Case report: First documented case of cerebral angiostrongyliasis caused by Angiostrongylus costaricensis in a free-ranging opossum.

Angiostrongylus costaricensis is a metastrongyloid nematode that primarily infects the mesenteric arteries of wild rodents. This parasite is endemic in several regions of the American continent, and in humans, causes a disease known as abdominal angiostrongyliasis. Despite the important health implications of this nematode, there are limited studies investigating the involvement of wild animals in its life cycle. In this study, we present the clinical manifestations, pathologic findings, and molecular diagnosis, to the best of our current knowledge, of the first documented onset of cerebral angiostrongyliasis because of A. costaricensis infection in a juvenile free-ranging opossum (Didelphis marsupialis). Histopathological findings stress the presence of eosinophilic meningoencephalitis with nematodes present within the lesions, and PCR was positive for cox1 and ITS1 reactions. The obtained sequences for a 279 bp fragment of ITS1 were 100% identical to A. costaricensis from Costa Rica. This case highlights the substantial difficulties in diagnosing neuroangiostrongyliasis, yet underscores the importance of considering A. costaricensis as a potential culprit behind neurological conditions in wild marsupials. It acts as an urgent call to action to improve surveillance programs tracking infectious and parasitic diseases causing mortality in wildlife populations.

Passive epidemiological surveillance in wildlife in Costa Rica identifies pathogens of zoonotic and conservation importance.

Epidemiological surveillance systems for pathogens in wild species have been proposed as a preventive measure for epidemic events. These systems can minimize the detrimental effects of an outbreak, but most importantly, passive surveillance systems are the best adapted to countries with limited resources. Therefore, this research aimed to evaluate the technical and infrastructural feasibility of establishing this type of scheme in Costa Rica by implementing a pilot program targeting the detection of pathogens of zoonotic and conservation importance in wildlife. Between 2018 and 2020, 85 carcasses of free-ranging vertebrates were admitted for post-mortem and microbiology analysis. However, we encountered obstacles mainly related to the initial identification of cases and limited local logistics capacity. Nevertheless, this epidemiological surveillance scheme allowed us to estimate the general state of health of the country's wildlife by establishing the causes of death according to pathological findings. For instance, 60% (51/85) of the deaths were not directly associated with an infectious agent. Though in 37.6% (32/85) of these cases an infectious agent associated or not with disease was detected. In 27.1% (23/85) of the cases, death was directly related to infectious agents. Furthermore, 12.9% (11/85), the cause of death was not determined. Likewise, this wildlife health monitoring program allowed the detection of relevant pathogens such as Canine Distemper Virus, Klebsiella pneumoniae, Angiostrongylus spp., Baylisascaris spp., among others. Our research demonstrated that this passive surveillance scheme is cost-effective and feasible in countries with limited resources. This passive surveillance can be adapted to the infrastructure dedicated to monitoring diseases in productive animals according to the scope and objectives of monitoring wildlife specific to each region. The information generated from the experience of the initial establishment of a WHMP is critical to meeting the challenges involved in developing this type of scheme in regions with limited resources and established as hotspots for emerging infectious diseases.

National Seroprevalence and Risk Factors for Eastern Equine Encephalitis and Venezuelan Equine Encephalitis in Costa Rica.

Eastern equine encephalitis and Venezuelan equine encephalitis are endemic neglected tropical diseases in the Americas, causing encephalitis in both horses and humans. In 2013, a cross-sectional study was performed in 243 horses located in the highlands and lowlands throughout Costa Rica. Serum samples were analyzed with an IgG ELISA and confirmed by the plaque-reduction neutralization test (PRNT80). Venezuelan equine encephalitis virus (VEEV) and Eastern equine encephalitis virus (EEEV) overall seroprevalences by the PRNT80 were 36% (95% confidence interval [CI]: 29.9-42.5; 78/217 horses) and 3% (95% CI: 1.3-5.9; 6/217 horses), respectively. Both the viruses occurred in the lowlands and highlands. Rainfall and altitude were associated with VEEV seropositivity in the univariate analysis, but only altitude <100 meters above sea level was considered a risk factor in the multivariate analysis. No risk factors could be identified for the EEEV in the multivariate analysis. This is the first study that estimates the seroprevalence of the EEEV and VEEV in Costa Rican horses. The VEEV is widely distributed, whereas the EEEV occurs at a much lower frequency and only in specific areas. Clinical cases and occasional outbreaks of both viruses are to be expected.

Leptospira Seroprevalence Detection and Rabies Virus Absence in an Urban Raccoon (Procyon lotor) Population in a Highly Populated Area, Costa Rica.

Leptospirosis and rabies are zoonotic diseases of public health importance and endemic diseases in tropical countries such as Costa Rica. Peridomestic wild animals such as raccoons (Procyon lotor) have been implicated as competent hosts of Leptospira spirochetes and rabies virus. This study focused on understanding the role of urban raccoons in the dynamics of leptospirosis and rabies in a tropical environment. A total of 97 specimens of the common raccoon were captured within the Greater Metropolitan Area of Costa Rica; 32.6% (31/95) of raccoons presented evidence of antibodies (> 1: 100) against Leptospira sp. Attempts to cultivate Leptospira failed, but 19 serovars were identified, which are also responsible for causing disease in humans in Costa Rica. Detected titers ranged from 1: 100 to 1: 6400. Lymphoid hyperplasia in kidneys and spirochetes were demonstrated in 3 of 20 necropsied cases (15%). Twenty brain samples were analyzed by hematoxylin and eosin stain for evidence of encephalitis and Negri body detection and simultaneously frozen brain material was employed to perform a rapid immunoassay test for rabies antigen. All tested samples were negative. This study is the first report of Leptospira seroprevalence in raccoons that cohabit urban areas in Costa Rica. We also highlight the importance of the raccoon as one of their natural competent host and sentinel animals within highly populated urban environments in tropical cities.

Salmonellosis detection and evidence of antibiotic resistance in an urban raccoon population in a highly populated area, Costa Rica.

Wild animals are involved in zoonotic disease transmission cycles. These are generally complex and poorly understood, especially among animals adapted to life in human ecosystems. Raccoons are reservoirs and effective carriers for infectious agents such as Salmonella throughout different environments and contribute to the transference of resistance genes. This study examined the presence of circulating Salmonella sp. in a population of raccoons in a tropical urban environment and evaluated resistance to antibiotics commonly used to treat salmonellosis. A total of 97 raccoons of different ages and sex were included in this study. 49% (38-60 CI) of the faecal samples were positive for Salmonella spp. The study identified 15 circulating serovars with the most prevalent being S. Hartford (7/15), S. Typhimurium (4/15) and S. Bovismorbificans (4/15). These serovars correspond to the serovars detected in humans with clinical symptoms in Costa Rica. 9.5% of the Salmonella strains recovered demonstrated ciprofloxacin resistance, and 7.1% showed resistance to nalidixic acid. This study provides evidence of multiple Salmonella serovars circulating in a population of urban raccoons in Costa Rica. Furthermore, the study confirms the existence of antimicrobial resistance to two antibiotics used to treat human salmonellosis. The findings emphasize the role of the raccoon as a reservoir of Salmonella in the Greater Metropolitan Area of Costa Rica (GAM) and stress the need for active monitoring of the presence and possible spread in antibiotic resistance due to this peri-domestic carnivore.

Multipoint left ventricular pacing improves response to cardiac resynchronization therapy with and without pressure-volume loop optimization: comparison of the long-term efficacy of two different programming strategies.

PURPOSE: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing (MultiPoint™ Pacing [MPP]) improves long-term LV reverse remodeling, though questions persist about how to program LV pacing vectors and delays. We evaluated if an empirical method of programming MPP vectors and delays between pacing pulses improved CRT response similar to pressure-volume loop (PVL) optimized MPP programming. METHODS: Patients undergoing CRT implant (Quadra Assura MP™ CRT-D and Quartet™ LV lead) received MPP with programmed settings optimized either by PVL measurements at implant (PVL-OPT group) or empirically determined by maximizing the spatial separation between the two cathodes and minimal delays between the three ventricular pacing pulses (MAX-SEP group). CRT response was prospectively defined as a reduction in end-systolic volume (ESV) of ≥ 15% relative to baseline at 6 months as determined by a blinded observer. RESULTS: Patient characteristics at baseline (NYHA II-III, ejection fraction [EF] 27 ± 6%, QRS 151 ± 17 ms) were not significantly different between the PVL-OPT (n = 27) and MAX-SEP (n = 26) groups. During the follow-up period, there were no differences in the number of patients requiring reprogramming due to phrenic nerve stimulation or a high threshold for PVL-OPT vs. MAX-SEP (5/27 [19%] vs. 7/26 [27%], p = 0.53). After 6 months, ESV reduction, EF increase, and CRT response rate (RR) were similar for PVL-OPT vs. MAX-SEP (ESV - 20 ± 11 vs. - 22 ± 11%, p = 0.59; EF + 10 ± 4 vs. + 9 ± 7%, p = 0.53; RR 20/27 [74%] vs. 21/26 [81%], p = 0.74), while fewer patients in the PVL-OPT group experienced NYHA class reduction ≥ 2 (4/27 [15%] vs.15/26 [58%], p = 0.002). CONCLUSIONS: Both evaluated methods of MPP programming resulted in similar CRT outcomes. Empirical MPP programming by maximum spatial separation of LV cathodes may be an effective, simple, and non-invasive alternative to pressure-volume optimization.

Assessing changing weather and the El Niño Southern Oscillation impacts on cattle rabies outbreaks and mortality in Costa Rica (1985-2016).

BACKGROUND: Rabies is a major zoonotic disease affecting humans, domestic and wildlife mammals. Cattle are the most important domestic animals impacted by rabies virus in the New World, leading to thousands of cattle deaths per year and eliciting large economic losses. In the New World, virus transmission in cattle is primarily associated with Desmodus rotundus, the common vampire bat. This study analyses the association of weather fluctuations and the El Niño Southern Oscillation (ENSO), with the occurrence and magnitude, in terms of associated mortality, of cattle rabies outbreaks. Data from the 100 cattle rabies outbreaks recorded between 1985 and 2016 in Costa Rica were analyzed. Periodograms for time series of rabies outbreaks and the El Niño 4 index were estimated. Seasonality was studied using a seasonal boxplot. The association between epidemiological and climatic time series was studied via cross wavelet coherence analysis. Retrospective space-time scan cluster analyses were also performed. Finally, seasonal autoregressive time series models were fitted to study linear associations between monthly number of outbreaks, monthly mortality rates and the El Niño 4 index, temperature, and rainfall. RESULTS: Large rabies mortality occurred towards the Atlantic basin of the country. Outbreak occurrence and size were not directly associated with ENSO, but were sensitive to weather variables impacted by ENSO. Both, ENSO phases and rabies outbreaks, showed a similar 5 year period in their oscillations. Cattle rabies mortality and outbreak occurrence increased with temperature, whereas outbreak occurrence decreased with rainfall. These results suggest that special weather conditions might favor the occurrence of cattle rabies outbreaks. CONCLUSIONS: Further efforts are necessary to articulate the mechanisms underpinning the association between weather changes and cattle rabies outbreaks. One hypothesis is that exacerbation of cattle rabies outbreaks might be mediated by impacts of weather conditions on common vampire bat movement and access to food resources on its natural habitats. Further eco-epidemiological field studies could help to understand rabies virus transmission ecology, and to propose sound interventions to control this major veterinary public health problem.

Parámetros sanguíneos y perfil de hormonas reproductivas de hembras de Choloepus hoffmanni en cautiverio / Blood parameters and reproductive hormone profile of female Choloepus hoffmanni in captivity

Resumen El uso de técnicas no invasivas ni estresantes para determinar perfiles hormonales, como la medición de esteroides fecales, ha incrementado la comprensión de la fisiología reproductiva en animales silvestres. Debido a la escasa información con respecto a perfiles hormonales reproductivos del perezoso de dos dedos, Choloepus hoffmani, se realizó un estudio en hembras en cautiverio en el centro de rescate "Sloth Sanctuary" (Cahuita, Limón, Costa Rica) con el fin de determinar (i) la confiabilidad de la extracción de progesterona y estradiol en heces, y su cuantificación en el analizador AIA-360®, (ii) evaluar los parámetros sanguíneos en esta especie y (iii) establecer si existe una correlación entre los esteroides plasmáticos y fecales. El estudio se realizó en un periodo de tres meses, durante noviembre de 2013 a enero de 2014, con un total de 208 muestras de heces provenientes de cinco hembras sexualmente maduras, con peso promedio de 6.32 kg. El promedio de las concentraciones medianas en las heces de las cinco hembras fue 124.21 ng/g para progesterona y 1 708.95 pg/g de estradiol. En plasma, los valores de mediana fueron 1.26 ng/mL con un mínimo de 0.32 ng/mL y 12.84 ng/mL como valor máximo; los valores plasmáticos de estrógeno se encontraron por debajo del límite de detección del equipo (25 pg/mL). Aunque no se encontró una correlación estadísticamente significativa entre la progesterona plasmática y la fecal, nuestros datos sugieren que los eventos plasmáticos se reflejan en heces durante los dos días posteriores. Asimismo, los niveles de progesterona se mantuvieron elevados durante la primera mitad de noviembre, y posteriormente mostraron una reducción importante en todas las hembras. Nuestros resultados demuestran que las extracciones en heces y su medición en el AIA-360® permiten la detección y el seguimiento de variaciones hormonales en C. hoffmani, aunque no remplaza las mediciones plasmáticas para determinar valores absolutos.

Abstract In wild animal species, the use of non-invasive and non-stressful procedures to determine hormone profiles, such as fecal steroid measurements, has considerably increased the comprehension of their reproductive physiology. Since there is limited information related to the reproductive hormone profiles of the two-toed sloth, Choloepus hoffmani, a study was conducted in captive specimens at the "Sloth Sanctuary" (Cahuita, Limón, Costa Rica), in order to determine: (i) the reliability of the fecal progesterone and estrogen extraction and its quantification with an AIA-360® analyzer, (ii) assess blood parameters in this species and (iii) evaluate if there is a correlation between fecal and plasmatic steroids. The study was performed over a three-month period, from November, 2013 to January, 2014, with a total amount of 208 fecal samples collected from five sexually mature females weighing 6.32 kg in average. The average of the median concentrations of progesterone in feces of the five females was 124.21 ng/g, and 1 708.95 pg/g for estrogen. The average minimal and maximal values were 50.96 ng/g and 1 057.46 ng/g for progesterone and, 1 191.77 pg/g and 2 159.24 pg/g for estradiol. In plasma, progesterone median values were 1.26 ng/mL, showing a minimum of 0.32 ng/mL and 12.84 ng/mL as maximum values. The plasmatic estrogen levels were below the detection limit of the equipment (25 pg/mL). Although there was no strong statistical correlation between the fecal and plasmatic progesterone fluctuations, our data suggests that the plasmatic events are mostly reflected in feces two days afterwards. Also, the levels of progesterone were elevated during the first half of November and, subsequently, showed a successive and important reduction in all the females tested. Finally, our results demonstrated that fecal steroid extractions and their measurement in a AIA-360®, allowed the successful detection and represents an alternative non-invasive determination of hormone profiles in C. hoffmani. Rev. Biol. Trop. 66(1): 280-292. Epub 2018 March 01.

Thrombosis on a left atrial appendage occluder device: the double-edged sword of stroke prevention strategies in atrial fibrillation.

: A huge thrombus, developing after percutaneous left atrial appendage occlusion, has been successfully treated with dabigatran and aspirin as combination therapy.Although novel oral anticoagulants alone may be effective in thrombus dissolution, the association of an antiplatelet drug may safely enhance this process.

Brucellosis in mammals of Costa Rica: An epidemiological survey.

Brucellosis has been an endemic disease of cattle and humans in Costa Rica since the beginning of XX century. However, brucellosis in sheep, goats, pigs, water buffaloes, horses and cetaceans, has not been reported in the country. We have performed a brucellosis survey in these host mammal species, from 1999-2016. In addition, we have documented the number of human brucellosis reported cases, from 2003-2016. The brucellosis seroprevalence in goat and sheep herds was 0.98% and 0.7% respectively, with no Brucella isolation. Antibodies against Brucella were not detected in feral or domestic pigs. Likewise, brucellosis seroprevalence in horse and water buffalo farms was estimated in 6.5% and 21.7%, respectively, with no Brucella isolation. Six cetacean species showed positive reactions against Brucella antigens, and B. ceti was isolated in 70% (n = 29) of striped dolphins (Stenella coeruleoalba). A steady increase in the diagnosis of human brucellosis cases was observed. Taking into account the prevalence of brucellosis in the various host mammals of Costa Rica, different measures are recommended.

SEROPREVALENCE AND MOLECULAR CHARACTERIZATION OF FERLAVIRUS IN CAPTIVE VIPERS OF COSTA RICA.

Ferlaviruses (FV, previously referred to as ophidian paramyxoviruses, OPMV), are enveloped viruses with a negative-strand RNA genome, affecting snakes in captivity worldwide. Infection is characterized by respiratory and nervous clinical signs and carries high mortality rates, but no specific treatment or vaccine is currently available. Costa Rica has 16 species of vipers, found in captivity in collections essential for antivenom production, reintroduction, and public education. FV circulation in these populations was previously unknown, and the risk of introducing the viruses into naïve collections or free-ranging populations exists if the virus's presence is confirmed. The objective of this study was to determine seroprevalence and FV shedding in 150 samples from captive vipers in nine collections across Costa Rica. A hemagglutination inhibition (HI) assay was performed to determine the antibody titer against two Ferlavirus strains, Bush viper virus (BV) and Neotropical virus (NT), and reverse-transcriptase polymerase chain reaction (RT-PCR) and sequencing to determine virus secretion in cloacal swabs. Ferlavirus strains were replicated in Vero cells, and chicken anti-FV polyclonal antibodies were produced and used as a positive control serum for the HI. Results demonstrate that seroprevalence of anti-FV antibodies in viper serum was 26.6% (n = 40) for the BV strain and 30% (n = 45) for the NT strain in the population tested. Furthermore, molecular characterization of FV group A was possible by sequencing the virus recovered from three cloacal swabs, demonstrating circulation of FV in one collection. This study demonstrates for the first time serological evidence of FV exposure and infection in vipers in captivity in Costa Rica, and suggests cross reactivity between antibodies against both strains. Appropriate biosafety measures could prevent the spread of FV between and within collections of reptiles in the country.

Atrial fibrillation detection using a novel three-vector cardiac implantable monitor: the atrial fibrillation detect study.

AIMS: Continuous rhythm monitoring is valuable for adequate atrial fibrillation (AF) management in the clinical setting. Subcutaneous leadless implantable cardiac monitors (ICMs) yield an improved AF detection, overcoming the intrinsic limitations of the currently available external recording systems, thus resulting in a more accurate patient treatment. The study purpose was to assess the detection performance of a novel three-vector ICM device equipped with a dedicated AF algorithm. METHODS AND RESULTS: Sixty-six patients (86.4% males; mean age 60.4 ± 9.4 years) at risk to present AF episodes, having undergone the novel ICM implant (BioMonitor, Biotronik SE&Co. KG, Berlin, Germany), were enrolled. External 48-h ECG Holter was performed 4 weeks after the device implantation. The automatic ICM AF classification was compared with the manual Holter arrhythmia recordings. Of the overall study population, 63/66 (95.5%) had analysable Holter data, 39/63 (62%) showed at least one true AF episode. All these patients had at least one AF episode stored in the ICM. On Holter monitoring, 24/63 (38%) patients did not show AF episodes, in 16 of them (16/24, 67%), the ICM confirmed the absence of AF. The AF detection sensitivity and positive predictive value for episodes' analysis were 95.4 and 76.3%, respectively. CONCLUSION: Continuous monitoring using this novel device, equipped with a dedicated detection algorithm, yields an accurate and reliable detection of AF episodes. The ICM is a promising tool for tailoring individual AF patient management. Further long-term prospective studies are necessary to confirm these encouraging results.

Survey of wild mammal hosts of cutaneous leishmaniasis parasites in panamá and costa rica.

The eco-epidemiology of American cutaneous leishmaniasis (ACL) is driven by animal reservoir species that are a source of infection for sand flies that serve as vectors infecting humans with Leishmania spp parasites. The emergence and re-emergence of this disease across Latin America calls for further studies to identify reservoir species associated with enzootic transmission. Here, we present results from a survey of 52 individuals from 13 wild mammal species at endemic sites in Costa Rica and Panama where ACL mammal hosts have not been previously studied. For Leishmania spp. diagnostics we employed a novel PCR technique using blood samples collected on filter paper. We only found Leishmania spp parasites in one host, the two-toed sloth, Choloepus hoffmanni. Our findings add further support to the role of two-toed sloths as an important ACL reservoir in Central America.

Improving cardiac resynchronization therapy response with multipoint left ventricular pacing: Twelve-month follow-up study.

BACKGROUND: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing (MultiPoint™ Pacing [MPP], St. Jude Medical) improves acute LV function and LV reverse remodeling at 3 months. OBJECTIVE: The purpose of this study was to test the hypothesis that MPP can also improve LV function at 12 months. METHODS: Consecutive patients receiving a CRT implant (Unify Quadra MP™ or Quadra Assura MP™ CRT-D and Quartet™ LV lead, St. Jude Medical) were randomized to receive pressure-volume (PV) loop optimized biventricular pacing with either conventional cardiac resynchronization therapy (CONV) or MPP. CRT response was defined by a reduction in end-systolic volume (ESV) ≥15% relative to BASELINE as determined by a blinded observer and alive status. RESULTS: Forty-four patients (New York Heart Association class III, ejection fraction [EF] 29% ± 6%, QRS 152 ± 17 ms) were enrolled and randomized to either CONV (N = 22) or MPP (N = 22). During the observation period, 2 patients died of noncardiac causes and 2 patients were lost to follow-up. After 12 months, 12 of 21 patients (57%) in the CONV group and 16 of 21 patients (76%) in the MPP group were classified as CRT responders (P = .33). ESV reduction and EF increase relative to BASELINE were significantly greater with MPP than with CONV (ESV: median -25%, interquartile range [IQR] [-39% to -20%] vs median -18%, IQR [-25% to -2%], P = .03; EF: median +15%, IQR [8% to 20%] vs median +5%, IQR [-1% to 8%], P <.001). CONCLUSION: Sustaining the trend observed 3 months postimplant, PV loop-guided multipoint LV pacing resulted in greater LV reverse remodeling and increased LV function at 12 months compared to PV loop-guided conventional CRT.

Multipoint left ventricular pacing in a single coronary sinus branch improves mid-term echocardiographic and clinical response to cardiac resynchronization therapy.

INTRODUCTION: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing in a single coronary sinus branch improves acute LV function. We hypothesized that multipoint pacing (MPP) can improve midterm echocardiographic and clinical response compared with conventional CRT. METHODS AND RESULTS: Consecutive patients receiving a CRT implant (Unify Quadra MP™ or Quadra Assura MP™ CRT-D and Quartet™ LV lead, St. Jude Medical, Sylmar, CA, USA) were randomized to receive biventricular (BiV) pacing with either conventional LV pacing (CONV group) or MPP (MPP group). For each patient, an optimal pacing configuration for the assigned pacing mode was programmed based on intraoperative pressure-volume (PV) loop measurements. A clinical evaluation and transthoracic echocardiogram were performed before implant (BASELINE) and at 3 months postimplant and analyzed by a blinded observer. A reduction in end-systolic volume (ESV) of ≥15% relative to BASELINE was prospectively defined as response to CRT. Forty-four patients (NYHA Class III, EF 29 ± 6%, QRS duration 152 ± 17 milliseconds) were enrolled and randomized. One patient in the MPP group was lost to follow-up and excluded from further analysis. After 3 months, 11 of 22 (50%) CONV patients and 16 of 21 (76%) MPP patients were classified as responders. ESV reduction, EF increase, and NYHA class reduction relative to BASELINE were significantly greater in the MPP group than in the CONV group (ESV: -21.0 ± 13.9 vs. -12.6 ± 11.1%, P = 0.03; EF: +9.8 ± 5.1 vs. +2.0 ± 7.8 percentage points, P < 0.001; ΔNYHA: -1.05 ± 0.22 vs. -0.72 ± 0.46 functional classes, P = 0.006). CONCLUSION: PV loop optimized BiV pacing with MPP resulted in an improved rate of response to CRT.

Wolff-Parkinson-White syndrome in the era of catheter ablation: insights from a registry study of 2169 patients.

BACKGROUND: The management of Wolff-Parkinson-White is based on the distinction between asymptomatic and symptomatic presentations, but evidence is limited in the asymptomatic population. METHODS AND RESULTS: The Wolff-Parkinson-White registry was an 8-year prospective study of either symptomatic or asymptomatic Wolff-Parkinson-White patients referred to our Arrhythmology Department for evaluation or ablation. Inclusion criteria were a baseline electrophysiological testing with or without radiofrequency catheter ablation (RFA). Primary end points were the percentage of patients who experienced ventricular fibrillation (VF) or potentially malignant arrhythmias and risk factors. Among 2169 enrolled patients, 1001 (550 asymptomatic) did not undergo RFA (no-RFA group) and 1168 (206 asymptomatic) underwent ablation (RFA group). There were no differences in clinical and electrophysiological characteristics between the 2 groups except for symptoms. In the no-RFA group, VF occurred in 1.5% of patients, virtually exclusively (13 of 15) in children (median age, 11 years), and was associated with a short accessory pathway antegrade refractory period (P<0.001) and atrioventricular reentrant tachycardia initiating atrial fibrillation (P<0.001) but not symptoms. In the RFA group, ablation was successful in 98.5%, and after RFA, no patients developed malignant arrhythmias or VF over the 8-year follow-up. Untreated patients were more likely to experience malignant arrhythmias and VF (log-rank P<0.001). Time-dependent receiver-operating characteristic curves for predicting VF identified an optimal anterograde effective refractory period of the accessory pathway cutoff of 240 milliseconds. CONCLUSIONS: The prognosis of the Wolff-Parkinson-White syndrome essentially depends on intrinsic electrophysiological properties of AP rather than on symptoms. RFA performed during the same procedure after electrophysiological testing is of benefit in improving the long-term outcomes.

Multipoint left ventricular pacing improves acute hemodynamic response assessed with pressure-volume loops in cardiac resynchronization therapy patients.

BACKGROUND: Conventional cardiac resynchronization therapy (CRT) improves acute cardiac hemodynamics. OBJECTIVE: To investigate if CRT with multipoint left ventricular (LV) pacing in a single coronary sinus branch (MultiPoint Pacing [MPP], St Jude Medical, Sylmar, CA) can offer further hemodynamic benefits to patients. METHODS: Forty-four consecutive patients (80% men, New York Heart Association III, end-systolic volume 180 ± 77 mL, ejection fraction 27% ± 6%, and QRS duration 152 ± 17 ms) receiving a CRT device implant (Unify Quadra MP or Quadra Assura MP and Quartet LV lead, St Jude Medical) underwent intraoperative assessment of LV hemodynamics by using a pressure-volume loop system (Inca, CD Leycom). A pacing protocol was performed, including 9 biventricular pacing interventions with conventional CRT (CONV) using distal and proximal LV electrodes and various MPP configurations. Each pacing intervention was performed twice in randomized order with right ventricular pacing (BASELINE) repeated after every intervention. RESULTS: Evaluable recordings were obtained in 42 patients. Relative to BASELINE, the best MPP intervention significantly increased the rate of pressure change (dP/dtmax; 15.9% ± 10.0% vs 13.5% ± 8.8%; P < .001), stroke work (27.2% ± 42.5% vs 19.4% ± 32.2%; P = .018), stroke volume (10.4% ± 22.5% vs 4.1% ± 13.1%; P = .003), and ejection fraction (10.5% ± 20.9% vs 5.3% ± 13.2%; P = .003) as compared with the best CONV intervention. Moreover, the best MPP intervention improved acute diastolic function, significantly decreasing -dP/dtmin (-13.5% ± 10.2% vs -10.6% ± 6.8%; P = .011), relaxation time constant (-7.5% ± 9.0% vs -4.8% ± 7.2%; P = .012), and end-diastolic pressure (-18.2% ± 22.4% vs -8.7% ± 21.4%; P < .001) as compared with the best CONV intervention. CONCLUSIONS: CRT with MPP can significantly improve acute LV hemodynamic parameters assessed with pressure-volume loop measurements as compared with CONV.