Correlation of Right Ventricular Wall Stress With Plasma B-Type Natriuretic Peptide Levels in Patients With Pulmonary Hypertension.

BACKGROUND: This study was designed to investigate the relationship between right ventricular wall stress (RVWS) and plasma B-type natriuretic peptide (BNP) levels in patients with pulmonary hypertension (PH). Methods and Results: The 57 consecutive PH patients and 8 control subjects were enrolled. Right heart catheterization (RHC), echocardiography, and BNP measurements were performed, and RVWS and left ventricular wall stress (LVWS) were calculated with the formula based on Laplace's law. Systolic RVWS and end-diastolic RVWS were higher in PH patients compared with controls (systolic RVWS: 77±41 vs. 17±5 kdynes/cm2(P<0.0001), end-diastolic RVWS: 15±12 vs. 8±2 kdynes/cm2(P<0.0005)). Univariate analyses showed that logBNP at baseline correlated with systolic RVWS (r=0.58, P<0.0001) and end-diastolic RVWS (r=0.61, P<0.0001). We performed multivariate regression analysis and determined that end-diastolic RVWS was an independent determinant of logBNP in patients with PH. In addition, change in plasma BNP levels after treatment correlated with change in systolic RVWS (r=0.70, P<0.0001) and change in end-diastolic RVWS (r=0.68, P<0.0001). CONCLUSIONS: Both systolic and end-diastolic RVWS were elevated in patients with PH, and correlated with the symptoms of PH. End-diastolic RVWS was an independent determinant of plasma BNP levels in PH patients.

Analysis of Biphasic Right Ventricular Outflow Doppler Waveform in Patients with Pulmonary Hypertension.

Pulmonary hypertension (PH) with pulmonary vascular disease (PVD) is a progressive and debilitating disease associated with increased pulmonary vascular resistance (PVR). Biphasic right ventricular outflow tract (RVOT) Doppler flow is frequently seen in severe PH patients with PVD. In association with hemodynamics, the precise analysis of biphasic RVOT Doppler flow (RVDF) has not been fully elucidated. Therefore, the purpose of the present study is to analyze the relation between the hemodynamics and indices of biphasic RVDF in PH patients with PVD.Seventy PH patients with biphasic RVDF were analyzed. All patients underwent transthoracic echocardiography and right heart catheterization. For the analysis of biphasic RVDF, the early waveform was determined as P1 while the late waveform was determined as P2. For each P1 and P2, the duration (D, seconds) and peak flow velocity (PFV, in m/second) were measured.P1D and P2PFV were significantly correlated with PVR (P1D: r = -0.542, P < 0.0001, P2PFV: r = -0.513, P < 0.0001). Therefore, we propose a novel RVDF formula for estimation of PVR, as follows. PVR = 26 - 77 × P1D - 14 × P2PFV. The PVR could be estimated by this proposed formula (r = 0.649, P < 0.0001), which is derived from one Doppler image only unlike previously used PVR prediction formula.P1D and P2PFV were associated with PVR. Moreover, this simple RVDF formula proposed herein can estimate PVR in PH patients with PVD.

Fabry disease.

Fabry disease resulting from a deficiency of α-galactosidase A leads to the accumulation of globotriaosylceramide in various organs. Because the disease is an X-linked recessive disorder, males tend to develop more symptoms and more severe symptoms than females. There are also some variants of Fabry disease, and cardiac variant (cardiac Fabry disease) has the dysfunctions only in heart. Cardiac manifestations in Fabry disease are initially symmetrical and concentric left ventricular hypertrophy, and later progressive cardiac dysfunction with localized thinning of the basal posterior wall. In recent years, enzyme replacement therapy has been performed as a treatment for Fabry disease, and the initiation of this therapy is expected before the cardiac fibrosis develops. Therefore, early diagnosis of Fabry disease is essential, and echocardiography is an indispensable tool for clinical practice of this disease. Then, it is necessary to remember this disease as a differential diagnosis when encountering unexplained left ventricular hypertrophy.

Validity of a Novel Method for Estimation of Low-Density Lipoprotein Cholesterol Levels in Diabetic Patients.

AIM: Low-density lipoprotein cholesterol (LDL-C) is routinely estimated using the Friedewald equation [LDL-C(F)]. A novel method for LDL-C [LDL-C(M)] estimation recently proposed by Martin et al. was reported to be more accurate than the Friedewald formula in subjects in the United States. The validity of LDL-C(M) in different races and patients with diabetes mellitus (DM) has not been elucidated. The purpose of this study was to validate the LDL-C(M) estimates in Japanese population with type 2 DM by comparing with LDL-C(F) and directly measured LDL-C [LDL-C(D)]. METHODS: Both LDL-C(M) and LDL-C(F) levels were compared against LDL-C(D) measured by selective solubilization method in 1,828 Japanese patients with type 2 DM. RESULTS: On linear regression analysis, LDL-C(M) showed a stronger correlation than that shown by LDL-C(F) (R=0.979 vs. R=0.953, respectively) with LDL-C(D). We further analyzed the effect of serum triglyceride (TG) concentrations on the accuracy of LDL-C(F) and LDL-C(M). Although LDL-C levels showed a positive correlation with TG levels, the LDL-C(F) levels tended to show a greater divergence from LDL-C(D) levels than that shown by LDL-C(M) with changes in TG levels. CONCLUSION: We for the first time demonstrated a more useful measurement of LDL-C levels estimated by Martin's method than that estimated by the Friedewald equation in Japanese patients with DM.

Prosthetic tricuspid valve dysfunction assessed by three-dimensional transthoracic and transesophageal echocardiography.

A 39-year-old male who had undergone tricuspid valve replacement for severe tricuspid regurgitation was admitted with palpitation and general edema. Two-dimensional (2D) echocardiography showed tricuspid prosthetic valve dysfunction. Additional three-dimensional (3D) transthoracic and transesophageal echocardiography (TEE) could clearly demonstrate the disabilities of the mechanical tricuspid valve. Particularly, 3D TEE demonstrated a mass located on the right ventricular side of the tricuspid prosthesis, which may have caused the stuck disk. This observation was confirmed by intra-operative findings.

Left ventricular dysfunction assessed by cardiac time interval analysis among different geometric patterns in untreated hypertension.

BACKGROUND: Left ventricular (LV) hypertrophy is a powerful independent predictor of morbidity and mortality in hypertensive patients. Abnormal LV geometric patterns are also associated with hypertensive complications, and concentric hypertrophy is associated with the highest mortality in hypertensive patients. However, the relationship between geometric patterns and cardiac dysfunction is not fully established. We hypothesized that the Tei index, which is a measure of global cardiac function, is a feasible parameter for estimating cardiac dysfunction among the different LV geometric patterns in hypertensive patients. METHODS AND RESULTS: We enrolled 60 consecutive patients with untreated essential hypertension. Subjects were divided into 4 groups: normal geometry, concentric remodeling, eccentric hypertrophy and concentric hypertrophy. We measured ejection fraction, mitral E/A ratio, Tei index, ejection time, and isovolumic contraction and relaxation times. There were significant correlations between LV mass index and systolic blood pressure (P<0.01), ejection fraction (P<0.05), mitral E/A ratio (P<0.05) and Tei index (P<0.0001). In multiple regression analysis, only the Tei index independently correlated with LV mass index (P<0.01). Concentric hypertrophy significantly increased the Tei index compared with the other 3 groups. CONCLUSIONS: The Tei index provides a better marker for LV dysfunction by hypertensive hypertrophy than conventional parameters. LV function in concentric hypertrophy was most impaired among all the geometric patterns in untreated hypertensive patients.

Highly sensitive cardiac troponin T in heart failure: comparison with echocardiographic parameters and natriuretic peptides.

BACKGROUND: Circulating cardiac troponin T is a marker of cardiomyocyte injury, and predicts adverse outcomes in patients with chronic heart failure. However, the significance of highly sensitive cardiac troponin T (hs-TnT) in cardiac dysfunction remains uncertain. The purpose of this study is to evaluate the correlation between hs-TnT and echocardiographic parameters or natriuretic peptides in patients with heart failure. METHODS AND RESULTS: We analyzed 283 consecutive out- or in-patients who had B-type natriuretic peptide (BNP) ≥20 pg/mL and were examined by echocardiography (mean age 66.5±13.9 years old; 159 males). Hs-TnT, BNP, N-terminal pro-BNP (NT-proBNP), and creatinine levels were measured simultaneously. LVEDD (left ventricular end-diastolic dimension), LVEF (left ventricular ejection fraction), E', E/E', left ventricular (LV) Tei index, and right ventricular (RV) Tei index were determined with echocardiography. The linear regression analyses demonstrated that loghs-TnT correlated with LVEDD (R=0.242, p<0.0001), LVEF (R=-0.369, p<0.0001), E' (R=-0.447, p<0.0001), E/E' (R=0.364, p<0.0001), LV Tei index (R=0.303, p<0.0001), RV Tei index (R=0.443, p<0.0001), and estimated glomerular filtration rate (eGFR) (R=-0.489, p<0.0001). Using multiple variable regression analysis, loghs-TnT independently correlated with LVEF, E/E', RV Tei index, and eGFR. Furthermore, loghs-TnT significantly correlated with logBNP (R=0.567, p<0.0001) or logNT-proBNP (R=0.647, p<0.0001). Multiple variable regression analysis demonstrated that loghs-TnT independently correlated with logBNP, age, and eGFR, or with logNT-proBNP, age, sex, and eGFR. CONCLUSIONS: The hs-TnT correlated with cardiac dysfunction evaluated by echocardiography and natriuretic peptides in patients with heart failure. The elevation of hs-TnT levels in heart failure may represent cardiac dysfunction due to minor and ongoing myocardial injury.

Different flow patterns between left and right internal thoracic artery grafts influence the evaluation of severe graft stenosis by transthoracic Doppler echocardiography.

OBJECTIVE: An increase in the diastolic to systolic flow velocity ratio (D/S) in the proximal left internal thoracic artery (ITA) after coronary artery bypass grafting (CABG) enables noninvasive assessment of graft patency by transthoracic Doppler echocardiography (TTDE). The increase in the D/S can be less pronounced at a site distant from the anastomosis. We postulated that proximal ITA flow patterns differ between the left and right ITAs and that the increase in D/S is less pronounced in the right than in the left proximal ITA. METHODS: Proximal ITA flow was examined by TTDE in 129 consecutive patients after CABG of the left (75) or right (69) ITA to the left coronary artery. The mean D/S of the ITAs was compared with coronary angiography. RESULTS: The D/S was lower in the group with a patent right ITA than in the group with a patent left ITA (P < .05). The D/S of both the left and right ITAs negatively correlated with angiographic stenosis (r = 0.56 or 0.67, P < .001, respectively). The regression line was significantly shifted downward in the right ITA compared with the left ITA, according to analysis of covariance (P = .01). Graft stenosis was predicted by a D/S of <0.57 and <0.28 with an accuracy of 91% and 97% in the left and right ITAs, respectively. CONCLUSION: The patency of both left and right ITA grafts to the left coronary artery can be assessed using TTDE, but different cutoff values of D/S are required to diagnose severe ITA stenosis.

Recurrent mitral regurgitation late after annuloplasty for ischemic mitral regurgitation.

In 106 patients who had mitral annuloplasty for ischemic mitral regurgitation (MR), 71 patients (67%) had satisfactory outcomes with <2+ MR (grade 0-4) throughout the follow-up period (44 ± 31 months), while 35 patients (33%) had significant recurrent MR (≥2+) late after annuloplasty (≥6 months) during the follow-up period (45 ± 30 months). Compared to those with recurrent MR, the success group had a significantly higher proportion of patients whose left ventricular (LV) ejection fraction (EF) stayed stable or increased over the follow-up period postoperatively (47/70 = 67% vs. 14/35 = 40%, P < 0.01). The success group had a higher proportion of patients whose LV end-systolic volume stayed stable or decreased (37/63 = 59% vs. 6/35 = 17%, P < 0.01) and lower LV sphericity in systole (0.46 ± 0.096 vs. 0.60 ± 0.10, P < 0.01). In conclusion, recurrent ischemic MR after annuloplasty is associated with increasing LV size, decreasing LVEF, and increasing sphericity of the LV.

Echocardiographic predictors for persistent functional mitral regurgitation after aortic valve replacement in patients with aortic valve stenosis.

Moderate functional mitral regurgitation (MR) in patients with aortic valve stenosis (AS) is often left unaddressed at the time of aortic valve replacement (AVR) because it is expected to decrease after AVR. However, some patients have persistent moderate MR after AVR. We sought to determine the preoperative echocardiographic predictor for persistent functional MR after AVR in patients with AS. Pre- and postoperative echocardiograms were reviewed in 110 patients with severe AS and functional MR who underwent AVR without mitral valve (MV) surgery. Fifty-eight patients received concomitant coronary artery bypass graft surgery. In patients with MV tenting, defined as apical displacement of mitral leaflets in the apical 4-chamber view, MV tenting area and tenting height were measured at midsystole. Eighty patients had MV tenting (mean MV tenting area 1.4 +/- 0.5 cm(2), mean MV tenting height 0.8 +/- 0.2 cm) and 30 did not have it before AVR. MR severity decreased in 51 of 80 patients (64%) with MV tenting after AVR and in 25 of 30 patients (83%) without MV tenting (p <0.05). In patients with MV tenting, multivariate analysis revealed that presence of long-term atrial fibrillation and MV tenting area were independent predictors of postoperative MR severity (all p values <0.05). The sensitivity and specificity in predicting persistent moderate MR after AVR were 72% and 82% for MV tenting area >1.4 cm(2). In conclusion, preoperative MV tenting predicts persistent functional MR after AVR in patients with severe AS.

Left ventricular global systolic dysfunction has a significant role in the development of diastolic heart failure in patients with systemic hypertension.

Regional left ventricular (LV) systolic dysfunction has been identified in diastolic heart failure (DHF). However, the relationship between regional or global LV systolic function and heart failure symptoms in DHF has not been evaluated in detail. The present study evaluates such relationships in patients with systemic hypertension (HT) and DHF. We assessed LV systolic and diastolic function in 220 consecutive patients with systemic HT and in 30 normal individuals (Control) using Doppler echocardiography. Patients with HT were assigned to groups with DHF, asymptomatic diastolic dysfunction (ADD) and no diastolic dysfunction (Simple HT). Ejection fraction in DHF was significantly decreased (63±8%) compared with the Control, Simple HT and ADD groups (67±5, 66±7 and 68±8%, respectively). Isovolumetric contraction time in DHF (70±30 msec) was significantly increased compared with those in the ADD, Simple HT and Control groups (31±17, 31±15 and 30±19 msec, respectively). Mitral annular systolic velocities were significantly decreased in the DHF and ADD groups (6.4±1.5 and 7.2±1.3 cm sec⁻¹, respectively) compared with those in the Simple HT and Control groups (8.5±1.8 and 8.4±3.0 cm sec⁻¹, respectively), and in the DHF group compared with the ADD group. LV global systolic dysfunction has a significant role in the development of heart failure symptoms associated with DHF in patients with systemic HT.

Left atrial function assessed by real-time 3-dimensional echocardiography is related to right ventricular systolic pressure in chronic mitral regurgitation.

BACKGROUND: Left atrial (LA) volume is a prognostic index in chronic mitral regurgitation (MR). However, little is known about LA function in this setting. We hypothesized that LA dysfunction is related to pulmonary hypertension in chronic MR. METHODS: Seventy-one patients with organic chronic MR who underwent real-time 3-dimensional transthoracic echocardiography (RT3DE) were studied. Left atrial volumes and peak passive and active LA emptying rates were obtained. Total LA emptying fraction was calculated as follows: [(maximum - minimum LA volume)/maximum LA volume] x 100. Similarly, active and passive LA emptying fractions were calculated. From transmitral flow, the peak early (E) and late (A) diastolic filling velocities and E/A ratio were obtained. The early (E') and late (A') diastolic myocardial velocities were obtained by tissue Doppler interrogation of mitral annulus. RESULTS: Effective regurgitant orifice area (EROA) was 0.57 +/- 0.29 cm(2). Right ventricular systolic pressure (RVSP) was measured in 57 patients and averaged 37 +/- 13 mm Hg. Patients with MR and high RVSP displayed higher minimum LA volume, E/A ratio, E/E' ratio, EROA, and MR volume, and lower A' velocity, peak active LA emptying rate, active LA emptying fraction, and total LA emptying fraction than patients with MR and normal RVSP. Multiple regression analysis revealed that EROA (r = 0.51, P = .01) active LA emptying fraction (r = -0.53, P = .02), E/E' ratio (r = 0.50; P = .04), and the lateral A' velocity (r = -0.46; P = .003) were independently correlated with RVSP. CONCLUSIONS: Left atrial function determined by RT3DE had significant correlation with RVSP in chronic MR, irrespective of MR severity. Thus, pulmonary hypertension in chronic MR may depend not only on MR severity but also on LA function.

Mitral regurgitation associated with mitral annular dilation in patients with lone atrial fibrillation: an echocardiographic study.

BACKGROUND: Whether and how lone atrial fibrillation (AF) is associated with functional mitral regurgitation (MR) remain unclear. METHOD: We studied 12 lone AF patients without left ventricular (LV) dysfunction and/or dilatation, who underwent mitral valve annuloplasty for functional mitral regurgitation (MR). Ten lone AF patients without MR served as controls. RESULTS: Lone AF Patients with MR had a greater mitral valve annular area and left atrial area than those without MR. There were no differences in LV volumes or LV ejection fraction. CONCLUSIONS: Therefore, we concluded that left atrial dilation and corresponding mitral annular dilation may cause MR in lone AF patients without LV dysfunction and/or dilatation.

Left ventricular systolic function is abnormal in diastolic heart failure: re-assessment of systolic function using cardiac time interval analysis.

OBJECTIVES: The purpose of this study was to re-assess the left ventricular (LV) systolic function in diastolic heart failure (DHF) using Doppler echocardiography. BACKGROUND: Systolic function in DHF is defined as the preserved LV ejection fraction (EF). EF may not fully reflect the systolic function in DHF, especially in the presence of abnormalities during the isovolumetric contraction time (ICT). METHODS: We examined LV systolic and diastolic function in 80 consecutive patients with DHF, 30 patients with asymptomatic diastolic dysfunction (ADD), and 30 normal subjects (Control). The LV and left atrial volumes, LV EF, LV ICT, and isovolumetric relaxation time (IRT), early diastolic mitral flow velocity, systolic mitral annular velocity (S'), and early diastolic mitral annular velocity were obtained. RESULTS: LV ICT in DHF (69+/-30 ms) was significantly increased compared to those with ADD (37+/-23 ms) and Control (35+/-26 ms) (P<0.0001). ICT in ADD was equal to that in Control. The LV end-diastolic volume index in DHF (49+/-14 ml/m(2)) was significantly increased compared to those with ADD (42+/-12 ml/m(2)) and Control (43+/-8 ml/m(2)) (P<0.05). S' in DHF (5.9+/-1.4 cm/s) and ADD (6.7+/-1.1 cm/s) was significantly decreased compared to that in Control (8.7+/-2.5 cm/s). CONCLUSIONS: Our results revealed that the major differences between ADD and DHF were global and longitudinal LV systolic dysfunction and LV enlargement. This study suggests that LV systolic dysfunction plays an important role in the development of DHF.

Different determinants of residual tricuspid regurgitation after tricuspid annuloplasty: comparison of atrial septal defect and mitral valve prolapse.

We analyzed 20 patients with atrial septal defect (ASD) who underwent tricuspid valve (TV) annuloplasty and ASD closure, 21 patients with mitral valve prolapse (MVP) who underwent mitral valve (MV) and TV annuloplasty, and 20 healthy controls. Severity of tricuspid regurgitation (TR) was assessed by maximal TR jet area/RA area (%TR) using echocardiography before and early after surgery. Before surgery, 2 groups of patients showed significantly greater RA area, TV annulus diameter, RV systolic pressure, and %TR than controls. %TR was significantly decreased after surgery, whereas residual TR was shown in 19% of the MVP group and 25% of the ASD group. Preoperative TV tethering height and %TR were significantly associated with postoperative %TR in the MVP group, whereas preoperative RV fractional area change, RV spherical index, and RV systolic pressure were significantly associated with postoperative %TR in the ASD group. Risk stratification after TV annuloplasty should take the structural abnormality into consideration.

Detection of left ventricular dysfunction with Tei index in normal ejection fraction patients with mitral regurgitation before mitral valve surgery.

Ejection fraction (EF) was not considered a reliable parameter of left ventricular (LV) function and was normal in most patients with chronic mitral regurgitation (MR), whereas LV dysfunction expressed as decreased EF was often shown after mitral valve surgery. This study sought the ability of the Tei index to detect latent LV dysfunction in patients with MR and apparently normal EF. One hundred eight patients with apparently normal EF (EF > or =50%) and chronic severe MR who underwent mitral valve repair were investigated. EF was significantly decreased after surgery and LV dysfunction (EF <50%) was shown in 37 patients (34% of all patients). The preoperative Tei index significantly correlated with postoperative EF in all patients (r = -0.64, p <0.0001) and asymptomatic patients (n = 44; r = -0.57, p <0.0001). By setting the preoperative Tei index >0.5 to predict postoperative EF <50%, this index had sensitivity, specificity, and accuracy of 89%, 85%, and 86% in all patients and 80%, 85%, and 84% in asymptomatic patients, respectively. In conclusion, a preoperative Tei index >0.5 allowed prediction of postoperative LV dysfunction in patients with MR with apparently normal EF. Thus, earlier surgery is recommended in asymptomatic patients with MR with normal EF, but Tei index >0.5.

Preoperative and postoperative mitral valve prolapse and regurgitation in adult patients with secundum atrial septal defects.

BACKGROUND: Little attention is given to development of mitral regurgitation (MR) in adults with atrial septal defect (ASD). The aim of the study was to determine the associated factors of MR in ASD adults before surgical repair and the fate of moderate to severe MR after surgery. METHODS: We examined 71 consecutive patients with secundum ASD (47 +/- 16 years) who underwent surgical repair. Clinical and echocardiographic variables including size of left and right heart systems and severity of MR and tricuspid regurgitation (TR) were investigated before and early after surgery. RESULTS: Before ASD closure, 14 patients (20%) had moderate to severe MR and 25 patients (35%) showed mitral valve (MV) prolapse. The ASD patients with moderate to severe MR showed worse cardiovascular symptoms, increased occurrence of atrial fibrillation and MV prolapse, and greater left ventricular (LV) end-diastolic volume, left atrial area, and TR severity than those with none to mild MR (all P < 0.05). Among preoperative variables, TR severity, left atrial area, LV end-diastolic volume, and MV prolapse were associated with preoperative MR severity in all the patients (all P < 0.03). Isolated ASD closure (n=46) decreased MV prolapse (P=0.008). Preoperative moderate to severe MR decreased after ASD closure with and without MV surgery (n=9 and 5, respectively; both P < 0.05). CONCLUSIONS: Preoperative MR severity was associated with TR severity, dilated left heart chambers, and MV prolapse. MR decreased after ASD closure with and even without MV surgery.

No reflow-like pattern in intramyocardial coronary artery suggests myocardial ischemia in patients with hypertrophic cardiomyopathy.

BACKGROUND AND PURPOSE: To evaluate intramyocardial coronary flow velocity pattern by transthoracic Doppler echocardiography and its clinical significance in patients with hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: In 48 patients with HCM who had angiographically normal coronary artery, coronary flow velocity in the left anterior descending coronary artery (LAD) and intramyocardial coronary artery (IMCA) derived from LAD were evaluated using transthoracic Doppler echocardiography. Two clearly different flow patterns in the IMCA were observed in patients with HCM. Twenty-seven HCM patients (group A) had slow deceleration slope in the IMCA flow (average diastolic deceleration time, 989+/-338; range, 585-1680) and the remaining 21 patients (group B) had steep deceleration slope with diastolic deceleration time <300 ms, resulting in a no reflow-like pattern in the IMCA flow (average diastolic deceleration time, 166+/-67; range, 55-280). There were no significant differences in the clinical characteristics and LAD flow velocity profiles between the two groups. The incidence of cardiovascular symptoms (chest pain or syncope) was significantly higher in group B than in group A (67% vs. 26%, p<0.01). Additionally, exercise-induced ischemia as detected by thallium-201 scintigraphy was significantly more frequent in group B than in group A (6 of 9 (67%) vs. 0 of 9 (0%), p<0.01). CONCLUSIONS: Two different intramyocardial coronary flow velocity patterns are observed in patients with HCM using transthoracic Doppler echocardiography. No reflow-like pattern in the IMCA is strongly related to myocardial ischemia in the absence of epicardial coronary artery stenosis, suggesting that coronary microvascular dysfunction may be a causative mechanism.

Usefulness of a novel ultrasound transducer for continuous monitoring treadmill exercise echocardiography to assess coronary artery disease.

BACKGROUND: The feasibility of a novel ultrasound probe, which can be attached to the left ventricular (LV) apex chest wall and allows free rotation around its long axis direction for the continuous monitoring of LV wall motion, was tested. METHODS AND RESULTS: There were 36 subjects who had coronary artery disease (CAD). By attaching a novel ultrasound probe to the chest wall, the LV apical views were recorded during treadmill exercise stress echocardiography (Echo). The continuous monitoring of LV wall motion was satisfactorily feasible in 30 of 36 patients. The visualization rate of the overall LV segments was higher at rest (90%) compared to that during peak exercise (77%). The segments were better visualized in apical portions (90-100%) than in mid (77-96%) or basal portions (68-87%). The sensitivity, specificity, and accuracy for detecting CAD were 61, 100 and 77%, respectively. The wall motion score index 3 and 6 min after exercise decreased significantly compared to those at peak exercise. The number of segments with dyssynergy was highest at the peak exercise. Ischemic ST-T depression on electrocardiography was observed only at peak stress periods. CONCLUSIONS: Continuous monitoring treadmill exercise Echo using a novel ultrasound probe seems feasible for the non-invasive and physiological assessment of CAD.