Functional assessment of the fontan operation: Combined M-mode, two-dimensional and doppler echocardiographic studies

Combined M-mode, two-dimensional and Doppler echocardiographie studies were used to assess the postoperative status of 33 patients who had undergone the modified Fontan procedure. Twenty-four patients had surgical repair with use of a simple direct right atrium to pulmonary artery anastomosis. The remaining patients had repair with use of a prosthesis or associated Glenn shunt. Twenty-seven patients were studied early in the postoperative period (2 months or less) and the remaining patients were studied up to 6 years postoperatively. A total of 36 examinations were performed. Of the 33 patients, 13 had tricuspid atresia, 12 had double inlet left ventricle with hypoplastic right ventricular outlet chamber and 8 had complex lesions with atrioventricular canal, double outlet right ventricle or a hypoplastic ventricle.Postoperative assessment by M-mode and two-dimensional echocardiography demonstrated normal or mildly reduced ventricular function (ejection fraction > 40%) in 22 patients. In 24 patients, a “normal” (low pattern was observed in the pulmonary artery by pulsed Doppler echocardiography, with predominant diastolic flow and accentuation by atrial systole somewhat similar to the venous flow pattern observed in the superior vena cava. “Abnormal” flow patterns (disorganized systolic flow, absence of atrial waves and little or no increase with inspiration) were observed in nine patients with reduced ventricular function or residual shunt. Continuous wave Doppler study also demonstrated mild dynamic subaortic obstruction in two patients. Combined pulsed and continuous wave studies showed atrioventricular valve insufficiency in 10 patients. Follow-up studies revealed a satisfactory clinical course in most patients. Three patients died approximately 4 to 8 months after their Fontan operation

Outcome of Patients With Hypertrophic Cardiomyopathy and a Normal Electrocardiogram

ObjectivesThis study sought to clarify the frequency, clinical phenotype, and prognosis of those patients with hypertrophic cardiomyopathy (HCM) who present with a normal electrocardiogram (ECG).BackgroundHypertrophic cardiomyopathy is the most common cause of sudden death in young people. Screening advocates have recommended a 12-lead ECG for the early detection of HCM in athletes, yet the clinical outcomes of those presenting with a normal ECG remains to be fully delineated.MethodsBaseline characteristic and echocardiographic data were collected on all patients with HCM who initially presented to our institution with a diagnostic echocardiogram but a normal ECG. Follow-up was obtained and compared with the prognosis of HCM patients who presented with abnormal ECGs.ResultsWe compared 135 HCM patients with a normal ECG with 2,350 HCM patients with an abnormal ECG. The latter group was more likely to have worse symptoms, have higher gradients, and a greater degree of septal wall thickness than the patients with a normal ECG. Severe obstructive symptoms requiring surgical myectomy and implantation of an implantable cardioverter-defibrillator were more common in patients with abnormal ECGs. Cardiac survival was significantly better in the group with a normal ECG at presentation—none of these patients had a cardiac death at follow-up.ConclusionsAlmost 6% of patients presenting with demonstrable echocardiographic evidence of HCM had a normal ECG at the time of diagnosis. This subset of patients with normal ECG-HCM appears to exhibit a less severe phenotype with better cardiovascular outcomes

A serial evaluation of electrocardiographic indices and cardiac arrhythmias during pregnancy, lactation and dry periods in Saanen goats

Aim of this study was to investigate the effects of lactation, pregnancy and dry period on electrocar-diographic (ECG) parameters and cardiac arrhythmias in the Saanen goat. A total of twenty female adult clinically healthy Saanen goats 3 years of age with a body condition score of 3.5 and average weight of 30.2±2.20 kg were randomly selected. The whole duration of the study (8 months) was divided into four periods including dry and non-pregnant (P1), 2 months pregnant (P2), 4 months pregnant (P3), and lactating (P4) periods. In late pregnancy and lactation periods, the amplitudes of P, QRS and T waves were significantly higher compared to other periods (P<0.01). P-R, Q-T and R-R intervals in late pregnancy were significantly shorter and heart rate was significantly higher than those in other periods. Sinus arrhythmias were the only irregularity observed on the ECG traces and were diagnosed in 30%, 15%, 20% and 35.25% of the goats in P1, P2, P3 and P4, respectively. There were no significant difference in configuration of ECG waves and cardiac arrhythmias among different periods. Based on the results of the present study, it was concluded that although no cardiac morpho-logical changes have been reported in goats during the lactation, late pregnancy and dry periods, sig-nificant changes in ECG parameters were observed in base-apex lead in Saanen goats during late pregnancy and lactation periods. The physiological cardiac arrhythmias and variations in ECG pa-rameters observed during different periods in the current study can be used as a base to achieve more accurate diagnoses of heart diseases using ECG

Non-Equilibrium Pathways for Excitation of Bulk and Surface Phonons through Anharmonic Coupling

Upon impulsive optical excitation of solid-state materials, the non-equilibrium flow of energy from the excited electronic system to the lattice degrees of freedom typically happens in a few picoseconds. Here we identified the surface of thin Bi films grown on Si(001) as an additional subsystem which is excited much slower on a 100 ps timescale that is caused by decoupling due to mismatched phonon dispersions relations of bulk and surface. Anharmonic coupling among the phonon systems provides pathways for excitations which exhibits a 1/T-dependence causing a speed-up of surface excitation at higher temperatures. A quantitative justification is provided by phonon Umklapp processes from lattice thermal conductivity of the Bi bulk. Three-temperature model simulations reveal a pronounced non-equilibrium situation up to nanoseconds: initially, the surface is colder than the bulk, that situation is then inverted during cooling and the surface feeds energy back into the bulk phonon system

Violation of Boltzmann Equipartition Theorem in Angular Phonon Phase Space Slows down Nanoscale Heat Transfer in Ultrathin Heterofilms

Heat transfer through heterointerfaces is intrinsically hampered by a thermal boundary resistance originating from the discontinuity of the elastic properties. Here, we show that with shrinking dimensions the heat flow from an ultrathin epitaxial film through atomically flat interfaces into a single crystalline substrate is significantly reduced due to violation of Boltzmann equipartition theorem in the angular phonon phase space. For films thinner than the phonons mean free path, we find phonons trapped in the film by total internal reflection, thus suppressing heat transfer. Repopulation of those phonon states, which can escape the film through the interface by transmission and refraction, becomes the bottleneck for cooling. The resulting nonequipartition in the angular phonon phase space slows down the cooling by more than a factor of 2 compared to films governed by phonons diffuse scattering. These allow tailoring of the thermal interface conductance via manipulation of the interface

Eliminacija kloramfenikola u kalifornijskoj pastrvi

Chloramphenicol muscle residue levels in rainbow trout were determined after oral administration of 84 μg kg−1d−1 of chloramphenicol for four days. Samples were taken one day before treatment and for 43 days after the treatment was over. Chloramphenicol was analysed using an in-house enzyme linked immunoassay (ELISA) validated against the criteria of the Commission Decision 2002/657/EC. Validation parameters confi rmed that the method was appropriate for the detection of chloramphenicol at levels below the minimum required performance limit (MRPL) of 0.3 μg kg−1. The highest chloramphenicol levels were observed on the fi rst day after the treatment had ended (144.3 μg kg−1). Elimination was signifi cant over the fi rst seven days; signifi cant differences were detected between days 1 and 3 (p<0.001), 3 and 5 (p<0.001), and 5 and 7 (p<0.05). Chloramphenicol levels dropped below MRPL to 0.17 μg kg−1 on day 9 after the end of treatment. From day 11 to 43, chloramphenicol residues were detectable in a range from 0.091 μg kg−1 (highest) to 0.011 μg kg−1 (lowest). Our results indicate that trout muscle tissue could be compliant with health requirements for consumption 10 days after withdrawal from chloramphenicol treatment.Određivani su ostaci kloramfenikola u mišićnom tkivu kalifornijske pastrve nakon oralne primjene u dozi od 84 μg kg−1d−1 tijekom 4 dana. Uzorkovanje je provedeno dan prije tretmana te tijekom 43 dana nakon tretmana. Maseni udjeli kloramfenikola određivani su primjenom in-house imunoenzimske metode (ELISA) validirane prema kriterijima Odluke Komisije 2002/657/EC. Dobiveni validacijski parametri pokazuju da je metoda prikladna za određivanje kloramfenikola na nivou manjem od vrijednosti granice najmanje zahtijevane učinkovitosti izvedbe metode (MRPL) od 0,3 μg kg−1. Najviši maseni udjeli kloramfenikola utvrđeni su prvog dana nakon završetka tretmana (144,3 μg kg−1). Statistički značajna eliminacija utvrđena je tijekom sedam dana te je značajno smanjenje određeno između prvog i trećeg (p<0,001), trećeg i petog (p<0,001) te petog i sedmog dana nakon tretmana (p<0,05). Razina kloramfenikola ispod MRPL vrijednosti utvrđena je devetog dana (0,17 μg kg−1) nakon tretmana. U vremenu od 11. do 43. dana nakon tretmana određeni su ostaci kloramfenikola od maksimalno 0,091 μg kg−1 do minimalno 0,011 μg kg−1. Prikazani rezultati pokazuju da se 10 dana nakon završetka tretmana tkivo pastrve može smatrati prikladnim za konzumaciju bez potencijalne štete za zdravlje

Architecture and Design of the McMaster NEUDOSE Communication Radio Subsystem

The communication subsystem is responsible for ensuring robust communication between the McMaster NEUDOSE CubeSat and the Ground Station located at McMaster University. This subsystem sends the collected scientific data, system telemetry (health), and telecommand from the onboard instruments using two different communication radio frequencies