Preprocedural and procedural variables that predict new-onset conduction disturbances after transcatheter aortic valve replacement.

BACKGROUND: Conduction disturbances are a common complication after transcatheter aortic valve replacement (TAVR). The aim of this study was to investigate the preprocedural and procedural variables that predict new-onset conduction disturbances post-TAVR (hereafter CD/CDs). METHODS: Consecutive patients who underwent TAVR during December 2009-March 2021 at the Faculty of Medicine Siriraj Hospital, Mahidol University-Thailand's largest national tertiary referral center-were enrolled. Patients with prior implantation of a cardiac device, periprocedural death, or unsuccessful procedure were excluded. Clinical and electrocardiographic data, preprocedural imaging, including membranous septum (MS) length, and procedural variables, including implantation depth (ID), were analyzed. CD was defined as new left or right bundle branch block, significant intraventricular conduction disturbance with QRS interval ≥ 120 ms, new high-grade atrioventricular block, or complete heart block. Multivariate binary logistic analysis and receiver operating characteristic (ROC) curve analysis were used to identify independent predictors and the optimal ∆MSID (difference between the MS length and ID) cutoff value, respectively. RESULTS: A total of 124 TAVR patients (mean age: 84.3 ± 6.3 years, 62.1% female) were included. The mean Society of Thoracic Surgeons score was 7.3%, and 85% of patients received a balloon expandable transcatheter heart valve. Thirty-five patients (28.2%) experienced a CD, and one-third of those required pacemaker implantation. The significant preprocedural and procedural factors identified from univariate analysis included intraventricular conduction delay, mitral annular calcification, MS length ≤ 6.43 mm, self-expanding device, small left ventricular cavity, and ID ≥ 6 mm. Multivariate analysis revealed MS length ≤ 6.43 mm (adjusted odds ratio [aOR] 9.54; 95% CI 2.56-35.47; p = 0.001) and ∆MSID < 0 mm (adjusted odds ratio [aOR] 10.77; 95% CI 2.86-40.62; p = < 0.001) to be independent predictors of CD. The optimal ∆MSID cutoff value for predicting conduction disturbances was less than 0 mm (area under the receiver operating characteristic curve [AuROC]: 0.896). CONCLUSION: This study identified MS length ≤ 6.43 mm and ∆MSID < 0 mm as independent predictors of CDs. ∆MSID < 0 was the strongest and only modifiable predictor. Importantly, we expanded the CD criteria to cover all spectrum of TAVR-related conduction injury to lower the threshold of this sole modifiable risk. The optimal ∆MSID cutoff value was < 0 mm. TRIAL REGISTRATION: TCTR, TCTR20210818002. Registered 17 August 2021-Retrospectively registered, http://www.thaiclinicaltrials.org/show/TCTR 20210818002.

An 80-Year-Old Man with Inferior Wall Myocardial Infarction and Cardiogenic Shock: Case Report.

We report a case of ruptured head of posteromedial papillary muscle and prolapse of anterior mitral valve leaflet that caused severe mitral regurgitation (MR) and cardiogenic shock as a complication of inferior wall myocardial infarction in an 80-year-old man. Emergency coronary angiogram revealed thrombotic occlusion at proximal right coronary artery. Transesophageal echocardiogram revealed ruptured head of posteromedial papillary muscle and prolapse of anterior mitral valve leaflet causing severe MR. After percutaneous coronary intervention with bare metal stent, the patient underwent mitral valve repair with saphenous vein graft to the posterolateral branch of the right coronary artery. The patient was discharged from hospital on day 14 of admission.

Prevalence and echocardiographic characteristics of common congenital heart disease in adult patients at Siriraj Hospital: 10-year study.

BACKGROUND: The number of adult patients with congenital heart disease (CHD) has increased rapidly and represents a major challenge in cardiovascular medicine. Data regarding the prevalence and characteristics of adult CHD in Thai population over the past decade are lacking. MATERIAL AND METHOD: Patients who underwent comprehensive transthoracic echocardiographic study at Siriraj Hospital during January 2003 to May 2013 with the diagnosis of unrepaired CHD and complete data were enrolled in the study Patients with uncertain diagnosis, prior cardiac intervention, bicuspid aortic valve, patent foramen ovale, mitral valve prolapse, isolated persistent left superior vena cava and congenital cardiomyopathies were excluded. RESULTS: Among 27,132 patients underwent transthoracic echocardiography, 1,082 (age 36.7 ± 14.7 years, 75.3%female) had the diagnosis of CHD and the prevalence was 4.0% (95% confidence interval = 3.76-4.23%). The majority were isolated simple left-to-right shunt lesions: atrial septal defect (43%), ventricular septal defect (27%) and patent ductus arteriosus (11%). Eisenmenger syndrome was reported in 77 patients (age 39.1 ± 10.8 years, 71.4% female). Pulmonic stenosis and Ebstein's anomaly were reported in 2.9% and 2.8% of patients, respectively. Tetralogy of Fallot was the most common cyanotic defect (3.5%). The combinations of shunts and/or right-sided obstructive lesions were reported in 4.8%. CONCLUSION: The prevalence of adult CHD diagnosed by echocardiography at Siriraj Hospital was 4.0% and atrial septal defect was the most common form. Simple shunt lesions represent more than 80% of patients. Female predominance was reported in all common forms of CHD. Echocardiography is fundamental for the diagnosis and management of patients with CHD.

Left atrial volume as an independent predictor of exercise capacity in patients with isolated diastolic dysfunction presented with exertional dyspnea.

BACKGROUND: Left atrial volume (LAV) and exercise capacity are important prognostic determinants of cardiovascular risk. Exercise intolerance and increased LAV are expected in patients with diastolic dysfunction. While dyspnea is the symptom reported by the patient and considered subjective, exercise capacity obtained by exercise testing provides an objective measure of cardiovascular fitness. The objective of this study is to determine the relationship between LAV index and exercise capacity in patients with isolated diastolic dysfunction who presented with exertional dyspnea. METHODS: We studied consecutive patients with dyspnea who underwent treadmill exercise testing and transthoracic echocardiography on the same day. LAV was assessed using the biplane area-length method. Symptom-limited exercise testing was performed immediately after echocardiography. Patients with coronary artery disease, valvular or congenital heart disease, left ventricular systolic dysfunction, pulmonary hypertension or positive exercise test were excluded. RESULTS: The study consisted of 111 patients (58.1 ± 9.2 years of age, 54.1% male, 64% hypertension, 57.7% dyslipidemia and 20.7% diabetes). The exercise duration and capacity were 6.8 ± 2.1 minutes and 7.7 ± 1.9 METs, respectively. Left ventricular ejection fraction and LAV index was 71.0 ± 5.8% and 31.4 ± 10.5 ml/m2, respectively. In multivariate analysis, age [odds ratios (OR) 0.94; 95% confidence interval (CI) 0.89-0.99], body mass index (OR 0.82, 95% CI 0.72-0.93), and LAV index (OR 0.92, 95% CI 0.87-0.97) were associated with good exercise capacity. CONCLUSION: In patients with isolated diastolic dysfunction and exertional dyspnea, an increased LAV index, a marker of chronic diastolic dysfunction, is associated with poor exercise capacity.

Prognostic value of normal dobutamine stress echocardiography in renal transplant candidates.

BACKGROUND: Renal transplant candidates are at high-risk for cardiovascular events. No definite screening tool has been recommended for the pre-operative evaluation. OBJECTIVE: The authors studied the prognostic value of normal dobutamine stress echocardiography in this population. MATERIAL AND METHOD: Dobutamine stress echocardiography was performed for the pre-operative assessment in 107 renal transplant candidates (age 53.2 +/- 6.2 years, 66.4% male). The mean follow-up time was 2.8 +/- 1.7 years. The primary endpoint was total mortality. RESULTS: During follow-up, 16 (15.0%) died and 26 (24.3%) patients underwent kidney transplantation. The overall survival probabilities at 1, 3 and 5 years were 87, 83 and 79%, respectively. Among those who underwent renal transplantation, the survival probabilities at 1, 3 and 5 years were 100, 100 and 89%, respectively CONCLUSION: In renal transplant candidates, normal dobutamine stress echocardiography portends a good long-term prognosis.

Echocardiography as a simple initial tool to assess right ventricular dimensions in patients with repaired tetralogy of Fallot before undergoing pulmonary valve replacement: comparison with cardiovascular magnetic resonance imaging.

OBJECTIVE: Accurate assessment of the right ventricle (RV) is essential in patients with repaired tetralogy of Fallot (TOF). We proposed a simple echocardiographic method to assess the RV dimensions and evaluated the relationship between linear echocardiographic measures of the RV and RV volumes obtained by cardiovascular magnetic resonance imaging (CMR). METHODS: A total of 45 patients (27.4 ± 11.2 years; 40% male) with repaired TOF underwent CMR and echocardiography. Using echocardiography, RV dimensions were assessed from the parasternal short-axis view using the longest RV internal diameter perpendicular to the mid-interventricular septum. Significant RV dilatation was defined as an RV end-diastolic volume index >160 mL/m(2) on CMR. RESULTS: There were significant correlations between RV dimensions determined by echocardiography and the pulmonary regurgitation fraction, RV size, and function determined by CMR. The cutoff values of echocardiographic RV outflow tract (RVOT), end-systolic and end-diastolic dimension indices, and the combination of RVOT and end-diastolic dimension indices to determine significant RV dilatation were 19.0, 19.4, 24.5, and 45.2 mm/m(2) , respectively. The positive and negative predictive values for significant RV dilatation were 89.7% and 68.8% with RVOT diameter index ≥19.0 mm/m(2) , 85.0% and 52.4% with RV end-systolic dimension index ≥19.4 mm/m(2) , 87.5% and 64.7% with RV end-diastolic dimension index ≥24.5 mm/m(2) , and 92.3% and 80.0% with the combination of RVOT and end-diastolic dimension indices ≥45.2 mm/m(2) , respectively. CONCLUSION: Echocardiography can be used to assess RV size in patients with repaired TOF with acceptable correlations with CMR as the reference standard.

Transcatheter aortic valve implantation (TAVI): first case in Thailand.

Aortic valve replacement (AVR) is the standard treatment for patients with symptomatic severe aortic stenosis (AS). However many patients are not offered surgery due to high surgical risk for open AVR. Transcatheter aortic valve implantation has been an alternative to open heart surgery in patients with symptomatic severe aortic stenosis (AS) who are not suitable for open surgery. The first transcatheter aortic valve implantation in Thailand via the transapical route is described. An 87-year-old woman with symptomatic severe AS, calcified aorta and peripheral arterial disease, who was at high surgical risk, was successfully treated, and had good functional and haemodynamic results at six-months follow-up.

Comparison of aortic diameter in normal subjects and patients with systemic hypertension.

BACKGROUND: Standard aortic root dimensional measurement by the two dimensional echocardiography should be routinely performed in all patients. There is limited data on the normal reference on Thai population. OBJECTIVE: Aims of this study were (1) to determine the normal reference of aortic root dimension in Thai population and (2) to determine the difference in the aortic root size in patients with hypertension comparing with normal population. MATERIAL AND METHOD: We retrospectively reviewed 81 patients who had the transthoracic echocardiographic examinations in our echocardiographic lab and had the aortic root measurement data. The patients with ascending aortic aneurysm, aortic dissection, aortic stenosis and/or regurgitation more than mild in degree, Marfan's syndrome and annuloaortic ectasia were excluded. The echocardiographic data of were collected; the aortic root dimensions at four levels; aortic valve annulus, sinus of Valsava, sinotubular junction and tubular parts. Hypertension was indentified if the patient had the prior diagnosis of hypertension and on antihypertensive medications, or who had blood pressure more than 140/90 mmHg for two or more occasions. RESULTS: Eighty-one patients were enrolled. Sixty patients (74.1%) were diagnosed hypertension. Mean age was 66.9 +/- 11.2 years in hypertensive patients and 49.1 +/- 16.4 years in normotensive patients. Normal reference values based on 95% upper normal limit of aortic valve annulus, sinus of Valsava, sinotubular junction and tubular part were 2.30 (2.21-2.38), 3.56 (3.35-3.77), 2.79 (2.61-2.97), and 3.36 (3.13-3.59), respectively. Patients with hypertension had significant larger sinus of Valsava and tubular part of aortic root than patients with normotension. CONCLUSION: We reported a normal reference value for aortic root size in Thai population. The aortic root sizes are influenced by hypertensive status, age and gender.

Patients with non-sT-segment elevation myocardial infarction present with more severe systolic and diastolic dysfunction than patients with unstable angina.

BACKGROUND: Patients with non ST-segment elevation acute coronary syndrome (NSTEACS) present with diverse clinical, electrocardiographic, cardiac biomarker, echocardiographic and angiographic characteristics. We sought to determine whether there was any difference in the indices of left ventricular systolic and diastolic function among subgroups of patients with NSTEACS. MATERIAL AND METHOD: We studied 121 consecutive patients (mean age 68.6 +/- 11.3 years, 45% male) with NSTEACS who underwent comprehensive echocardiography within 48 hours of admission. Two-dimensional and Doppler echocardiography was performed for the evaluation of left ventricular systolic and diastolic function. RESULTS: Non ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA) were reported in 59% and 41% of patients, respectively. Clinical characteristics (such as age, gender, cardiovascular risk factors, prior myocardial infarction and revascularization, medication) were not significantly different between patients with NSTEMI and UA. Patients with NSTEMI were more likely to have wall motion abnormalities and lower left ventricular ejection fraction (p < 0.05) as compared to those with UA. Diastolic dysfunction was significantly more frequent and more severe in patients with NSTEMI than in those with UA. CONCLUSION: Among patients with NSTEACS, left ventricular systolic and diastolic dysfunction was more frequent and more severe in patients with NSTEMI that in those with UA. These findings may be used to characterize the sicker group among patients with NSTEACS.

Immediate aortic dissection after transcatheter aortic valve replacement: A case report and review of the literature.

-Aortic dissection of descending aorta was detected by intraoperative TEE in a case of 67-year-old man with symptomatic severe aortic stenosis after TAVR. -Transesophageal echocardiogram after TAVR procedure is helpful to detect this rare complication.

A retrospective study of bosentan in pulmonary arterial hypertension associated with congenital heart disease.

BACKGROUND: Pulmonary Arterial Hypertension (PAH) plays a significant role in morbidity and mortality of patients with congenital heart disease (CHD). Bosentan, a dual endothelin receptor antagonist has been approved for PAH patients with Eisenmenger physiology (EP). The authors retrospectively reviewed the efficacy and safety of bosentan in Thai PAH patients associated with CHD. MATERIAL AND METHOD: The study population was obtained from the databases of the CHD patients at Siriraj Hospital from October 2004 to April 2007 who received 6 months of bosentan treatment. Inclusion criteria are: CHD with Eisenmenger physiology (EP) or those with severe PAH after surgical repair or interventional cardiac catheterization. Clinical characteristics including the 6-- minute walk test (6MWT) distances, oxygen saturation (O2 sat), New York Heart Association (NYHA) functional class, and right ventricular systolic pressure (RVSP) at baseline were compared with those at 1, 3, and 6 months post bosentan treatment. Signs and symptoms of adverse events were also recorded. RESULTS: There were 11 patients from among those who fitted the inclusion criteria and whose records were examined. Their average age was 51.1 +/- 10.1 years old (13-61 years old). Patients were divided into 2 groups; Group A (6 patients) was PAH with EP and Group B (5 patients) was PAH post intervention. In group A, the 6MWT increased from 151 +/- 69 meters to 293 +/- 61 meters (p = 0.001) with the average increase of 38 +/- 61 meters. The 2O sat increased from 83 +/- 12.7% to 91.8 +/- 5.6% (p = 0.038) with an average increase of 1.4 +/- 0.07%. There was no significant change in right ventricular systolic pressure (RVSP). In group B, there was a trend in 6MWT improvement from 274 +/- 69 meters to 312 +/- 38 meters but this was not statistically different. There were improvements in the NYHA functional class in both groups. There was no significant increase in serum aminotransferase at the end of 6 months in each patient. CONCLUSION: There are benefits of bosentan for treatment of severe PAH in CHD, especially in patients with Eisenmenger physiology. Obvious benefits are an improvement of 6MWT and O2 sat.

Dobutamine stress echocardiography for the evaluation of coronary artery disease in Thai population: Siriraj experience.

OBJECTIVE: No previous report of dobutamine stress echocardiography in the Thai population has been available. The present study seeks to document the protocol, indications, results and safety of dobutamine stress echocardiography performed at Siriraj Hospital. MATERIAL AND METHOD: The authors studied 421 [mean age 67.7 +/- 11.0 years, 179 (43%) men] consecutive Thai patients undergoing dobutamine stress echocardiography at Siriraj Hospital. The protocol, indications and echocardiographic analysis were described. Clinical characteristics, hemodymanics, results and adverse effects were recorded at the time of dobutamine stress echocardiography. RESULTS: Dobutamine stress echocardiography was performed for preoperative assessment before non-cardiac surgery in 212 patients (50%), for the diagnosis of suspected Coronary Artery Disease (CAD) in 179 patients (43%), for risk stratification of CAD in 24 patients (6%), and for other reasons in six patients (1%). The results were normal and positive for inducible ischemia in 276 (66%) and 80 (19%) patients, respectively. Limiting side effects were observed in 3%. No death, myocardial infarction or life-threatening arrhythmias occurred. Transient stress-associated tachyarrhythmias, such as atrialfibrillation, nonsustained ventricular tachycardia or supraventricular tachycardia, occurred in 3.5% of patients. CONCLUSION: Dobutamine stress echocardiography was considered a safe and tolerable technique for the evaluation of CAD in Thai population.

One-year outcome of cardioversion of atrial fibrillation in patients with mitral stenosis after percutaneous balloon mitral valvuloplasty.

Our objectives were to study the success rate of electrical cardioversion after percutaneous balloon mitral valvuloplasty (PBMV) in patients with symptomatic moderate-to-severe mitral stenosis and atrial fibrillation (AF) and the maintenance rate of sinus rhythm for < or =1 year. We studied patients with mitral stenosis and AF who were scheduled for PBMV. Electrical cardioversion was performed 1 month after PBMV. Amiodarone 200 mg/day was started the day after PBMV. The primary outcomes studied were the rate of successful cardioversion and the maintenance rate of sinus rhythm at 12 months. Of 272 patients scheduled for PBMV, 70 were enrolled. The average age was 45 +/- 10 years. The average mitral valve area was 0.82 +/- 0.22 cm(2). Cardioversion was successful in 50 patients (71%). Logistic regression analysis revealed that left atrial size and associated aortic valvular disease were predictors of successful cardioversion. Of the 50 patients with successful cardioversion, AF recurred in 24 (48%). An increased left atrial diameter was the only factor associated with AF recurrence at 12 months. In conclusion, good candidates for cardioversion after PBMV were those with a left atrial diameter of <60 mm and no associated aortic valvular disease -- approximately 43% of patients with AF scheduled for PBMV. In this group, about 2/3 were in sinus rhythm at 12 months after cardioversion.

Combination therapy of prostacyclin for pulmonary hypertension in congenital heart disease.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a recognized complication of congenital heart disease. Despite differences in etiology and pathophysiology, successful therapy for idiopathic PAH may benefit in patients with congenital heart disease. We theorized that combination of oral and aerosolization prostacyclin will benefit this group of patients in long-term. MATERIAL AND METHOD: The study design was single group and open label study with intention to treat for patients with congenital heart disease with pulmonary artery (PA pressure) more than 50% of systemic pressure. All patients were given a combination of orally given beraprost sodium and inhalation of iloprost for 12 months. Data were collected prospectively consisting of functional class, O2 saturation, 6-minute walk test and right ventricular systolic pressure (RVSP). RESULTS: There were 23 patients with an average right ventricular systolic pressure (+/- SD) of 94.8 +/- 14.5 mmHg and with average age of 27.8 +/- 14.9 years (2.5 to 50 years). The average oxygen saturation was 87.9 +/- 7 %. There were 12 patients with post surgical repair or cardiac catheterization interventional procedure and 11 with and Eisenmenger's syndrome. There were significant improvement of 6-minute-walk test from an average of 268 +/- 70 meters to 308 +/- 57 meters at the end of 12 months. The functional class of patients was also improving. However, there were no significant different in oxygen saturation. CONCLUSION: Combination therapy of oral and inhalation of aerosolized vasodilators is a fascinating concept in the therapy of pulmonary hypertension. Treated patients showed an improvement in exercise capacity and right ventricular systolic pressure without a worsening in oxygen saturation.

Three-Dimensional Echocardiography: Precision and Accuracy of Left Ventricular Volume Measurement Using Rotational Geometry with Variable Numbers of Slice Resolution.

We developed a new, rapid (6 seconds) acquisition technique allowing collection of approximately six through nine apical rotational tomograms for three-dimensional (3-D) echocardiography. To justify an appropriate sampling density for precise and accurate measurement of chamber volumes in left ventricles with complicated shape, we designed a validation study in vitro using six canine heart specimens with irregular, asymmetric left ventricles with known volumes (28.5 to 104.3 ml; mean, 71.2 ml). The number of equally spaced slices were incrementally deleted from the original high resolution scans (48 slices) to 2 slices in 3-D reconstruction. We created subgroups of 48- and 36-, 24- and 16-, 12- and 8-, 6- and 4-, and 3- and 2-component slices to compare left ventricular (LV) volumes measured in 3-D images with different slice resolution with the reference standard measured in the specimen. The accuracy and precision of LV volume were relatively constant in the subgroup of 4- and 6- through 36- and 48-component slices. When the subgroup with 6- and 4-component slices was used, the correlation was r = 0.991, P < 0.0001, root-mean-square percent error of 5.0%, bias of 0.5 +/- 3.7 ml, and interobserver variability of 5.0%. With the reduction in component slices equal or less than three, the accuracy decreased significantly (root-mean-square percent error = 8.1% and bias = -2.0 +/- 5.7 ml) compared with higher slice resolutions. This study demonstrated that 3-D echocardiography using apical rotational techniques can accurately quantify LV volume in the canine heart specimens with irregular shapes with as few as 4-6 axial slices. The rapid 3-D acquisition technique is therefore anticipated to yield precise and accurate LV volumetry.

Changes in hematologic markers in patients with mitral stenosis after successful percutaneous balloon mitral valvuloplasty.

Systemic embolism is a major complication of mitral stenosis which is usually related to a presence of left atrial thrombus. Percutaneous balloon mitral valvuloplasty (PBMV) was previously reported to reduce the incidence of this complication. However, the mechanisms of this beneficial procedure was under investigated. The aim of this study was to investigate the changes in coagulation activity, platelet activity and endocardial function in 29 patients with mitral stenosis after successful PBMV. All subjects had good left ventricular systolic function and 48.3% had atrial fibrillation. There was a significant reduction in thrombin-antithrombin complex (TAT) after a successful procedure and the level of thrombomodulin was also significantly higher one month after successful procedure. However, the level of platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) were increased after this procedure but not achieved the statistical significance. In conclusion, successful PBMV can reduce the prethrombotic state in patients with mitral stenosis. In addition, it may improve endocardial function of the left atrium in those without atrial fibrillation.

Efficacy and safety of percutaneous metallic mitral valvuloplasty in rheumatic mitral stenosis at Siriraj Hospital.

Mitral stenosis is an important problem that leads to heart failure and stroke in Thailand. The options of treatment at present are either surgical or balloon mitral commissurotomy. However, the cost of balloon is very expensive. To reduce the expense of the procedure, the authors prospectively did a study using a new device called the metallic valvulotome in symptomatic severe mitral stenosis to assess the safety, feasibility and immediate outcomes. Fifty-seven patients were included in the study. The successful outcome achieved by the metallic valvulotome was 96.2 per cent in patients in whom the procedure was actually performed. The mean transmitral gradient, left atrial pressure and pulmonary artery pressure were significantly decreased and the mitral valve area was also significantly increased. Three cases failed the procedure due to inappropriate position of the septal puncture. No death occurred in the study and complications of the procedure included only two cases of hemopericardium. In the future, it is believed that this new innovative device will provide improvement and reduce the cost of the procedure in patients with severe mitral stenosis.

An abnormal systemic and regional hypercoagulable state in patients with mitral stenosis.

Mitral stenosis still remains a major problem in Southeast Asia including Thailand. It contributes to the morbidity and mortality related to thromboembolism which was associated with the left atrial thrombus. However, the pathogenesis of left atrial thrombus in these patients is not completely understood. Therefore, the objective of this study was to investigate the coagulation and platelet activity including the function of the endocardium in the left atrium and peripheral circulation in patients with mitral stenosis who were free of left atrial thrombus and to compare those hematologic markers activity in the peripheral venous blood between the patients with mitral stenosis and the control. Thirty-six patients with moderate to severe mitral stenosis were included in the study. Most of the patients were in functional class II and 50 per cent had atrial fibrillation. Blood was obtained from the femoral vein, femoral artery, pulmonary artery and left atrium of these patients before heparin was administered to determine the value of various hematologic markers. In the control group, blood for determining the hematologic markers was collected only from the antecubital vein. The results of this study demonstrated that the levels of prothrombin activation fragment 1+2 (F1+2), thrombin-antithrombin III complex (TAT) and Beta-thromboglobulin (beta-TG) in the left atrium of the patients with mitral stenosis were significantly higher than those in the femoral vein and femoral artery, whereas the level of thrombomodulin was significantly lower in the left atrium compared with the femoral artery and vein. When comparing with the control group, the levels of TAT, plasminogen activator inhibitors-1 (PAI-1) from the peripheral vein were significantly higher and the level of thrombomodulin was also significantly lower in the patients with mitral stenosis. In conclusion, the present study demonstrated an abnormal hypercoagulable state of the left atrium and systemic circulation related to the abnormalities of coagulation, platelets and the endocardium which may cause the formation of left atrial thrombus in patients with mitral stenosis.