Biomedical subjects

Rimantas Benetis

Publications and source records attributed to Rimantas Benetis.

32 records · Page 2Linked to original sources

PubMed2004

[Effect of pyruvate on the dependence of electromechanical activity on stimulation frequency in human myocardium].

The aim of the study was to determine the effect of pyruvate, a substrate of energetic metabolism, on the dependence of electromechanical activity on stimulation frequency in human myocardium. The experiments were performed on human ventricle myocardium from patients undergoing cardiac corrective open heart surgery at Clinic of Cardiac Surgery in Kaunas University of Medicine by using standard method of registration of myocardium electromechanical activity. The stimulation frequency of myocardial strips were 0.2, 0.5, 1.0, 1.5, 2.0, 2.5 and 3 Hz, duration of pulses -2-5 ms. In control, i.e. at perfusion of mycoardial strips by Tyrode solution and stimulation frequency 1 Hz, an average of contraction force (P) was 0.94+/-0.18 mN (n=12), half time of relaxation (t(a)) - 178.88+/-9.31 ms (n=12), and action potential duration measured at 50% repolarization level (VP(50)) - 294.75+/-27.95 ms (n=9). Pyruvate (10 mM) increased P to 159.9+/-13.4% (p<0.00), t(a)- 106.9+/-2.2% (n=12) (p<0.001), and VP(50)- 111.1+/-7.4% (n=5) (p<0.05), as compared to control. In the absence of pyruvate values of P, t(a) and VP(50) of myocardial strips were higher at 0.2 Hz and 0.5 Hz and lower at 3 Hz compared with those at 1 Hz of stimulation frequency. Although the dependence of these parameters on stimulation frequency in the presence of pyruvate (10 mM) was not altered but their values were persistently increased at all stimulation frequencies. The present data indicate that pyruvate is an effective inotropic agent, which can improve contractility function in wide-ranging diapason of stimulation frequency in failing human heart.

Action Potentials↗

PubMed2003

[Combined coronary artery bypass grafting and carotid endarterectomy: early postoperative results and perspectives].

OBJECTIVE: The aim of this study was to review early postoperative results of the combined coronary artery bypass grafting and carotid endarterectomy (CABG/CEA) performed at the Clinic of Cardiac Surgery Heart Center of Kaunas University of Medicine. MATERIAL AND METHODS: A series of consecutive 19 patients (64.5+/-8.2 years old, 17 (89.5%) male patients) with coexisting severe ischemic cardiac and carotid artery disease were operated on during 8-year period ending December 2001. Seven (36.8%) patients with carotid artery stenosis were asymptomatic. Previous neurological events had occurred in 12 (63.2%) patients: five (26.4%) patients presented with a previous stroke, seven (36.8%) - with a transient ischemic attack. Demographics and perioperative variables of these patients were compared with variables of 42 patients, that underwent isolated CABG during this period (control group). RESULTS: After introducing of the routine preoperative screening carotid ultra-sonography in the year 2000, the rate of asymptomatic carotid artery stenosis among all diagnosed hemodynamically significant carotid stenoses has raised up to 43.8%. The in-hospital results were similar between the two groups with regard to 30-day perioperative mortality, stroke and major postoperative complications. CONCLUSIONS: Based on our results, combined interventions of CEA and CABG can be performed with an acceptable morbidity and mortality when severe carotid stenosis is associated with advanced, symptomatic ischemic heart disease. Patients with total occlusion of the carotid artery compose a high-risk subgroup for perioperative stroke. The introduction of routine preoperative carotid duplex scanning resulted in higher rate of asymptomatic carotid artery disease among the patients scheduled for combined CABG/CEA procedure.

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PubMed2003

[Influence of surgery on survival in infective endocarditis].

An impact of surgery for infective endocarditis on survival and heart failure has been analyzed. A total of 131 patients with IE have been observed during 1999-2001. Eighty seven of them were male and 44 female, mean age - 50+/-16 years. Sixty three (48.1%) patients underwent surgery, remaining 68 (51.9%) were treated conservatively. The surgical patients had signs of remarkably worse heart failure (p=0.0001), higher grade aortic (p=0.0001) and mitral (p=0.001) valve regurgitation. Surgery resulted in significant improvement of heart failure (p=0.01). Hospital mortality was 25.2% and did not differ between the groups. Elimination of the influence of complications revealed reduced hospital mortality of all patients by 9.9% and mortality of NYHA III-IV patients by 23.9% (p=0.02) as a result of surgery.

Adult↗

PubMed2003

[Surgeon's view on optimal anesthesia].

Technological development, implementation of new techniques and scientific knowledge into clinical practice, has a strong impact on development of surgical and anesthesiological professions. However, it creates new and unknown ethical issues within surgeons-anesthesiologist and their patient's relationship. Development of physiological-individualized anesthesia techniques focused on patient's outcome unquestionably is related to more general organizational ethical issues. Presented article analyzes factors influencing unavoidable, concomitant development of surgical and anesthesiological professions. It also addresses several ethical issues within the context of society development. There is a body of evidence ascribing identities of profession and different attitudes as well as interpretations of inter specialty relations. There is a need for constant discussion between the specialty representatives groups elaborating professional recommendations for further co-operation accepted by both sides.

Anesthesia↗

PubMed2002

[Simultaneous myocardial revascularization and abdominal aortic aneurysm repair (report of a fatal case)].

Patients with coronary disease associated with abdominal aortic aneurysm or aortoiliac occlusive disease often raise problems of operative strategy. In particular, the order in which these lesions should be treated is a frequent source of controversy. Our approach for the past two years has been a combined myocardial revascularization with abdominal aortic reconstruction in patients with both lesions. From 1999 through 2001 seven patients underwent combined abdominal aortic reconstruction with coronary artery bypass grafting. We report here the fatal case of combined coronary artery bypass grafting and abdominal aortic aneurysm repair. Partial heparinization and operation without extracorporeal circulation caused acute thrombosis of abdominal aortic aneurysm and femoral arteries. Our first experience advocates using total heparinisation and cardiopulmonary bypass for combined cardiac-aortic procedures.

Aortic Dissection↗

PubMed2002

[Initial results of left ventricular remodelling operations].

UNLABELLED: The aim of our study was to evaluate the initial results of left ventricular CABG and left ventricular remodelling operations. Study group consisted of 47 patients (pts) who underwent left ventricular geometry and volume restoration operations at the Kaunas University of Medicine Hospital during 1996 to 2002. Protocol included general clinical data, NYHA functional class, pre- and postoperative echocardiographic data, left ventricular aneurysm repair procedures. Pts mean age was 63.4+/-1.2 years. Men/women ratio 38/9. At admission NYHA functional class was 3.5+/-0.1. Mean left ventricular ejection fraction preoperatively was 24.2+/-0.9%, LV end diastolic diameter - 60.3+/-1.2 mm. Correction of left ventricular aneurysm consisted of: 1) direct aneurysmectomy - 11 pts, 2) endoventricular patch plasty - 7 pts, 3) circular suture - 19 pts, 4) aneurysmal reinforcement - 10 pts. RESULTS: Early postoperative NYHA functional class decreased from 3.5+/-0.1 to 2.8+/-0.1 (p<0.0001) and late postoperative to 2.7+/-0.2 (p<0.0001). Within 2 weeks LV morphometric parameters, left ventricular ejection fraction, mean pulmonary artery pressure didn't change significantly. There was a significant reduction of mitral regurgitation in all survivals from grade 2.5+/-0.1 to 1.4+/-0.2 (p<0.0001). Hospital mortality - 25.5%, late mortality - 22.2%. Late postoperative LV end diastolic and systolic diameters had a tendency to increase. All of the patients showed late postoperative increase in deceleration time from 0.13+/-0.01 to 0.18+/-0.02 s (p<0.05), decrease in degree of MR from 2.6+/-0.1 to 1.8+/-0.3 (p<0.05). LV systolic function has a tendency to increase from 25.6+/-1.4 to 29.1+/-1.4. In conclusion, effective LV surgical remodelling combined with CABG improves pts functional status: NYHA functional class, LV diastolic function. But the results of these combined cardiac operations are not so excellent. The hospital mortality remains high, correction of LV morphometric parameters is not preferable.

Adult↗

PubMed2002

[Contraversions of simultaneous coronary artery bypass grafting, abdominal aorta and major vascular operations].

OBJECTIVE: Patients with coronary artery disease associated with peripheral vascular disease often raise problems of operative strategy. Particularly the sequence of procedures in which lesions must be treated is a frequent source of controversy. The aim of this study was to research surgical strategy, early and late clinical outcomes for patients undergoing one-stage coronary and abdominal aortic or magistral artery surgical interventions. MATERIAL AND METHODS: From 1999 through 2002 twenty eight patients underwent combined major vascular reconstruction with coronary artery bypass grafting. RESULTS: In group with abdominal aortic aneurysm 2 patients died. One patient died from intraoperative acute abdominal aortic aneurysm and bifemoral artery thrombosis with continuous bleeding from the vascular prosthesis in association with disseminated intravascular coagulation. Another patient died from bleeding from the sudden multiple gastroduodenal ulcers on post-operative day eight. In groups with peripheral vascular occlusive disease and carotid artery disease there were no deaths. CONCLUSIONS: The data show that combined coronary artery bypass grafting and vascular operations are feasible on patients with concomitant carotid artery or peripheral vascular occlusive disease. Management of CAD associated with abdominal aortic aneurysm remains controversial.

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PubMed2002

[Late results of minimally invasive operations of myocardial revascularization].

Minimally invasive operations of myocardial revascularization (MIMR) are done using usual approaches, but without extracorporeal circulation and cardioplegia. Doing these operations according to indications, there is no difference in early results of these operations and the operations with extracorporeal circulation and extracorporeal circulation (1, 2). OBJECTIVE. To evaluate the late results of minimal invasive operations of myocardial revascularization 1 year after intervention, according to detection of patient's functional class, findings of echocardiography and stress test. Also to compare the results of operations in patient's groups of age up to 65 years old and over 65 years old. MATERIAL AND METHODS. From 88 patients, that underwent minimal invasive operations of myocardial revascularization, 34 patients were checked according to investigation protocol, evaluating functional class, myocardial contractility and stress test tolerance. The late results of two different groups of age were compared (each group includes 17 cases). RESULTS. All patients have survived 1 year after operation. Findings of stress test showed, that 60% of patients have reached 100 W and more strain tolerance. Pectoral angina was detected in 12% of cases. There was no difference, that was improved statistically in findings of myocardial contractility before and after operation. CONCLUSIONS. Evaluating the late results of minimally invasive operations of myocardial revascularization (1 year after operation), we can consider, that these operations, that were done according to indications, are improved, safe and suitable also to elderly patients.

Age Factors↗

PubMed2002

[Clinical, functional and prognostic evaluation of ischemic mitral insufficienty surgical correction].

UNLABELLED: The aim of our study was to evaluate the patients' (pts) survival, changes of functional status after repair of ischemic mitral insufficiency (IMI) and to determine their prognostic determinants. Study group consisted of 128 pts who underwent mitral valve (MV) repair for IMI at Kaunas University of Medicine hospital during 1996 to 2002. Study protocol included general clinical data, coronary artery involvement, patients NYHA functional class, pre, post and operative echocardiographic data, mitral valve repair procedures. RESULTS: There was a significant reduction of MR in all survivals from grade 2.8+/-0.1 to 1.5+/-0.1 (p<0.0001). All of the patients showed late postoperative increase in LVEF from 32.2+/-1.0 to 37.1+/-1.1% (p<0.0001). Late postoperative NYHA functional class changed significantly from 3.3+/-0.1 to 2.3+/-0.1 (p<0,0001). Two-year years survival without heart failure was 51.6+/-7.9%. Prognostic markers of late postoperative heart failure (II-IV NYHA functional class): LVEF</=24% and residual MR>/=II grade late postoperatively. Two-year years survival without residual MR was 51.1+/-7.8%. Predictors of late residual MR are early residual MR>I grade (p<0.0001), LVEF<30% early postoperatively (p<0.0001) and LVEDDI late postoperatively >/=28 mm/m(2) (p<0,01). Hospital mortality - 17.2%, late mortality - 7.9%. Two and four-year years survival after combined heart surgery - 66.7%. CONCLUSIONS: Repair of IMI - effective method in treating ischemic heart disease complicated with MV regurgitation: late postoperatively patients functional status improves, LVEF increase. Prognostic markers of late postoperative heart failure (II-IV NYHA functional class) are: LVEF</=24% and residual MR>/=II grade late postoperatively.

Actuarial Analysis↗

PubMed2002

[Retrospective evaluation with Euroscore of postoperative mortality after coronary artery bypass grafting].

OBJECTIVE: This retrospective study was undertaken to evaluate the accuracy of risk-adjusted EuroSCORE models in predicting mortality in individual patients who are undergoing coronary artery bypass grafting. MATERIAL AND METHODS: The study population is a consecutive series of 1698 isolated primary and repeat coronary artery bypass grafting patients, inclusive patients in cardiogenic shock or resuscitation, operated in Kaunas Heart Center from January 1997 to December 2001. The pre-operative risk of death was calculated with EuroSCORE models and then compared with the actual outcome. The accuracy score was used to evaluate the reliability of each score to predict the individual outcome. The studied event was in-hospital death, defined as mortality during hospital stay, which was unlimited in time and included a stay in a secondary hospital without discharge home. RESULTS: Eighty deaths (4.7%) were observed. The age of this patients was 66.0+/-9.5 years, 73.7% were male and 3.7% were repeat procedures. In most patients who died the mean predictive scores were high. The EuroSCORE average was 11.0+/-4.3, with a range from 3 to 21. CONCLUSIONS: The EuroSCORE presurgical predictive models were highly accurate to predict overall mortality, but were inaccurate to predict mortality in individual patients.

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PubMed2002

[The first clinical experience and technical peculiarities of mitral valve homograft implantation].

INTRODUCTION: Surgical interventions because of mitral valve disease have been ascribed since 1951. Many changes within mitral valve replacement have passed including closed and open mitral commissurotomy, mitral valve repair operations implantation of mechanical, biological heart valve and finally use of mitral valve homograft. Despite changes in chirurgical tactics and medico-technical environment, mitral valve homograft implantation remains one of the most complex surgical interventions. Surgical and technical details of mitral valve homograft implantation are discussed. OBJECTIVE: to estimate technical difficulties and anatomical positioning of mitral valve homograft considering a spectrum of indications of mitral valve replacement. CASE REPORT: 62-year-old woman 26 years ago underwent mitral valve replacement with Starr-Edwards mitral valve prosthesis, because of rheumatic heart disease by homograft. Due to malfunction of the mitral valve prosthesis, and progressive left ventricular failure patient was reoperated on 26(th) of February 2002. Fresh antibiotic preserved mitral valve homograft was implanted. Surgical techniques were guided using left ventricle size measurement indicated by echocardiography. RESULTS: The technique described by Acar/Carpentier was used except of mitral valve annuloplasty ring implantation. Peri- and early postoperative period was free of homograft related complications. The left ventricle function was improving and the heart size decreased dramatically during first postoperative week. CONCLUSION: The most important peculiarities for mitral valve homograft implantation are echocardiography data and intraoperative left ventricle measurements. Homograft implantation techniques are rather demanding therefore indications for mitral valve replacement have to be selected carefully and should be based on the presence of severe mitral valve dysfunction in order to achieve best hemodynamic results and prevent patient from anticoagulation therapy.

Echocardiography↗

PubMed2002

[Coronary atherosclerosis and blood groups of ABO system in women (own data and review)].

UNLABELLED: Earlier we have shown significantly more frequent B blood group and a significantly more rare O blood group of ABO blood group system in men aged under 45 years suffering from coronary atherosclerosis compared with these frequencies in the population of Lithuania. The aim of the study was to investigate the frequency of blood groups of ABO system in women with coronary atherosclerosis. MATERIALS: The frequency of the ABO blood groups was examined in 441 women, suffering from coronary atherosclerosis, divided into two groups: I group - 109 women till 60 years old (mean age 55.1+/-4.8) and II group - 332 women aged over 60 years (mean age 68.1+/-5.0). For all patients coronary atherosclerosis was diagnosed by coronary angiography and confirmed during coronary bypass surgery. The frequency of the ABO blood group in the studied pts was compared with the frequency of the blood group in the control group of healthy blood donors (n=595). To evaluate the significance of data, we compared the frequency of ABO blood groups with the data in women long-livers (n=75, mean age 94.1+/-3.8). Earlier our studies showed that long-livers are an important antiatherosclerotic control group for evaluation of the genetic markers of atherosclerosis. RESULTS: The O blood group was found significantly more rarely in the women group I as compared to that of healthy donors group (28.4% vs 38.2%, p<0.04). The B blood group was significantly more often in group II (22.9% vs 15.0%, p<0.04) compared with the frequency of the B blood group in the healthy donors' group. In the long-livers' group the frequency of the B group was significantly more rare than in healthy donors (6.7% vs 15%, p<0.01) as well as in the groups of tested pts (20.2% and 22.9% respectively, p<0.01). We did not find any significant changes in the frequency of AB blood group in women with coronary atherosclerosis. CONCLUSIONS: The B blood group can be related with coronary atherosclerosis in women. The O blood group can possibly serve as a protective antiatherogenic factor in women. The A blood group is not a risk factor for atherosclerosis in women in Lithuanian population. Long-livers are an important antiatherogenic control group for evaluation of atherogenetic markers of coronary atherosclerosis.

ABO Blood-Group System↗

PubMed2002

[Timing of surgery in infective endocarditis: impact on the outcome and recurrence].

Timing of surgery in infective endocarditis remains a challenge in the face of potential drug toxicity on one hand and recurrence of endocarditis on the other. The aim of the study was analysis of risk factors for hospital mortality and recurrent endocarditis. A total of 131 patients with infective endocarditis have been observed during 1999-2001. Eighty seven of them were male and 44 female with mean age of 50+/-16 years. Sixty three (48.1%) patients underwent surgery, remaining 68 (51.9%) were treated conservatively. Hospital mortality was 25.2%. Postoperative perivalvular leak was associated with culture negative endocarditis (p=0.09) as well as with positive valve culture (p=0.04). Recurrence was related to positive valve culture (p=0.08) and embolism (p=0.02). Increased risk of death was associated with neurologic, embolic, renal complications, myocardial abscess, NYHA IV f.cl. and extracardial surgery. According to the data obtained, optimal surgery time in the group appeared to be between 17 and 45 days after the diagnosis of infective endocarditis has been made (p=0.049).

Adult↗

PubMed2002

[Central nervous system complications after coronary artery bypass grafting].

OBJECTIVE: The aim of this prospective study was to review incidence of neurological and cognitive complications after coronary artery bypass graft surgery and find out predictive factors, associated with perioperative cerebral dysfunction. MATERIAL AND METHODS: A prospective pilot study of 35 (27 men and 8 women, mean age 64.5+/-4.3 year) patients with identified coronary artery disease was conducted using Case Report data collection document. All patients underwent isolated elective CABG procedure at Cardiac center of Kaunas University of Medicine Hospital. RESULTS: There were two cases (5.7%) of postoperative transient ischemic attack, two cases (5.7%) of restless agitation with delirium, characterised as an postoperative encephalopathy and eight patients (22.8%) with cognitive abnormalities. CONCLUSIONS: The Canadian Stroke Scale and The Confusion Assessment Scale are sensitive and objective methods for diagnostics of postoperative neurological dysfunction. To characterize the incidence and severity of neuropsychological dysfunction, a concise battery of neuropsychologic tests that provides reliable evidence of subtle brain trauma should be used.

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