and 13 (25%) in class III/IV. Ventricular and supraventricular escape beats were found in 40% and 26.4%, respectively. Holter showed premature ventricular contractions in 32% and sustained ventricular tachycardia in 7.5%. Ventricular noncompaction was an isolated finding in 74% of cases and was associated with other congenital heart disease in 26%. Noncompacted ventricular myocardium involved only left ventricle in 62% of the patients and both ventricles in 38%. The mean ratio of noncompacted to compacted myocardial layers at the site of maximal wall thickness was 3.4 +/- 0.87 mm (range 2.2-7.5). The presence of ventricular noncompaction in more than three segments was associated with a functional class greater than II and ventricular arrhythmia with demonstrable statistical significance by chi2(p < 0.003). CONCLUSION: a) Noncompacted cardiomyopathy is a congenital pathological entity that can occur in isolated form or associated with other heart disease and often involves both ventricles. b) A ratio of noncompacted to compacted myocardium greater than 3 and involvement of three or more segments are indicators of poor prognosis. c) Since the clinical manifestations are not sufficient to establish diagnosis, echocardiography is the diagnostic tool that makes it possible to document ventricular noncompaction and establish prognostic factors.

Adolescent↗
PubMed2006

Atrial septal defect: anatomoechocardiographic correlation.

This study was undertaken to enhance understanding of the anatomic abnormalities involved in atrial septal defect (ASD) based on the anatomoechocardiographic comparison of equivalent specimens of ASD and the echocardiograms of patients with this anomaly. Of the 72 heart specimens, two had common atrioventricular canal (2.8%) and one had absence of right atrioventricular connection (1.4%). In all, 46 (63.8%) had fossa ovalis type ASD, two (2.8%) had true ostium secundum type ASD, two (2.8%) had ostium primum type ASD, two (2.8%) had superior sinus venosus type ASD, and two (2.8%) had inferior sinus venosus type ASD. One (1.4%) specimen had a coronary venous sinus type ASD and 14 (19.4%) had mixed type ASD. Of the 144 patients evaluated with echocardiography 15 (10.4%) had common atrioventricular canal, one (0.7%) had right absence of atrioventricular connection, 105 (72.9%) had ostium secundum type ASD (fossa ovalis), 10 (7%) had mixed type ASD, 9 (6.2%) had superior venous sinus type ASD, two (1.4%) had ostium primum type ASD, and two (1.4%) had true fossa ovalis type ASD. This series leads us to conclude that the key to successful management of ASD depends on understanding echocardiographic images in terms of anatomic specimens to provide appropriate evaluations for therapeutic decisions and establishment of prognoses.

Adult↗
PubMed2005

Anatomoechocardiographic correlation double inlet left ventricle.

Double inlet left ventricle (LV) is a type of atrioventricular connection in which the morphologically LV receives more than 50% of the atrioventricular valves when they are separate, or more than 75% of a common atrioventricular valve. The aim of this study was to establish an anatomoechocardiographic correlation between the morphologic features of equivalent anatomic specimens and the echocardiographic images of patients to provide a means of interpreting the image correctly and a more precise diagnosis of the cardiac defect. Echocardiography was used to study 18 patients with LV double inlet who were seen in a congenital heart disease clinic. The morphology of 17 hearts with this malformation from the department of embryology was analyzed to compare the anatomic features with their echocardiographic images. Echocardiography proved to be a noninvasive diagnostic tool that allowed characterization of anatomic and functional aspects of double inlet LV.

Adolescent↗
PubMed2005

Coronary reserve in Takayasu's arteritis: transesophageal echocardiographic analysis.

BACKGROUND: The incidence of coronary arteries lesion in Takayasu's arteritis varies from 9% to 10% and is usually discovered at autopsy. Recent studies have demonstrated the value of echocardiography in noninvasive detection of significant coronary stenosis. AIM: The aim of our study was to evaluate coronary reserve in 15 patients with Takayasu's arteritis using contrast transesophageal echocardiography (Optison). METHODS: Transesophageal echocardiogram under basal conditions and in the hyperemic phase with dipyridamole challenge, myocardial perfusion studies and coronary angiography were performed on all patients. Seventy-three percent of them had histories of systemic hypertension, and the most frequent cardiovascular symptoms were shortness of breath (80%), headache (46%), angina (40%), and dizziness (33%). RESULTS: The transthoracic echocardiogram showed left ventricular systolic dysfunction in 6% and diastolic dysfunction in 53%. Aortic regurgitation was found in 67% of the patients, and 60% had mitral and/or tricuspid regurgitation. Coronary reserve was diminished in 3 patients with significant coronary lesions and in 2 patients with coronary dilation (33%). In the 3 patients with obstructive lesions and diminished coronary reserve, reversible perfusion defects were found with thallium-201 single-photon emission computed tomography. One patient with coronary dilation had normal perfusion, while the other demonstrated reversible and irreversible perfusion defects. One patient without coronary lesions and with normal coronary reserve had an irreversible fibrotic changes and the other reversible defects due to abnormal microcirculation. CONCLUSIONS: Transesophageal echocardiography is a feasible and promising technique for assessing coronary reserve in patients with Takayasu's arteritis.

Adolescent↗
PubMed2004

Right ventricular function and ventricular perfusion defects in adults with congenitally corrected transposition: correlation of echocardiography and nuclear medicine.

We undertook our study in order to evaluate right ventricular function and perfusion by conventional and contrast echocardiography in adults with congenitally corrected transposition who had not undergone cardiac surgery, comparing the echocardiographic findings with those obtained using equilibrium radionuclide ventriculography and gated single-photon emission computed tomography with Technetiumc-99 m sestamibi. We discovered severe tricuspid regurgitation in 8 patients (61%). Right ventricular ejection fraction, as calculated by nuclear medicine, had a correlation of 0.67 (p = 0.059) with area fractional shortening and 0.84 (p = 0.01) with ejection fraction calculated by the method depending on descent of the tricuspid ring. All patients with severe tricuspid regurgitation also had right ventricular dysfunction. Of these 8 patients, 7 had persistent perfusion defects, while 6 also had ischemic perfusion defects. Echo contrast had a high sensitivity, at 91%, and also specificity and positive predictive value, both at 100%, for persistent defects, and a negative predictive value of 66% compared to methods depending on nuclear medicine. The sensitivity of contrast echocardiography for detection of ischemic defects was 66%, the specificity 100%, the positive predictive value 100%, and the negative predictive value 77% compared to the methods involving nuclear medicine. The method depending on descent of the tricuspid ring had the highest correlation with equilibrium radionuclide ventriculography in evaluation of right ventricular function in patients with congenitally corrected transposition. We conclude that contrast echocardiography is extremely valuable when assessing right ventricular myocardial perfusion, having high sensitivity and specificity for detecting persistent defects, although sensitivity was less for detection of ischemic defects than that of gated single-photon emission computed tomography with Technetium-99 m Sestamibi. Persistent and ischemic perfusion defects, together with chronic volume overload from tricuspid regurgitation, are the determining factors of right ventricular dysfunction.

Adolescent↗
PubMed2003

Anatomic three-dimensional echocardiographic correlation of bicuspid aortic valve.

This study was undertaken to verify the echocardiographic characteristics of bicuspid aortic valve (AV) using 3-dimensional transesophageal echocardiography by comparing the findings with anatomic examination of autopsy specimens from carriers of this condition. Three-dimensional reconstructions of transesophageal echocardiograms were performed on 14 patients with bicuspid AV, and 20 autopsy specimens of bicuspid AVs were analyzed. Echocardiographic images and autopsy material were correlated. Two variants of bicuspid aorta were identified. In group I the AV had 2 leaflets. This group included 9 (9/14) 3-dimensional echocardiographic studies and 13 (13/20) necropsies. In group II 3 sigmoid leaflets had originally developed and 2 underwent dysplastic fusion, resulting in functionally bicuspid valves. Five (5/14) echocardiographic studies and 7 (7/20) anatomic specimens fell into this category. There was a clear correspondence between anatomic and echocardiographic findings, which leads to the conclusion that 3-dimensional echocardiography is a technique that reliably defines the morphological details of bicuspid AV with the precision of anatomopathologic examination.

Adolescent↗
PubMed2002

The impact of right atrial ischemia on inferior myocardial infarction with extension to right ventricle: transesophageal echocardiographic examination.

BACKGROUND: The role of the right atrium in adaptation to the hemodynamic changes produced by extension of myocardial infarction (MI) of the left ventricular inferior wall to the right ventricle is fundamental. HYPOTHESIS: The aim of this study was analyze a group of patients with MI with extension of right chambers, and particularly right atrial alterations, by transesophageal echocardiography and to correlate it with clinical and angiographic variables. METHODS: Thirty patients with right ventricular (RV) MI involving obstruction of the right coronary artery without stenosis of the left coronary artery were included; 18 underwent early reperfusion. Transesophageal echocardiography was performed on all within 5 days of coronary angiography. Follow-up was continued from hospitalization to the present. RESULTS: When patients with right atrial ischemia were compared with those with normal right atrium, the RV wall movement score was significantly greater in the group with right atrial ischemia, severe RV dilatation was more frequent, and association with proximal occlusion of the artery responsible for the MI, as well as absence of right atrial branches and poor collateral circulation, were significant. Hospitalization was more prolonged in this group, and there was a higher incidence of arrhythmias, complete atrioventricular block, and mortality. CONCLUSIONS: Right atrial ischemia associated with RV infarction leads to a higher incidence of complications and higher mortality. Transesophageal echocardiography is a safe, reproducible technique that provides detailed anatomic information about right chambers and aids in the determination of prognosis and therapeutic decisions.

Adult↗
PubMed2002

Three-dimensional echocardiography in congenital malformations of the mitral valve.

Three-dimensional echocardiography has proved to be valuable in congenital heart disease by enhancing the evaluation of morphologic abnormalities and increasing the understanding of complex relationships. This study was undertaken to determine how 3-dimensional echocardiography could be best used to study some of the congenital malformations of the mitral valve such as mitral arcade, double orifice mitral valve, accessory mitral tissue, cleft mitral valve, and unicuspid mitral valve. Five patients were studied. Three-dimensional echocardiography was found to be helpful in defining spatial location and extent of deformities.

Adult↗
PubMed2002

Three-dimensional transesophageal echocardiography in tumors of the heart.

Three-dimensional echocardiography was used to study 5 women, 4 with intracardiac tumors and 1 with a paracardial neoplasia. Three-dimensional transesophageal echocardiography was found to be a valuable way to define the morphologic and spatial characteristics of cardiac and paracardial tumors in vivo, establish their relationships with adjacent structures, and assess the hemodynamic effects they can produce.

Adult↗
PubMed1999

Myelolipoma: A New Adrenal Finding in Carney's Complex?

Pigmented nodular cortical hyperplasia. a rare cause of Cushing's syndrome, is characterized by resistance to inhibition with dexamethasone and normal sized adrenal glands with multiple, small, pigmented nodules. The disorder may be a component of a syndrome inherited as an autosomal dominant pattern that includes intra- and extracardiac myxomas, lentiginous lesions, blue nevi, other functional endocrire tumors, and perppheral nerve tumors (Carney's complex). We report a patient in whom bilateral myelolipomas were found, in addition to the usual features of this complex. A 29-yr old man was admitted to the hospital for Cushing's syndrome of probably more than 15 yr duration. Physical examination showed diffuse facial hyperchromatic macules. 02-05 cm, predominantly around the lips and on the palmar surfaces of the fingers. Results with dexamethasone suppression nocturnal testing (1 and 8 mg) were compatible with an adrenal adenoma. The computed tomography (CT) of the sella turcica was normal. Adrenal CT showed a tumor in the left gland with a double component one solid and another suggestive of fat, consistent with an angiomyelolipoma. Following 5 wk treatment with ketoconazole, 800 mg per day po, serum cortisol decreased to 5.9 Ag/dL. morning and evening, respectively. Bilateral adrenalectomy was performed. Pathologic examination revealed pigmented nodular cortical hyperplasia and a dominant myelolipoma in the left adrenal. A microscopic myelolipoma was identified in the right adrenal. An echocardiogram showed a mass on the posterior wall of the left ventricle which was a myxoma. Study of the patient's family disclosed two sisters with facial lentigines. Echocardiograms were performed on all available first degree relatives: all were normal. Nocturnal inhibition with dexamethasone revealed that one of the patient's sisters with lentigines also had hypercortisolism. Myelolipoma has been reported in association to Cushing syndrome in humans and experimentally after pituitary extracts in animals. The relationship between this finding and the Carney's complex remain elusive.

Journal Article↗
PubMed1999

Echocardiographic Evaluation of Patients with Primary Pulmonary Hypertension Before and After Atrial Septostomy.

OBJECTIVES: To characterize the early changes in right ventricular [right ventricle (RV)] geometry and function, as assessed by two-dimensional (2-D) and Doppler echocardiography, after balloon-dilation atrial septostomy (BDAS) in patients with severe primary pulmonary hypertension (PPH). BACKGROUND: Survival in PPH is to a great extent dependent on the functional status of the RV. BDAS recently has been shown to improve functional class and hemodynamics in patients with PPH nonresponsive to conventional vasodilator treatment. METHODS: Ten patients with severe PPH who underwent BDAS were studied with transthoracic and transesophageal 2-D and Doppler echocardiography. RV dimensions were measured in the apical four-chamber view. Continuous-wave Doppler echocardiography was used to obtain peak velocity of tricuspid regurgitation. Transesophageal echocardiography (TEE) primarily was used for the follow-up of the atrial septal defects (ASDs). RESULTS: In the early post-BDAS studies, right atrial and ventricular dimensions significantly decreased in all patients (P < 0.05). Global right ventricular wall motion (RVWM) also improved. RV percent change in area after septostomy inversely correlated with the changes in RV systolic area (r = -0.75; P < 0.05) and also with the baseline (preprocedure) values of RV percent change in area (r = -0.77; P < 0.05). Neither RV wall thickness nor the degree of tricuspid regurgitation were modified significantly after the procedure. CONCLUSIONS: BDAS in the setting of severe PPH results in moderate and salutary changes in geometry and function of the RV as assessed by 2-D echocardiography. These changes mainly appear to be the result of the decompression effect of atrial septostomy.

Journal Article↗
PubMed1999

Transesophageal Echocardiographic Evidence for Acute Right Atrial Dysfunction.

We describe the clinical course and echocardiographic findings of a 64-year-old man who was hospitalized with an infarction of the inferior myocardial wall of 5 days' evolution and extension to the right ventricle. Transesophageal echocardiography showed biventricular inferior dyssynergia and akinesis of the right atrial wall. One thrombus was visible in the right atrial appendage, and another crossed the foramen ovale and reached the mitral valve. After the patient received anticoagulant agents, transesophageal studies showed the disappearance of atrial thrombi, as well as recuperation of right atrial movement and active participation of atrial contraction in right ventricular filling. The findings of these serial echocardiograms support the existence of ischemic right atrial stunning manifested by wall akinesis that favored slow atrial flow and the formation of thrombi.

Journal Article↗
PubMed1998

Clinical-Echocardiographic Correlation of Myocardial Infarction with Extension to Right Chambers.

In order to determine the transesophageal echocardiographic characteristics in patients with acute myocardial infarction of right ventricle and establish the relationship between these findings, the clinical condition, and their prognostic value, 38 patients consecutively admitted to the Instituto Nacional de Cardiología with a diagnosis of acute left ventricular myocardial infarction with extension to right ventricle and/or atrium were retrospectively studied. Of the left ventricular infarctions, 37 were posteroinferior and one anterior. Significant elevations of CPK and DHL were found in 35. In 30 patients (78%) electrocardiographic evidence of extension of infarction to the right ventricle was found, and in 3, evidence of right atrial infarction. Twenty-one patients presented clinical data compatible with right ventricular infarction. In 19, cardiac rhythm and atrioventricular conduction disturbances were documented. Coronary angiograms practiced on 34 patients demonstrated single-vessel (right coronary) disease in 12, affection of two vessels in 14, and lesions in three or more in 6. Coronary arteries presented no significant lesions in two cases. With TEE, alterations of right ventricular segmental mobility were demonstrated in all patients, and in 6, alterations of right atrial mobility as well. As respects the ventricular wall movement index, 68.5% had total scores (RV + LV) of <5. The other 31.5% had scores >/= 5. In 26%, the right ventricular wall movement index was >/=4. The RVDD/LVDD ratio was 1 or less in 30 patients (78%) and >1 in only 8 (22%). The conclusions from these findings are that: (1) TEE is an excellent diagnostic means of identifying right ventricular and/or atrial infarction; and (2) a relationship exists between the magnitude of right ventricular damage and a wall movement index of 5 or more or an RV/LV diastolic diameter ratio > 1:postinfarction hemodynamic deterioration is significantly greater and the incidence of intrahospitalary complications higher.

Journal Article↗