High sensitivity C-reactive protein: a novel predictor for recurrence of atrial fibrillation after successful cardioversion.

OBJECTIVES: We sought to test the hypothesis that C-reactive protein (CRP) can predict the recurrence of atrial fibrillation (AF) after successful electrical cardioversion (CV). BACKGROUND: In patients with AF, CRP levels are predictive of immediate failure of CV. METHODS: We prospectively measured high-sensitivity CRP in 67 patients with AF or atrial flutter who underwent successful electrical CV. RESULTS: At one-month follow-up, 22 patients (33%) had recurrence of their arrhythmia. Arrhythmia recurrence was associated with significantly higher pre-CV CRP levels (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.14 to 2.98; p = 0.013) even after adjusting for age (OR 2.22; 95% CI 1.25 to 3.93; p = 0.006), for gender (OR 1.89; 95% CI 1.16 to 3.09; p = 0.011), or duration of arrhythmia (OR 1.86; 95% CI 1.13 to 3.07; p = 0.015). On multivariate analysis, CRP was the only independent predictor of arrhythmia recurrence (OR 2.19; 95% CI 1.05 to 4.55; p = 0.036). CONCLUSIONS: Our data suggest that high levels of CRP are associated with an increased risk of recurrence of AF within one month. These data support the hypothesis that anti-inflammatory interventions may help in maintenance of normal sinus rhythm after CV. These data also may have implications for the identification of patients who are most likely to experience substantial benefit from CV therapy for AF.     

Comparison of usefulness of tissue Doppler imaging versus brain natriuretic peptide for differentiation of constrictive pericardial disease from restrictive cardiomyopathy

Brain (B-type) natriuretic peptide (BNP) and tissue Doppler imaging may distinguish restrictive cardiomyopathy (RCMP) from idiopathic constrictive pericardial disease (CP). However, their comparative efficacy is unknown for patients with CP from secondary causes (e.g., surgery or radiotherapy). We compared the efficacy of tissue Doppler imaging and BNP for differentiation of RCMP (n = 15) and CP (n = 16) were compared. BNP was higher in patients with RCMP than CP (p = 0.008), but the groups overlapped, particularly for BNP <400 pg/ml. BNP was lower with idiopathic CP than secondary CP (139 +/- 50 vs 293 +/- 69 pg/ml; p <0.001) or RCMP (139 +/- 50 vs 595 +/- 499 pg/ml; p <0.001), but not significantly different between those with secondary CP and RCMP (293 +/- 69 vs 595 +/- 499 pg/ml; p = 0.1). Patients with CP and RCMP had less overlap in early diastolic and isovolumic contraction tissue Doppler imaging velocities compared with BNP, with clear separation of groups evident with mean early diastolic annular velocities (averaged from 4 walls). Early diastolic tissue Doppler imaging velocity was superior to BNP for differentiation of CP and RCMP (area under the curve 0.97 vs 0.76, respectively; p = 0.01). In conclusion, mean early diastolic mitral annular velocity correctly distinguished CP from RCMP even when there was a large overlap of BNP between the 2 groups.     

Disparities in Women with Heart Failure

Despite comprising over half of the heart failure population, women have been under-represented in most major clinical heart failure trials. Women with heart failure are more likely to have a preserved systolic function, be older compared to men, and are more likely to have hypertension, diabetes, and obesity as the etiology of their heart failure. Furthermore, overall survival is better for women. These factors suggest that the disease process in women is not entirely the same as in men, and perhaps should not be treated the same. However, given the lack of prospective large number trials looking specifically at women and heart failure, there have been no statistically significant data to support tailoring medical therapy differently between men and women.     

Fibrinogen Philadelphia, a hypodysfibrinogenemia characterized by abnormal polymerization and fibrinogen hypercatabolism due to gamma S378P mutation

Fibrinogen Philadelphia, a hypodysfibrinogenemia described in a family with a history of bleeding, is characterized by prolonged thrombin time, abnormal fibrin polymerization, and increased catabolism of the abnormal fibrinogen. Turbidity studies of polymerization of purified fibrinogen under different ionic conditions reveal a reduced lag period and lower final turbidity, indicating more rapid initial polymerization and impaired lateral aggregation. Consistent with this, scanning and transmission electron microscopy show fibers with substantially lower average fiber diameters. DNA sequence analysis of the fibrinogen genes A, B, and G revealed a T>C transition in exon 9 resulting in a serine-to-proline substitution near the gamma chain C-terminus (S378P). The S378P mutation is associated with fibrinogen Philadelphia in this kindred and was not found in 10 controls. This region of the gamma chain is involved in fibrin polymerization, supporting this as the polymerization defect causing the mutation. Thus, this abnormal fibrinogen is characterized by 2 unique features: (1) abnormal polymerization probably due to a major defect in lateral aggregation and (2) hypercatabolism of the mutant protein. The location, nature, and unusual characteristics of this mutation may add to our understanding of fibrinogen protein interactions necessary for normal catabolism and fibrin formation.     

Dynamic faces speed up the onset of auditory cortical spiking responses during vocal detection

How low-level sensory areas help mediate the detection and discrimination advantages of integrating faces and voices is the subject of intense debate. To gain insights, we investigated the role of the auditory cortex in face/voice integration in macaque monkeys performing a vocal-detection task. Behaviorally, subjects were slower to detect vocalizations as the signal-to-noise ratio decreased, but seeing mouth movements associated with vocalizations sped up detection. Paralleling this behavioral relationship, as the signal to noise ratio decreased, the onset of spiking responses were delayed and magnitudes were decreased. However, when mouth motion accompanied the vocalization, these responses were uniformly faster. Conversely, and at odds with previous assumptions regarding the neural basis of face/voice integration, changes in the magnitude of neural responses were not related consistently to audiovisual behavior. Taken together, our data reveal that facilitation of spike latency is a means by which the auditory cortex partially mediates the reaction time benefits of combining faces and voices.In noisy environments, the audiovisual nature of speech is a tremendous benefit to sensory processing. While holding a conversation in a large social setting, your brain must deftly detect when a person is saying something, who is saying it, and discriminate what she is saying. To make the task easier, our brains do not rely entirely on the person’s voice but also take advantage of the speaker’s mouth movements. This visual motion provides spatial and temporal cues (1, 2) that readily integrate with the voice, enhancing both detection (3–10) and discrimination (11–15). How the brain mediates the behavioral benefits achieved by integrating signals from different modalities is the subject of intense debate and investigation (16). For face/voice integration, traditional models emphasize the role of association areas embedded in the temporal, frontal, and parietal lobes (17). Although these regions certainly play important roles, numerous recent studies demonstrate that they are not the sole regions for multisensory convergence (18, 19). The auditory cortex, in particular, has many sources of visual input, and an increasing number of studies in both humans and nonhuman primates demonstrate that dynamic faces influence auditory cortical activity (20).However, the relationship between multisensory behavioral performance and neural activity in the auditory cortex remains unknown for two reasons. First, methodologies typically used to study the auditory cortex in humans are unable to resolve neural activity at the level of action potentials. Second, regardless of the areas explored, none of the face/voice neurophysiological studies in monkeys to date, including auditory cortical studies (21–24) and studies of association areas (25–27), have required monkeys to perform a multisensory task. All these physiological studies demonstrated that neural activity in response to faces combined with voices is integrative, exhibiting both enhanced and suppressed changes in the magnitude of response when multisensory conditions are compared with unisensory ones. It is presumed that such changes in firing rate mediate behavioral benefits (e.g., faster reaction times, better accuracy) of multisensory signals, but it is possible that integrative neural responses—particularly in the auditory cortex—are epiphenomenal.In this study, we combined an audiovisual vocal-detection task with auditory cortical physiology in macaque monkeys. When detecting voices alone, our data show that the signal-to-noise ratio (SNR) systematically influences behavioral performance; the same systematic effects are observed in the magnitude and latency of spiking activity. The addition of a dynamic face leads to audiovisual neural responses that are faster than auditory-only responses—dynamic faces speed up the latency of auditory cortical spiking activity. Surprisingly, the addition of dynamic faces does not systematically change the magnitude or variability of the firing rate. These data suggest that visual influences have a role in facilitating response latency in the auditory cortex during audiovisual vocal detection. Facial motion speeds up the spiking responses of the auditory cortex but has no systematic influence on firing rate magnitudes.     

DOTS reaches socially marginalized population in the community: a study from a rural area of South India

We report here that the Directly Observed Treatment, Short course (DOTS) is reaching all tuberculosis patients in the community irrespective of social classification based on the analysis from the tuberculosis prevalence survey and programme performance during 1999-2003 from a rural area in Tamilnadu, South India. New smear- positive cases treated under a DOTS programme were classified in two groups namely; scheduled caste living in colony and other population. The prevalence of smear- positive cases among the scheduled caste population was 1.9 times higher than the other population and this was reflected in the notification also. The successful treatment outcome was also similar in these two groups (75% and 78% respectively; overall 77%). From these findings it is concluded that people living in colony have equal access to DOTS as those in the village.     

Effect of gender on sympathovagal imbalance in prehypertensives

Although recently the incidence of prehypertension has increased considerably, the pathophysiological mechanisms and the effects of gender in its causation have not yet been fully elucidated. Therefore, in this study body mass index (BMI), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), rate pressure product (RPP), and spectral indices of heart rate variability (HRV) were reordered and analyzed in normotensive and prehypertensive males and females. It was observed that low frequency-high frequency (LF-HF) ratio, the sensitive indicator of sympathovagal imbalance (SVI), is significantly more (P < .001) in male prehypertensives compared with female prehypertensives. Although SVI in prehypertensives was found to be due to both sympathetic activation and vagal inhibition, contribution of vagal withdrawal was prominent in males. The LF-HF ratio was significantly correlated with BMI, WHR, BHR, BP, and RPP, which was more prominent in male prehypertensives and the degree of correlation was more for WHR and diastolic pressure. It was concluded that vagal inhibition plays an important role in critical alteration of SVI in the genesis of prehypertension, especially in males, and WHR could be a better indicator of SVI in prehypertensives. It was suggested that prehypertensives should improve their vagal tone to restore the sympathovagal homeostasis.     

Twisting of fibrin fibers limits their radial growth.

Electron microscopy of freeze-dried, shadowed fibrin fibers has demonstrated that these structures are twisted. The pitch and radius of many fibers were measured from the micrographs. Although there is some variability, the average pitch of 1930 +/- 280 (SD) nm is independent of radius. The distribution of observed radii of fibers assembled in vitro is highly skewed, suggesting that individual fibers grow to a maximum radius of about 50 nm, except when both pH and ionic strength are high; fibers aggregate to form thicker fiber bundles under some conditions. The observed twisting may be responsible for limiting the lateral growth of individual fibers. Protofibrils near the surface of a twisted fiber are stretched relative to those near the center. Consequently, the degree to which a protofibril can be stretched limits the radius of a fiber; protofibrils can be added to a growing fiber until the energy required to stretch an added protofibril exceeds the energy of binding. These properties of assembly arise directly from the intrinsic twist of the fibrinogen molecule determined from structural evidence. Simple geometric considerations lead to conclusions regarding the locations of the binding sites for assembly of the protofibril and the flexibility of the fibrin molecule.     

Assessment of aortic regurgitation by transesophageal echocardiography: correlation with angiographic determination

Transthoracic echocardiographic studies have shown that color Doppler mapping of the aortic regurgitation (AR) jet correlated well with the severity of regurgitation as assessed by contrast aortography. The present study was performed to assess whether these parameters could be similarly applied to measurements determined by transesophageal echocardiography (TEE). In order to determine and validate criteria for the assessment of AR severity, 39 clinically stable patients with a TEE color Doppler study and contrast aortography within a 2-week period were identified. The ratio of the jet area (JA) to left ventricular diastolic area (LVDA) had the best correlation to AR severity as determined by contrast aortography (r = 0.89). Jet length, JA, the ratio of jet width to the width of the left ventricular outflow tract and jet width had r values of 0.88, 0.88, 0.83, and 0.84, respectively. The best sensitivity and specificity for the assessment of AR by TEE were obtained as follows: JA/LVDA ratio of 0%-7% predicts 0-1 + AR; 8%-20% 2-3 + AR, and greater than 20% 4 + AR. Of the three patients miscategorized, none was misgraded by more than one angiographic grade of AR. Jets that measure more than 6 cm in length or have an area of greater than 10 cm 2 have a 100% sensitivity and specificity for diagnosing 4 + AR. In the present study the ratio of JA to LVDA area correlates best with AR severity as determined by angiography.