Validation of a multipolar pulsed field ablation catheter for endpoint assessment in pulmonary vein isolation procedures

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): FP7/2007-2013, №602299, EU-CERT-ICD

Objective

To validate the performance of a multipolar PFA catheter compared to a standard pentaspline 3D-mapping catheter for endpoint assessment of PVI.

Background

Pulsed field ablation (PFA) for pulmonary vein isolation (PVI) using single-shot devices combines the benefits of high procedural efficacy and safety. A newly available multipolar PFA catheter allows real-time recording of pulmonary vein (PV) signals during PVI.

Methods

Patients undergoing first PVI using PFA with the standard ablation protocol (8 applications per PV) were studied. Entrance- and exit-block (10V/2ms) were assessed using the PFA catheter. Subsequently, a high-density bipolar voltage 3D electro-anatomical map (3D-EAM) was constructed using a standard pentaspline 3D-mapping catheter. Additional PFA applications were delivered only after confirmation of residual PV-connection by 3D-EAM.

Results

In 56 patients, 213 PVs were targeted for ablation. Acute PVI was achieved in 100% of PVs: in 199/213 (93%) PVs with the standard ablation protocol alone and in the remaining 14 PVs after additional PFA applications. Accuracy of PV assessment with the PFA catheter after the standard ablation protocol was 91% (194/213 veins). In 5/213 (2.3%) PVs, the PFA catheter incorrectly indicated PV-isolation. In 14/213 (6.6%) the PFA catheter incorrectly indicated residual PV-conduction due to high-output pace-capture. When the output was reduced to 5V/1ms, pace-capture was reduced to 0.9% (2/213).

Conclusion

A novel multipolar PFA catheter allows reliable endpoint assessment for PVI. Due to its design, far-field sensing and high-output pace-capture can occur, which may require adjustment of standard pacing outputs for verification of exit-block.

[Composting of poultry carcasses as an alternative method for disposal in case of an outbreak of an epizootic disease: first results]

Composting of poultry carcasses represents an alternative method for disposal in case of an outbreak of an epizootic disease. Two composting experiments, each with a different construction of the compost pile, were carried out in a stable. In the first experiment two layers of turkey carcasses were formed. This compost pile covered with straw was directly built on the ground. In the second experiment no layers of carcasses were formed, and it was assembled on straw bales covered with plastic foil. One part of this compost pile was covered with straw, the other one was additionally covered with plastic foil. In the first experiment in the upper layers of the compost pile temperatures of up to 54.9 degrees C were reached and the decomposition of carcasses was very advanced with no soft tissues remaining after 30 days. In contrast temperatures of only 45.2 degrees C were reached in the lower layers and decomposition was far less advanced. This difference in decomposition was most likely caused by the temperature difference observed. In the second experiment the near complete decomposition seen in the upper layers of the compost pile at the first trial, was not achieved. Decomposition was more advanced in the straw covered part of this compost pile than in the part covered with straw and plastic foil. On the other hand, higher temperatures of up to 48.4 degrees C were measured in the lower layers of this compost pile most likely as a result of the increased heat insulation in particular to the ground.

[Occurrence of foot and mouth disease--a historical survey]

FMD--the most economically significant animal disease in the world during the last two centuries--has caused the last great panzootic from 1965 to 1967 in Europe. Since then it has become possible to eradicate centres of the epidemic still being present on the continent, mainly by means of the annual mass vaccination of cattle combined with rigid antiepizootic measures which include culling of infected animals. During the years after however there has been sporadic outbreaks again and again. They were mainly caused by virus that escaped from FMD laboratories and by the application of vaccines with residual infectiousity but also to an increasing extent they resulted from virus brought in from endemic regions of the world. The now as before high incidence of FMD in Asia and in wide parts of Africa and South America--after all 71 countries in these regions have been affected by outbreaks of FMD, the classic carrier disease, from 1998 to 2000--resulted in the spread of virus over far distances due to the globalization of world trade and the increasing traveling favoured by modern traffic facilities. Since 1980 in Europe particularly virus strains from the Middle East but also from other parts of Northern Africa and Asia have dominated the epidemiological situation such as the current epizootic in the United Kingdom and the outbreaks resulting from in three other member states of the European Union. In accordance with the EU guidelines the control of occurring outbreaks is exclusively carried out by stamping out. The limits of this procedure have become clearly obvious during the current epizootic in Britain. The use of emergency vaccination in the Netherlands shows a practicable alternative to the excessive mass culling of both infected animals and those being suspected of. The plurality and variability of the causative agent require a permanent observation of the epidemiological situation and of the virus strains involved in order to prevent the disease and to ensure the diagnosis and the topicality of the vaccines being available in the vaccine banks. Long-term success in the global combat against FMD can only be achieved on the basis of close international co-operation intended to restrain the disease significantly in the still endemically infected regions.

Keys to success in orthotopic bladder substitution

Orthotopic bladder substitution is here to stay. Excellent long term functional results can be obtained. However, careful, restrictive patient selection before surgery, strict attention to some special surgical details during surgery and, probably most important, meticulous postoperative instruction and follow-up of the patient with an orthotopic bladder substitute are mandatory.

Experiments on an early protection against foot-and-mouth disease virus

The influence of the peptide diacetylsplenopentin (SP5) on an early protection of guinea pigs against foot-and-mouth disease (FMD) was investigated. 80% protection was achieved if SP5 was applied in a dose of 2 mg one day before challenge with FMD virus (FMDV) type O1 Lausanne strain. In comparison with this a conventional commercial adsorbate vaccine protected guinea pigs about 7 days after vaccination. An earlier protection can be obtained in general by vaccination with a higher content of the immunogen. A tenfold increase of the 146 S particle dose in a conventional oil adjuvanted FMDV vaccine protected pigs about 2 days earlier as observed after inoculating a "normal" vaccine (about 11 days).

Radical prostatectomy or wait-and-watch?

With intensified screening and the use of new diagnostic tools for prostate cancer (prostate-specific antigen, rectal ultrasound, magnetic resonance imaging with rectal coils, etc), the number of newly diagnosed cases of prostate cancer is rising rapidly, whereas the frequency of death due to prostate cancer remains almost stable. It must therefore be assumed that the number of patients in whom a diagnosed prostate cancer will not be fatal is also increasing. Consequently, not every prostatic carcinoma requires radical treatment when diagnosed. Also, it must be concluded that not every man who is a long-term survivor after radical prostatectomy owes his survival to the treatment. Long-term survivorship may reflect the relatively benign biological potential of this disease in an individual patient. Therefore, there is an inherent risk of overtreating patients and this must be weighed against the costs, the postoperative morbidity and the, albeit low, mortality of a radical prostatectomy. Nevertheless, as long as we do not have diagnostic tools which, at an early stage of prostate cancer, enable us to determine whether a carcinoma will ultimately have a fatal outcome, we are obliged to offer radical prostatectomy to younger patients (who have a life expectancy of more than 10 years) as long as they have organ-confined disease.

RGD-containing peptides of VP1 of foot-and-mouth disease virus (FMDV) prevent virus infection in vitro

RGD-containing peptides from the immunodominant region of VP1 between amino acids 135-160 from foot-and-mouth disease virus (FMDV) type O1 Kaufbeuren (O1K) prevented virus adsorption to piglet kidney (PK) cells. The highly conserved amino acid RGD sequence (Arg.-Gly.-Asp.) was a prerequisite of this effect. To prevent infection with 100-200 TCID50 in 10(6) PK cells, 20-250 micrograms of each peptide should have been added.