Comparative value of transthoracic and transoesophageal echocardiography before balloon dilatation of the mitral valve

Objective—To assess the relative merits of transthoracic and transoesophageal echocardiography before balloon dilatation of the mitral valve.

Design—Transthoracic and transoesophageal echocardiograms were prospectively performed in 35 patients being considered for balloon dilatation of the mitral valve. Echocardiograms were analysed for image quality, the assessment of valve morphology, the detection of left atrial thrombus, and the assessment of mitral regurgitation and other valvar pathology.

Patients—35 consecutive patients with symptomatic dominant mitral stenosis.

Interventions—30 eventually underwent balloon dilatation of the mitral valve by the Inoue technique. Five patients had mitral valve replacement.

Main outcome measures—Echocardiographic and surgical detection of left atrial thrombus and successful, uncomplicated balloon dilatation of the mitral valve.

Results—Left atrial thrombus was detected in 1/35 patients by transthoracic studies compared with 6/35 from transoesophageal studies. Otherwise both techniques gave comparable results. Thrombus was confirmed at mitral valve replacement in five patients. Successful dilatation of the mitral valve was performed in 30 patients.

Conclusions—Transthoracic echocardiography is a useful screening procedure but transoesophageal echocardiography is mandatory before balloon dilatation of the mitral valve for the detection of left atrial thrombus.

     

Use of transoesophageal echocardiography to detect left atrial thrombi before percutaneous balloon dilatation of the mitral valve: a prospective study.

OBJECTIVE--Systemic emboli related to atrial thrombi are a well known complication of percutaneous balloon dilatation of the mitral valve. The presence of left atrial thrombi therefore, is believed to be a contraindication to balloon dilatation. The purpose of this study was to determine the frequency of left atrial thrombi in patients referred for balloon dilatation of the mitral valve, the added benefit of pre-procedural transoesophageal echocardiography, and to identify factors that predicted left atrial thrombi. DESIGN--Prospective study over a 14 month period of 20 consecutive patients by cross sectional transthoracic echocardiography 24-48 hours before balloon dilatation of the mitral valve and by transoesophageal echocardiography immediately before the procedure. RESULTS--One patient had a left atrial thrombus detected by transthoracic study. Two patients (10%) had left atrial thrombi identified by transoesophageal echocardiography. In both valve dilatation was not attempted and the thrombi were confirmed at surgery. The remaining 18 patients all underwent successful balloon dilatation of the mitral valve without clinical evidence of an embolic event. No association was found between patient age, mitral valve area, transmitral gradient, left atrial size, presence of atrial fibrillation, severity of mitral regurgitation, cardiac output, or the presence of left atrial swirling and an increased prevalence of atrial thrombi. CONCLUSION--Left atrial thrombi are often seen despite long term systemic anticoagulation in patients referred for balloon dilatation of the mitral valve. The frequency of unsuspected left atrial thrombi detected by transoesophageal echocardiography was similar to the reported frequency of embolic events after balloon dilatation of the mitral valve. Transoesophageal echocardiography for the identification of left atrial thrombi is strongly recommended in all patients before balloon dilatation of the mitral valve including those treated with systemic anticoagulation and those who have had a normal transthoracic echocardiographic study.     

Use of transoesophageal echocardiography to detect left atrial thrombi before percutaneous balloon dilatation of the mitral valve: a prospective study.

OBJECTIVE--Systemic emboli related to atrial thrombi are a well known complication of percutaneous balloon dilatation of the mitral valve. The presence of left atrial thrombi therefore, is believed to be a contraindication to balloon dilatation. The purpose of this study was to determine the frequency of left atrial thrombi in patients referred for balloon dilatation of the mitral valve, the added benefit of pre-procedural transoesophageal echocardiography, and to identify factors that predicted left atrial thrombi. DESIGN--Prospective study over a 14 month period of 20 consecutive patients by cross sectional transthoracic echocardiography 24-48 hours before balloon dilatation of the mitral valve and by transoesophageal echocardiography immediately before the procedure. RESULTS--One patient had a left atrial thrombus detected by transthoracic study. Two patients (10%) had left atrial thrombi identified by transoesophageal echocardiography. In both valve dilatation was not attempted and the thrombi were confirmed at surgery. The remaining 18 patients all underwent successful balloon dilatation of the mitral valve without clinical evidence of an embolic event. No association was found between patient age, mitral valve area, transmitral gradient, left atrial size, presence of atrial fibrillation, severity of mitral regurgitation, cardiac output, or the presence of left atrial swirling and an increased prevalence of atrial thrombi. CONCLUSION--Left atrial thrombi are often seen despite long term systemic anticoagulation in patients referred for balloon dilatation of the mitral valve. The frequency of unsuspected left atrial thrombi detected by transoesophageal echocardiography was similar to the reported frequency of embolic events after balloon dilatation of the mitral valve. Transoesophageal echocardiography for the identification of left atrial thrombi is strongly recommended in all patients before balloon dilatation of the mitral valve including those treated with systemic anticoagulation and those who have had a normal transthoracic echocardiographic study.     

Assessment of mitral valve commissural morphology by transoesophageal echocardiography predicts outcome after balloon mitral valvotomy

BackgroundBalloon mitral valvotomy (BMV) is a safe and an effective treatment in patients with symptomatic rheumatic mitral stenosis. This study was conducted to validate the importance of assessing the morphology of mitral valve commissures by transoesophageal echocardiography and thereby predicting the outcome after balloon mitral valvotomy [BMV].Materials and methodsStudy consisted of 100 patients with symptomatic mitral stenosis undergoing BMV. The Commissural Morphology and Wilkins score were assessed by transoesophageal echocardiography. Both the commissures (anterolateral and posteromedial) were scored individually according to whether non-calcified fusion was absent (0), partial (1), or extensive (2) and calcification (score 0) and combined giving an overall commissural score of 0–4. Outcome of BMV was correlated with commissural score and Wilkins score.ResultsThe commissural score and outcome after BMV correlated significantly. 66 of 70 patients (94%) with a commissural score of 3–4 obtained a good outcome compared with only six (20%) patients of 30 with a commissural score of 0–2 (positive and negative predictive accuracy 94% and 80%, respectively, p < 0.001). Increase in 2DMVA post BMV was more in patients with higher commissural score (score of 3–4). Wilkins score <8 usually predicts a good outcome but even in patients with Wilkins score >8 a commissural score >2 predicts a 50% chance of a good result.ConclusionsA higher commissural score predicts a good outcome after BMV hence it can be concluded that along with Wilkins score, commissural morphology and score should be assessed with TOE in patients undergoing BMV.     

Diagnosis of mitral valve aneurysm by transoesophageal echocardiography.

In a patient with mitral valve aneurysm precordial echocardiography suggested a mistaken diagnosis of infective endocarditis. Transoesophageal echocardiographic examination established the correct diagnosis, which was subsequently confirmed at operation. Transoesophageal echocardiography gives better resolution of lesions associated with the mitral valve than precordial examination and may improve the diagnostic accuracy.     

Doppler echocardiographic assessment of transmitral gradients and mitral valve area before and after mitral valve balloon dilatation

This is a comparative study of 60 sets of observations of mitral valve end-diastolic gradient, mean diastolic gradient, and mitral valve area obtained by Doppler echocardiography and cardiac catheterization. The studies were performed in 28 patients, 16 of whom underwent mitral valve balloon valvuloplasty. These 16 patients had studies performed before, immediately after valvuloplasty, and one week later. Thus 28 studies were performed before or without valvuloplasty (Group I) and 32 after valvuloplasty (Group II). The time interval between Doppler echocardiography and cardiac catheterization was less than 24 hours in 44 studies and 24 to 72 hours in 16 studies. In Doppler echocardiography the gradients were obtained by simplified Bernoulli's equation and the mitral valve area by pressure half-time method. There was excellent correlation between end-diastolic gradients (r = 0.96, p less than 0.001) and mean diastolic gradients (r = 0.92, p less than 0.001) measured by the two techniques. A statistically significant correlation also existed in the mitral valve area values (r = 0.53, p less than 0.005). On separate analysis Group I showed excellent correlation for all three variables (r values of 0.90, 0.87, and 0.82 for end-diastolic gradients, mean-diastolic gradients, and mitral valve area, respectively). Group II also showed excellent correlation of end-diastolic gradients (r = 0.80) and mean diastolic gradients (r = 0.87), but poor correlation of the mitral valve areas (r = 0.17; p = NS) by the two techniques. Doppler echocardiography can accurately measure transmitral gradients both before and after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of mitral valve aneurysm by transoesophageal echocardiography

In a patient with mitral valve aneurysm precordial echocardiography suggested a mistaken diagnosis of infective endocarditis. Transoesophageal echocardiographic examination established the correct diagnosis, which was subsequently confirmed at operation. Transoesophageal echocardiography gives better resolution of lesions associated with the mitral valve than precordial examination and may improve the diagnostic accuracy.     

Exercise ventilation after balloon dilatation of the mitral valve.

BACKGROUND--Exertional dyspnoea is a limiting symptom in many patients with mitral stenosis but its causes remain incompletely understood. Ventilation during exercise is abnormal in chronic heart failure of all causes and there is increased ventilatory cost of carbon dioxide production. PATIENTS--23 patients with rheumatic mitral stenosis undergoing percutaneous balloon dilatation of the mitral valve were studied to investigate exercise ventilation. METHODS--Treadmill exercise tests with respiratory gas analysis were performed before and 1 day, 7 days, and 10 weeks after balloon dilatation of the mitral valve. The relation between ventilation (VE) and production (VCO2) was analysed by linear regression. RESULTS--The VE/VCO2 slope was linear in all patients and before balloon dilatation of the mitral valve it correlated inversely with peak minute oxygen consumption (VO2) (rs = -0.47, P < 0.05), exercise duration (rs = -0.66, P < 0.01), and mitral valve area (rs = -0.5, P < 0.05). The VE/VCO2 slope declined acutely after balloon dilatation of the mitral valve (n = 10) (mean (SD) 41 (4) v 36 (2.9), P < 0.05) and did not change again thereafter. At 10 weeks (n = 23) exercise duration (460 (230) v 630 (240) s, P < 0.01) and peak VO2 (12.7 (4.3) v 14.9 (4.8) ml/kg/min, P < 0.05) increased significantly. CONCLUSIONS--Patients with rheumatic mitral stenosis have a similar increase in the VE/VCO2 slope to that of patients with heart failure from other causes. Successful balloon dilatation of the mitral valve is associated with an acute reduction in the exercise VE/VCO2 slope.     

Infective endocarditis following balloon dilatation of mitral valve.

Three cases of infective endocarditis were encountered following balloon dilatation of the mitral valve. The diagnosis was difficult due to negative blood cultures and nondiagnostic transthoracic echocardiogram, the latter the consequence of the preexisting severe rheumatic valvar disease. Transoesophageal echocardiography proved superior in diagnosis. The possible causes and means of preventing this potentially lethal complication are discussed.     

Evaluation of mitral valve repair by intraoperative transoesophageal echocardiography

Background: Mitral valve repair is the procedure of choice in the surgical management of mitral regurgitation. Intraoperative confirmation of successful repair is essential to the effectiveness of this procedure.
Aims: The aims of this study were: (a) to compare intraoperative transoesophageal echocardiography (TOE) with the surgeon's assessment of valve competence; (b) to assess the impact of routine intraoperative imaging on the hospital echocardiography laboratory.
Methods: Eighty-six consecutive patients undergoing mitral valve repair formed the study population. Valve competence following repair was assessed intraoperatively by: TOE; saline insufflation of the flaccid left ventricle; and evaluation of the pulmonary capillary wedge pressure for the presence of a significant V wave.
Results: TOE demonstrated successful valve repair (≤ 1 + residual regurgitation) in 75 patients (87%) and detected significant residual regurgitation (≥3 +) in seven (8.2%). The mechanism of regurgitation was also clearly shown. Of these seven patients, four underwent immediate valve replacement, two had successful revision of the initial repair and one required valve replacement one week later. In all seven patients the valve repair had been assessed as successful by saline testing and only one had a post-repair V wave 10 mmHg above the mean pulmonary capillary wedge pressure. In 30 non-selected patients the imaging equipment was required in theatre for 43 ± 18 minutes.
Conclusions : TOE is currently the most sensitive method for detection and quantitation of residual mitral regurgitation following valve repair. Evaluation can be performed within a similar time to that required for one complete transthoracic study and can usually be performed with minimal disruption to the hospital echocardiography laboratory. (Aust NZ J Med 1993; 23: 463–469.)     

Usefulness of transthoracic echocardiography for identification of left atrial thrombus before balloon mitral valvuloplasty

The objectives of this study were (1) to identify clinical and transthoracic echocardiographic features of patients with mitral stenosis who have thrombus recognized on transesophageal echocardiography, and (2) to define a clinical and echocardiographic model to predict the presence of left atrial thrombus in these patients.     

Residual atrial septal defects following balloon mitral valvuloplasty using different techniques. A transthoracic and transoesophageal echocardiography study demonstrating an advantage of the Inoue balloon.

The incidence and severity of atrial septal defects following balloon mitral valvuloplasty have been assessed using transthoracic and transoesophageal echocardiography in 20 patients 3-36 months following the procedure. In eight patients (group A) the atrial septum was dilated with an 8 mm Olbert balloon and either a double or bifoil balloon used to dilate the mitral valve. In 12 patients (group B) the Inoue balloon, with a slimmer deflated profile, was used following dilatation of the interatrial septum with a 14 French vessel dilator. In group A, using transthoracic echocardiography, one atrial septal defect was imaged and transatrial flow detected by colour flow Doppler in five patients. In seven of the eight patients transoesophageal echocardiography clearly imaged an atrial septal defect and left-to-right shunting was demonstrated by colour flow Doppler. Valsalva contrast studies revealed residual transatrial flow in all eight patients. The mean width of the colour flow jet was 5.8 mm. In group B patients, using transthoracic echocardiography, only one patient had evidence of residual transatrial flow (demonstrated by Valsalva contrast). Using transoesophageal echocardiography Valsalva contrast studies, transatrial flow was seen in 11 of the 12 patients. However, no defects were imaged and colour flow Doppler indicated left-to-right shunting in only two patients. The mean width of the colour flow jet was 1.5 mm. Transoesophageal echocardiography with colour flow Doppler and Valsalva contrast studies therefore provides a sensitive method for the detection of residual atrial septal defects following balloon mitral valvuloplasty. Transatrial flow persists in the majority of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal balloon dilatation of the mitral valve in pregnancy.

Pregnancy can cause life threatening complications in women with mitral stenosis, and there is a substantial risk of fetal death if valvotomy under cardiopulmonary bypass is required. A patient is described in whom pulmonary oedema developed after delivery of her first child by caesarean section 13 months previously. Subsequent cardiac catheterisation showed severe mitral stenosis (valve area 0.96 cm2, valve gradient 12 mm Hg, pulmonary artery pressure 30/16 mm Hg). Before valvotomy could be performed the patient again became pregnant and presented in pulmonary oedema at twenty two weeks' gestation. Medical treatment was unsuccessful and she underwent percutaneous transluminal balloon dilatation of the mitral valve. This increased the valve area to 1.78 cm2 and reduced the transmitral gradient to 6 mm Hg. The procedure was uncomplicated, and she remained symptom free on no medication. She delivered vaginally at 37 weeks' gestation. Percutaneous transluminal balloon dilatation of the mitral valve is a safe and effective alternative to mitral valvotomy in pregnancy.     

Percutaneous transluminal balloon dilatation of the mitral valve in pregnancy

Pregnancy can cause life threatening complications in women with mitral stenosis, and there is a substantial risk of fetal death if valvotomy under cardiopulmonary bypass is required. A patient is described in whom pulmonary oedema developed after delivery of her first child by caesarean section 13 months previously. Subsequent cardiac catheterisation showed severe mitral stenosis (valve area 0.96 cm2, valve gradient 12 mm Hg, pulmonary artery pressure 30/16 mm Hg). Before valvotomy could be performed the patient again became pregnant and presented in pulmonary oedema at twenty two weeks' gestation. Medical treatment was unsuccessful and she underwent percutaneous transluminal balloon dilatation of the mitral valve. This increased the valve area to 1.78 cm2 and reduced the transmitral gradient to 6 mm Hg. The procedure was uncomplicated, and she remained symptom free on no medication. She delivered vaginally at 37 weeks' gestation. Percutaneous transluminal balloon dilatation of the mitral valve is a safe and effective alternative to mitral valvotomy in pregnancy.     

Diagnosis of prosthetic heart valve thrombosis. The respective values of transthoracic and transoesophageal Doppler echocardiography

Early diagnosis of acute prosthetic thrombosis remains a challenge,in 20 patients with 23 thrombosed cardiac valves, we evaluatedthe respective value of transthoracic (TTE) and transoesophageal(TEE) Doppler echocardiography. According to the presence orabsence of prosthetic obstruction by continuous-wave Doppler,prostheses were separated into two groups. Group 1 included nine thrombosed prostheses (8 mitral, 1 aortic)with severe obstruction. All patients presented with severesymptoms of heart failure. Transthoracic Doppler echocardiographyallowed immediate diagnosis of prosthetic thrombosis, even incritically ill patients, showing (1) eccentric transprostheticcolour flow jets in all eight mitral prostheses, (2) severeobstruction on Doppler examination (mean gradient = 18 to 36mmHg in eight mitral prostheses, and 69 mmHg in one aortic valve),and (3) direct echocardiographic evidence of thrombosis (i.e.thrombus or abnormal disc or leaflet motion) in four patients.All nine patients were immediately treated by surgery (n=8)or fibrinolysis (n =1) on the basis of TTE results only. TEEallowed better visualization of thrombus and restricted leafletor disc motion, but had little influence on patient management. Group 2 included 14 thrombosed prostheses (10 mitral, 4 aortic)with mild or absent obstruction, in three patients with massivemitral prosthetic thrombosis, an associated minimal thrombosisof a prosthetic aortic valve was found at surgery, but was detectedneither by TTE, nor by TEE. The 11 remaining patients presentedwith isolated partial mitral (n = 10) or aortic (n = 1) thrombosis.Clinical presentation was fever, cerebral embolism, or milddyspnoea, but no heart failure. TTE was normal in all. Continuous-waveDoppler showed normal prosthetic function in five patients andmild obstruction in six. TEE allowed diagnosis of prostheticthrombosis in all, showing an abnormal mobile echo around theprosthesis, despite normal disc or leaflet motion. In conclusion, transthoracic Doppler echocardiography is thediagnostic procedure of choice in patients with severely obstructiveprosthetic thrombosis, while the transoesophageal approach appearspromising in partial thrombosis with mild or absent obstruction.