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Natesa G Pandian

Publications and source records attributed to Natesa G Pandian.

At least 19 recordsLinked to original sources
PubMed2006

Hypertrophic cardiomyopathy is predominantly a disease of left ventricular outflow tract obstruction.

BACKGROUND: Nonobstructive hypertrophic cardiomyopathy (HCM) has been regarded as the predominant hemodynamic form of the disease on the basis of assessment of outflow gradient under resting conditions. We sought to prospectively define the prevalence, clinical profile, and significance of left ventricular (LV) outflow tract obstruction under resting conditions and with physiological exercise in a large HCM cohort. METHODS AND RESULTS: We prospectively analyzed 320 consecutive HCM patients (age, 47+/-17 years), measuring LV outflow gradient at rest, with Valsalva maneuver, and with exercise echocardiography. LV outflow obstruction was present at rest and/or with exercise in 225 patients (70%); 119 had rest gradients > or = 50 mm Hg and were not exercised. Of the other 201 patients with gradients < 50 mm Hg at rest (average, 4+/-9 mm Hg), 106 developed mechanical obstruction to LV outflow resulting from mitral valve-septal contact after exercise (80+/-43 mm Hg), including 76 with marked gradients > or = 50 mm Hg and 46 with heart failure symptoms. The remaining 95 patients (30%) had no or small gradients (< 30 mm Hg) both at rest and with exercise. Valsalva maneuver underestimated the presence and magnitude of exercise-induced obstruction. CONCLUSIONS: Among those patients who come to clinical evaluation, HCM is a predominantly obstructive disease in which LV outflow gradients, frequently associated with heart failure symptoms and often identified only with exercise, are evident in most patients (ie, 70%). Identification of LV outflow obstruction with exercise echocardiography may broaden management options in HCM by identifying symptomatic patients not otherwise regarded as potential candidates for septal reduction therapy. Assessment of subaortic gradients with exercise should be a routine component of the evaluation of HCM patients without outflow obstruction under resting conditions.

Adult↗
PubMed2006

Left ventricular remodelling index (LVRI) in various pathophysiological conditions: a real-time three-dimensional echocardiographic study.

BACKGROUND: Various studies have reported a close correlation between real-time three-dimensional echocardiography (RT3DE) and cine magnetic resonance imaging studies for the assessment of cardiac volumes and mass. OBJECTIVE: The aim of our study was to evaluate changes in left ventricular volumes and mass in subjects with different pathophysiological conditions. A ratio between left ventricular mass and end-diastolic volume (LVRI), detected by RT3DE, was used to describe various patterns of left ventricular remodelling. METHODS: RT3DE was performed to calculate left ventricular end-diastolic (LVEDV) and end-systolic volume (LVESV), ejection fraction (LVEF) and mass in 220 selected subjects. Of these, 152 were healthy volunteers, 19 top-level rowers, 23 patients with dilated cardiomyopathy and 26 patients with hypertrophic cardiomyopathy. Off-line analysis was performed by two independent operators by tracing manual endocardial and epicardial borders of the left ventricle through eight cutting planes. Inter- and intra-observer variability were calculated. RESULTS: Despite the increase in LV volume and mass in the rowers, LVRI remained unchanged compared with control subjects (p = 0.455), while significantly lower values were found patients with dilated cardiomyopathy (p<0.001) and significantly higher values in patients with hypertrophic cardiomyopathy (p<0.001). There was inter- and intra-observer variability. CONCLUSION: The LVRI may serve as a simple and useful indicator of left ventricular adaptation to physiological and pathological conditions.

Adult↗
PubMed2006

Epicardial real-time three-dimensional echocardiography in cardiac surgery: a preliminary experience.

PURPOSE: Intraoperative two-dimensional transesophageal echocardiography (2DTEE) is a widely accepted method to guide cardiac valve surgery. The aim of our study was to evaluate the feasibility, effectiveness, and incremental value of intraoperative epicardial real-time three-dimensional echocardiography (RT3DE). DESCRIPTION: Thirty consecutive patients (18 aortic and 12 mitral valve diseases) underwent intraoperative 2DTEE and RT3DE before and after cardiopulmonary bypass. Five observers compared independently 2DTEE to live and full volume images and to the surgical view, to assess the incremental value of RT3DE in depicting the different anatomic structures. EVALUATION: Epicardial RT3DE was feasible in all patients. Qualitative evaluation determined RT3DE superiority in depicting aortic cusp morphologic lesions; left ventricular outflow tract spatial relationships with mitral apparatus and aortic root; and both anterior and posterior mitral leaflet scallops, particularly posterior commissure. CONCLUSIONS: In our study, epicardial RT3DE has been demonstrated to improve morphologic definition of anatomic valvular lesions and their relationship with cardiac adjacent structures. It may be a valid substitute when the 2DTEE approach is contraindicated, or it could have a complementary role, coupled with 2DTEE, to give additional information for surgical planning.

Cardiac Surgical Procedures↗
PubMed2006

What is the best approach for the assessment of left atrial size? Comparison of various unidimensional and two-dimensional parameters with three-dimensional echocardiographically determined left atrial volume.

BACKGROUND: Left atrial (LA) size has prognostic importance in a variety of cardiac conditions. Diameters, area, or volume derived from 2-dimensional (2D) echocardiography (2DE) are commonly used to measure LA size, but involve numerous assumptions. This study examined the accuracy of these 2DE parameters compared to 3-dimensional echocardiographic LA volume (3DV). METHODS: LA diameters, area, and volume measured from 2DE were correlated with 3DV in 118 patients with dilated cardiomyopathy, hypertrophic cardiomyopathy, or without structural heart disease. RESULTS: Diameter (anterior-posterior, superior-inferior, and medial-lateral) and 2DE area measurements had statistically significant, but modest, correlations with 3DV, and exhibited a large degree of scatter in comparison with 3DV. The 2DE-derived volume had an excellent correlation with 3DV, but consistently underestimated LA volume. CONCLUSION: The 2DE LA volume correlates better than other parameters with 3DV, but often results in underestimation. Thus, caution should be exercised when using unidimensional and 2D measurements of LA size.

Adolescent↗
PubMed2006

Echocardiographic detection of intrapulmonary shunting in a patient with hepatopulmonary syndrome: case report and review of the literature.

Transthoracic echocardiography is a useful tool in the evaluation of patients with intrapulmonary and intracardiac shunts. We describe a case of a 49-year-old female with severe hypoxemia in the setting of aortic stenosis and cirrhosis of the liver. The use of agitated saline contrast during an echocardiography study helped to establish the diagnosis of intrapulmonary arteriovenous shunting consistent with the hepatopulmonary syndrome, thereby confirming the etiology of her symptoms and laboratory findings. This case report highlights the utility of echocardiography in diagnosing intrapulmonary shunts and assists in the understanding of the pathophysiology of hypoxemia in such patients.

Aortic Valve Stenosis↗
PubMed2006

Echocardiographic diagnosis of air embolism associated with central venous catheter placement: case report and review of the literature.

Transthoracic echocardiography (TTE) is a valuable tool in the evaluation of patients with suspected air embolism. This report describes the presentation and evaluation of a critically ill woman with spontaneous air embolism occurring during a central venous catheter replacement. Bedside TTE established the diagnosis of air embolism, allowing prompt initiation of appropriate therapy. This case report highlights this uncommon but potentially life-threatening complication of central line placement and the utility of echocardiography in its evaluation.

Catheterization, Central Venous↗
PubMed2006

A head-to-head comparison of infusion and bolus doses of adenosine for stress myocardial contrast echocardiography.

BACKGROUND: This study was a head-to-head, intraindividual comparison of the diagnostic accuracy and side effect profile of bolus and infusion administration of adenosine for stress myocardial contrast echocardiography (MCE). METHODS: Adenosine MCE was performed in 64 subjects, referred for stress thallium-201 single-photon emission computed tomography (SPECT) for known or suspected CAD. Each patient received adenosine by multiple boluses (6-12 mg/bolus) and infusion (140 mug/kg per min for 6 min) forms in random order, given at least 20 minutes apart. RESULTS: No prolonged or serious adverse events occurred during either adenosine bolus or infusion. Compared to SPECT imaging, the sensitivity, specificity, and concordance for the diagnosis of CAD were 77%, 87%, and 82% for adenosine infusion MCE and 81%, 90%, and 86% for adenosine bolus MCE, respectively. CONCLUSIONS: Both adenosine infusion and adenosine bolus protocols are safe for MCE in humans and can be used for the diagnosis of CAD.

Adenosine↗
PubMed2006

Feasibility and clinical impact of live three-dimensional echocardiography in the management of congenital heart disease.

BACKGROUND: Precise assessment of congenital heart lesions requires inferential evaluation from multiple two-dimensional echocardiographic images (2DE). The aim of our study was to assess the usefulness of transthoracic live three-dimensional echocardiography (3DE) in the evaluation of congenital heart disease. METHODS: Eighty-two patients (from 4 months to 31 years, mean age 12 +/- 7.5, 38 males and 44 females), known to have congenital heart lesions, prospectively underwent both 2DE and 3DE. Conventional data acquisition by 2DE and "full volume" 3DE acquisition (apical four chambers, parasternal long and short axes, subcostal windows) were carried out by two independent and blinded operators. Data derived from 3DE were compared to 2DE, and 3DE results were graded into three categories: (A) new findings not seen on 2D echo studies, but not critical to therapeutic decision making; (B) additional anatomic information useful in therapeutic decision making; and (C) information equivalent to 2D echo studies. RESULTS: Two out of 82 patients (2%) were excluded because of suboptimal 3DE images. In comparison with 2DE studies, 3DE was graded A in 23 patients (29%), B in 28 patients (35%), and C in 29 patients (36%). In the patients with group B results, atrial and ventricular septal defects, endocardial cushion defects, and l-transposition of great vessels were the most represented pathologies in which 3DE aided medical or surgical therapeutic options. While the new findings in group A did not influence therapy, they defined the whole spectrum of abnormalities in those patients. In patients who fell under group C results, 3DE provided a direct realistic display of the pathology detected by 2DE. CONCLUSIONS: Our study demonstrates that live 3DE, easily performed at the bedside, provides incremental information on patients with a variety of congenital heart lesions. In the clinical scenario, it clarifies the pathology in all its dimensions, particularly in complex lesions with the incremental information having impact on therapeutic decision making.

Adolescent↗
PubMed2006

Quantitation of right ventricular volumes and ejection fraction by three-dimensional echocardiography in patients: comparison with magnetic resonance imaging and radionuclide ventriculography.

Three-dimensional echocardiography (3DE) provides volumetric measurements without geometric assumptions. Volume-rendered 3DE has been shown to be accurate for the measurement of right ventricular (RV) volumes in vitro and in animal studies; however, few data are available regarding its accuracy in patients. This study examined the accuracy of 3DE for quantitation of RV volumes and ejection fraction (EF) in patients, compared to magnetic resonance imaging (MRI) and radionuclide ventriculography (RNV). Twenty patients underwent MRI, gated equilibrium RNV, and 3DE using rotational acquisition from both the transesophageal and transthoracic approaches. RV volumes and EF were calculated from the 3DE data using multislice analysis (true Simpson's rule). RV volumes calculated by MRI (end-diastolic volume (EDV) 109.4 +/- 34.3 mls, end-systolic volume (ESV) 59.6 +/- 31.0 mls, and EF 47.7 +/- 17.1%) agreed closely with 3DE. For transesophageal echocardiography, EDV was 108.1 +/- 29.7 mls (r = 0.86, mean difference 1.3 +/- 17.8 mls); ESV was 62.5 +/- 23.8 mls (r = 0.85, mean difference 2.8 +/- 15.1 mls); and EF was 43.2 +/- 11.7% (r = 0.84, mean difference 4.5 +/- 9.7%). For transthoracic echocardiography, EDV was 107.7 +/- 27.5 mls (r = 0.85, mean difference 1.6 +/- 18.2 mls); ESV was 59.7 +/- 22.1 mls (r = 0.93, mean difference 3.2 +/- 19.6 mls); and EF was 45.2 +/- 11.5% (r = 0.86, mean difference 2.0 +/- 9.4%). There were close correlations, small mean differences and narrow limits of agreement between RNV-derived EF (43.4 +/- 12.1%) and both transesophageal (r = 0.95 mean difference 0.2 +/- 3.7%) and transthoracic 3DE (r = 0.95, mean difference 1.8 +/- 5.4%). Three-dimensional echocardiography is a promising new method of calculating RV volumes and EF, comparing well with MRI and RNV. The accuracy of transthoracic 3DE was comparable to that of the transesophageal approach. Three-dimensional echocardiography has the potential to be useful in the clinical assessment of RV disorders.

Adult↗
PubMed2006

Quantification of right ventricular volumes and function by real time three-dimensional echocardiographic longitudinal axial plane method: validation in the clinical setting.

BACKGROUND: Measurement of right ventricular (RV) volumes and right ventricular ejection fraction (RVEF) by three-dimensional echocardiographic (3DE) short-axis disc summation method has been validated in multiple studies. However, in some patients, short-axis images are of insufficient quality for accurate tracing of the RV endocardial border. This study examined the accuracy of long-axis analysis in multiple planes (longitudinal axial plane method) for assessment of RV volumes and RVEF. METHODS: 3DE images were analyzed in 40 subjects with a broad range of RV function. RV end-diastolic (RVEDV) and end-systolic volumes (RVESV) and RVEF were calculated by both short-axis disc summation method and longitudinal axial plane method. RESULTS: Excellent correlation was obtained between the two methods for RVEDV, RVESV, and RVEF (r = 0.99, 0.99, 0.94, respectively; P < 0.0001 for all comparisons). CONCLUSION: 3DE longitudinal-axis analysis is a promising technique for the evaluation of RV function, and may provide an alternative method of assessment in patients with suboptimal short-axis images.

Adult↗
PubMed2005

[Mechanism of cardiac resynchronization therapy by real-time three-dimensional echocardiography in patients with heart failure].

We report the case of a 66-year-old man with heart failure NYHA class IV treated with biventricular pacing for cardiac resynchronization. The patient was evaluated by real-time three-dimensional transthoracic echocardiography before and 48 hours after pacemaker implantation. The use of three-dimensional echocardiography contributed to understanding the underlying mechanism involved in cardiac resynchronization therapy by demonstrating enhanced synchrony of myocardial segments, which resulted in the patient's clinical improvement.

Aged↗
PubMed2005

Gender-based differences in brachial artery flow-mediated vasodilation as an indicator of significant coronary artery disease.

Ultrasound of the brachial artery is widely used to assess endothelial function, but whether brachial artery flow-mediated vasodilation (FMD) differs between women and men who have coronary artery disease (CAD) has not been examined. To investigate gender-based differences in brachial artery FMD as an indicator of significant CAD, FMD was measured in women and men outpatients who had CAD (coronary stenosis >50%, n = 64) and those who did not have significant CAD (n = 145). FMD in women who had CAD (n = 33, 9.1 +/- 0.8%) was higher than that in similarly aged men who had CAD (n = 31, 6.4 +/- 0.5%; p = 0.008). The FMD cutpoint that maximized sensitivity with least effect on specificity for screening CAD was 15% (91% sensitivity, 25% specificity) in women but 10% (90% sensitivity, 43% specificity) in men. If the cutpoint as defined in men were used to evaluate women, brachial artery ultrasound would fail to diagnose 42% of women who do not have significant CAD; thus, a higher FMD cutpoint is required to optimize the sensitivity of FMD for identifying women who have significant CAD compared with similarly aged men. In studies using FMD to evaluate cardiovascular risk, different standards should be applied for women and men.

Brachial Artery↗
PubMed2005

Effects of levosimendan on systemic and regional hemodynamics in septic myocardial depression.

OBJECTIVE: Calcium desensitization plays an important part in the pathophysiology of septic myocardial depression. We postulated that levosimendan, a new calcium sensitizer, would be beneficial in sepsis-induced cardiac dysfunction. DESIGN AND SETTING: Prospective, randomized, controlled study in two university hospital intensive care units. PATIENTS AND PARTICIPANTS: Twenty-eight patients with persisting left ventricular dysfunction related to septic shock after 48 h of conventional treatment including dobutamine (5 microg/kg per minute). INTERVENTIONS: After 48 h of conventional treatment patients were randomized to receive a 24-h infusion of either levosimendan (0.2 microg/kg per minute, n=15) or dobutamine (5 microg/kg per minute, n=13). MEASUREMENTS AND RESULTS: Data from right heart catheterization, echocardiography, gastric tonometry, laser-Doppler flowmetry, and lactate concentrations and creatinine clearance were obtained before and after the 24-h drug infusion. Dobutamine did not change systemic or regional hemodynamic variables. By contrast, at the same mean arterial pressure levosimendan decreased pulmonary artery occlusion pressure and increased cardiac index. Levosimendan decreased left ventricular end-diastolic volume and increased left ventricular ejection fraction. Levosimendan increased gastric mucosal flow, creatinine clearance, and urinary output while it decreased lactate concentrations. CONCLUSIONS: These findings show that levosimendan improves systemic hemodynamics and regional perfusion in patients with septic cardiac dysfunction under conditions where administration of 5 microg/kg dobutamine per minute is no longer efficacious. Accordingly, our results suggest that levosimendan can be an alternative to the strategy of increasing the dose of dobutamine under such conditions.

Cardiac Output, Low↗
PubMed2005

Comparison of flow-mediated dilatation of the brachial artery in coronary patients with low-density lipoprotein cholesterol levels <80 mg/dl versus patients with levels 80 to 100 mg/dl.

Testing of peripheral vascular endothelial function was performed in subjects who had coronary artery disease and a low-density lipoprotein (LDL) cholesterol level <100 mg/dl. LDL cholesterol was an independent predictor of flow-mediated dilation of the brachial artery (p = 0.010). The 63 subjects who had an LDL cholesterol level <80 mg/dl had better endothelial function (flow-mediated dilation 8.4 +/- 3.8%) than did 47 subjects whose level of LDL cholesterol was 80 to 100 mg/dl (flow-mediated dilation 6.8 +/- 4.0%, p = 0.03). The beneficial effects of LDL cholesterol levels <80 mg/dl on endothelial function were more apparent in subjects who had low levels of high-density lipoprotein cholesterol than in those who had normal levels. These data support recent reports that decreasing levels of LDL cholesterol below those currently recommended provides additional benefits and suggest that this benefit may be due in part to increased endothelial function.

Brachial Artery↗
PubMed2005

Peripheral vascular endothelial function correlates with exercise capacity in women.

BACKGROUND: Vascular endothelial function has been observed to correlate with exercise capacity in predominantly male populations. Gender-based differences exist in the clinical course of coronary artery disease, and previous studies indicate that estrogen may influence endothelial function. These observations raise the possibility that the relationship between endothelial function and exercise capacity in women may differ from that in men. HYPOTHESIS: This study aimed to determine whether peripheral vascular endothelial function correlates with exercise capacity in women. METHODS: Women who were referred for clinically indicated exercise testing with technetium-99 myocardial perfusion imaging were consecutively recruited. To ensure a population free of exercise limitation due to ischemic heart disease, women without myocardial perfusion defects were included for analysis in this study (n = 105). Endothelial function was assessed by brachial artery ultrasound flow-mediated vasodilation (FMD). Exercise capacity was defined as the duration of exercise on a symptom-limited Bruce protocol. RESULTS: Mean FMD was 11.8 +/- 0.6%, and median FMD was 12%. Subjects with an FMD less than the median of 12% had a significantly shorter exercise time than those with FMD > or = 12% (411 +/- 17 vs. 482 +/- 24 s, p = 0.014). There was a significant correlation between FMD and exercise time (r = 0.34, p < 0.001). Age and body mass index were additional predictors of exercise time; however, the relationship between FMD and exercise time was independent of these variables. CONCLUSION: Brachial artery FMD correlates with exercise capacity in women, even in the absence of ischemic heart disease.

Adult↗