Browsing by Author "Stradiņš, Peteris"

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    Biomechanical properties of human dilated ascending aorta
    (2019-05-01) Brečs, Ivars; Stradiņš, Peteris; Kalejs, Martiņš; Strazdiņš, Uldis; Ozolanta, Iveta; Kasyanov, Vladimir; Rīga Stradiņš University; Biomehānikas zinātniskā laboratorija
    Aneurysms of ascending aorta are dilatation of the first part of the human aorta. They commonly show no clinical symptoms. This condition increases the risk of aorta dissection, which is a life-threatening condition. In this study we attempted to elucidate the changes in the biomechanical properties that occur in the dilated human ascending aorta. Fourteen specimens of ascending aorta wall were mechanically tested under a uniaxial tensile test. Two specimens from each ascending aorta anterior region were cut in longitudinal and circumferential directions. The samples were stretched until rupture of the sample occurred. The obtained experimental data were processed to determine maximal stress, maximal strain and the tangential modulus of elasticity in the linear part of the stress-strain curve. The obtained results showed a remarkable anisotropy of the ascending aorta tissue. We found higher strength of the tissue in the circumferential direction than in the longitudinal direction. There were no statistically significant differences between the strains of the samples. Tangential modulus of elasticity of the aortic samples in the longitudinal direction was significantly lower than the elastic modulus of the samples in the circumferential direction. The tissue in the circumferential direction is stronger and stiffer than in the longitudinal direction.
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    Incidence of permanent pacemaker implantation after cardiac surgery : A single centre experience
    (2019-08-01) Kalējs, Mārtiņš; Prozorovskis, Edgars; Kupics, Kaspars; Brečs, Ivars; Strazdiņš, Uldis; Stradiņš, Peteris; Biomehānikas zinātniskā laboratorija; Rīga Stradiņš University
    Permanent pacemaker implantation (PPI) after open heart surgery is required in 0.4-8.5% of patients. The aim of our study was to determine the incidence of PPI after cardiac surgery at Pauls Stradiņš Clinical University Hospital and to assess its influence on intrahospital outcomes. This was a single-centre retrospective study. We reviewed all patients who underwent either open heart surgery or transcatheter aortic valve implantation (TAVI) between the years 2015 and 2017. Included were all patients with PPI postoperatively before discharge. We compared the patient demographics, and perioperative state, incidence of PPI and intrahospital stay among groups. After cardiac surgery a total of 135 (4.2%) patients received a PPI. The PPI incidence was highest in the tricuspid valve intervention group - 8.8% followed by aortic valve replacement (AVR) patients with 3.3%. After TAVI incidence of PPI was 4.0% after Sapien valve and 8% after CoreValve implantations, respectively. Incidence of PPI after TAVI with the Sapien valve was not significantly higher when compared to conventional AVR, but it was significantly higher after TAVI with CoreValve. Regardless of the initial procedure a need for PPI significantly increased the total length of hospital stay.
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    Transcatheter vs. surgical closure of atrial septal defects in adults
    (2018-02) Rudzītis, Ainars; Šablinskis, Kristaps; Luriņa, Baiba; Cgojeva-Sproge, Irina; Grave, Aļona; Dombrovskis, Andis; Stradiņš, Peteris; Erglis, Andrejs; Rīga Stradiņš University
    Percutaneous transcatheter device closure of secundum atrial septal defects (ASD) has now largely replaced surgical closure in most centres. The aim of this study was to compare results of transcatheter and surgical ASD closure in adults in Latvia during the years 2002-2014 and to analyse long-term outcomes of transcatheter closure. We analysed data from 334 patients with secundum ASD who underwent ASD closure in Pauls Stradiņč Clinical University Hospital. Patients were included into device or surgical closure groups. In the device group, three follow-ups were made 1, 6, and 12 months after the procedure. No follow-up data were available for surgical arm patients beyond their hospitalisation period. The mean age of patients was 45.3 ± 19.9 years for the device group and 40.0 ± 16.9 years for the surgical group (p = 0.023). The mean secundum ASD size in the device and surgical groups was 14.2 ± 5.6 mm and 28.7 ± 10.0 mm, respectively (p < 0.001). No differences were observed regarding procedure success rates: 99.2% in the device group and 100% in the surgical group (p = 0.451). Periprocedural complications generally were more common in the surgical closure group. The study results show a successful introduction of the percutaneous ASD closure method in Latvia with good early and late outcomes and without significant differences in procedure success rate compared to surgical closure.