A Short-Term In Vivo Evaluation of the Istanbul Heart Left Ventricular Assist Device in a Pig Model.

OBJECTIVES: A continuous-flow centrifugal blood pump system has been recently developed as an implantable left ventricular assist device for patients with endstage heart failure. The objective of this study was to evaluate the initial in vivo performance of a newly developed left ventricular assist device (iHeart or Istanbul heart; Manufacturing and Automation Research Center, Koc University, Istanbul, Turkey) in an acute setting using a pig model. MATERIALS AND METHODS: Three pigs (77, 83, 92 kg) received implants via a median sternotomy, with animals supported for up to 6 hours. An outflow cannula was anastomosed to the ascending aorta. Anticoagulation was applied by intravenous heparin administration. During the support period, pump performance was evaluated under several flow and operating conditions. All pigs were humanely sacrificied after the experiments, and organs were examined macroscopically and histopathologically. RESULTS: Flow rate ranged between 1.5 and 3.6 L/min with pump speeds of 1500 to 2800 revolutions/min and motor current of 0.6 to 1.3 A. Initial findings confirmed thatthe iHeart ventricular assist device had sufficient hydraulic performance to support the circulation. During the experimental period, plasma free hemoglobin levels were found to be within normalranges.Thrombus formation was not observed inside the pump in all experiments. CONCLUSIONS: The iHeart ventricular assist device demonstrated encouraging hemodynamic performance and good biocompatibility in the pig model for use as an implantable left ventricular assist device. Further acute in vivo studies will evaluate the short-term pump performance prior to chronic studies for long-term evaluation.

Fine-tuning management of the Heart Assist 5 left ventricular assist device with two- and three-dimensional echocardiography.

INTRODUCTION: Left ventricular assist device (LVAD) implantation is a viable therapy for patients with severe end-stage heart failure, providing effective haemodynamic support and improved quality of life. The Heart Assist 5 (Micromed Cardiovascular Inc, Houston, TX) continuous-flow LVAD has been on the market in Europe since May 2009. METHODS: We evaluated nine Heart Assist 5 LVAD patients with two- and three-dimensional transthoracic echocardiographic (TTE) and transoesophageal echocardiographic (TEE) parameters between December 2011 and December 2013. The pre-operative TTE LVAD evaluations included left ventricular (LV) function and structure, quantification of right ventricular (RV) function and tricuspid regurgitation (TR), assessment of aortic and mitral regurgitation, and presence of patent foramen ovale and intra-cardiac clots. Peri-operative TEE determined the inflow cannula and septum position, and assessed the de-airing process while weaning from cardiopulmonary bypass. Post-operative serial follow-up TTE showed the surgical results of LVAD implantation, determined the overall structure and function of the LV, RV and TR, and observed the inflow and outflow cannula position. RESULTS: Nine patients who had undergone Heart Assist 5 LVAD implantation and had been followed up for more than 30 days were included in this study. Eight patients had ischaemic cardiomyopathy and one had adriamycin-induced cardiomyopathy. Pre-implantation data: the mean age of the patients was 52 ± 13 (34-64) years, mean body surface area (BSA) was 1.8 ± 0.2 (1.6-2.0) m2, mean cardiac index (CI) was 2.04 ± 0.4 (1.5-2.6) l/min/m2, mean cardiac output (CO) was 3.7 ± 0.7 (2.6-4.2) l/min, mean ejection fraction (EF) was 23 ± 5 (18-28)%, and right ventricular fractional area contraction (RVFAC) was 43 ± 9 (35-55)%. One patient had aortic valve replacement (AVR) during the LVAD implantation, and excess current alarms and increased power were suspected to be caused by a possible thrombus. Close follow up with TTE studies were carried out to clear the LV of thrombus formation, and the inflow cannula position was checked to maintain the septum in the midline, so preventing the suction cascade. Four patients were followed up for more than two years, and two were followed up for more than a year. Three patients died due to multi-organ failure. Follow-up speed-change TTE studies of six patients showed that the mean speed was 9 800 ± 600 (9 500-10 400) rpm, and mean CO was 4.7 ± 0.3 (4.3-5.0) l/min during the three-month post-implant period. CONCLUSION: We believe that TTE can play a major role in managing LVAD patients to achieve optimal settings for each patient. A large series is mandatory for assessment of echocardiographic studies on Heart Assist 5 LVAD.

Cardiac involvement of primary hyperoxaluria accompanied by non-compaction cardiomyopathy and patent ductus arteriosus.

Primary hyperoxaluria is a rare hereditary metabolic disorder resulting in accumulation of calcium oxalate in visceral organs, including the heart. We report a 19-year-old male with non- compaction cardiomyopathy combined with patent ductus arteriosus awaiting combined liver-kidney transplantation for primary hyperoxaluria. After surgical closure of the patent ductus arteriosus, the patient underwent a successful renal and subsequent liver transplantation. The presence of hypertrophic cardiomyopathy in hyperoxaluria patients has been reported before, but this is the first report of non-compaction myocardium with patent ductus arteriosus in a patient with primary hyperoxaluria. At the third month after combined liver and renal transplantation, improvement in cardiac functions were observed. Primary hyperoxaluria is a clinical entity to be taken into consideration in differential diagnosis of hypertrophied myocardium with high myocardial echocardiographic intensity. In cases of hyperoxaluria, additional congenital abnormalities may complicate the clinical picture.

Myocardial integrated ultrasonic backscatter for early detection of cardiac involvement in patients with Wilson disease.

BACKGROUND/AIMS: Videodensitometry is a feasible noninvasive ultrasound tissue characterization method allowing early detection of myocardial changes. This study aimed to investigate ultrasonic backscatter properties of the myocardium in Wilson disease patients. MATERIALS AND METHODS: We compared cardiologically asymptomatic Wilson disease patients (W group) (n=18) with age-matched (26.7±9.6 years) healthy controls (C group) (n=15). Diagnosis of Wilson disease was made on the basis of clinical manifestations, family history, and laboratory findings and confirmed by liver biopsy. Transthoracic echocardiographic quantitative texture analysis was performed on data from the septum and left ventricular posterior wall, and mean gray level (MGL) histograms at end-diastole (d) and end-systole (s) were obtained after background correction (c). Cyclic variation index (CVI) was calculated using the formula [(cMGLd - cMGLs) / cMGLd] ×100. RESULTS: There were no significant differences in sex, age, body mass index, heart rate or blood pressure, and conventional echocardiographic parameters between the 2 groups. The cMGLs value of the posterior wall was higher in the W group than in the C group (30.9±2.6 vs. 22.2±2.7, p=0.033). The W group had a significantly lower CVI of the septum than did the C group (-22±4.4% vs. 43.4 ±12.9%, p<0.001), and there was no significant difference in the CVI of the posterior wall (-67.0±15.9% vs. 41.7±18.6%, p=0.32). CONCLUSION: Abnormalities in two-dimensional echocardiographic grey-level distributions were present in Wilson disease patients. These videodensitometric myocardial alterations were significantly lower in Wilson disease patients than in the controls, and this probably represents an early stage of cardiac involvement.

Remote monitoring of left ventricular assist device parameters after HeartAssist-5 implantation.

Although several left ventricular assist devices (LVADs) have been used widely, remote monitoring of LVAD parameters has been available only recently. We present our remote monitoring experience with an axial-flow LVAD (HeartAssist-5, MicroMed Cardiovascular, Inc., Houston, TX, USA). Five consecutive patients who were implanted a HeartAssist-5 LVAD because of end-stage heart failure due to ischemic (n=4) or idiopathic (n=1) cardiomyopathy, and discharged from hospital between December 2011 and January 2013 were analyzed. The data (pump speed, pump flow, power consumption) obtained from clinical visits and remote monitoring were studied. During a median follow-up of 253 (range: 80-394) days, fine tuning of LVADs was performed at clinical visits. All patients are doing well and are in New York Heart Association Class-I/II. A total of 39 alarms were received from three patients. One patient was hospitalized for suspected thrombosis and was subjected to physical examinations as well as laboratory and echocardiographic evaluations; however, no evidence of thrombus washout or pump thrombus was found. The patient was treated conservatively. Remaining alarms were due to insufficient water intake and were resolved by increased water consumption at night and summer times, and fine tuning of pump speed. No alarms were received from the remaining two patients. We believe that remote monitoring is a useful technology for early detection and treatment of serious problems occurring out of hospital thereby improving patient care. Future developments may ease troubleshooting, provide more data from the patient and the pump, and eventually increase physician and patient satisfaction. Despite all potential clinical benefits, remote monitoring should be taken as a supplement to rather than a substitute for routine clinical visits for patient follow-up.

Right ventricular and septal function in patients with pulmonary hypertension.

OBJECTIVE: Pulmonary hypertension (PHT) exacerbates the functions of both ventricles. This prospective, randomised study was planned to investigate the effects of PHT on kinetics of both ventricles and the septum. METHODS: Twenty-five patients were randomly selected among the patients who had been planned to undergo mitral valve replacement (MVR) because of isolated mitral stenosis and divided into two groups according to their preoperative pulmonary artery pressure (PAP) values. Blood pool gated single photon emission tomography (BPGS) and transthoracic echocardiography were performed. Ventricles' regional, global and functional parameters were also assessed by using pulsed wave Doppler tissue imaging (DTI). RESULTS: Preoperative and postoperative PAP of the group 1 (PAP < 50 mmHg) were 40.0 ± 2.8 and 30.0 ± 2.6 mmHg (p = 0.03), group 2 (PAP ≥ 50 mmHg) were 71.9 ± 4.7 and 50.6 ± 3.5 mmHg (p < 0.05). The global right and left ventricle scores were decreased after the operation. The decrement was only significant in group 2. Considering the septal kinetics, right ventricle septal score was decreased from 7.6 to 3.3 (p < 0.05) in group 1, from 3.8 to 1.6 (p < 0.05) in group 2 postoperatively. CONCLUSION: Following MVR, a decrement in PAP values, and an improvement in ventricular function, especially in the right ventricular and septal kinetics were achieved. Furthermore, it was found that both DTI and BPGS techniques are beneficial to investigate the functional changes postoperatively and in the follow-up period of the patients who undergo mitral valve surgery.

[Coronary artery ectasia: its frequency and relationship with atherosclerotic risk factors in patients undergoing cardiac catheterization]. / Koroner arter ektazisi: Koroner anjiyografi uygulanan hastalardaki sikligi ve aterosklerotik risk faktörleri ile iliskisi.

OBJECTIVE: Coronary artery ectasia (CAE) is defined as local or generalized aneurysmal dilatation of the coronary arteries. We aimed to determine the frequency of CAE at our center and to compare clinical and angiographic characteristics between patients with isolated CAE and CAE with coronary artery disease (CAD). METHODS: From February 2004 to December 2005, 12.514 patients were retrospectively analyzed by two independent operators who underwent coronary angiography. Coronary artery diameters were measured using qualitative computed angiography. CAD risk factors were recorded for all patients. Unpaired Student's t-test and Chi-square test were used for statistical analysis. RESULTS: CAE was diagnosed in 201 patients (1.59%). The majority (78%) were male. The mean age was 61±10.8 years (range, 25 to 82 years). The cases were divided into 2 groups as isolated CAE (Group 1) (14.9%) and CAE with CAD (Group 2) (85.1%). The risk factors of CAD were similar between two groups. The frequency of arterial involvement was: the right coronary artery (RCA) 54.3%; circumflex artery (Cx), 48.3%; the left anterior descending artery (LAD), 40.4%. CAE affected only one major vessel in 64.2% of cases and all 3 vessels in 9%. Isolated CAE was most commonly detected in Cx (47%). The type of CAE was determined according to Markis and Harikrishnan classification. The most prevalent involvement was Markis type 4 and Harikrishnan type 4a. Although atypical angina was the most common clinical presentation in both groups, acute coronary syndrome was more frequent in Group 2 (p=0.018). CONCLUSION: The risk factors of CAD and the manner of clinical presentation were considerably similar in both groups and this situation was consistent with similar etiopathogenesis of two diseases.

The use of three-dimensional echocardiography in the visualization of pseudoaneurysm of the mitral-aortic intervalvular fibrosa.

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (MAIF) is an uncommon but serious complication of aortic valve endocarditis. A 23-year-old woman was referred to our institution with the diagnosis of aortic valve endocarditis thought to be complicated by an aortic root abscess. Two-dimensional transthoracic echocardiography revealed a vegetation attached to the left coronary cuspis of the aortic valve and a false aneurysm-like structure in the MAIF at the left ventricular outflow tract. The diagnosis of MAIF pseudoaneurysm was confirmed by three-dimensional echocardiography. The patient died a few hours after admission because of worsening of her neurological status. An abscess-like structure detected in a patient with aortic valve endocarditis should be differentiated from a pseudoaneurysm of the MAIF.

A case of simultaneous anterior, inferior, and right ventricular ST-segment elevation myocardial infarction due to occlusion of the wrapped left anterior descending coronary artery.

Simultaneous anterior, inferior, and right ventricular ST-segment elevation myocardial infarction is an unusual condition. A 50-year-old male patient presented with severe, squeezing chest pain of an hour onset. ST-segment elevations were detected in all precordial derivations, DII, DIII, aVF and V3R, V4R. Coronary angiography showed a significant lesion in the left anterior descending (LAD) coronary artery, just below the second diagonal branch. Balloon predilatation was performed after 40 minutes of admission, followed by bare metal stent implantation, which resulted in ST-segment resolution in all leads and relief of chest pain. Echocardiography showed dyskinesia of the left ventricular apical wall, and hypokinesia of the interventricular septum and inferior wall. Left ventricular ejection fraction was 40%. Coronary angiography and cardiac CT angiography demonstrated a wrapped LAD. The patient was discharged five days after percutaneous coronary intervention (PCI) with stabilization of his clinical status. Ten days after PCI, he presented with chest pain associated with left ventricular anterior and inferior reinfarction. Successful balloon dilatation was performed for thrombotic in-stent restenosis. His clinical condition improved and he was asymptomatic for a month, during which no signs of deterioration were observed in electrocardiographic and echocardiographic findings.

The effect of baseline pulmonary artery pressure on right ventricular functions after mitral balloon valvuloplasty for rheumatic mitral stenosis: a tissue Doppler imaging study.

OBJECTIVES: We evaluated the effect of baseline pulmonary artery pressure (PAP) on right ventricular functions after percutaneous mitral balloon valvuloplasty (PMBV) for rheumatic mitral stenosis (MS). STUDY DESIGN: The study included 56 patients (15 males, 41 females; mean age 35 years) who underwent PMBV for isolated rheumatic MS. The patients were divided into two groups according to the baseline median systolic pulmonary artery pressure (PAP > or =40 mmHg, n=33; PAP <40 mmHg, n=23) measured before PMBV by echocardiography. Right ventricular function was assessed by pulse wave Doppler tissue imaging and the Tei index. Assessments were repeated 48 hours and three months after PMBV. RESULTS: The peak systolic (S) velocity of the lateral tricuspid annulus did not differ between the two groups at baseline. In patients with pulmonary artery hypertension (PAH), it showed a slight increase at 48 hours, but fell behind the baseline at three months. In patients without PAH, it showed a significant increase at 48 hours and remained unchanged at three months. Peak late diastolic (A) velocities were significantly higher at all times in patients without PAH. Patients with PAH had a significantly higher E/A ratio both at baseline and at 48 hours; however, at three months, this difference disappeared. Patients with PAH had higher isovolumic relaxation time (IVRT) at baseline and 48 hours; however, final IVRT was lower than the baseline only in patients with PAH. Isovolumic contraction time showed a steady but insignificant increase in both groups over three months. E-wave deceleration time showed a significant increase and contraction time showed a slight increase over three months only in patients with PAH. The baseline Tei index was higher in patients with PAH (p=0.004). Changes in the Tei index over time were not significant. CONCLUSION: Our findings suggest that, If PMBV is performed before the development of PAH, it may be more effective in the improvement of right ventricular longitudinal functions in patients with rheumatic MS.

Diverse effects of oxygen inhalation on the regional myocardial functions related to the degree of coronary artery stenosis.

In patients with stable coronary artery disease, the effect of oxygen (O2) inhalation to regional myocardial functions and its relation to the degree of the coronary artery stenosis is still unclear. This article investigates the effect of O2 therapy on regional myocardial functions in patients with coronary atherosclerosis according to the severity of stenosis. Myocardial segments were evaluated via tissue velocities, strain, strain rate, and tissue tracking. While O2 inhalation improves late diastolic myocardial velocity and tissue tracking in normally perfused myocardial regions, a negative effect was observed on systolic and diastolic parameters of myocardial segments, which are perfused by insignificantly stenotic coronary arteries. Although nasal O2 treatment has unfavorable effects on regional myocardial functions in patients with coronary artery disease, this effect remains subclinic with short-term inhalation. However, it is reasonable to pursue the effects of longer-term O2 inhalation on myocardial function especially in patients with insignificant coronary stenosis.

[Exercise capacity in patients with metabolic syndrome in the presence of normal coronary arteries]. / Koroner arterleri normal bulunan metabolik sendromlu hastalarda egzersiz kapasitesi.

OBJECTIVES: We evaluated exercise capacity and other exercise parameters in patients with metabolic syndrome and angiographically normal coronary arteries. STUDY DESIGN: Sixty-one patients with angiographically normal coronary arteries were evaluated in two groups according to the presence (n=32; 24 females, 8 males; mean age 59+/-10 years) or absence (n=29; 18 females, 11 males; mean age 59+/-9 years) of metabolic syndrome as proposed by the International Diabetes Federation. All the patients underwent exercise treadmill testing with the modified Bruce protocol, whereby the following variables were determined: workload achieved in metabolic equivalents, total exercise time, percentage of target heart rate achieved, double product, heart rate recovery, chronotropic response and incompetence. The relationships between exercise parameters and echocardiographic and clinical variables were evaluated. RESULTS: The two groups were similar with respect to age, left ventricular dimensions, left ventricular mass index, ejection fraction, and left atrial diameters. The incidence of diastolic dysfunction was significantly higher in patients with metabolic syndrome (71.9% vs 41.4%; p=0.016). The maximum workload achieved was significantly lower (10+/-2 ml/kg/min vs 12+/-2 ml/kg/min; p=0.024) and the initial double product was significantly higher (11.6x10(3) mmHg.pulse/min vs 10.1x10(3) mmHg.pulse/min, p=0.04) in patients with metabolic syndrome. Hypertensive patients exhibited significantly lower maximum workload and total exercise time (p<0.05). Hyperglycemic subjects had significantly lower maximum workload (p<0.05). CONCLUSION: Metabolic syndrome is associated with decreased exercise capacity and each component of this syndrome affects exercise test parameters individually.

P wave dispersion is prolonged in patients with Wilson's disease.

AIM: To investigate the P wave dispersion as a non-invasive marker of intra-atrial conduction disturbances in patients with Wilson's disease. METHODS: We compared Wilsonos disease patients (n = 18) with age matched healthy subjects (n = 15) as controls. The diagnosis was based on clinical symptoms, laboratory tests (ceruloplasmin, urinary and hepatic copper concentrations). P wave dispersion, a measurement of the heterogeneity of atrial depolarization, was measured as the difference between the duration of the longest and the shortest P-waves in 12 lead electrocardiography. RESULTS: All the patients were asymptomatic on cardiological examination and have sinusal rhythm in electrocardiography. Left ventricular and left atrial diameters, left ventricular ejection fraction and left ventricular mass index were similar in both groups. The Wilson's disease patients had a significantly higher P wave dispersion compared with the controls (44.7 +/- 5.8 vs 25.7 +/- 2.5, P < 0.01). CONCLUSION: There was an increase in P wave dispersion in cardiologically asymptomatic Wilson's disease patients which probably represents an early stage of cardiac involvement.

Left and right atrial myocardial deformation properties in patients with an atrial septal defect.

BACKGROUND: Atrial septal defect (ASD) is a common form of congenital heart defect in adults, which affects all cardiac chambers. Atrial myocardial function in patients with ASD has not yet been clearly elucidated. The aim of this study was to investigate atrial myocardial deformation properties in patients with ASDs. METHODS: The study involved 24 patients with a secundum type ASD, and 22 healthy subjects. Color Doppler myocardial imaging was used to measure left and right atrial myocardial systolic strain and strain rate values, together with peak systolic velocity, early velocity, and late diastolic velocity. RESULTS: There was no significant difference between the two groups with regard to age, gender, body mass index, heart rate, blood pressure, left atrial diameter, and ventricular function. The peak systolic atrial myocardial strain and strain rate values in each of the atrial walls studied were lower in the ASD group compared to those of the control group, but the difference reached statistical significance only in the case of the right atrial wall (right atrial strain: 48.0 +/- 32.7% vs 100.2 +/- 46.6%, P = 0.006; right atrial strain rate: 2.6 +/- 1.2/sec vs 3.8 +/- 1.2/sec, P = 0.024). CONCLUSION: The left to right cardiac shunt that results from ASD leads to a reduction in the right atrial myocardial longitudinal lengthening that occurs during ventricular ejection. These findings demonstrate that the reservoir function of the atrium is impaired and atrial stiffness increases in patients with ASDs.

Elastic properties of aorta are impaired in patients with slow coronary flow phenomenon.

BACKGROUND: Increased stiffening and decreased distensibility of the large arteries are associated with the presence of coronary artery disease and has been related to increased cardiovascular mortality in different populations. AIM: Aim of this present study was to investigate the elastic properties of the aortic wall in patients with slow coronary flow phenomenon. MATERIAL AND METHOD: We studied 20 patients with slow coronary flow phenomenon (age: 40+/-12 years)and 15 normal control subjects by echocardiography. Aortic strain (%) and distensibility (10(-3) mmHg(-1)) were calculated from the echocardiographically-derived thoracic Ao diameters (mm). The measurement of pulse pressure was obtained by cuff sphygmomanometry. RESULTS: There was no difference in the left ventricular ejection fraction, left ventricular end-diastolic and end-systolic diameters, left atrial diameters, left ventricular mass index between patients with slow coronary flow phenomenon and control groups. Maximal aortic diastolic diameter was increased in patients with slow coronary flow phenomenon compared with control group (p<0.05). Ao distensibility and Ao strain were lower in the patients with slow coronary flow phenomenon compared with control group (p<0.05). CONCLUSION: Reduced thoracic aortic elastic properties in patients with slow coronary flow phenomenon,assessed by echocardiography, apart from demonstrating subclinical atherosclerosis may also contribute to the etiopathogenesis of the slow coronary flow phenomenon necessitating more aggressive primary preventive measure.

Coronary artery to left ventricular fistula demonstrated by transthoracic echocardiography.

Coronary artery fistulas are rare coronary anomalies which generally require coronary angiography for definitive diagnosis. Improvements in ultrasound technology has enabled direct, transthoracic visualization of long portions of coronary arteries. We report a patient with a symptomatic coronary to left ventricular fistula, which was diagnosed with transthoracic echocardiography.

Complete regression of massive cardiac involvement associated with acute T cell leukemia following chemotheraphy.

Adult T cell leukemia/lymphomas are aggressive disorders, which infiltrate not only the bone marrow but extensively the visceral organs as well. A case with left ventricular systolic dysfunction with myocardial infiltration and massive pericardial effusion which was demonstrated with echocardiography is discussed. The patient responded well to pericardial drainage and subsequent chemotherapy. The dramatic improvement in echocardiographic findings after chemotherapy gave a clue to investigate suspected patients with aggressive leukemia and lymphomas for exclusion of leukemic infiltration of myocardium.

Evaluation of hemodynamic changes in patients with mitral valve replacement using dobutamine stress echocardiography.

OBJECTIVE: The aim of this study was to investigate the response of heart to stress according to the size of the prosthetic valve in patients who had undergone mitral valve replacement by using dobutamine stress echocardiography (DSE) and to evaluate the relationship between the size of the prosthetic valve and cardiac recovery-remodeling process. METHODS: Thirty-nine patients, who had undergone mitral valve replacement were compared in terms of left ventricular diameters, systolic functions and cardiac mass indexes in order to investigate the effect of the mechanical valve size on postoperative cardiac remodeling in this longitudinal study. They were divided into three groups according to their valve size: Group 1 (valve size<29 mm, n=11), Group 2 (valve size=29 mm, n=11) and Group 3 (valve size>29 mm, n=17). Statistical analysis was performed using Chi-square and one-way ANOVA tests to determine the statistical differences between the groups. The repeated measurements of two-way ANOVA test was used to analyze effects during long-term follow-up. RESULTS: Only Group 1 patients achieved a significant decrease in terms of left ventricular mass index and end-diastolic diameter (138.3+/-29.7 g/m2 vs 86.6+/-15.6 g/m2 and 5.1+/-0.5 cm vs. 4.4+/-0.4 cm, p<0.05). Group 3 patients' left ventricular ejection fraction become worse after the operation (64.0+/-5.6% vs. 55.9+/-6.5%, p<0.05). Maximum and mean pressure gradients across the mitral prosthesis as well as pulmonary artery pressure were significantly increased in all groups during DSE. Maximum gradients increased from 14.2+/-4.6 to 20.7+/-7.5 mmHg in Group 1 (p<0.05), 11.6+/-4.7 to 16.2+/-6.8 mmHg in Group 2 (p<0.05), and 10.6+/-3.1 to 20.8+/-12.7 mmHg in Group 3 (p<0.05). Isovolumic relaxation time decreased in all groups following the dobutamine infusion, as expected, but this decline was not significant in Group 3. CONCLUSION: A worsening in left ventricular systolic function was observed in large- sized valve prosthesis group. Only the patients who had undergone MVR with small-sized valve prosthesis achieved a decrease in cardiac mass index and preservation of the systolic function. The echocardiographically determined differences and mass index that appeared after the operation may point out that, the effect of the operation on cardiac remodeling can be related with the ventricular size.