Drainage of the inferior vena cava to the left atrium

Drainage of the inferior vena cava to the left atrium is an extremely unusual congenital heart disease. We describe a 54-year-old woman, in whom the diagnosis was suggested by transthoracic echocardiography, and then confirmed by a transesophageal exam and magnetic resonance imaging, which also revealed an associated secundum atrial septal defect. Surgical management involved reconstruction of the interatrial septum to include the inferior vena cava in the right atrium. The few previously reported cases in the literature are reviewed.     

Transplantation and prevention of reinfection

The outcome of orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related liver disease depends on the prevention of allograft reinfection. Over the past decade, major advances have been made in the management of HBV transplant candidates. The advent of longterm hepatitis B immunoglobulin (HBIG) administration as a prophylaxis of HBV recurrence and the introduction of new antiviral agents against HBV infection, such as lamivudine (LAM) or adefovir, were a major breakthrough in the management of these patients. The results of OLT for HBV infection are similar to those results achieved with other indications. Pre-OLT antiviral treatment such as LAM can suppress HBV replication before OLT and, thus, decrease the risk of reinfection of the graft. Combination prophylaxis with LAM and HBIG after transplantation is highly effective in reducing the rate of HBV reinfection even in HBV-replicative cirrhotic patients. The optimal HBIG protocol in the LAM and adefovir era has yet to be defined: dosing of HBIG, routes of administration, and the possibility of stopping HBIG.     

Encephalitozoon cuniculi strain III is a cause of encephalitozoonosis in both humans and dogs

Microsporidia are obligate intracellular eukaryotic organisms found in a wide range of vertebrate and invertebrate hosts. Encephalitozoon cuniculi is commonly found in domestic rabbits and rodents and also occurs in dogs, other canids, and primates, including humans. DNA sequencing of the ribosomal RNA genes has been used to identify these parasites to a species level and to define E. cuniculi strains I, II, and III. Eight new dog isolates were characterized as E. cuniculi strain III by use of molecular methods. This strain has also been identified in isolates from immunocompromised humans, suggesting the zoonotic potential of this parasite species. Prolonged microsporidial spore shedding from asymptomatic dogs is also reported.     

Role of beta-adrenoreceptor antagonism in the prevention of reperfusion ventricular arrhythmias: effects of acebutolol, atenolol, and d-propranolol on isolated working rat hearts subject to myocardial ischemia and reperfusion

The role of catecholamines in the genesis of ventricular arrhythmias during the reperfusion period following coronary occlusion remains incompletely understood. An isolated rat heart preparation, free from the influence of autonomic innervation or of circulating catecholamines, was used to assess the effects of beta-adrenoceptor blockade. The hearts were prelabeled with tritiated norepinephrine ( NE3H ), and the total radioactivity and that in NE3H were measured in the effluent coronary flow. The left main coronary artery was ligated for 10 minutes after which reperfusion followed. The liberation of NE3H and the development of ventricular tachycardia and fibrillation were monitored throughout. The cardioselective beta-antagonist agent, acebutolol, in a high concentration (1.1 X 10(-4)M), had good beta-antagonist effect in response to the added isoproterenol (10(-6)M); this concentration of acebutolol also suppressed sustained reperfusion ventricular arrhythmias but unexpectedly increased the release of NE3H . Atenolol, another cardioselective agent, did not prevent reperfusion ventricular arrhythmias even in a high concentration of 40 mg/L (1.5 X 10(-4)M). The d-isomer of propranolol, with poorer beta-antagonist properties than the l-isomer, prevented such ventricular arrhythmias in a concentration of 1.3 X 10(-5)M, which was low when compared to that of atenolol. It is proposed that the beta-antagonist activity of the compounds tested could not explain the inhibition of reperfusion ventricular arrhythmias and that another quality such as membrane-stabilizing activity may be involved.     

Does continuous positive airway pressure by face mask improve patients with acute cardiogenic pulmonary edema due to left ventricular diastolic dysfunction?

OBJECTIVE: Continuous positive airway pressure (CPAP) by face mask is an effective method of treating severe cardiogenic pulmonary edema (CPE). However, to our knowledge, no study has provided a precise evaluation of the effects of CPAP on cardiac function in patients presenting with CPE and preserved left ventricular (LV) function. DESIGN: Prospective observational clinical study. SETTING: A 14-bed, medical ICU at a university hospital. PATIENTS: Nine consecutive patients presenting with hypoxemic acute CPE. INTERVENTIONS: All patients were selected for 30 min of CPAP with 10 cm H(2)O by mask with fraction of inspired oxygen adjusted for a cutaneous saturation > 90%. Doppler echocardiography was performed before CPAP application and during the last 10 min of breathing with CPAP. Two-tailed, paired t-tests were used to compare data recorded at baseline (oxygen alone) and after CPAP. MEASUREMENTS AND RESULTS: Four patients presented CPE with preserved left ventricular (LV) function (a preserved LV ejection fraction [LVEF] > 45%, and/or aortic velocity time integral > 17 cm in the absence of aortic stenosis or hypertrophic cardiomyopathy). Oxygenation and ventilatory parameters were improved by CPAP in all patients. Hemodynamic monitoring and Doppler echocardiographic analysis demonstrated that in patients with preserved LV systolic function, mean arterial pressure and LV end-diastolic volume were decreased significantly by CPAP (p < 0.04). In patients with LV systolic dysfunction, CPAP improved LVEF (p < 0.05) and decreased LV end-diastolic volume (p = 0.001) significantly. CONCLUSION: CPAP improves oxygenation and ventilatory parameters in all kinds of CPE. In patients with preserved LV contractility, the hemodynamic benefit of CPAP results from a decrease in LV end-diastolic volume (preload).     

Imaging microdomain Ca2+ in muscle cells

Ca2+ ions passing through a single or a cluster of Ca2+-permeable channels create microscopic, short-lived Ca2+ gradients that constitute the building blocks of cellular Ca2+ signaling. Over the last decade, imaging microdomain Ca2+ in muscle cells has unveiled the exquisite spatial and temporal architecture of intracellular Ca2+ dynamics and has reshaped our understanding of Ca2+ signaling mechanisms. Major advances include the visualization of "Ca2+ sparks" as the elementary events of Ca2+ release from the sarcoplasmic reticulum (SR), "Ca2+ sparklets" produced by openings of single Ca2+-permeable channels, miniature Ca2+ transients in single mitochondria ("marks"), and SR luminal Ca2+ depletion transients ("scraps"). As a model system, a cardiac myocyte contains a 3-dimensional grid of 104 spark ignition sites, stochastic activation of which summates into global Ca2+ transients. Tracking intermolecular coupling between single L-type Ca2+ channels and Ca2+ sparks has provided direct evidence validating the local control theory of Ca2+-induced Ca2+ release in the heart. In vascular smooth muscle myocytes, Ca2+ can paradoxically signal both vessel constriction (by global Ca2+ transients) and relaxation (by subsurface Ca2+ sparks). These findings shed new light on the origin of Ca2+ signaling efficiency, specificity, and versatility. In addition, microdomain Ca2+ imaging offers a novel modality that complements electrophysiological approaches in characterizing Ca2+ channels in intact cells.     

Assessment of atrial septal defect size with 3D-transesophageal echocardiography: comparison with balloon method

BACKGROUND: Transcatheter closure of atrial septal defect (ASD) is an alternative approach to surgery in selected patients. Balloon stretched diameter (BSD) is considered as the standard way of measuring ASD size. Three-dimensional transesophageal echocardiography (3D-TEE) provides views of the ASD allowing its measurement and identifying its spatial relation with neighboring structures. Our aim was to compare the BSD and 3D-TEE methods to measure the ASD size before transcatheter closure. METHODS AND RESULTS: Seventy-six consecutive patients were enrolled for ASD device closure. Three-dimensional transesophageal echocardiography and balloon sizing were adequately performed in 70 patients before the defect closure. The mean maximal diameter measured by 3D-TEE was 20 +/- 15 mm (range 10-28) while the mean BSD was 22 +/- 4.8 mm (range 9-31). When comparing the 3D-TEE and transcatheter measurements, there was a good correlation between the two methods (y = 3.15 + 0.77x; r = 0.8). The defect as viewed by 3D-TEE was unique in 54 patients and multiple in 16 patients. In patients with a single defect, the correlation between the two methods was high (y = 1.74 + 0.84x; r = 0.85) while patients with multiple ASDs, the correlation was poor (y = 12.4 + 0.4x; r = 0.45). Transcatheter closure was performed successfully in 86%. The mean size of the Amplatzer device was 23 +/- 4.8 mm (range 4-32). The reference to choose the size of the device was the BSD in single defects and the 3D-TEE maximal diameter in multiple defects. CONCLUSION: Three-dimensional transesophageal echocardiography and transcatheter methods are two complementary techniques for the success of transcatheter ASDs closure.     

Adjunctive therapies in severe sepsis and septic shock: Current place of steroids

For more than five decades, the use of corticosteroids as an adjunctive therapy to treat severe sepsis and septic shock has incited consistent debate. Negative results of the Corticosteroid Therapy of Septic Shock (CORTICUS) study evoked a revision of Surviving Sepsis Campaign guidelines suggesting a more restricted use of low-dose hydrocortisone only in patients with severe septic shock. Hemodynamic improvement by low-dose steroids was evident and independent from adrenal insufficiency, but did not improve survival. The roles of cortisol measurement and adrenal function tests for treatment decisions have been questioned. An international task force introduced the concept of critical illness-related corticosteroid insufficiency, which challenges the predominant role of adrenal dysfunction and underscores sustained inflammation due to tissue steroid resistance. Whether moderate steroid doses induce superinfections and muscle weakness is unclear. This article reviews recent publications, actual recommendations, ongoing discussions, and future perspectives.     

Speciation of human microsporidia by polymerase chain reaction single-strand conformation polymorphism.

We describe the application of single-strand conformation polymorphism (SSCP) analysis to the speciation of human microsporidia after polymerase chain reaction (PCR) amplification with the panmicrosporidian primers PMP1 and PMP2. We compared the DNA extracted and amplified from different genotypes or isolates of Enterocytozoon bieneusi, Encephalitozoon cuniculi, E. hellem, and E. intestinalis plus an isolate of Vittaforma corneae. The PCR-SSCP, when performed at 20 degrees C, generated 2 bands in distinctive, reproducible patterns in polyacrylamide gels for each species of microsporidia tested, regardless of genotype or isolate. We found PCR-SSCP to be an easy and reproducible method for speciation of human microsporidia when the primer pair PMP1 and PMP2 is used.