Tone-dependent waterfall behavior during venous pressure elevation in isolated canine hearts

We examined the "vascular waterfall" hypothesis, which proposes that coronary flow is unaffected by elevations in outflow pressure until the latter reaches a critical threshold level, in 29 isolated canine hearts. In fibrillating hearts vasodilated with adenosine or carbocromen, coronary flow and the coronary pressure-flow relation were not affected by changes in great cardiac vein pressure (PGCV) below a threshold value of 11 +/- 0.9 (mean +/- SEM) mm Hg. Further elevations of PGCV reduced flow and shifted the pressure-flow relation to the right, increasing its pressure-axis intercept (Pf=0). When vasomotor tone was augmented with vasopressin, threshold PGCV increased to 25 +/- 2.7 mm Hg (p less than 0.001). Once again, the pressure-flow relation was unaffected by changes in PGCV below the threshold value and shifted to the right when this value was exceeded. The amount by which spontaneous values of Pf=0 exceeded threshold values of PGCV was greater when vasomotor tone was augmented than during vasodilation. Pf=0 continued to exceed PGCV when the latter was raised above the threshold level. Both Pf=0 and threshold values of PGCV were less during a long diastole than during ventricular fibrillation. We reached the following conclusions. 1) During changes in PGCV below a threshold value, the coronary circulation exhibits traditional waterfall behavior. 2) The threshold pressure for altering waterfall behavior is affected by vascular tone and mechanical activity. 3) Pf=0 remains above PGCV when the latter is increased above the threshold value needed to alter flow.     

An experimental design for induction of non-specific aortoarteritis

BACKGROUND: An attempt was made to induce aortoarteritis in mice by using various antigens. METHODS AND RESULTS: The Swiss mice were immunized with eight different antigens and were grouped A to G. Group H served as control. The mice were then bled at 1st, 2nd, 4th, 6th and 8th month interval post-immunization for estimating antibody titer. Then the mice were sacrificed and the heart, aorta and kidney were taken out and processed for hematoxylin-eosin staining. There was gradual increase in the antibody titer from 1st month till 4th month within all the experimental groups (A-G), when compared with control group H. The titer started falling sharply from 6th month post-immunization. However, the control group H did not show much variation. When each individual group was compared separately with control group H, the significant statistical value was obtained. Histopathological examination revealed mild inflammation (+) in kidney by 2nd month, moderate inflammation (++) by 6th month, extensive inflammation (+++) by 8th month and alteration in the normal parenchyma of kidney by 8th month. CONCLUSIONS: The histopathological changes brought out through antigens were more pronounced by 8th month following injection of tunica media, tunica adventitia, tunica intima and aorta collagen as compared to that of standard collagen and mouse aorta injections.     

Tumoral non-amyloidotic monoclonal immunoglobulin light chain deposits ('aggregoma'): presenting feature of B-cell dyscrasia in three cases with immunohistochemical and biochemical analyses

Tumoral monoclonal immunoglobulin (Ig) light chain non-fibrillar deposits ('aggregomas'), which can be considered analogous to solitary light chain amyloidomas, are a rare presenting feature of B-cell dyscrasias. It is not certain if they are truly localized or if in reality they represent an initial expression of a silent systemic non-amyloid light chain deposition disease (LCDD). This report describes three patients, two of whom presented with cervical masses and the third with a solitary lung nodule, each comprising granular aggregates of monoclonal kappa light chain. Extracted deposits from the lymph node of one patient were shown by N-terminal amino acid sequence analysis to belong to the variable-region kappa I (Vkappa I) light chain subgroup, the first reported kappa-LCDD protein encoded by the L9 gene and the first report of an expressed protein related to this gene. Extracted deposits from the lung nodule of the second patient belonged to the Vkappa IV light chain subgroup encoded by the B3 germ line gene. The N-terminal amino acid sequences of the light chains from the aggregomas were compared with the related germ line sequences and to the N-terminal amino acid sequences of the nine other known kappa-LCDD light chains reported thus far from patients with systemic LCDD.     

Assessment of coronary bypass graft patency by electron-beam computed tomography

Twenty-one patients undergoing coronary artery bypass grafting were prospectively evaluated by conventional selective coronary angiography and electron-beam computed tomography. Eighty bypass grafts (60 saphenous vein and 20 left or right internal mammary artery) were evaluated for patency. The sensitivity and specificity of electron-beam computed tomography were 72% and 100%, respectively; positive and negative predictive values were 100% and 92.5%, respectively. Sensitivity and specificity according to coronary region were: left anterior descending artery, 33% and 100%; diagonal artery, 67% and 100%; circumflex artery, 75% and 100%; right coronary artery, 100% and 100%. Electron-beam computed tomography is relatively accurate and a promising tool for noninvasive evaluation of graft patency after coronary artery bypass graft surgery.     

Long-term results of cusp-level chordal shortening for anterior mitral leaflet prolapse

The technique and early results of cusp-level chordal shortening for isolated anterior mitral leaflet prolapse in rheumatic mitral regurgitation were presented by us earlier. Here we present our experience from January 1989 through December 2000. Two hundred twenty-six patients underwent this procedure. The mean age was 18 +/- 7.22 years. Preoperatively, 38 (16.8%) patients were in New York Heart Association functional class 11, 160 (70.8%) were in class IIl, and 28 (12.4%) were in class IV. All patients underwent chordal shortening at the cusp level. In addition, 8 patients (3.5%) underwent chordal transfer, and 4 patients (1.8%) received neochordae. Two hundred twenty-one (97.8%) patients underwent posterior annuloplasty using a C-shaped polytetrafluoroethylene collar. In 85 (37.6%) patients, cuspal thinning was also performed. Early mortality was 3.5% (8 patients). Follow-up ranged from 1 to 144 months (mean, 53.02 +/- 31.10 months) and was 94% complete. In 68% of survivors, there was no or trivial mitral regurgitation. Ten patients required reoperation. There were 8 late deaths. Actuarial survival, mitral regurgitation-free survival, and event-free survival were 93.3% +/- 1.7%, 41.8% +/- 8.4%, and 73.6% +/- 6.6%, respectively. Among the 210 survivors, 159 (75.7%) were in New York Heart Association class I, 26 (12.4%) were in class II, 22 (10.5%) were in class III, and 3 (1.4%) were in class IV. We conclude that cusp-level chordal shortening for isolated anterior mitral leaflet prolapse is an effective procedure for correction of anterior mitral leaflet prolapse.     

Evaluation of delivery of enhanced diabetes care to patients of South Asian ethnicity: the United Kingdom Asian Diabetes Study (UKADS).

AIMS: We tested the hypothesis that enhanced care for diabetes, tailored to the needs of the South Asian community with Type 2 diabetes, would improve risk factors for diabetic vascular complications and ultimately reduce morbidity and mortality. PATIENTS AND METHODS: The study was a cluster randomized controlled trial (RCT) with general practice the unit of randomization. Six West Midlands general practices with a high proportion of South Asian patients were randomized to 'enhanced care' using Asian link workers and extra community diabetes specialist nurse sessions (intervention) or continued standard practice care (control). RESULTS: Of 401 patients recruited to the study, 361 (90%), comprising 178 from Coventry and 183 from Birmingham were eligible and included in the analyses. The mean age at baseline (standard deviation, SD) was 58.9 (11.7 years) with median (interquartile range; IQR) duration of diabetes 6.5 (3-11) years. At one year follow-up there was a significant difference in reduction of systolic (4.6 mmHg, P = 0.035) and diastolic blood pressure (3.4 mmHg, P = 0.003) and total cholesterol (0.4 mmol/l, P = 0.005), comparing the intervention and control groups. After adjusting for baseline measurement and age, only differential reduction in diastolic blood pressure remained significant. There was no significant change in HbA(1c) and no difference between the groups. CONCLUSIONS: Using link workers and extra community diabetes specialist nurse input together with treatment protocols in primary care might prove a useful strategy in working towards NSF targets for diabetes management. In this study, small reductions in blood pressure and cholesterol were achieved. Improvement in glycaemic control may require longer and possibly different strategies. Further research is required to evaluate fully the effectiveness, including the costs and longer term sustainability of culturally sensitive initiatives.     

Impact of Obesity on Outcomes of Pregnancy in Women With Heart Disease

BackgroundWomen with heart disease are at risk for complications during pregnancy. This study sought to examine the effect of maternal obesity on pregnancy complications in women with heart disease.ObjectivesThe objective was to determine the incidence of adverse cardiac events (CE) in pregnant women with heart disease and obesity.MethodsAdverse CE during pregnancy were examined in a prospective cohort of women with heart disease. CE were a composite of the following: cardiac death/arrest, arrhythmias, heart failure, myocardial infarction, stroke, aortic dissection, and thromboembolic events. Pre-eclampsia and post-partum hemorrhage were also studied. Outcomes were examined according to body mass index (BMI). To identify additional predictors of CE, a baseline risk score (CARPREG [Canadian Cardiac Disease in Pregnancy Study] II score) for predicting cardiac complications was calculated for all pregnancies and included in a multivariable logistic regression model.ResultsOf 790 pregnancies, 19% occurred in women with BMI ≥30 kg/m² (obesity), 25% in women with BMI 25 to 29.9 kg/m² (overweight), 53% in women with BMI 18.5 to 24.9 kg/m² (normal weight), and 3% in women with BMI <18.5 kg/m² (underweight). Women with obesity were at higher risk of CE when compared with women with normal weight (23% vs. 14%; p = 0.006). In a multivariable model, obesity (odds ratio: 1.7; 95% confidence interval: 1.0 to 2.7) and higher CARPREG II risk scores (odds ratio: 1.7; 95% confidence interval: 1.5 to 1.9) predicted CE. Pre-eclampsia was more frequent in women with obesity compared with those with normal weight (8% vs. 2%; p = 0.001).ConclusionsObesity increases the risk of maternal cardiovascular complications in pregnant women with heart disease. This modifiable risk factor should be addressed at the time of preconception counseling.