Comparison of the Diagnostic Accuracies of 1.5T and 3T Stress Myocardial Perfusion Cardiovascular Magnetic Resonance for Detecting Significant Coronary Artery Disease

OBJECTIVE: To compare the diagnostic performance of cardiovascular magnetic resonance (CMR) myocardial perfusion at 1.5- and 3-tesla (T) for detecting significant coronary artery disease (CAD), with invasive coronary angiography (ICA) as the reference method. MATERIALS AND METHODS: We prospectively enrolled 281 patients (age 62.4 ± 8.3 years, 193 men) with suspected or known CAD who had undergone 1.5T or 3T CMR and ICA. Two independent radiologists interpreted perfusion defects. With ICA as the reference standard, the diagnostic performance of 1.5T and 3T CMR for identifying significant CAD (≥ 50% diameter reduction of the left main and ≥ 70% diameter reduction of other epicardial arteries) was determined. RESULTS: No differences were observed in baseline characteristics or prevalence of CAD and old myocardial infarction (MI) using 1.5T (n = 135) or 3T (n = 146) systems. Sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) for detecting significant CAD were similar between the 1.5T (84%, 64%, 74%, 76%, and 0.75 per patient and 68%, 83%, 66%, 84%, and 0.76 per vessel) and 3T (80%, 71%, 71%, 80%, and 0.76 per patient and 75%, 86%, 64%, 91%, and 0.81 per vessel) systems. In patients with multi-vessel CAD without old MI, the sensitivity, specificity, and AUC with 3T were greater than those with 1.5T on a per-vessel basis (71% vs. 36%, 92% vs. 69%, and 0.82 vs. 0.53, respectively). CONCLUSION: 3T CMR has similar diagnostic performance to 1.5T CMR in detecting significant CAD, except for higher diagnostic performance in patients with multi-vessel CAD without old MI.

Diagnostic Accuracy of Electrocardiogram-Gated Thoracic Computed Tomography Angiography without Heart Rate Control for Detection of Significant Coronary Artery Stenosis in Patients with Acute Ischemic Stroke: A Comparative Study

OBJECTIVE: To compare the diagnostic performance of electrocardiogram (ECG)-gated thoracic computed tomography angiography (TCTA) without heart rate (HR) control in ischemic stroke patients with coronary CTA (CCTA) in non-stroke patients for detection of significant coronary artery stenosis. MATERIALS AND METHODS: From September 2009 through August 2014, we retrospectively enrolled 138 consecutive patients diagnosed with acute ischemic stroke who had undergone ECG-gated TCTA and conventional coronary angiography (CCA). Over the same period, we selected 167 non-stroke patients with suspected or known coronary artery disease who had undergone CCTA and CCA. With CCA as the reference standard, the diagnostic performance of TCTA and CCTA for identification of significant coronary stenosis (diameter reduction ≥ 50%) was calculated. RESULTS: There was no significant difference in baseline characteristics between TCTA (n = 132) and CCTA (n = 164), except for the higher prevalence of atrial fibrillation in the stroke group. There was significant difference (p < 0.001) between TCTA and CCTA in average HR (68 ± 12 vs. 61 ± 10 beats per minute) and image quality score (1.3 ± 0.6 vs. 1.2 ± 0.6). Significant coronary stenosis was identified in 101 (77%) patients, 179 (45%) vessels, and 293 (15%) segments of stroke patients, and in 136 (83%) patients, 259 (53%) vessels, and 404 (16%) segments of non-stroke patients. Diagnostic performance on a per-vessel and per-patient basis was similar in both TCTA and CCTA groups. There was only significant difference in area under receiver-operating characteristic curve between TCTA and CCTA groups (0.79 vs. 0.87, p < 0.001) on per-segment basis. CONCLUSION: Electrocardiogram-gated TCTA without HR control facilitates the identification of significant coronary stenosis in patients with ischemic stroke.

Diagnostic Performance of Coronary CT Angiography, Stress Dual-Energy CT Perfusion, and Stress Perfusion Single-Photon Emission Computed Tomography for Coronary Artery Disease: Comparison with Combined Invasive Coronary Angiography and Stress Perfusion Ca

OBJECTIVE: To investigate the diagnostic performance of coronary computed tomography angiography (CCTA), stress dual-energy computed tomography perfusion (DE-CTP), stress perfusion single-photon emission computed tomography (SPECT), and the combinations of CCTA with myocardial perfusion imaging (CCTA + DE-CTP and CCTA + SPECT) for identifying coronary artery stenosis that causes myocardial hypoperfusion. Combined invasive coronary angiography (ICA) and stress perfusion cardiac magnetic resonance (SP-CMR) imaging are used as the reference standard. MATERIALS AND METHODS: We retrospectively reviewed the records of 25 patients with suspected coronary artery disease, who underwent CCTA, DE-CTP, SPECT, SP-CMR, and ICA. The reference standard was defined as ≥ 50% stenosis by ICA, with a corresponding myocardial hypoperfusion on SP-CMR. RESULTS: For per-vascular territory analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 96, 96, 68, 93, and 68%, respectively, and specificities were 72, 75, 89, 85, and 94%, respectively. The areas under the receiver operating characteristic curve (AUCs) were 0.84 ± 0.05, 0.85 ± 0.05, 0.79 ± 0.06, 0.89 ± 0.04, and 0.81 ± 0.06, respectively. For per-patient analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 100, 100, 89, 100, and 83%, respectively; the specificities were 14, 43, 57, 43, and 57%, respectively; and the AUCs were 0.57 ± 0.13, 0.71 ± 0.11, 0.73 ± 0.11, 0.71 ± 0.11, and 0.70 ± 0.11, respectively. CONCLUSION: The combination of CCTA and DE-CTP enhances specificity without a loss of sensitivity for detecting hemodynamically significant coronary artery stenosis, as defined by combined ICA and SP-CMR.

A Case of Hepatopulmonary Syndrome in a Patient with Child-Pugh Class A Liver Cirrhosis / 결핵및호흡기질환

Hepatopulmonary syndrome (HPS) is characterized by a defect in arterial oxygenation that's induced by pulmonary vascular dilatation in the setting of liver disease. Some studies have shown the relationship between the presence of the HPS and the severity of liver disease, but there are only rare cases of HPS inpatient with Child-Pugh class A liver cirrhosis. We report here on a case of a 58 years-old male who suffered from progressive dyspnea for the previous few years. He was diagnosed with alcoholic liver cirrhosis 5 years previously. There was no significant abnormality on the chest radiograph and transthoracic echocardiography, but the arterial blood gas analysis revealed severe hypoxemia. Contrast-enhanced transesophageal echocardiograpy with agitated saline demonstrated a delayed appearance of microbubbles in the left cardiac chambers. Thus, he was finally diagnosed with HPS. This case suggests that we should consider HPS when a patient with compensated liver cirrhosis has unexplained dyspnea.

Deep Vein Thrombosis and Pulmonary Embolism in the 8th Week of Pregnancy

A 29-year-old woman in her 8th week of pregnancy was referred to our hospital for swelling in the lower extremities, rapid onset of dyspnea (1 hr) and pre-syncope. Severe right ventricular dysfunction and moderate pulmonary hypertension were detected using 2-dimentional Doppler echocardiography. In addition, left calf vein and proximal thromboses were detected by venous compression ultrasound imaging. After successful thrombolytic treatment, the patient quickly recovered and was discharged from hospital on subcutaneous low-molecular-weight heparin. She delivered a normal, healthy infant at full-term (40 weeks).

Significance of Microembolic Signals during Oxygen Inhalation in Patients with Prosthetic Mechanical Heart Valve / 대한흉부외과학회지

BACKGROUND: Transcranial Doppler ultrasonography (TCD) can detect microembolic signals (MES) in the patients with a potential embolic source. Clinical significance of MES has not been demonstrated in patients with prosthetic mechanical heart valves. We studied the correlation between cerebral thromboemoblic events after the mechanical heart valve surgery (MHVS) and residual MES during TCD monitoring with 100% oxygen inhalation in patients with mechanical heart valves. MATERIAL AND METHOD: Twenty patients with previous cerebral thromboemoblic events after MHVS and a sex- and age-matched control group (n=30) were studied. TCD monitoring was performed from unilateral middle cerebral artery. After baseline monitoring for 20 minutes, 6L of oxygen was inspired for 40 minutes. RESULT: The site of valve and the duration after MHVS of the patients did not differ from those of controls. During baseline monitoring, there was no significant difference in MES prevalence or counts compared to controls. During oxygen inhalation, patients showed a higher MES prevalence (55%, 27.6%, p=0.045) and a more frequent MES counts (p=0.027) compared to controls. CONCLUSION: TCD monitoring with oxygen inhalation may be useful to differentiate clinically significant MES in patients with mechanical heart valve.

A Case of Isolated Left Main Coronary Ostial Stenosis Due to Acute Angle Take-off with Clockwise Rotation of Coronary Sinus confirmed by MRI Image

Isolated left main coronary ostial stenosis is a very rare condition. In the majority of cases there are coexisting diseases in multiple coronary vessels. Here, a case of isolated left main coronary ostial stenosis due to an acute angle take-off, with clockwise rotation of the coronary sinus, confirmed by cardiac MRI is presented. A 44-year old female patient presented with an exertional and stabbing anterior chest pain. The patient had no premedical history. A coronary angiogram showed an isolated left main coronary ostial stenosis due to an acute take-off of the left main coronary artery. A cardiac MRI showed an acute angle take-off of the left main coronary artery, with clockwise rotation of the coronary sinus. The patient underwent surgical angioplasty of the coronary ostia, with a patch of autologous pericardium. This acute angle take-off may be due to rotation of the coronary sinus.

Immediate and long-Term Results of Percutaneous Mitral Valvuloplasty Using the Inoue Balloon

BACKGROUND AND OBJECTIVES: The objective of this study was to assess the short- and long-term clinical outcomes and valvular changes after percutaneous mitral valvuloplasty (PMV) in Sejong Hospital. SUBJECTS AND METHOD: Four hundred sixty-seven patients received PMV (Ed-already defined above) using the Inoue Balloon at Sejong hospital from 1990 to 2002. Short and long-term results, restenosis-free survival rate and prognostic factors for each result were analyzed by Chi-square, Cox regression analysis, Life table method and Cox proportional hazard model. RESULTS: After PMV, mitral valve area increased from 0.94+/-0.21 cm2 to 1.76+/-0.37 cm2 and the success rate (MVA>1.5 cm2 or increased by at least 50% without the development of moderate to severe mitral regurgitation) was 78.9%. Age ( or =1.1 cm2, p=0.001) were independent favorable prognostic factors for short-term result. As for the development of moderate to severe mitral regurgitation, pre-procedural MVA (9, p=0.043) were independent predictive factors. Median restenosis-free survival was 82.98 months and the restenosis-free survival rate was 70.9% at 3 years post-PMV, 48.1% at 6 years and 29.6% at 10 years. The independent prognostic factor for restenosis-free survival rate was left atrial dimension (LAD or =1.0 cm2, p=0.24) and ejection fraction (EF> or =55%, p=0.146) had an effect on the good long-term results of PMV from multivariate analysis. CONCLUSION: PMV was a very successful treatment method for mitral stenosis. Pre-procedural MVA was a representative predictive factor for short and long-term outcomes and the development of mitral regurgitation.

Familial Sick Sinus Syndrome

This paper presents a family with sick sinus syndrome, spanning three generations and with an autosomal dominant trait. The proband was affected by atrial fibrillation with a slow ventricular rhythm that required a permanent pacemaker. Her three sons were affected with a sinus node dysfunction and one daughter died suddenly at the age of 32 years. A pacemaker was implanted in the proband and her two sons with symptoms related to bradycardia. One of her sons with the pacemaker died of a cerebrovascular accident several months later. We report a family with sick sinus syndrome requiring the implantation of a pacemaker with a review of the literature.

A Case of Mitral Regurgitation due to Windsock Deformity with Perforations of the Anterior Mitral Leaflet-a Late Complication of Endocarditis

A valvular perforation is a well-known, and common, complication of infective endocarditis that may adversely affect the clinical outcome. However, a 'windsock' deformity of the mitral valve, as a delayed presentation of infective endocarditis, affecting the mitral valve alone, is very rare. A 42-year-old man, who underwent a mitral valvuloplasty and annuloplasty six years previously, suddenly developed pulmonary edema. He had also had a previous history of infective endocarditis, dating back three years. A transthoracic echocardiogram revealed a 'windsock' deformity of the anterior mitral leaflet (AML), resulting in an acute severe mitral regurgitation. During the operation, the AML was found to have been damaged by the previous endocarditis, resulting in an aneurysmal change of the central scallop, and a rupture of the roof. A mitral valve replacement was successfully performed, and the patient recovered uneventfully. Here, we report a rare case of a 'windsock' deformity of the mitral valve, with two perforations as a delayed complication of a healed infective endocarditis.

A Case of Acute Myocardial Infarction due to Coronary Microembolism in Bacterial Endocarditis

Spontaneous coronary artery embolization is a known complication of infective endocarditis. However, a microembolism from the aortic valve into the left anterior descending artery resulting in an acute anterior myocardial infarction is very rare. A 44-year-old male patient suffered from chest pain and fever of seven days duration. The echocardiogram demonstrated severe aortic stenosis, aortic root abscess and mobile vegetation on bicuspid aortic valve near the left coronary artery ostium. The electrocardiogram revealed ST segment elevation in lead V1-3 and heart enzyme analysis showed LD 936 IU/L, CK 299 IU/L, CK-MB 7.2 U/L, Troponin I 9.94 ng/mL. Diagnostic coronary angiogram revealed insignificant coronary lesion. Emergent operation was required because of aortic root abscess formation and high risk of recurrent embolization. He underwent surgery for aortic valve replacement and conservative management for acute myocardial infarction. The purpose of this article is to report the successful emergent aortic valve replacement of a patient with myocardial infarction due to coronary microembolism in a case of bacterial endocarditis.

A Case of Three Major Coronary Arteries to Left Ventricular Fistulae via Common Channel

Multiple coronary arteries to communicating with the left ventricular fistulae is a very rare congenital anomaly in adults. This anomaly involves three major coronary arteries that have a direct communication between these arteries and the left ventricle. Hemodynamically, it induces myocardial ischemia due to coronary steal syndrome and diastolic volume overload from a left-to-left shunt. A 70-year-old woman with essential hypertension was admitted to our clinic to evaluate complaints of exertional dyspnea. Clinical examination revealed a diastolic murmur at the apex. A coronary angiogram showed a common fistular channel connecting the right coronary artery, the left circumflex coronary artery, and the first large diagonal branch of the left anterior descending coronary artery with the left ventricular chamber. The patient's symptoms were relieved by the administration of calcium channel blocker and angiotensin II receptor blocker. We report a very rare case of three major coronary arteries communicating to the left ventricular fistulae via a common channel.

Results of Eight-Year Follow-Up of Omniscience Cardiac Prosthetic Valve

BACKGROUND AND OBJECTIVES: This study was performed to assess the morbidity and mortality of 311 patients implanted with at least one Omniscience prosthetic valve between January 1992 and January 2000. SUBJECTS AND METHODS: Following valve implantation all patients were followed up with routine interviews, physical examination and echocardiography. RESULTS: The mean follow-up duration was 5.8+/-0.9 (standard error, SE) years with a mean follow-up interval of 8.5+/-0.7 (SE) months. The 311 patients received the following type (s) of valve: mitral, aortic, both or tricuspid valve, in 166 (47.9%), 99 (32.0%), 44 (19.5%) and 2 (0.6%) of cases, respectively. The cumulative follow up was 1143.4 patient-years (pt-yr). Death occurred in eight patients (0.7%/ pt-yr at linearized rate), and redo-operations were required in 27 patients (2.4%/pt-yr) due to valve failure. Actuarial freedom from all complication was 72.5%+/-8.2% (SE). Freedom from pannus formation, paravalvular leak, or thromboembolism plus anticoagulant related bleeding were 83.1%+/-3.5% (MVR/AVR 92.7%+/-4.7%/73.4%+/-2.8%), 95.2%+/-2.1% (MVR/AVR 96.8%+/-4.2%/93.6%+/-3.2%), and 96.1%+/-2.5% (MVR/AVR 95.6%+/-5.6%/96.7%+/-4.7%) respectively. CONCLUSION: Our results with this prosthesis demonstrate relatively high incidences of valve related complication especially due to pannus formations and paravalvular leaks. We could reduce the incidences of mortality by earlier detection of complications, redo-operations and routine checks.

A Case of Mitral Regurgitation due to Isolated Cleft Mitral Valve

A cleft in the anterior mitral valve leaflet is commonly associated with an atrioventricular septal defect, but an isolated cleft mitral valve is a rare condition. We report a case of a 27-year-old woman with severe mitral regurgitation due to an isolated cleft mitral valve. The echocardiography showed an anterior cleft on the mitral valve, but a normal sized and positioned left ventricular papillary muscle without septal defect. Under the diagnosis of mitral regurgitation due to the isolated cleft mitral valve the patient underwent mitral cleft repair. After surgery, the further echocardiography showed no mitral regurgitation.

A Case Report on the Inflation Failure of Distal Portion of Inoue Balloon during Percutaneous Mitral Valvuloplasty in a Patient with Rheumatic Mitral Stenosis

Since Inoue et al introduced a specially designed balloon catheter for percutaneous mitral valvuloplasty (PMV) in 1984, the Inoue balloon catheter has been a popular device for the management of mitral stenosis. During the procedure several fatal complications, such as cardiac tamponade, perforation of a cardiac chamber, atrial septal defect, thromboembolism, mitral regurgitation and death have all been reported in the literature. There have also been several international reports regarding deformities of the Inoue balloon, but few reports in Korea. We recently experienced a case of an inflation failure of the distal portion of the Inoue balloon during a percutaneous mitral valvuloplasty in a 34 year old female patient with a tight mitral stenosis. To the best of our knowledge, a similar deformity of an Inoue balloon has never been reported in Korea.

A Case Report of Inoue Balloon Deformity Recognized during Percutaneous Mitral Valvuloplasty

Since the Inoue balloon was first introduced for percutaneous mitral valvuloplasty (PMV) in 1984, this procedure has come into widespread use because of its effectiveness, simplicity, and reduced exposure to X-ray radiation. It's the procedure's complications include cardiac tamponade, atrial septal defect, thromboembolism, ventricular perforation, mitral regurgitation, and rarely balloon rupture. We report a case of Inoue balloon deformity during PMV in 62-year old woman with rheumatic mitral stenosis. Echocardiography revealed severe rheumatic mitral stenosis with a valvular area of 0.95 cm2 (by pressure half-time method), and an Echo score of 10 points. The PMV with Inoue balloon 28 mm was performed. We inflated the balloon to 28 mm in diameter first, and to 29 mm second. A bulging deformity with asymmetrical overinflation of one side of both proximal and distal balloon was recognized. A bulging deformity at the proximal part of Inoue balloon after second inflation. Balloon was not ruptured. Following completion of the procedure, the mitral valve area increased to 1.8 cm2. Moderate mitral regurgitation (grade II) was newly developed. This may be the first case of asymmetrical one side inflation and focal bulging deformity reported in Korea.

A Case of Isolated Left Main Coronary Ostial Stenosis due to Acute Angle Takeoff

Isolated and severe left main coronary ostial stenosis is a rare case. In the majority of these patients ostial stenosis was associated with any of the conditions known to involve the coronary ostia. These conditions include syphilitic aortitis, Takayasu's aortitis, familial hypercholesterolemia, and aortic valve disease. A 34-year young female patient was presented with exertional and stabbing anterior chest pain. There was no history of syphilis, diabetes mellitus, hypertension, hyperlipidemia and smoking. Coronary angiogram showed isolated left main coronary ostial stenosis. Transesophageal echocardiography(TEE) showed acute angle takeoff of the left main coronary artery. She underwent surgical angioplasty of coronary ostia with a patch of autologous pericardium. After angioplasty, TEE showed dilatation of left main coronary ostium and her clinical symptom improved.

Implantation Metastasis of Lung Cancer to Chest Wall after Percutaneous Fine-Needle Aspiration Biopsy / 결핵

The implatnation of malignant cells along the needle tract is an extremely rare complication after a percutaneous fine-needle aspiration biopsy(FNAB). However, it is very serious and may result in a change in the prognosis of lung cancer, especially in the curable early stage(T1-2,N0,M0). Recently, we experienced two cases of such complications. A 43 years old female underwent a fine needle aspiration biopsy and a right middle lobectomy with adjuvant chemotherapy due to an adenocarcinoma(T2N0M0). Two years later, a new tumor developed at the site of the needle aspiration biopsy. It had the same pathological findings as the previous lung cancer. Therefore, it was concluded to be an implantation metastasis, and she was treated successfully by a right pneumonectomy and a resection of the chest wall mall with adjuvant radiotherapy. In another case, a 62 years old man was diagnosed with squamous cell lung cancer by a fine needle aspiration biopsy and underwent a right upper lobectomy(T2N0M0) with adjuvant chemotherapy. eight months later, a protruding chest wall mass developed at the aspiration site. It showed the same pathological findings as the previous lung cancer. Consequently, a total excision of the mass with adjuvant radiotherapy was done. Two years after the second operation, although the right lung was intace a metachronous squamous cell lung cancer was found at the left lower lobe. The two patients were still alive 15 and 37 months after thenresection of the chest wall mass, respectively.

Replacement of the aortic root with a pulmonary autograft; short term results from 8 patients / 대한내과학회지

BACKGROUND: Ross procedure is the pulmonary valve autograft in the aortic valve disease, and its use trends to increase after introduced by Ross in 1967, firstly. The most important point is that it is a permanent valve replacement. It is to be ideal method to the young patient because the graft is a viable tissue to be able to grow, and hemodynamically, most similar to the normal aortic valve, and doesn't need to do anticoagulation therapy due to not having the thromboembolism, but not popular because it has a lot of technical problem and doesn't have the long-term follow-up METHODS: The patients were 8 admitted between October 1997 and October 1998, the age from 15 to 39 ; 6 males and 2 females. The causes of disease were 4 patients of rheumatic disease, 1 of a infective endocarditis with the aortic annular abscess,1 of recurred severe aortic insufficiency 2 years after replacement. Two patients used the homograft and 6 patients switched a diseased aortic valve with the pulmonary autograft. RESULTS: There were no death and the preoperative dyspnea nearly disappeared (NYHA FC III-IV -> I-II). The diastolic diameter of left ventricle decreased significantly when we compared to the previous echocardiography 1 month after the operation, and we observed the mild aortic valve insufficiency in 3 patients, severe in 4, mild pulmonary valve insufficiency in 4, severe in 1, and mild pulmonary valve stenosis in 4. CONCLUSION: The operative death rate of Ross procedure in the aortic valve disease was not higher than the artificial valve replacement. Therefore, if we find the appropriate indication of operation, we can expect better results and think that we should have the long-term follow-up furthermore.

Clinical Observation of Myocardial Bridge

BACKGROUND AND OBJECTIVE: A myocardial bridge(MB) is an anatomical arrangement in which an epicardial coronary artery becomes engulfed for a limited segment by myocardial fibers. Although it has generally been felt that most instance of bridge are benign. Recent reports have suggested that MB can be associated with evidence of myocardial ischemia, myocardial infarction, arrhythmia and sudden death. This study investigated clinical characteristics of myocardial bridge and significance of treadmill test(TMT). METHOD: Among 4317 consecutive coronary angiograms performed from November 1995 to June 1999, 52 patients had a myocardial bridge. For the patients with MB, the clinical data, coronary angiography and the results of treadmill tests were reviewed. RESULT: The overall prevalence of myocardial bridge was 1.22%. Stable angina, atypical chest pain, variant angina, AMI were 33(63%), 15(29%), 2(4%), 2(%) cases, respectively. Electrocardiographic finding were normal in 31 cases(59%), ST-T change in 20 cases(38%), OMI in 1 case(3%). Mean systolic stenosis of MB was 54%, Mean length of segment of MB was 11.96 4.96mm and all patients had MBs of left anterior descending(LAD) coronary artery. Among 23 cases which had been performed TMT, 17 were positive(77%). There was no significant statistical difference between TMT(+) and TMT(-) in clinical characteristic and coronary angiographic data. We divided the patients with MB into two groups [group I(34 cases): systolic compression < 50%(mean 35.1 10.7%), group II(18 cases): systolic compression 50%(mean 63.6 14.7%)] and there were no statistical difference in clinical characteristics, TMT and angiographic data. CONCLUSION: The patients with MB present variable clinical characteristics of stable angina, atypical chest pain, variant angina, acute myocardial infarction. There is no relationship between the degree of systolic compression and TMT positive in MB. We think that symptoms of MB are not developed only by mechanical compression but concerned with other variable mechanism.