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Biomedical subjects

C M Otto

Publications and source records attributed to C M Otto.

At least 73 records · Page 4Linked to original sources
PubMed1992

Influence of mitral valve morphology on mitral balloon commissurotomy: immediate and six-month results from the NHLBI Balloon Valvuloplasty Registry.

Echocardiographic data were analyzed in 555 patients undergoing mitral balloon commissurotomy (MBC). Patients were enrolled in the National Heart, Lung, and Blood Institute Balloon Valvuloplasty Registry from 24 centers. There were 456 women and 99 men with a mean age of 54 years. Before MBC the two-dimensional echocardiographic variables of mitral valve thickness, mobility, calcification, and subvalvular disease were evaluated and assigned scores of 1 to 4. The mitral valve morphology score was related to mitral valve area (MVA) measured after MBC by cardiac catheterization. The leaflet mobility score was related to the immediate post-MBC MVA: 2.2 +/- 0.8 cm2 for grade 1, 1.9 +/- 0.7 cm2 for grade 2, 1.7 +/- 0.7 cm2 for grade 3, and 1.9 +/- 0.9 cm2 for grade 4 (p less than 0.001). Results of the MVA after MBC showed a similar relationship for each echocardiographic variable. The total morphology score (sum of the four variables) showed a weak relationship to MVA immediately after MBC (r = 0.24), which was persistent at 6 months after MBC (r = -0.25). Multiple regression analysis showed that the MVA after MBC is predicted by pre-MBC MVA (p less than 0.001), left atrial size (p = 0.01), balloon diameter (p = 0.02), cardiac output (p = 0.004), and leaflet mobility (p = 0.01). The R2 of the model was 0.31 (p less than 0.001). Total morphology score, leaflet thickness, calcification, and subvalvular disease were not important univariate or multivariate predictors of the results of MBC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Monoclonal antibodies to porcine tumor necrosis factor alpha: development of an enzyme-linked immunosorbent assay.

Five hybridomas (4F4, 14H1, 9B4, 6E10, and 8G7) secreting antibodies to porcine tumor necrosis factor alpha (PTNF-alpha) were obtained from one fusion. Four of the 5 monoclonal antibodies (Mab) recognized recombinant PTNF-alpha (rPTNF-alpha) on western blot and were able to neutralize both rPTNF-alpha and native (released by porcine macrophages) PTNF (nPTNF-alpha, only 4F4, 14H1, and 9B4 tested for the neutralization of nPTNF-alpha) in vitro. A sandwich enzyme-linked immunosorbent assay (ELISA) for PTNF-alpha was developed using Mab 4F4 and purified rabbit polyclonal antibodies against PTNF-alpha. The test detected PTNF-alpha concentrations as low as 400 pg/ml and did not cross react with native porcine TNF-beta, recombinant human TNF-alpha, recombinant mouse TNF-beta or native mouse TNF-alpha. The Mabs and the ELISA should be useful for assessing PTNF-alpha levels in swine serum during disease processes and possibly for alleviation of toxic effects of TNF-alpha.

Animals↗
PubMed1991

Doppler echocardiographic findings in adults with severe symptomatic valvular aortic stenosis. Balloon Valvuloplasty Registry Echocardiographers.

Baseline echocardiographic data in 680 adults (mean age 78 years) undergoing balloon aortic valvuloplasty at 24 medical centers were analyzed to describe the degree of outflow obstruction in patients with symptomatic aortic stenosis. Maximal aortic jet velocity ranged from 2.3 to 6.6 m/s (mean 4.4 +/- 0.8) and continuity equation valve area ranged from 0.1 to 1.4 cm2 (mean 0.6 +/- 0.2). Of note, 36% had a jet velocity less than or equal to 4.0 m/s but only 3% had a valve area greater than 1.0 cm2 due to a high prevalence of impaired systolic function (54%). Outflow tract diameter was poorly correlated with body surface area (p = 0.26), although the group mean diameter was smaller in women than in men (1.9 +/- 0.2 vs 2.1 +/- 0.3 cm, p = 0.0001). Mean pressure gradient was related closely to maximal gradient (r = 0.92) and to maximal jet velocity (mean delta P = 2.4 V2 + 0.75 mm Hg). Simpler measures of aortic stenosis severity were correlated with Doppler and invasive valve area as follows: maximal jet velocity (r = -0.36 and -0.32), mean gradient (r = -0.33 and -0.29), outflow tract to jet velocity ratio (r = 0.67 and 0.40), and the fractional shortening velocity ratio (r = 0.29 and 0.22). This study demonstrates marked variability in stenosis severity in symptomatic adults referred for balloon aortic valvuloplasty. The absence of a predictable relation between outflow tract diameter and body size emphasizes the importance of this measurement in each patient if definition of valve area is needed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Factor XII and partial prekallikrein deficiencies in a dog with recurrent gastrointestinal hemorrhage.

Factor XII deficiency and impaired prekallikrein activity were diagnosed in a 1-year-old Chinese Shar Pei. The dog experienced repeated episodes of intestinal hemorrhage and diarrhea. Laboratory findings were compatible with blood loss (iron deficiency anemia and hypoproteinemia). Necropsy findings suggested mild infiltrative bowel disease that could have been responsible for the dog's diarrhea, but no explanation for the severe recurrent gastrointestinal hemorrhage could be found. Factor XII deficiency is uncommon in the dog and is not associated with hemorrhagic tendencies. The factor XII deficiency in this case may have contributed to the gastrointestinal hemorrhage.

Animals↗
PubMed1991

Tricuspid valve repair for tricuspid valve endocarditis: tricuspid valve "recycling".

Tricuspid valve endocarditis traditionally has been treated with either valve excision or valve replacement. To avoid implantation of foreign material in an infected field, we have applied the principles of mitral valve repair to 4 patients with tricuspid valve endocarditis. On preoperative echocardiography, all patients had 3 to 4+ tricuspid regurgitation, evidence of progressive right ventricular enlargement, and mobile vegetations. In each case, up to three quarters of the anterior leaflet was excised en bloc with infected chordae and papillary muscle heads. Surgical procedures included standard quadrangular resection, conversion to a bicuspid valve, and pericardial patch replacement of the anterior leaflet with mobilization of basal chordae to replace resected marginal chordae. On postoperative echocardiography, tricuspid regurgitation and right ventricular dimensions were reduced in 2 of 4 patients in spite of loss of leaflet tissue. All excised valve tissue demonstrated bacteria on Gram stain or culture. Nonetheless, all repaired valves were successfully sterilized without recurrent infections. Tricuspid valve repair can allow eradication of infection with potential for improving valve competency in complicated tricuspid valve endocarditis.

Echocardiography↗
PubMed1990

Echocardiographic evaluation of segmental wall motion early and late after thrombolytic therapy in acute myocardial infarction: the Western Washington Tissue Plasminogen Activator Emergency Room Trial.

In 92 acute myocardial infarction (AMI) patients treated with tissue plasminogen activator 2.3 +/- 1.2 hours after the onset of chest pain, echocardiography was performed at 11 +/- 14 hours (early) and, in 49 patients, again at 13 +/- 7 weeks (late). Infarct location and the left ventricular wall motion score index--the average score (normal = 1, hypokinetic = 2, akinetic = 3, dyskinetic = 4) for 20 segments--were determined by 2 observers unaware of clinical, angiographic or electrocardiographic data. Concordance between noninvasive infarct location by electrocardiography or echocardiography and infarct-related artery at angiography 4 +/- 2 days later (n = 85) was 76 and 81%, respectively. The early wall motion score index was worse for anterior (1.8 +/- 0.4) versus inferior (1.3 +/- 0.2, p less than 0.0001) or posterior-lateral (1.6 +/- 0.2, p = 0.0003) infarcts. Overall, the wall motion score index improved from early to late echocardiography (n = 49, 1.5 +/- 0.3 to 1.3 +/- 0.3, p = 0.0008). However, improvement was confined to those with time to treatment less than or equal to 2 hours (n = 22, 1.4 +/- 0.3 to 1.2 +/- 0.2, p less than 0.0001), and evidence of reperfusion at angiography (n = 38, 1.5 +/- 0.3 to 1.2 +/- 0.3, p less than 0.0001). The decrease in the wall motion score index was related to a decrease in the number of adjacent involved segments (5.5 +/- 3.0 to 3.7 +/- 3.9/patient, p = 0.0006). Thus, echocardiography early after AMI identifies infarct location. Improvement in regional wall motion is seen after early treatment with intravenous tissue plasminogen activator.

Aged↗
PubMed1990

Infective endocarditis, 1983-1988: echocardiographic findings and factors influencing morbidity and mortality.

The echocardiograms and clinical records of 70 patients with infective endocarditis seen between 1983 and 1988 were examined to evaluate the role of two-dimensional and Doppler echocardiography in the diagnosis of infective endocarditis and identify risk factors for morbidity and mortality. A blinded observer reviewed the echocardiograms for the presence and size of vegetations and the severity of the valvular regurgitation. Vegetations were identified in 54 (78%) of 69 technically satisfactory echocardiograms. In 38 patients whose heart was examined at surgery or autopsy, all vegetations diagnosed by echocardiography were confirmed, but six additional vegetations were found. Abnormal (greater than or equal to 2+) valvular regurgitation was present in 88% of patients. No patient with less than or equal to 1+ regurgitation (n = 8) died or required valve surgery for heart failure, but three of the eight patients did undergo surgery for mycotic aneurysm, recurrent embolism or paravalvular abscess. In patients without embolism before echocardiography, there was a trend toward a greater incidence of subsequent embolism in those with vegetations greater than 10 mm in size (26% [8 of 31] compared with 11% [2 of 18] with vegetations less than or equal to 10 mm) (p = 0.19). By multivariate analysis, risk factors for in-hospital death (n = 7) were an infected prosthetic valve (p less than 0.007), systemic embolism (p less than 0.02) and infection with Staphylococcus aureus (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1990

A case of delayed postoperative cardiac tamponade with unusual echocardiographic findings.

Postoperative cardiac tamponade due to localized compression of the atria occurred in a 64-year-old man after aortic valve replacement and repair of an ascending aortic dissection. The clinical findings were subtle and the echocardiographic findings were unusual. Color Doppler flow imaging assisted in making the diagnosis of localized atrial compression.

Aortic Aneurysm↗
PubMed1990

Doppler echocardiographic evaluation of aortic stenosis.

Doppler echocardiography allows accurate noninvasive measurement of transaortic velocity and pressure gradient in patients with valvular aortic stenosis. Because pressure gradients vary with transaortic volume flow, calculation of aortic valve area with the continuity equation is essential for complete echocardiographic evaluation of adult patients. The physician and sonographer should be aware of potential technical and physiologic pitfalls in applying Doppler echocardiographic techniques to the evaluation of the adult with aortic stenosis. With proper training and experience, however, the needed data can be obtained reliably and reproducibly. Doppler evaluation of patients with aortic stenosis has improved our understanding of the prevalence and natural history of this disease. In addition, Doppler measures of stenosis severity can be used in a cost-effective manner for clinical decision making regarding the need for valve replacement in symptomatic adults. It now has supplanted the need for invasive measures of stenosis severity in many of these patients.

Adult↗
PubMed1989

Hemodynamic progression of aortic stenosis in adults assessed by Doppler echocardiography.

Doppler echocardiography was used to follow the hemodynamic severity of aortic stenosis. First, the reproducibility of repeat recordings (mean interval 28 +/- 36 days) of aortic jet velocity, made by two independent observers, was tested in 38 adults with aortic stenosis and unchanged clinical status. The two recordings of maximal velocity correlated well (r = 0.96, y = 0.88x + 0.46m/s, SEE = 0.21 m/s) with a mean coefficient of variation of 3.2%. Repeat recording of left ventricular outflow tract velocity by two independent observers in 10 other patients with aortic stenosis also correlated well (r = 0.94, y = 1.06x + 0.0 m/s, SEE = 0.06 m/s) with a mean coefficient of variation of 4.6%. Next, Doppler echocardiography was used to study 42 patients with aortic stenosis (mean age 66 years) over a follow-up interval of 6 to 43 months (mean 20). Maximal aortic jet velocity increased by 0.36 m/s per year (range -0.3 to +1.0 m/s per year). Mean transaortic pressure gradient changed by -7 to +23 (mean 8) mm Hg/year. Aortic valve area by the continuity equation (n = 25) decreased by 0 to 0.5 cm2/year (mean decrease 0.1 cm2/year). Some patients had a worsening of stenosis (decrease in valve area) even though they had no change or a decrease in pressure gradient, because of concurrent decreases in transaortic volume flow. Twenty-one patients (50%) developed new or progressive symptoms of aortic stenosis necessitating valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Doppler echocardiographic evaluation of left ventricular diastolic filling in isolated valvular aortic stenosis.

Doppler echocardiography was used to study left ventricular (LV) diastolic filling in 49 adults with isolated aortic stenosis (AS), selected from 155 consecutive patients with AS by excluding coexisting mitral disease (n = 41) and/or significant aortic regurgitation (n = 80). There were no differences between patients with AS and age-matched normal subjects for early diastolic filling (E) velocity (68 +/- 17 vs 67 +/- 13 cm/s), late diastolic filling (A) velocity (79 +/- 25 vs 67 +/- 21 cm/s), E/A ratio (1.00 +/- 0.78 vs 1.06 +/- 0.32) or early diastolic deceleration slope (264 +/- 151 vs 319 +/- 137 cm/s2, differences not significant for all). There was no correlation between any LV filling parameter and AS severity, but late diastolic filling velocity was higher in patients with AS who had LV hypertrophy (n = 33) vs those who did not (n = 16) (86 +/- 23 vs 65 +/- 26 cm/s, p less than 0.01). In the patients with AS and systolic dysfunction (LV ejection fraction less than 50%) (n = 6), early diastolic filling velocity was higher (88 +/- 20 vs 65 +/- 15 cm/s, p less than 0.01), late diastolic filling velocity lower (53 +/- 23 vs 83 +/- 23 cm/s, p less than 0.01), E/A ratio higher (2.20 +/- 1.80 vs 0.84 +/- 0.28, p less than 0.01), deceleration slope steeper (439 +/- 230 vs 240 +/- 121 cm/s2, p = 0.02) and LV end-diastolic pressure higher (23 +/- 9 vs 10 +/- 6 mm Hg, p less than 0.01) than in patients with AS and normal systolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Postinfarction left ventricular pseudoaneurysm: echocardiographic diagnosis and prolonged survival in three patients.

Both echocardiography and radionuclide angiography have been proposed as noninvasive modalities for the diagnosis of left ventricular pseudoaneurysm. In the only three cases seen at our institution over the past five years, this diagnosis was missed with radionuclide blood pool imaging, while two-dimensional echocardiography demonstrated the typical features of a pseudoaneurysm. Our patients were asymptomatic and diagnosis was made incidentally 4 to 6 years after myocardial infarction. Although the patients survived an extended period without surgery, the reported incidence of rupture is high, and prophylactic surgical repair probably is indicated. It is likely that the increased use of noninvasive cardiac imaging techniques will lead to the detection of other cases of unsuspected left ventricular pseudoaneurysm. Two-dimensional echocardiography appears superior to planar radionuclide ventriculography in establishing the diagnosis.

Aged↗
PubMed1988

Experimental validation of Doppler echocardiographic measurement of volume flow through the stenotic aortic valve.

In aortic stenosis, evaluation of aortic valve area by the continuity equation assumes that the volume of flow through the stenotic valve can be measured accurately in the left ventricular outflow tract. To test the accuracy of Doppler volume-flow measurement proximal to a stenotic valve, we developed an open-chest canine model in which the native leaflets were sutured together to create variable degrees of acute aortic stenosis. Left ventricular and aortic pressures were measured with micromanometer-tipped catheters. Volume flow was controlled and varied by directing systemic venous return through a calibrated roller pump and back to the right atrium. Because transaortic volume flow will not equal roller pump output when there is coexisting aortic insufficiency (present in 67% of studies), transaortic flow was measured by electromagnetic flowmeter with the flow probe placed around the proximal descending thoracic aorta, just beyond the ligated arch vessels. In 12 adult, mongrel dogs (mean weight, 25 kg), the mean transaortic pressure gradient ranged from 2 to 74 mm Hg, and transaortic volume flow ranged from 0.9 to 3.2 l/min. In four dogs, electromagnetic flow that was measured distal to the valve was accurate compared with volume flow determined by timed collection of total aortic flow into a graduated cylinder (n = 24, r = 0.97, electromagnetic flow = 0.87 Direct +0.13 l/min). In eight subsequent dogs, electromagnetic flow was compared with transaortic cardiac output measured by Doppler echocardiography in the left ventricular outflow tract as circular cross-sectional area [pi(D/2)2] x left ventricular outflow tract velocity-time integral x heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Doppler echocardiography in adults with symptomatic aortic stenosis. Diagnostic utility and cost-effectiveness.

To evaluate the diagnostic utility and cost-effectiveness of Doppler echocardiography in adults with symptomatic aortic stenosis, we performed a prospective study in which the need for aortic valve replacement (AVR) was the outcome event. The total sample consisted of 103 adults (mean age, 69 years) undergoing cardiac catheterization for suspected aortic stenosis. Twenty-six patients (25%) were used as a training set to develop a clinical prediction rule. (1) If maximum aortic jet velocity (Vmax) was more than 4.0 m/s, AVR was recommended. (2) If Vmax was less than 3.0 m/s, AVR was not needed. (3) If Vmax was 3.0 to 4.0 m/s and (a) Doppler aortic valve area (AVA) was 1.0 cm2 or less, AVR was recommended, while (b) if Doppler AVA was 1.7 cm2 or greater, AVR was not needed, and (c) if Doppler AVA was 1.1 to 1.6 cm2, consideration of the degree of coexisting aortic insufficiency was necessary. When this rule was applied to the test set (n = 77), the sensitivity was 98%, with a specificity of 89% and a total error rate of 3.9%. The approach could have resulted in cost savings between 24% and 34% compared with an invasive diagnostic approach.

Adult↗