Clinical implications of left superior vena cava persistence in candidates for pacemaker or cardioverter-defibrillator implantation

Persistence of a left superior vena cava (LSVC) has been reported in 0.3%–0.4% of candidates for pacemaker (PM) or cardioverter-defibrillator (ICD) implantation. The aim of the study was to evaluate the clinical implications of LSVC persistence for proper device performance. We observed the prevalence of LSVC during a 15-year period. A total of 2077 consecutive patients underwent PM implantation over a 15-year period: 7 had persistent LSVCs (0.34%). Among 599 patients undergoing ICD implantation, 4 LSVCs (0.66%) were observed. Overall LSVC persistence was found in 11/2676 (0.41%) patients. The right superior vena cava was absent in 4/11 (36%) patients. The leads were placed from the left subclavian approach in 5/7 PM patients: 2 received an elective right sided approach due to physician preference. All ICD patients had the device placed left pectoral with a single-coil lead: defibrillation therapy was effective in the long term in all but one patient, who required the addition of a subcutaneous array. Left superior vena cava persistence in PM/ICD patients is similar to the general population (0.41% in our study). The left-sided implant may be skill-demanding during lead placement; however, this task can be accomplished in the majority of cases, with a reliable outcome in the short term and appropriate device performance at follow-up.     

Predicting Success and Long-Term Outcomes of Percutaneous Mitral Valvuloplasty: A Multifactorial Score

Background

Percutaneous mitral valvuloplasty (PMV) success depends on appropriate patient selection. A multifactorial score derived from clinical, anatomic/echocardiographic, and hemodynamic variables would predict procedural success and clinical outcome.

Methods

Demographic data, echocardiographic parameters (including echocardiographic score), and procedure-related variables were recorded in 1085 consecutive PMVs. Long-term clinical follow-up (death, mitral valve replacement, redo PMV) was performed. Multivariate regression analysis of the first 800 procedures was performed to identify independent predictors of procedural success. Significant variables were formulated into a risk score and validated prospectively.

Results

Six independent predictors of PMV success were identified: age less than 55 years, New York Heart Association classes I and II, pre-PMV mitral area of 1 cm² or greater, pre-PMV mitral regurgitation grade less than 2, echocardiographic score of 8 or greater, and male sex. A score was constructed from the arithmetic sum of variables present per patient. Procedural success rates increased incrementally with increasing score (0% for 0/6, 39.7% for 1/6, 54.4% for 2/6, 77.3% for 3/6, 85.7% for 4/6, 95% for 5/6, and 100% for 6/6; P < .001). In a validation cohort (n = 285 procedures), the multifactorial score remained a significant predictor of PMV success (P < .001). Comparison between the new score and the echocardiographic score confirmed that the new index was more sensitive and specific (P < .001). This new score also predicts long-term outcomes (P < .001).

Conclusion

Clinical, anatomic, and hemodynamic variables predict PMV success and clinical outcome and may be formulated in a scoring system that would help to identify the best candidates for PMV.     

Ephedrine-induced acute myocardial infarction in a young athlete: a case of thrombus management

A case of acute myocardial infarction in a young athlete provoked by ephedrine abuse has been described in this study. An intracoronary thrombus found in the left anterior descending coronary artery at urgent angiography was successfully removed using the Pronto (Vascular Solutions, Minneapolis, Minnesota) aspiration catheter. The intravascular ultrasound examination performed thereafter showed a nonobstructive atherosclerotic plaque in the culprit artery; there was no evidence whatsoever of possible plaque disruption. The result of percutaneous coronary intervention was satisfactory, and no stent implantation was needed. The patient experienced no adverse events until his outpatient visit 3 months later.     

Molecular remodeling of potassium channels in fibroblasts from centenarians: A marker of longevity?

Aging is a complex process resulting from, among other, dynamic non-linear interactions between genetics and environment. Centenarians are the best example of successful aging in humans, as they escaped from, or largely postponed, major age-related diseases. Ionic fluxes changes play a key role in several patho-physiological cellular processes, but their relation to human aging is largely unexplored. In the present study we have compared patch-clamp potassium (K⁺) current recordings from dermal fibroblasts (DF) obtained from young, elderly and centenarian donors. We found that in DF from elderly donors, but not from centenarians, K⁺ current amplitude is significantly smaller with respect to DF from young donors. Moreover, cell membrane capacitance of DF from elderly donors is smaller with respect to young donors and centenarians. We also observed that the voltage-gated Shaker Kv1.1 channel is expressed in higher percentage of elderly's and centenarian's DF than young's, whereas the large-conductance calcium-activated K⁺ (BK_Ca) channel β1 subunit is expressed in lower percentage of centenarian's DF than in elderly's and young's. The maintenance of “young” K⁺ currents and the peculiar age-related remodeling of K⁺ channel subtypes in centenarian's DF is likely associated with successful aging and might provide a predictive marker of longevity.     

PROTOGIM: a novel tool to search motifs and domains in hypothetical proteins of protozoan genomes

Whole sequencing of protozoan trypanosomatid genomes revealed the presence of several predicted unknown genes coding for hypothetical proteins. Pairwise, alignment-based, computational methods available online are unable to identify the function of these sequences. To detect clues to identify the function of hypothetical proteins, a user-friendly, bioinformatic tool named PROTOzoan Gene Identification Motifs (PROTOGIM, available on ) was developed, which allows the user to search functional patterns of hypothetical proteins through the screening of regular expression in the sequences. The analysis of 1,194 trypanosomatid hypothetical proteins through PROTOGIM resulted in an identification of motifs and domains in 98% of the cases, demonstrating the reliability and accuracy of the employed method. The added value of this tool is the possibility to modify or insert new regular expressions to perform an analysis against either one or several sequences at the same time. An in silico strategy along with biochemical and molecular characterizations creates new possibilities to find the functions of hypothetical proteins at the postgenome era. Electronic supplementary material Supplementary material is available for this article at     

3000 years of solitude: extreme differentiation in the island isolates of Dalmatia, Croatia

Communities with increased shared ancestry represent invaluable tools for genetic studies of complex traits. "1001 Dalmatians" research program collects biomedical information for genetic epidemiological research from multiple small isolated populations ('metapopulation') in the islands of Dalmatia, Croatia. Random samples of 100 individuals from 10 small island settlements (n<2000 inhabitants) were collected in 2002 and 2003. These island communities were carefully chosen to represent a wide range of distinct and well-documented demographic histories. Here, we analysed their genetic make-up using 26 short tandem repeat (STR) markers, at least 5 cM apart. We found a very high level of differentiation between most of these island communities based on Wright's fixation indexes, even within the same island. The model-based clustering algorithm, implemented in STRUCTURE, defined six clusters with very distinct genetic signatures, four of which corresponded to single villages. The extent of background LD, assessed with eight linked markers on Xq13-21, paralleled the extent of differentiation and was also very high in most of the populations under study. For each population, demographic history was characterised and 12 "demographic history" variables were tentatively defined. Following stepwise regression, the demographic history variable that most significantly predicted the extent of LD was the proportion of locally born grandparents. Strong isolation and endogamy are likely to be the main forces maintaining this highly structured overall population.     

A preliminary survey of interprofessional education

The purpose of this article is to review the literature on interprofessional education (IPE) and report on a preliminary survey of the current status of interprofessional education in seven academic health centers (AHCs) that have schools of dentistry associated with them. There is wide variability in interpretation of the term "interprofessional," and many barriers to interprofessional education exist including already overcrowded curricula in health professions schools, lack of support from faculty and administration, and financial constraints. Based on interviews completed at the authors' home institutions, it was recommended that topics such as ethics, communication skills, evidence-based practice, and informatics could be effectively taught in an interprofessional manner. Currently, some academic health centers are attempting to develop interprofessional education programs, but most of these efforts do not include dental students. Of the seven AHCs investigated in this study, only two had formal interprofessional educational activities that involved students from two or more health professions education programs. Dental school participants in this study professed a strong interest in interprofessional programs, but many interviewees from other professional schools and AHC administrators perceived that the dental school was isolated from other schools and disinterested in IPE. Many health care setting models in the future will include dentists as part of an interdisciplinary health care team; consequently, it is important for dental schools to become an active participant in future interprofessional educational initiatives.