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Cardiovascular Journal of Africa • ABSTRACTS – SA HEART
®
CONGRESS 2019
S39
AFRICA
Results:
During this study period, 72 patients underwent balloon valvuloplasty. The age of the majority of patients (72%) was 12 - 60 months (mean 35.6).
The indications were severe PS defined as peak instantaneous gradient (PIG) >70mmHg in 81% of the patients and moderate PS, PIG >40 - 70mmHg in 19%
of the patients. There was a 90% success rate. A suboptimal reduction in pressure gradient was found in 10% of patients, with 8% having dysplastic valves. An
iatrogenic suicide right ventricle, where severe right ventricular outflow tract (RVOT) obstruction develops post PBPV, was observed in 2.7% of patients with
1.4% developing reperfusion pulmonary oedema. Moderate pulmonary regurgitation (PR) was observed in 25% of the patients. Only 3% developed severe PR.
Conclusion:
This analysis shows that PBPV is a safe and effective treatment for moderate to severe PS. The persistence of a gradient is associated with the
presence of dysplastic valves. A quarter of patients develop moderate PR, with few developing severe PR.
Post-resheathing complication of the self-expanding valve in aortic valve transcatheter implant
Raphael Ferreira Rossi, Alberto Fonseca, Luciano Liberato, Edmur Araujo, Marco Passos and Marco Passos
Heart Hospital of Brazil, São Paulo, Brazil
Introduction:
Transcatheter aortic valve (TAVI) implantation is an approved procedure for the treatment of severe aortic stenosis in selected patients. A rare
complication of the self-expanding valve implant is a fold of the valve’s nitinol structure, resulting in a segment of malposition, aortic perivalvular insufficiency
and possible valvular leaflet dysfunction.
Methods:
We report a case of TAVI. A self-expanding prosthesis, with failure of the valve to expand, causing an important fold throughout the nitinol
structure was observed after the aortic valve.
Results:
Failure of the valve to expand caused significant folding along the nitinol structure which resulted in a severe paravalvular leak. Balloon valvuloplasty
was employed which resulted in the restoration of the metallic structure geometry and reduction in leakage.
Conclusion:
Although recapture is a characteristic of this prosthesis, it is important to recognise the angiographic characteristics of a possible complication
(straight line signal) and to avoid them.
The AFROStrep registry: Report on the prevalence of pharyngeal group A streptococcal emm-types in Cape Town, South Africa
Mogamat Salie*, Kelin Engel*, Kimona Rampersadh
#
, Dylan Barth*, Babu Muhamed*, Liesl Zühlke*, James Dale
†
and Mark Engel*
*University of Cape Town, Rondebosch, South Africa.
#
University of Western Australia, Crawley, Australia.
†
University of Tennessee Health Science Centre,
Memphis, United States of America
Introduction:
The AFROStrep registry was established in 2016 for the surveillance of beta-haemolytic streptococcal infections in Africa. Of particular interest
is the documenting of group A streptococcal (Strep A) pharyngitis that may lead to rheumatic heart disease (RHD), the latter of which places a high burden
on the continent. This report presents Strep A emm-type distribution, as contained in AFROStrep to date, as part of the wider vaccine initiative spanning a
number of sites worldwide.
Methods:
Isolates were obtained, through both active and passive surveillance of patients, 5 years of age and older, presenting with sore throat to
local community clinics within a peri-setting of Cape Town, South Africa and through the National Health Laboratory Service. These were complemented with
samples collected previously through similar studies by our group. Patient demographics and clinical information were recorded on case report forms, which
were captured in a web-based database, together with isolates information. Streptococcal strains were subjected to the CDC emm-typing procedure.
Results:
We report on 750 samples which were obtained over a 10-year period. A diversity of emm-types were isolated (n=60). The prevalence of the top 5
emm-types circulating in the region were: emm76 (10%), emm81(8%), emm48.1(5%), emm183.2 (5%) and emm44 (4%). When comparing coverage against
the putative 30-valent vaccine under development, 43% of all circulating strains were included in the vaccine, with cross-protection potentially increasing
coverage to 63%.
Conclusion:
This report details epidemiological evidence of the diversity of GAS infections within the South African population. Furthermore, it highlights the
deficiencies in coverage of the 30-valent vaccine as pertaining to Strep A pharyngeal infection. Given the intention to include more sites within South Africa
and Southern African countries (including Namibia, Zambia and Botswana), the AFROStrep registry has tremendous potential to contribute to the prevention
and control of Strep A disease, including rheumatic heart disease.
Selective active shimming to reduce field inhomogeneities eliminates off-resonance and frequency artefacts without the need
for manipulation of the trufi delta frequency
Petronella Samuels, Stephen Jermy, Marcin Jankiewicz, Ernesta Meintjies and Ntobeko Ntusi
University of Cape Town, Rondebosch, Cape Town, South Africa
Introduction:
Balanced steady state free precession (bSSFP) is one of the sequences most susceptible to off-resonance artefacts. The standard approach to
dealing with off-resonance artefacts is to use a frequency scout to determine the ideal delta frequency offset but this technique has several limitations. The
objective of this pilot study was to examine the role of active shimming methods in modulating bSSFP off-resonance artefacts as a substitute to adjusting the
delta frequency.
Methods:
Eleven healthy volunteers were scanned on a 3Tesla Skyra (Siemens, Erlangen Germany) whole-body scanner. Prior to acquisition of cine images,
a frequency scout in the 4-chamber orientation was obtained to determine the delta frequency offset of the scanner. Two sets of cine images were acquired.
For the first set of images, a shim box was positioned over areas of high velocity flow (aorta, pulmonary vessels and superior vena cava) without changing the
trufi delta frequency and the size of the shim box varied according to the size of the vessels in each participant. For the second set of images, the shim box
size was adjusted to cover the entire heart, and the trufi delta frequency was unadjusted. Data analysis was based on visual interpretation.
Results:
From 88 images acquired with a small shim box, only 3 (4%) sequences were not diagnostic. In 2 of the 3 images, artefacts were resolved with a
larger shim box over the entire heart. From 88 images acquired with a large shim box, 29 (33%) images were not diagnostic and in 2 subjects all the data
acquired with a large shim were non-diagnostic (heart rates of 83 and 57bpm, respectively).
Conclusion:
Using a small shim box over the major vessels when acquiring cine images is superior for diminishing artefacts when compared to placement of
a large shim box positioned over the entire heart.