Real-time three-dimensional transthoracic echocardiography.

BACKGROUND: Complex anatomy of intra-cardiac structures requires spatial orientation of image in three dimensions for better understanding and enhanced image interpretation. We evaluated the feasibility and efficacy of the emerging 'real-time three-dimensional transthoracic echocardiography' technique for comprehensive assessment of cardiac anatomy, physiology, pathomorphology and pathophysiology in patients with structural heart disease. METHODS AND RESULTS: Patients with structural heart disease (n=152) were evaluated by conventional two-dimensional transthoracic echocardiography and real-time three-dimensional transthoracic echocardiography using standard protocol. Fifty-six cases were of rheumatic etiology with multi-valvular involvement (mitral stenosis: 32; mitral regurgitation: 29; tricuspid regurgitation: 8; aortic valve disease: 11) and 21 cases of non-rheumatic valvular heart disease. A total of 38 congenital heart disease patients were examined including 23 patients with atrial septal defect. Left ventricular function (n=20) and right ventricular function (n=10) were also assessed using dedicated software. CONCLUSIONS: Results of real-time three-dimensional transthoracic echocardiography mitral valve area assessment by planimetery are comparable to two-dimensional transthoracic echocardiography with additional information about surface anatomy of leaflets and the subvalvular apparatus in real time with clear demarcation of commissural fusion and scallops of leaflets. Enface view of atrial septal defect with direct visualization of shape, size and number of defects, tricuspid valve area by planimetery, right ventricular shape, objective assessment of ventricular volumes and regurgitation vena contracta area are the fields where three-dimensional transthoracic echocardiography was of additive value to conventional two-dimensional transthoracic echcardiography. This study proves clinical feasibility of real-time three-dimensional transthoracic echocardiography but requires further validation of quantitative observations.

Non-invasive assessment of endothelial function by brachial artery flow mediated vasodilatation and its association with coronary artery disease: an Indian perspective.

Endothelial dysfunction is the final common pathway through which various coronary risk factors culminate into atherosclerosis and subsequent coronary artery disease (CAD). Endothelial function can be reliably assessed by flow mediated vasodilatation (FMD) in the brachial artery using high-resolution ultrasonography and has been shown to be an excellent surrogate marker for the presence of CAD. Two hundred and forty-one individuals comprising of 101 patients with CAD (angiographically proven, or with history of documented myocardial infarction) and 140 individuals without CAD were included in the study. All subjects underwent clinical evaluation, fasting lipid profile, treadmill test and FMD assessment. Selected individuals underwent coronary angiography too. Brachial artery diameter and Doppler indices (systolic and diastolic velocity time integrals) were recorded using high resolution ultrasonography at baseline, immediately after and at one minute after release of cuff (occlusion time 5 minutes). FMD was calculated as percentage increase in brachial artery diameter at one minute. FMD index was calculated as the ratio of FMD and percentage increase in flow during reactive hyperaemia. Mean FMD was significantly higher in non-CAD group (8.71+/-4.77%) than in CAD group (3.77+/-2.03%; p < 0.0001). The FMD index was also significantly higher in the non-CAD group (0.031 ) than in CAD group (0.021; p=0.0117). On multiple regression analysis, FMD index was found to be significantly associated with presence of CAD (p=0.0015), independent of conventional cardiovascular risk factors. Endothelial function as assessed by FMD is significantly depressed in patients with established CAD and this association is independent of presence of conventional cardiovascular risk factors.

Carotid intima-media thickness and brachial-ankle pulse wave velocity in patients with and without coronary artery disease.

BACKGROUND: Carotid intima-media thickness and pulse wave velocity are non-invasive markers of atherosclerosis and have been shown to reliably predict presence and extent of atherosclerotic vascular disease. However, studies examining their association with each other have shown inconsistent results. Hence it was sought to assess correlation between carotid intima-media thickness and pulse wave velocity in patients with and without coronary artery disease. METHODS AND RESULTS: Sixty-four patients with angiographically proven coronary artery disease and 84 age-matched individuals without coronary artery disease but having one or more conventional cardiovascular risk factors were included in the study. Individuals with established cerebrovascular disease and peripheral vascular disease were excluded from the study. Carotid intima-media thickness of far wall was measured at three predefined sites (distal common carotid, carotid bifurcation and proximal internal carotid artery) on each side. Brachial-ankle pulse wave velocity was measured non-invasively using VP 1000 (Colin Corporation) automated ABI/ PWV analyzer. There was no significant difference in gender and presence of cardiovascular risk factors in the two groups. Mean and maximum carotid intima-media thickness and brachial-ankle pulse wave velocity were all significantly higher in coronary artery disease patients as compared to patients without coronary artery disease (0.842 v. ( 0.657 mm, p <0.0001; 1.076 v. 0.795 mm, p <0.0001; 1708.63 v. 1547.26 cm/s, p <0.0004 respectively). There was a significant correlation between brachial-ankle pulse wave velocity and both mean and maximum carotid intima-media thickness in patients with coronary artery disease (r = 0.47, p <0.0001 and r=0.41, p < 0.0008 respectively) but not in individuals without coronary artery disease (r=0.01 and -0.1 respectively). CONCLUSIONS: Presence of significant correlation between carotid intima-media thickness and brachial-ankle pulse wave velocity in patients with coronary artery disease but absence of the same in individuals without major atherosclerotic vascular disease suggests that the correlation between carotid intima-media thickness and brachial-ankle pulse wave velocity becomes stronger with increasing extent of atherosclerosis.