Color Doppler Visualization of Intramyocardial Coronary Arteries Using a New Echo System: Effect of Contrast Enhancement and Vasodilation

Utilizing a new echocardiographic system, intramyocardial coronary arteries could be demonstrated by color Doppler in a small number of open chest animals. Both intravenous and intracoronary injections of a contrast agent (Levovist) resulted in significant enhancement of color flow signals with an increase in the length, width, and the number of these vessels. Similar results were obtained with intravenous infusion and direct intracoronary injections of a vasodilator (adenosine).     

Efficient Closed Loop Simulation of Do-It-Yourself Artificial Pancreas Systems

Background:Numerical simulations, also referred to as in silico trials, are nowadays the first step toward approval of new artificial pancreas (AP) systems. One suitable tool to run such simulations is the UVA/Padova Type 1 Diabetes Metabolic Simulator (T1DMS). It was used by Toffanin et al. to provide data about safety and efficacy of AndroidAPS, one of the most wide-spread do-it-yourself AP systems. However, the setup suffered from slow simulation speed. The objective of this work is to speed up simulation by implementing the algorithm directly in MATLAB^®/Simulink^®.Method:Firstly, AndroidAPS is re-implemented in MATLAB^® and verified. Then, the function is incorporated into T1DMS. To evaluate the new setup, a scenario covering 2 days in real time is run for 30 virtual patients. The results are compared to those presented in the literature.Results:Unit tests and integration tests proved the equivalence of the new implementation and the original AndroidAPS code. Simulation of the scenario required approximately 15 minutes, corresponding to a speed-up factor of roughly 1000 with respect to real time. The results closely resemble those presented by Toffanin et al. Discrepancies were to be expected because a different virtual population was considered. Also, some parameters could not be extracted from and harmonized with the original setup.Conclusions:The new implementation facilitates extensive in silico trials of AndroidAPS due to the significant reduction of runtime. This provides a cheap and fast means to test new versions of the algorithm before they are shared with the community.     

In the Search of Marine Pestiviruses: First Case of Phocoena Pestivirus in a Belt Sea Harbour Porpoise

Pestiviruses are widespread pathogens causing severe acute and chronic diseases among terrestrial mammals. Recently, Phocoena pestivirus (PhoPeV) was described in harbour porpoises (Phocoena phocoena) of the North Sea, expanding the host range to marine mammals. While the role of the virus is unknown, intrauterine infections with the most closely related pestiviruses— Bungowannah pestivirus (BuPV) and Linda virus (LindaV)—can cause increased rates of abortions and deaths in young piglets. Such diseases could severely impact already vulnerable harbour porpoise populations. Here, we investigated the presence of PhoPeV in 77 harbour porpoises, 277 harbour seals (Phoca vitulina), grey seals (Halichoerus grypus) and ringed seals (Pusa hispida) collected in the Baltic Sea region between 2002 and 2019. The full genome sequence of a pestivirus was obtained from a juvenile female porpoise collected along the coast of Zealand in Denmark in 2011. The comparative Bayesian phylogenetic analyses revealed a close relationship between the new PhoPeV sequence and previously published North Sea sequences with a recent divergence from genotype 1 sequences between 2005 and 2009. Our findings provide further insight into the circulation of PhoPeV and expand the distribution from the North Sea to the Baltic Sea region with possible implications for the vulnerable Belt Sea and endangered Baltic Proper harbour porpoise populations.     

Safety and efficacy of transvenous lead extraction of very old leads

OBJECTIVESTransvenous lead extraction using mechanical rotational- or laser sheaths is an established procedure. Lead dwell time has been recognized as a risk factor for extraction failure and procedure-related complications. We therefore investigated the safety and efficacy of transvenous extraction of leads with an implant duration of more than 10 years.Open in a separate windowMETHODSBetween January 2013 and March 2017, a total of 403 patients underwent lead extraction in 2 high-volume lead extraction centres. One hundred and fifty-four patients with extraction of at least 1 lead aged over 10 years were included in this analysis. Laser lead extraction was the primary extraction method, with additional use of mechanical rotational sheaths or femoral snares, if necessary. All procedural- and patient-based data were collected into a database and retrospectively analysed.RESULTSMean patient’s age was 65.8 ± 15.8 years, 68.2% were male. Three hundred and sixty-two leads had to be extracted. The mean lead dwell time of treated leads was 14.0 ± 6.1 years. Complete procedural success was achieved in 91.6% of cases, while clinical success was achieved in 96.8%. Failure of extraction occurred in 3.2%. Leads that could not be completely removed had a significantly longer lead dwell time (18.2 vs 13.2 years; P = 0.016). Additional mechanical rotational sheaths or femoral snares were used in 26 (16.9%) patients. Overall complication rate was 4.6%, including 5 (3.3%) major and 2 (1.3%) minor complications. There was no procedure-related mortality.CONCLUSIONSTransvenous lead extraction in leads aged over 10 years is safe and effective when performed in specialized centres and with use of multiple tools and techniques. Leads that could not be completely extracted had a statistically significant longer lead dwell time.     

Effects of caffeine on the detection of ischemia in patients undergoing adenosine stress cardiovascular magnetic resonance imaging

Background

Adenosine stress cardiovascular magnetic resonance (CMR) can detect significant coronary artery stenoses with high diagnostic accuracy. Caffeine is a nonselective competitive inhibitor of adenosine2A-receptors, which might hamper the vasodilator effect of adenosine stress, potentially yielding false-negative results. Much controversy exists about the influence of caffeine on adenosine myocardial perfusion imaging. Our study sought to investigate the effects of caffeine on ischemia detection in patients with suspected or known coronary artery disease (CAD) undergoing adenosine stress CMR.

Methods

Thirty patients with evidence of myocardial ischemia on caffeine-naïve adenosine stress CMR were prospectively enrolled and underwent repeat adenosine stress CMR after intake of 200 mg caffeine. Both CMR exams were then compared for evaluation of ischemic burden.

Results

Despite intake of caffeine, no conversion of a positive to a negative stress study occurred on a per patient basis. Although we found significant lower ischemic burden in CMR exams with caffeine compared to caffeine-naïve CMR exams, absolute differences varied only slightly (1 segment based on a 16-segment model, 3 segments on a 60-segment model, and 1 ml in total ischemic myocardial volume, p?<?0.001 each). Moreover, no relevant ischemia (≥2 segments in a 16-segment model) was missed by prior ingestion of caffeine.

Conclusions

Although differences were small and no relevant myocardial ischemia had been missed, prior consumption of caffeine led to significant reduction of ischemic burden, and might lower the high diagnostic and prognostic value of adenosine stress CMR. Therefore, we suggest that patients should still refrain from caffeine prior adenosine stress CMR tests.