A Case of Possible Chagas Transmission by Blood Transfusion in Switzerland.

BACKGROUND: Transfusion-transmitted Chagas disease has been reported from endemic countries in Latin America. Switzerland is a non-endemic country but high prevalence of antibodies against Trypanosoma cruzi was found among immigrants. Immigrants may participate in blood donation; therefore, risk-adapted anti-T. cruzi screening for blood donors was implemented in Switzerland in 2013. METHODS: Between January 2013 and July 2015, 1 out of 1,183 at-risk donors, tested at Blood Transfusion Service Zurich, was found anti-T. cruzi IgG-positive. RESULTS AND CONCLUSION: Out of 54 donations given by the index donor (ID), we identified 77 blood products which were delivered to hospitals. Archived serum samples from the donations given during the prior 5 years were available for retrospective testing. All samples from ID revealed positive findings for anti-T. cruzi IgG. Donor-triggered look-back procedure identified a 70-year-old male recipient of a platelet concentrate (PC) donated by ID. The recipient succumbed of acute T. cruzi infection 2 years after transfusion of the PC.

Evaluation of left ventricular diastolic function by pulsed Doppler tissue imaging in mice.

BACKGROUND: Diastolic left ventricular (LV) function is commonly characterized by transmitral flow pattern in human beings. Recently, Doppler tissue imaging (DTI) was introduced to evaluate diastolic function. The aim of our study was to validate DTI in the evaluation of diastolic function in mice. METHODS: We measured indices of diastolic function using pulsed DTI, and transmitral Doppler and LV pressure and its maximal rate of decrease (LVdP/dt(min)), before and 4 weeks after aortic banding in C57BL/6 mice. RESULTS: Peak early diastolic velocity and ratio of peak early-to-late filling velocities, both measured by DTI, were significantly reduced after banding, thereby indicating diastolic dysfunction. Diastolic dysfunction was confirmed by impaired LV dP/dt(min), decreased transmitral early filling velocity, and transmitral early-to-late filling velocity ratio using transmitral Doppler. CONCLUSION: DTI detects diastolic dysfunction caused by chronic pressure overload in mice after aortic banding. DTI is suggested to be implemented as part of routine mouse echocardiography for evaluation of LV diastolic function.

Effects of anesthesia on diastolic function in mice assessed by echocardiography.

BACKGROUND: Transthoracic echocardiography is the predominant diagnostic tool to evaluate systolic and diastolic cardiac function noninvasively in mice. It is known that systolic function is substantially influenced by anesthetic agents used for sedation during echocardiography. However, the effect on diastolic function has not been investigated yet. The following study was conducted to evaluate the influence of different agents on diastolic left ventricular function in mice. METHODS AND RESULTS: The effect of ketamine/xylazine (K/X), ketamine/midazolam (K/M), and tribromoethanol (TBE, Avertin) on diastolic function was measured 5, 15, and 25 minutes after the onset of anesthesia. Ratio of peak early-to-late myocardial diastolic velocities (Ea/Aa; determined by tissue Doppler imaging; TDI), ratio of peak transmitral early (E)- and late-diastolic velocity (E/A), deceleration time (DT), and isovolumic relaxation time (IVRT) correlated significantly with heart rate (HR). Overall, increasing HR contributed to a decrease of E/A-, Ea/Aa ratio, IVRT, and DT, whereas agents characterized by the strongest variation of HR (K/M and TBE) were associated with the greatest effect on diastolic function. CONCLUSION: Left ventricular diastolic function in mice, determined by echocardiography, is dependent on anesthetic agent and timing of measurements after onset of anesthesia.

Evaluation of Tissue Doppler Tei index for global left ventricular function in mice after myocardial infarction: comparison with Pulsed Doppler Tei index.

AIM: The Pulsed Doppler Tei index is a parameter to evaluate combined systolic and diastolic function in humans. However, one major limitation is that the parameters of Pulsed Doppler Tei index cannot be measured within one cardiac cycle. Therefore, accuracy of the Pulsed Doppler Tei index may be affected by anesthesia induced heart rate variation in mice echocardiography. Tissue Doppler Imaging (TDI) enables us to measure both relaxation and contraction velocities simultaneously. Thus, the aim of our study was to validate TDI and Pulsed Doppler Tei index and their reproducibility in mice after experimental anterior myocardial infarction (MI). METHODS AND RESULTS: Pulsed Doppler Tei index and TDI Tei index were assessed before and 4 weeks after MI. Both parameters increased significantly after MI (Pulsed Doppler: 0.4+/-0.04 to 0.7+/-0.03; P<0.001; TDI: 0.2+/-0.03 to 0.5+/-0.04; P<0.0001). In addition, TDI Tei index showed a good correlation with ejection fraction and fractional shortening, and was indicated by better reproducibility than Pulsed Doppler Tei index. CONCLUSION: Tissue Doppler Tei index is appropriate to characterize global left ventricular function in mice after MI.