Elucidating the B bump on the mitral valve M-mode echogram in patients with severe left ventricular systolic dysfunction

BACKGROUND: The B bump on mitral valve M-mode echogram is predictive of significant elevation of left ventricular end-diastolic pressure (LVEDP). However, its pathophysiologic mechanism remains unclear. METHODS: We investigated, by means of Doppler echocardiography, the hemodynamic events that take place at late diastole in left atrium (LA) and left ventricle (LV). The study group consisted of 10 consecutive and strictly selected patients with severe dilated LV dysfunction. The noninvasive validated index used for definition of high LVEDP was the difference between the durations of atrial reverse (AR) wave in pulmonary venous flow (PVF) and atrial (A) wave in mitral flow (MF). Peak velocities of PVF and MF were measured. The time interval from ECG P wave to the end of B bump (P-B) and from P wave to the end of AR (P-AR) were measured and correlated. Mitral diastolic regurgitation (DR) was searched with M-mode color Doppler. RESULTS: All patients presented with restrictive diastolic signs on MF and PVF. The mean value of AR time minus A time was 61+/-12 ms. There was a strong linear correlation between P-B and P-AR (r=0.94, p<0.001). Only five patients had DR. No patient had LV inflow during B bump. CONCLUSIONS: (1) Mitral B bump is essentially a late diastolic phenomenon in which the leaflets keep a semi-open position without LV inflow effectiveness. (2) The resultant LA pressure which prolongates the duration of AR wave beyond A wave, analogously work over mitral leaflets, pushing them toward LV generating the bump. (3) DR is caused by LVEDP higher than LA pressure and coexists with B bump without a cause-effect relationship.     

Adjuvant Therapy With Sodium Alendronate for the Treatment of Experimental Periodontitis in Rats

Background: This study assesses the effects of topical sodium alendronate (SA) as an adjuvant to the mechanical treatment of ligature‐induced periodontitis in rats. Methods: Ninety animals were subjected to the induction of periodontitis via the installation of a ligature around the mandibular left first molar. After 7 days, the ligature was removed, and the animals were distributed into the following groups: 1) NT group (n = 30), no treatment; 2) SRP group (n = 30), scaling and root planing (SRP) and local irrigation with physiologic saline solution; and 3) SRP/SA group (n = 30), SRP and local irrigation with SA (10^?5 M). Ten animals from each group were euthanized at 7, 15, and 30 days after treatment. Histologic and histometric analyses were performed in the furcation region. The percentage of bone in the furcation (PBF) was measured. Immunohistochemical analyses for detecting the receptor activator of nuclear factor‐κB ligand (RANKL), osteoprotegerin (OPG), tartrate‐resistant acid phosphatase (TRAP), and activated caspase‐3 were performed at the furcation region. Results: Compared with the other groups, the SRP/SA group showed less local inflammation and better tissue reparation during the entire experiment. There was more PBF in the SRP/SA group than in the other groups at days 7 and 15. Stronger OPG immunolabeling and weaker RANKL immunolabeling were observed in the SRP/SA group at 15 and 30 days. There were fewer TRAP‐positive cells in the SRP/SA group than in the NT group at all of the time points. There was no difference in the number of activated caspase‐3‐positive osteocytes among groups and time points. Conclusion: It can be concluded that topical use of SA as an adjuvant to SRP is effective in the treatment of experimental periodontitis.     

Diagnostic decision support systems for atrial fibrillation based on a novel electrocardiogram approach

Background

The electrocardiogram (ECG) is one of the most non-invasive techniques to give support to the atrial fibrillation (AF) diagnosis. Several authors use the temporal difference between two consecutive R waves, a method known as RR interval, to perform the AF diagnosis. However, RR interval-based analysis does not detect distortions on the other ECG waves.

Comparison between reference values for FVC,FEV1, and FEV1/FVC ratio in White adults in Brazil and those suggested by the Global Lung Function Initiative 2012

OBJECTIVE:

To evaluate the spirometry values predicted by the 2012 Global Lung Function Initiative (GLI) equations, which are recommended for international use, in comparison with those obtained for a sample of White adults used for the establishment of reference equations for spirometry in Brazil.

METHODS:

The sample comprised 270 and 373 healthy males and females, respectively. The mean differences between the values found in this sample and the predicted values calculated from the GLI equations for FVC, FEV₁, and VEF₁/FVC, as well as their lower limits, were compared by paired t-test. The predicted values by each pair of equations were compared in various combinations of age and height.

RESULTS:

For the males in our study sample, the values obtained for all of the variables studied were significantly higher than those predicted by the GLI equations (p < 0.01 for all). These differences become more evident in subjects who were shorter in stature and older. For the females in our study sample, only the lower limit of the FEV₁/FVC ratio was significantly higher than that predicted by the GLI equation.

CONCLUSIONS:

The predicted values suggested by the GLI equations for White adults were significantly lower than those used as reference values for males in Brazil. For both genders, the lower limit of the FEV₁/FVC ratio is significantly lower than that predicted by the GLI equations.     

Age and distraction are determinants of performance on a novel visual search task in aged Beagle dogs

Aging has been shown to disrupt performance on tasks that require intact visual search and discrimination abilities in human studies. The goal of the present study was to determine if canines show age-related decline in their ability to perform a novel simultaneous visual search task. Three groups of canines were included: a young group (N = 10; 3 to 4.5 years), an old group (N = 10; 8 to 9.5 years), and a senior group (N = 8; 11 to 15.3 years). Subjects were first tested for their ability to learn a simple two-choice discrimination task, followed by the visual search task. Attentional demands in the task were manipulated by varying the number of distracter items; dogs received an equal number of trials with either zero, one, two, or three distracters. Performance on the two-choice discrimination task varied with age, with senior canines making significantly more errors than the young. Performance accuracy on the visual search task also varied with age; senior animals were significantly impaired compared to both the young and old, and old canines were intermediate in performance between young and senior. Accuracy decreased significantly with added distracters in all age groups. These results suggest that aging impairs the ability of canines to discriminate between task-relevant and -irrelevant stimuli. This is likely to be derived from impairments in cognitive domains such as visual memory and learning and selective attention.