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Paul Das

Publications and source records attributed to Paul Das.

5 recordsLinked to original sources
PubMed2007

Role of intravascular ultrasound in unprotected left main percutaneous coronary intervention.

Percutaneous coronary intervention (PCI) to the unprotected left main stem offers an attractive alternative to bypass grafting, but is associated with a significant clinical risk and therefore demands special consideration. Successful left main PCI is dependent upon the morphology of the lesion and the technical quality of the procedure. For these reasons, intravascular ultrasound (IVUS) has been the most popular adjunct to coronary angiography during left main PCI. However, trials of IVUS in left main PCI have produced inconclusive results, and most data predate the use of drug-eluting stents. Despite this, IVUS offers practical benefits in both case selection, and in guiding angioplasty and stenting. Here, we review the arguments for the present and future role of IVUS in left main PCI.

Angioplasty, Balloon, Coronary↗
PubMed2005

Exercise testing to stratify risk in aortic stenosis.

AIMS: The aims of this study were to assess the accuracy of exercise testing in predicting symptom onset within 12 months in patients with asymptomatic aortic stenosis and to establish the criteria that define a positive test. METHODS AND RESULTS: A total of 125 patients with aortic stenosis [effective orifice area (EOA) 0.9+/-0.2 cm2] were assessed by Specific Activity Scale (SAS) classification, transthoracic echocardiography, and treadmill exercise testing using the modified Bruce protocol. During follow-up, 36 patients (29%) developed spontaneous symptoms within 12 months. Of these, 26 (72%) had had symptoms revealed by exercise testing and 24 (67%) had severe stenosis (EOA < or = 0.8 cm2). Exercise-limiting symptoms were the only independent predictors of outcome at 12 months, and an abnormal blood pressure response or ST segment depression did not improve the accuracy of the exercise test. The positive predictive accuracy for exercise-induced symptoms was 57% in the whole population and 79% for patients aged <70 in SAS Class I. The negative predictive accuracy was 87% in the whole population and 86% in the subgroup. CONCLUSION: A significant proportion of patients with apparently asymptomatic aortic stenosis experience limiting symptoms on treadmill exercise testing. The subsequent development of spontaneous symptoms is strongly related to the severity of stenosis and to limiting symptoms on exercise testing, but less so to an abnormal blood pressure response or ST segment depression.

Aged↗
PubMed2003

Determinants of symptoms and exercise capacity in aortic stenosis: a comparison of resting haemodynamics and valve compliance during dobutamine stress.

AIMS: Valve compliance might determine the onset of symptoms better than resting measures of aortic stenosis. This study compared valve compliance measured by dobutamine stress echocardiography with resting haemodynamic variables against the end-point of symptoms at low workload during exercise testing. METHODS AND RESULTS: Echocardiography was performed at rest and during each stage of a dobutamine stress test in 65 asymptomatic patients with moderate or severe aortic stenosis. Each patient also completed a modified Bruce treadmill exercise test. During dobutamine stress, peak transaortic velocity increased by 1.0 (0.4) m/s and effective orifice area by 0.25 (0.22) cm(2). Valve compliance was 0.23 (0.10) cm(2)/100ml.s(-1), and was independent of baseline effective orifice area. In the 19 patients limited by symptoms on exercise testing, valve compliance was significantly lower (0.19 (0.09) cm(2)/100ml.s(-1)) than in those who remained asymptomatic (0.25 (0.10) cm(2)/100ml.s(-1), p=0.03). Effective orifice area at peak stress was also lower (1.0 (0.3) vs 1.2 (0.4) cm(2), p=0.03), but there were no significant differences in resting measures of effective orifice area, transaortic velocity, or mean pressure drop. CONCLUSIONS: Effective orifice area is flow-dependent in patients with moderate and severe aortic stenosis with preserved left ventricular function. Exertional symptoms are better predicted by compliance than resting effective orifice area, mean pressure drop or peak transaortic velocity.

Adult↗
PubMed2003

Imaging in mitral stenosis: assessment before, during and after percutaneous balloon mitral valvuloplasty.

Detailed assessment of mitral valve morphology is required to select patients for successful percutaneous balloon mitral valvuloplasty (PBMV). The mitral valve is routinely imaged using transthoracic and transesophageal echocardiography, which have more recently been supplemented with magnetic resonance imaging, 3D echocardiography and intracardiac echocardiography. The scope of PBMV is expanding and it is increasingly used for patients previously considered to have unfavorable mitral morphology. Here we review the evidence to support the examination of each component of the mitral valve and its surrounding structures and the advantages of each imaging modality. Appropriate echocardiographic views are recommended and periprocedural and postprocedural imaging techniques are discussed.

Catheterization↗