Intravascular ultrasound assessment of blood vessel morphology

Intravascular ultrasound (IVUS) is an invasive imaging technique, characterized by the ability to depict the tomographic section of blood vessels’ lumen and wall. Thus, it enables the performance of a unique in-vivo assessment of the luminal area and three-layer wall morphology, as well as atherosclerosis within the vessel. The typical composition of an IVUS image and the measurements of observed structures have been shown to correlate well with histology and angioscopy in several in vitro studies. The existing data on intravascular imaging of the aorta are scant. In this study, the preliminary results of in-vitro IVUS examination of human descending aorta morphology are presented, with reference to the corresponding histological section

Effect of exogenously added rhamnolipids on citric acid production yield

The influence of a biosurfactant (rhamnolipids) on the effectiveness of citric acid production by Yarrowia lipolytica from sunflower oil was studied. The surfactant-mediated solubilization of the hydrophobic substrate was assessed by particle size distribution characteristics with and without the presence of sunflower oil hydrolization products. The presence of rhamnolipids contributed to a decrease of the oil droplet size, most notably for samples containing sunflower oil and its hydrolization products. The citric acid yield for cultures not supplemented with rhamnolipids was at 82.9 g/l, with a 1:0.04 citric acid to isocitric acid ratio (CA:ICA). The addition of rhamnolipids at 1 g/l resulted in a 5% increased citric acid yield (87.1 g/l), however a decrease (79.0 g/l) was observed for samples containing 5 g/l of rhamnolipids. The rhamnolipids-induced emulsification of sunflower oil did not seem to influence the citric acid production efficiency. Additional research revealed that the biosurfactant was degraded by yeast cells during the bioconversion process. The possible explanations of this phenomenon include the utilization of rhamnolipids as an alternative carbon source or microbial destabilization of micelles formed by this biosurfactant due to potential bioavailability issues.Keywords: Yarrowia lipolytica, citric acid, rhamnolipids, sunflower oilAfrican Journal of Biotechnology Vol. 12(21), pp. 3313-332

Zastawki serca po 22 latach - prawidłowy obraz homograftu aortalnego, zaawansowane wady ujść przedsionkowo-komorowych

We report a case of a 61-year-old female patient with a history of aortic valve replacement, who was admitted to our hospital with symptoms and signs of decompensated heart failure (NYHA class III). Transthoracic echocardiogram revealed mitral valve and tricuspid valve regurgitation (III grade) with normal function of aortic valve homograft implanted 22 years ago. The patient underwent cardiosurgical mitral valve replacement and tricuspid valve annuloplasty with very good result. An aortic valve homograft may be the best alternative to a mechanical valves for a young female patients

Ocena zaburzeń oddychania w czasie snu z wykorzystaniem rejestracji holterowskiej u pacjentów z tętniczym nadciśnieniem płucnym oraz nadciśnieniem płucnym wtórnym do dysfunkcji lewej komory serca

Introduction. Sleep-disordered breathing (SDB) affects approximately 2–12% of the general population and the prevalence among patients with heart failure due to left ventricular dysfunction (LV–HF) is even higher. SDB is an important determinant of worse clinical outcomes in such patients. In contrast, the prevalence of SDB in pulmonary arterial hypertension (PAH) and its implications remain unclear. The purpose of this study was to compare relations between estimated apnea-hypopnoea index (eAHI) and clinical parameters in patients with LV–HF and PAH, with particular attention to the consequences of SDB.Material and methods. Eighty-one patients were screened for SDB using commercial Holter electrographic monitoring software that allowed evaluation of eAHI. The study population consisted of 39 LV–HF patients and 42 PAH patients. Results. While similar N-terminal pro B-type natriuretic peptide (NT-proBNP) levels were noted in both groups, LV–HF patients were characterized by higher age (63 vs. 50 years, respectively, p < 0.001), higher proportion of males (87% vs. 40%, p < 0.0001), and higher eAHI (24 vs. 14, p < 0.001) and body mass index (BMI) (28 vs. 25 kg/m2, p < 0.001) values compared to the PAH group. The prevalence of SDB, defined as eAHI > 15, was 64% in the LV–HF group and 36% in the PAH group. Parameters of time domain heart rate variability (HRV) analysis were lower in PAH vs. LV–HF. Patients with LV–HF had more ventricular arrhythmias than patients with PAH. In the LV–HF group, eAHI correlated positively with NT-proBNP level, and negatively with left ventricular ejection fraction and the mean heart rate. The median eAHI was 18.7, and patients with eAHI above the median had more supraventricular arrhythmias. In the PAH group, a negative correlation between eAHI and age was found. In the subgroup with eAHI < 15, rMSSD values were higher and idiopathic PAH predominated. The median eAHI was 8.4, and patients with eAHI above the median were younger and had higher BMI values. Conclusions. Sleep-disordered breathing was more frequent and eAHI was higher in patients with LV–HF compared to those with PAH, although it was present in more than one third of patients in the latter group. Higher eAHI values indicated more severe hemodynamic dysfunction in patients with LV–HF. In the PAH group, higher eAHI was associated with clinical presentation at a younger age. Patients with PAH seem to have worse HRV parameters compared to patients with left ventricular dysfunction.Wstęp. Zaburzenia oddychania w czasie snu (SDB) dotyczą 2–12% ogólnej populacji; jeszcze wyższy odsetek obserwuje się wśród pacjentów z niewydolnością serca spowodowaną dysfunkcją lewej komory (LV–HF). Występowanie SDB w tętniczym nadciśnieniem płucnym (PAH) oraz jego implikacje kliniczne pozostają niejasne. Celem pracy było porównanie relacji między oszacowanym wskaźnikiem bezdechu sennego (eAHI) a parametrami klinicznymi pacjentów z LV–HF i PAH, z uwzględnieniem konsekwencji obecności bezdechu sennego.Materiał i metody. Do badania włączono 81 chorych, u których wykonano 24-godzinne monitorowanie elektrokardiograficzne metodą Holtera w celu obliczenia eAHI. Populację podzielono na dwie grupy — 39 chorych z LV–HF o etiologii wieńcowej oraz 42 chorych z PAH.Wyniki. W grupie LV–HF dominowali mężczyźni (87% v. 40% w grupie PAH; p < 0,0001), w starszym wieku (63 v. 50 lat w grupie PAH; p < 0,001), z wyższymi wartościami wskaźnika masy ciała (BMI) (28 v. 25 kg/m2; p < 0,001) oraz niższą frakcją wyrzutową lewej komory (LVEF) (33 v. 56%; p < 0,000001), choć grupy charakteryzowała podobna średnia wartość stężenia N-końcowego fragmenty propetydu natriuretycznego typu B (NT-proBNP). Zaburzenia oddychania w czasie snu, zdefiniowane jako eAHI ponad 15, stwierdzono u 64% chorych z LV–HF i u 36% pacjentów z PAH. Wyższe wartości eAHI występowały w grupie LV–HF (24 v. 14; p < 0,001). Pacjenci z LV–HF cechowali się obecnością licznych arytmii komorowych, a przy wartościach eAHI powyżej mediany (> 18,7) potwierdzono zwiększoną częstość występowania arytmii nadkomorowej. W PAH obserwowano istotnie obniżone parametry czasowej zmienności rytmu zatokowego (HRV). W grupie LV–HF wykazano korelację eAHI z wartościami NT-proBNP i odwrotną korelację z LVEF oraz średnią dobową częstotliwością pracy serca. Z kolei eAHI w grupie chorych z PAH nie korelowało z NT-proBNP ani LVEF, ale było odwrotnie proporcjonalne do wieku. Wśród chorych z PAH i wartościami eAHI poniżej 15 przeważali pacjenci z PAH o etiologii idiopatycznej, z wyższymi wartościami rMSSD. Pacjentów z PAH i wartościami eAHI powyżej mediany (> 8,4) charakteryzowały młodszy wiek oraz wyższe wartości BMI.Wnioski. Zaburzenia oddychania podczas snu u pacjentów z PAH nie były tak częste jak u chorych z LV–HF, ale dotyczyły więcej niż 1/3 populacji. Wyższe wartości eAHI u chorych z LV–HF wskazują na zaawansowaną dysfunkcję hemodynamiczną. U pacjentów z PAH obecność SDB wiąże się z zachorowaniem w młodszym wieku i wskazuje na istotną dysregulację w zakresie autonomicznej kontroli pracy serca

Relationship between echocardiographic parameters and exercise test duration in patients after myocardial infarction

Background: The interdependence between echocardiographic parameters of left ventricle function, severity of heart failure (HF) and exercise test duration has not been thoroughly examined. Methods: We compared echocardiographic data in patients after myocardial infarction divided according to NYHA class to mild (class I and II, group 1 = 24 subjects) and advanced HF group (III and IV, group 2 = 36) and assessed their correlation with exercise duration (ED) in a symptom-limited treadmill test. Then we tried to determine independent predictors of ED. Results: The group with advanced HF had lower left ventricle ejection fraction, shorter duration and deceleration times of both mitral inflow waves (Et and At, Edt and Adt) and higher E/A ratio (1.4 &#177; 1.1 vs. 0.9 &#177; 0.4; p < 0.05) with more frequent restriction and pseudonormalization pattern (56% vs. 12%). Also early wave propagation (21 &#177; 7 vs. 29 &#177; 11 cm/s; p < 0.001) and all tissue Doppler velocities were lower, but ratio of early wave peak velocity to early diastolic velocity of mitral annulus was higher (E/E&#8217; 10.5 &#177; 5 vs. 6.1 &#177; 1.3 for velocity ratio; p < 0.001) in subjects with more severe clinical symptoms. Significant negative correlation with ED was observed for difference between duration of pulmonary vein atrial reversal flow and atrial wave of mitral inflow (&#8710;At; r = &#8211;0.54) and for E/E&#8217; ratio (r = &#8211;0.48), the highest positive correlation for left ventricular ejection fraction and duration of mitral inflow atrial phase (EF; r = 0.48, At; r = 0.46). In multivariate stepwise regression analysis two independent predictors of ED were identified: age and &#8710;At (Art&#8211;At). Conclusions: Diastolic parameters showing the strongest correlation with ED (&#8710;At and E/E&#8217;) are connected with restrictive left ventricle physiology. The only independent predictors of exercise duration in patients after myocardial infarction were: age and &#8710;At

Skrajnie poszerzony lewy przedsionek u chorej ze stenozą mitralną

W pracy przedstawiono przypadek chorej ze zwężeniem zastawki mitralnej i ze skrajnym poszerzeniem lewego przedsionka, ocenianym w badaniu echokardiograficznym. Pomimo znacznego zaawansowania patologicznych zmian serca, dotychczasowy przebieg kliniczny u pacjentki charakteryzuje się stosunkowo umiarkowanym nasileniem objawów. Z uwagi na morfologię uszkodzonej zastawki w ramach dalszego postępowania istnieją wskazania do przeprowadzenia przezskórnej walwotomii balonowej. (Folia Cardiol. 2003; 10: 707-709