Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: Three-year outcomes of the PREVENT AF I study

INTRODUCTION

The PREVENT AF I study demonstrated that prophylactic pulmonary vein isolation (PVI) in patients with pure typical atrial flutter (AFL) resulted in substantial reduction of new-onset atrial fibrillation (AF) during 1-year follow-up as assessed by continuous implantable cardiac monitor (ICM). The objective of this study was to assess 3-year outcomes.

METHODS AND RESULTS

Fifty patients with documented AFL were randomized to either cavotricuspid isthmus (CTI) ablation alone (n = 25) or CTI with concomitant PVI (n = 25). The primary endpoint of the study was the occurrence of any atrial tachyarrhythmia with the monthly burden exceeding 0.5% on the ICM. At the end of 3 years, freedom from any atrial tachyarrhythmia was 48% (95% confidence interval [CI]: 32-72%) in the CTI plus PVI group as compared to 20% (95% CI: 9-44%) in the CTI-only group (P = 0.01). Freedom from redo procedures was also higher: 92% (95% CI: 82-100%) versus 68% (95% CI: 52-89%), respectively (P = 0.027). The 3-year AF burden favored the combined ablation group: 6.2% versus 16.8% (P = 0.03). In the CTI-only group, 12 (48%) patients were hospitalized compared to 4 (16%) in the PVI + CTI group (P = 0.03). Two patients in the CTI-only group developed stroke with no serious adverse events in the PVI + CTI group.

CONCLUSION

Prophylactic PVI in patients with only typical AFL resulted in a significant reduction of new-onset AF and burden during long-term follow-up as assessed by ICM, with consequent reduction in hospitalizations and need to perform repeat ablation for AF.

Prevalence and Implications of Abnormal Respiratory Patterns in Cardiac Surgery: A Prospective Cohort Study

OBJECTIVE

To investigate the prevalence and impact of abnormal respiratory patterns in cardiac surgery patients.

DESIGN

Prospective cohort study.

SETTING

Tertiary hospital.

PARTICIPANTS

Patients scheduled for elective coronary artery bypass graft surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pulmonary function tests were performed in 454 patients before surgery. Abnormal respiratory patterns were defined as follows: obstructive (forced expiratory volume in 1 s [FEV₁]/forced vital capacity [FVC]<0.70), restrictive (FEV₁/FVC≥0.70 and FVC<80% of predicted), and mixed (FEV₁/FVC<0.70 and both FEV₁ and FVC<80% of predicted). Of the 31 patients with a history of chronic obstructive pulmonary disease, no abnormal respiratory pattern was confirmed in 5. Of the 423 patients without a history of lung disease, the authors newly identified 57 obstructive, 46 restrictive, and 4 mixed patterns. Therefore, lung disease was reclassified in 24.7% of cases. Independent predictors of obstructive pattern were age, male sex, history of smoking, and chronic obstructive pulmonary disease. Obstructive lung disease was associated with 16 hours or longer ventilation. A reduced FEV₁ was associated with a likelihood of atrial fibrillation (1-L decrement, odds ratio: 1.38, 95% confidence interval: 1.01-to-1.90, p = 0.04) and hospitalization time (regression coefficient: 1.23, 95% confidence interval: 0.54-to-1.91, p<0.001).

CONCLUSIONS

Abnormal respiratory patterns are common and often underdiagnosed in the cardiac surgery setting. Pulmonary function tests help reveal patients at risk of complications and may provide an opportunity for intervention.

Synchronous genetic turnovers across Western Eurasia in Late Pleistocene collared lemmings

Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D. torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next-generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D. torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50 000 years. The observation of repeated extinctions across such a vast geographical range indicates large-scale changes in the steppe-tundra environment in western Eurasia during the last glaciation. All Holocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D. torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D. groenlandicus and D. richardsoni were recovered from a Late Pleistocene site in south-western Canada. This suggests that D. groenlandicus had a more southern and D. richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex demographical history, which could have had bottom-up effects in the Late Pleistocene steppe-tundra ecosystem.

Complications following incident stroke resulting in readmissions: an analysis of data from three Scottish health surveys

BACKGROUND AND AIMS

Stroke is widely recognized as the major contributor to morbidity and mortality in the United Kingdom. We analyzed the data obtained from the three consecutive Scottish Health Surveys and the Scottish Morbidity records, with the aim of identifying risk factors for, and timing of, common poststroke complications.

METHODS

There were 19434 individuals sampled during three Scottish Health Surveys in 1995, 1998, and 2001. For these individuals their morbidity and mortality outcomes were obtained in 2007. Incident stroke prevalence, risk factors for a range of poststroke complications, and average times until such complications in the sample were established.

RESULTS

Of the total of 168 incident stroke admissions (0·86% of the survey), 16·1% people died during incident stroke hospitalization. Of the remaining 141 stroke survivors, 75·2% were rehospitalized at least once. The most frequent reason for readmission after stroke was a cardiovascular complication (28·6%), median time until event 1412 days, followed by infection (17·3%, median 1591 days). The risk of cardiovascular readmission was higher in those with 'poor' self-assessed health (odds ratio 7·70; 95% confidence interval 1·64-43·27), smokers (odds ratio 4·24; 95% confidence interval 1·11-21·59), and doubled with every five years increase in age (odds ratio 1·97; 95% confidence interval 1·46-2·65). 'Poor' self-assessed health increased chance of readmission for infection (odds ratio 14·11; 95% confidence interval 2·27-276·56).

CONCLUSIONS

Cardiovascular events and infections are the most frequent poststroke complications resulting in readmissions. The time period until event provides a possibility to focus monitoring on those people at risk of readmission and introduce preventative measures, thereby reducing readmission-associated costs.

Thermal imaging diagnostics of high-current electron beams

The thermal imaging diagnostics of measuring pulsed electron beam energy density is presented. It provides control of the electron energy spectrum and a measure of the density distribution of the electron beam cross section, the spatial distribution of electrons with energies in the selected range, and the total energy of the electron beam. The diagnostics is based on the thermal imager registration of the imaging electron beam thermal print in a material with low bulk density and low thermal conductivity. Testing of the thermal imaging diagnostics has been conducted on a pulsed electron accelerator TEU-500. The energy of the electrons was 300-500 keV, the density of the electron current was 0.1-0.4 kA/cm(2), the duration of the pulse (at half-height) was 60 ns, and the energy in the pulse was up to 100 J. To register the thermal print, a thermal imager Fluke-Ti10 was used. Testing showed that the sensitivity of a typical thermal imager provides the registration of a pulsed electron beam heat pattern within one pulse with energy density over 0.1 J/cm(2) (or with current density over 10 A/cm(2), pulse duration of 60 ns and electron energy of 400 keV) with the spatial resolution of 0.9-1 mm. In contrast to the method of using radiosensitive (dosimetric) materials, thermal imaging diagnostics does not require either expensive consumables, or plenty of processing time.

Plasmacytoma of the lung: an indolent disease resistant to conventional myeloma treatment: report of a case

Solitary lung plasmacytoma is a rare form of plasma cell tumors. The case of a 56-yr-old man is presented, who had a massive tumor of the right pulmonary apex. Percutaneous transthoracic lung biopsy demonstrated a tumor-cell population consisting of mature plasma cells, proplasmacytes, and rare plasmablasts. Immunohistochemically, the cells were CD79a+, kappa+, cyclin D1-, p53-, MDR-. Proliferative index was low (number of Ki-67+ tumor cells was 8%). Serum and urine immunoelectrophoresis did not show the presence of paraprotein. Screening for multiple myeloma with skeletal X-ray survey and bone marrow biopsy were negative. Radiotherapy and chemotherapy with alkylating agents were ineffective. However, the course of the disease is indolent and the patient is well, alive, and with no signs of multiple myeloma >5 yr after the diagnosis was established. Some pathogenetic aspects of tumor resistance to conventional myeloma treatment in this case are discussed.

[Personal experience in the treatment of tuberculosis in patients in war areas]

In the four-year period (1991-1995), 96 tuberculosis patients from the war areas of former Yugoslavia were treated in the Clinic for Lung Diseases of Military Medical Academy, that makes 31% of total number of sick and treated for tuberculosis-309 (100%). In group I (patients from war areas) there were 45 cases of cavernous pulmonary tuberculosis (47%), 28 bilateral (29%), 16 pleurisy (16.7%) and 6 cases of extensive pulmonary tuberculosis (5.1%). Among 213 patients (100%) from group II (patients from FR Yugoslavia), 81 patients had cavernous pulmonary tuberculosis (38%), 49 patients had bilateral (23%), 33 patients had pleurisy (15.5%) and 6 patients had extensive pulmonary tuberculosis (2.8%). In group I the diagnosis was bacteriologically and/or histopathologically proved in 94.8% cases: by finding of acid-resistant bacilli in sputum and other biological materials in 69 patients (72%), by positive Löwenstein's cultures in 73 patients (76%) and by histopathological result of tuberculosis inflammation in 34 patients (35.4%). In group II tuberculosis was bacteriologically and/or histopathologically proved in 134 patients (63%) by acid-resistant bacilli in sputum and other biological materials, in 141 patient (66%) by positive Löwenstein's culture and in 71 patient by positive histopathological results. Pulmonary tuberculosis in war areas is characterized by greater frequency of severe clinical forms (cavernous, bilateral and extensive) and by high direct bacillarity.

[Treatment of pneumonia under hospital conditions]

A random sample of 24 patients affected by bacterial pneumonia has been investigated whether their illness is treated etiologically. The agents have been detected from the endoscopically obtained samples of blood or chest punctate (percutaneous needle aspirate--PNA) and their sensitivity to antibacterial drugs, used in our institution, have been investigated. The obtained results have been compared to the empirically applied drugs. In only three patients the first given drug corresponded to the later obtained finding of the agent's sensitivity and in one patient third and the fourth drug has been adequate. The rational initial therapy has been proposed on the basis of investigation of the sensitivity of the bacterial pneumonia agents.

[Contribution of fiber optic bronchoscopy to the etiologic diagnosis of bacterial pneumonia]

In 24 patients with bacterial pneumonia, reliability of the samples routinely taken for etiologic diagnosis (sputum, throat swab, bronchial brushing, bronchoalveolar lavage fluid--BALF, blood, pleural fluid) was determined. Organisms detected in blood, pleural fluid, transbronchial biopsy (TBB) or percutaneous transthoracic needle aspiration biopsy (PTNAB) samples were considered as truly causative, whereas those isolated in at least two various samples from a single patient were considered as presumably causative. Most sensitive diagnostic samples were BALF, TBB and PTNAB (100% each). However, the specificity of BALF was very low (17%). Bronchial aspirate was highly sensitive (95%) but not specific (14%). Bronchial brushing was sensitive (86%) but its specificity low (14%). Sputum was hardly sensitive (40%) and had no specificity. Throat swab had virtually no diagnostic value because of its low sensitivity (10.5%) and specificity (50%).