The Accuracy of Aortic Valve Area Determined by Transesophageal Echocardiography using Direct Planimetry According to the Changes of Cardiac Output and Left Ventricular Ejection Fraction

> BACKGROUND: The accuracy of flow-related changes in aortic valve area (AVA) determined by the Gorlin formula or the continuity equation remains disputable. However, anatomic AVA can be determined by using by direct planimetry of transesophageal echocardiography (TEE). The purpose of this study was to assess the impact of changes in flow on AVA determined by TEE using direct planimetry. METHOD: Determination of AVA by TEE using direct planimetey was performed intraoperatively under three different hemodynamic conditions - pre-dobutamine (baseline) period, post-dobutamine period, post-CABG period - in 17 CABG patients and cardiac output (CO) with left ventricular ejection fraction (EF) were also determined by TEE simutaneously. The changes in aortic flow were induced by dobutamine infusion. RESULTS: AVA at pre-dobumaine period, post-dobutamine period, and post-CABG period were 2.99+/-0.80 cm2, 3.01+/-0.79 cm2, and 3.01+/-0.80 cm2, respectively. Before dobutamin infusion, CO and EF were 2.01+/-0.64 L/min and 47+/-10%. After dobutamine infusion, CO and EF were 3.03+/-1.05 L/min, 54+/-9% respectively and significantly increased by 54%, 18% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. After CABG, CO and EF were 3.86+/-1.86 L/min and 58+/-11% and also significantly increased by 98%, 26% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. However, despite of these significant hemodynamic changes, there were no significant changes in AVA and no significant correlations between these hemodynamic and AVA changes, neither at post-dobutamine period nor post-CABG period. CONCLUSION: The acute changes in CO and EF do not result in significant alterations in the anatomic AVA determined by TEE using direct planimetry. Thus, TEE using direct planimetry could be accurate and useful in the determination of AVA in hemodynamically unstable patient.

The Accuracy of Aortic Valve Area Determined by Transesophageal Echocardiography using Direct Planimetry According to the Changes of Cardiac Output and Left Ventricular Ejection Fraction

> BACKGROUND: The accuracy of flow-related changes in aortic valve area (AVA) determined by the Gorlin formula or the continuity equation remains disputable. However, anatomic AVA can be determined by using by direct planimetry of transesophageal echocardiography (TEE). The purpose of this study was to assess the impact of changes in flow on AVA determined by TEE using direct planimetry. METHOD: Determination of AVA by TEE using direct planimetey was performed intraoperatively under three different hemodynamic conditions - pre-dobutamine (baseline) period, post-dobutamine period, post-CABG period - in 17 CABG patients and cardiac output (CO) with left ventricular ejection fraction (EF) were also determined by TEE simutaneously. The changes in aortic flow were induced by dobutamine infusion. RESULTS: AVA at pre-dobumaine period, post-dobutamine period, and post-CABG period were 2.99+/-0.80 cm2, 3.01+/-0.79 cm2, and 3.01+/-0.80 cm2, respectively. Before dobutamin infusion, CO and EF were 2.01+/-0.64 L/min and 47+/-10%. After dobutamine infusion, CO and EF were 3.03+/-1.05 L/min, 54+/-9% respectively and significantly increased by 54%, 18% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. After CABG, CO and EF were 3.86+/-1.86 L/min and 58+/-11% and also significantly increased by 98%, 26% than those measured before dobutamine infusion (p<0.01, p<0.01), respectively. However, despite of these significant hemodynamic changes, there were no significant changes in AVA and no significant correlations between these hemodynamic and AVA changes, neither at post-dobutamine period nor post-CABG period. CONCLUSION: The acute changes in CO and EF do not result in significant alterations in the anatomic AVA determined by TEE using direct planimetry. Thus, TEE using direct planimetry could be accurate and useful in the determination of AVA in hemodynamically unstable patient.

Transesophageal echocardiographic detection of thoracic aortic plaque could noninvasively predict significant obstructive coronary artery disease

OBJECTIVE: Previous pathologic and roentgenographic studies have suggested a relation between aortic plaque and coronary artery disease but have lacked clinical utility. The study was undertaken to elucidate whether atherosclerotic aortic plaque detected by transesophageal echocardiography can be a clinically useful marker for significant obstructive coronary artery disease. METHODS: Clinical and angiographic features and intraoperative transesophageal echocardiographic findings were prospectively analyzed in 131 consecutive patients (58 women and 73 men, aged 17 to 75 years [mean 54 +/- 12]) undergoing open heart surgery. Significant obstructive coronary artery disease was defined as > or = 50% stenosis of > or = 1 major branch. RESULTS: Seventy-six (58%) of 131 patients were found to have obstructive coronary artery disease. In 76 patients with significant coronary artery disease, 71 had thoracic aortic plaque. In contrast, aortic plaque existed in only 10 of the remaining 55 patients with normal or minimally abnormal coronary arteries. The presence of aortic plaque on transesophageal echocardiographic studies had a sensitivity of 93%, a specificity of 82% and positive and negative predictive values of 88% and 90%, respectively, for significant coronary artery disease. There was a significant relationship between the degree of aortic intimal changes and the severity of coronary artery disease (r = 0.74, P < 0.0001). Multivariate logistic regression analysis of patient age, sex, risk factors of cardiovascular disease and transesophageal, echocardiographic findings revealed that atherosclerotic aortic plaque was the most significant independent predictor of coronary artery disease. CONCLUSION: This study indicates that transesophageal echocardiographic detection of atherosclerotic plaque in the thoracic aorta is useful in the noninvasive prediction of the presence and severity of coronary artery disease.

Intraoperative Low-dose Dobutamine Echocardiography Predicts the Post-pump Response of Dysfunctioning Myocardial Segments to Coronary Artery Bypass Grafting

BACKGROUND: Low dose dobutamine echocardiography has recently been introduced for use in identification of viable myocardium in patients with acute myocardial infarction and prediction of the response of dysfunctioning myocardial segments to coronary angioplasty. The aim of this study was to evaluate wheter tihs test could be used to predict the early response of dysfunctioning myocardial segements to coronary artery bypass grafting(CABG). METHODS: We studied in 23 patients with multi-vessel disease during CABG. Myocardial segments were monitored by intraoperative transesophageal echocardiography(TEE) in the transgastric short-axis view at papillary muscle level. The left ventricle was divided into five segments and sixty eight myocardial segments in 23 patients were analyzed. Percentage of systolic wall thickening(PSWT) was calculated in each segment for three times: at basline(early after pericardiectomy);before bypass during dobutamine infusion(3-5ug/kg/min);and after seperation from cardiopulmonary bypass. Segments showing baseline PSWT >_30% were considered normal and those _10% during dobutamine infusion were considered responders and those 30%(normal) and 44(68%) had PSWT _10%(from 12.3+/-7.2% to 33.5+/-11.8%, p<0.01 ; responder segments), and 23(52.3%) showed increase in PSWT < 10%(from 14.7+/-6.5% to 17.4+/-7.4%, p=NS ; nonresponder segments). After CABG, responder segments showed a significant increase in PSWT in comparison with baseline values(from 12.3+/-7.2% to 32.1 +/-11.0%,p<0.01). Segments not responded to dobutamine showed no significant changes in PSWT after CABG(from 14.7+/-6.5% to 16.0+/-8.2%, p=NS). Twenty-four normal segments (PSWT 41.9+/-6.2%) showed a slight but significant reduction in PSWT both during dobutamine infusion(38.7+/-6.9%;p<0.05) and after CABG(38.9+/-6.3%, p<0.05), suggesting that compensatory hyperfunction was present at baseline. Estimation of clinical accruacy of low dose dobutamine TEE yieded to 69% sensitivity, 93.9% specificity, 95.2% positive predictive value, 60.9% negavive predictive value, and 77.3% overall accuracy. In both responders and nonresponders of dysfunctioning segments, there was a correlation between PSWT during dobutamine infusion and that after CABG(r=0.61, r=0.63, respectively). CONCLUSION: Low dose dobutamine TEE test well predicts the early response of dysfunctioning myocardial segments to CABG.

Two-Dimensional Echocardiographic Predictors of Ventricular Enlargement after Acute Myocardial Infarction

BACKGROUND: Ventricular remodeling after myocardial infarction increase mortality and morbidity. Two-dimensional echocardiography in acute myocardial infarction provides a useful diagnostic tool for evaluation of ventricular remodeling. The aims of this study were to verify whether follow-up two-dimensional echocardiography could detect ventricular enlargement after acute myocardial infarction and to find early echocardiographic predictors and clinical charateristics of ventricular enlargement. METHODS: Two-dimensional echocardiography was done prospectively at 2 week, 3 month, and 6 month after the first Q-wave acute myocardial infarction in 18 patients. The control group was 11 patients of a normal chest roentgenogram and echocardiogram who were studied for chest pain or arrhythmia. The patients were divided by the mean value of the control group left ventricular end-diastolic volume index(LVEDVI) 56.8ml/m2. The group A was more than 60ml/m2(the control group LVEDVI 56.8ml/m2) and the group B was less than 60ml/m2 of LVEDVI at 2 week post myocardial infarction. The left vantricular volume was measured by the modified disk method at the apical four chamber view. The wall motion abnormality of left ventricle was examined by the recommendation of the American Society of Echcardiography. RESULTS: The left vntricular end-diastolic volume and the left ventricular end-systolic volume were enlarged after 3 month of acute myocardial infarction in the group A compare with those of the control group. There was no ventricular enlargement during 6 month after myocardial infarction in the group B. The frequency of ventricular enlargement was increased in anterior myocardial infarction. There was no difference in left ventricular ejection fraction at 2 week post myocardial infarction between the group A(51.4+/-15.7%) and the group B(50.8+/-10.3%). The wall motion score index more than 1.5 at 2 week post myocardial infarction means the enlarged LVEDVI more than 60ml/m2 and the group of ventricular enlargement. CONCLUSION: The left ventricular enlargement could be diagnosed by the follow-up two-dimensional echocardiography in acute myocardial infarction. The echocardiographic early predictors of ventricular enlagement were the left ventricular end-diastolic volume greater than 60ml/m2 and increased wall motion score index more than 1.5 at 2 week post myocardial infarstion. The anterior myocardial infarction was the electrocardiographic predictor of ventricular dilatation. Therefore these early predictors could identify the patients of ventricular enlargement and these patients could be a candidate of follow-up echocardiography and of a specific treatment for limiting ventricular remodeling.

A Case of Single Coronary Artery with Bicuspid Aortic Valve

Single coronary artery is one of coronary artery anomalies, which originates from single aortic ostium and distributes blood to whole myocardium and is reported to occur in about 0.02 percent of general population. Although this condition does not produce severe clinical complications, it is often combined with other congenital cardiac anomaly and may produce angina pectoris, arrythmia, and sudden cardiac death syndrome rarely. Bicuspid aortic valve is anomalous aortic valve which consists of two commisure and two cusps and is said to occur in about 2 percent of the population. In some cases, the valve may function normally for many decades, but in others, it may produce aortic stenosis and/or aortic regurgitation frequently. We report here a case of single coronary artery combined with bicuspid aortic valve.