Harvinder S. Dod

Quantification of Mitral Regurgitation by Live Three-Dimensional Transthoracic Echocardiographic Measurements of Vena Contracta Area: 3D TTE VENA CONTRACTA AREA FOR MR

We evaluated 44 consecutive patients who underwent standard two‐dimensional (2D) and live three‐dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs= 0.88) with very little overlap. VCA of <0.2 cm2 correlated with mild MR, 0.2–0.4 cm2 with moderate MR, and >0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs= 0.79) and RJA alone (rs= 0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs= 0.51 and rs= 0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.

Effect of intensive lifestyle changes on endothelial function and on inflammatory markers of atherosclerosis.

Intensive lifestyle changes have been shown to regress atherosclerosis, improve cardiovascular risk profiles, and decrease angina pectoris and cardiac events. We evaluated the influence of the Multisite Cardiac Lifestyle Intervention Program, an ongoing health insurance-covered lifestyle intervention conducted at our site, on endothelial function and inflammatory markers of atherosclerosis in this pilot study. Twenty-seven participants with coronary artery disease (CAD) and/or risk factors for CAD (nonsmokers, 14 men; mean age 56 years) were enrolled in the experimental group and asked to make changes in diet (10% calories from fat, plant based), engage in moderate exercise (3 hours/week), and practice stress management (1 hour/day). Twenty historically (age, gender, CAD, and CAD risk factors) matched participants were enrolled in the control group with usual standard of care. At baseline endothelium-dependent brachial artery flow-mediated dilatation (FMD) was performed in the 2 groups. Serum markers of inflammation, endothelial dysfunction, and angiogenesis were performed only in the experimental group. After 12 weeks, FMD had improved in the experimental group from a baseline of 4.23 + or - 0.13 to 4.65 + or - 0.15 mm, whereas in the control group it decreased from 4.62 + or - 0.16 to 4.48 + or - 0.17 mm. Changes were significantly different in favor of the experimental group (p <0.0001). Also, significant decreases occurred in C-reactive protein (from 2.07 + or - 0.57 to 1.6 + or - 0.43 mg/L, p = 0.03) and interleukin-6 (from 2.52 + or - 0.62 to 1.23 + or - 0.3 pg/ml, p = 0.02) after 12 weeks. Significant improvement in FMD, C-reactive protein, and interleukin-6 with intensive lifestyle changes in the experimental group suggests > or = 1 potential mechanism underlying the clinical benefits seen in previous trials.

Live Three‐Dimensional Transthoracic Echocardiographic Assessment of Left Atrial Tumors

This preliminary study demonstrates the superiority of live three‐dimensional transthoracic echocardiography (3D TTE) over two‐dimensional (2D) TTE in the assessment of left atrial (LA) tumors in four patients studied by us (three myxomas, one hemangioma, all subsequently pathologically proven). Because of the unique ability of live 3D TTE to systematically section and view the contents of an intracardiac mass, LA myxomas in the three patients studied could be more confidently diagnosed by noting isolated echolucent areas consistent with hemorrhage/necrosis in the tumor mass. On the other hand, a definite echolucent area was found by 2D TTE in only two of the three patients with myxoma. In the fourth patient with a hemangioma, live 3D TTE showed much more extensive and closely packed echolucencies with little solid tissue as compared to a myxoma consistent with a highly vascularized tumor. In contrast, 2D TTE demonstrated only two isolated echolucencies in the tumor suggesting an erroneous diagnosis of myxoma.

Assessment of Systolic and Diastolic Left Ventricular and Left Atrial Function Using Vector Velocity Imaging in Takotsubo Cardiomyopathy

Five adult patients with Takotsubo cardiomyopathy (TC) diagnosed by usual criteria were studied with velocity vector imaging (VVI) on admission and at follow‐up, when their LV function had improved, as assessed by 2D TTE wall‐motion score (WMS) index. Averaged peak segmental longitudinal strain (S) in systole, and velocity (V) and strain rate (SR) in both systole and diastole were measured from apical 4‐ (A4C) and 2‐chamber views (A2C) in all patients. The data obtained by VVI were analyzed separately for involved and uninvolved segments, which were independently assessed by WMS. In the involved segments, systolic S, V, SR, and diastolic SR improved (P‐value < 0.05) on follow‐up. Diastolic V showed a trend toward improvement but did not reach statistical significance. In the uninvolved segments, none of the parameters improved significantly either during systole or diastole. In three of these five patients, left atrial (LA) walls were also studied by placing region of interest (ROI) points in the middle of each wall. Peak segmental LA systolic and diastolic V and SR as well as systolic S were obtained for both involved and uninvolved LA walls which were assessed independently using WMS similar to LV. In the involved LA walls, none of the atrial systolic and diastolic parameters changed significantly but all parameters with the exception of systolic V showed a tendency toward improvement during follow‐up. Among the uninvolved LA walls, none changed significantly but atrial systolic SR and, diastolic V and SR tended to increase during follow‐up. Our retrospective study using VVI demonstrates that TC patients also have LV systolic and diastolic longitudinal dysfunction, not just systolic radial dysfunction as assessed by traditional 2D TTE indices. Longitudinal LA dysfunction may also be present.

Incremental Value of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Assessment of Right Ventricular Masses

This case series demonstrates the incremental value of three‐dimensional transthoracic echocardiography (3D TTE) over two‐dimensional transthoracic echocardiography (2D TTE) in the assessment of 11 patients with right ventricular (RV) masses or mass‐like lesions (three cases of RV thrombus, one myxoma, one fibroma, one lipoma, one chordoma, and one sarcoma and three cases of RV noncompaction, which are considered to be mass‐like in nature). 3D TTE was of incremental value in the assessment of these masses in that 3D TTE has the capacity to section the mass and view it from multiple angles, giving the examiner a more comprehensive assessment of the mass. This was particularly helpful in the cases of thrombi, as the presence of echolucencies indicated clot lysis. In addition, certainty in the number of thrombi present was an advantage of 3D TTE. Also, sectioning of cardiac tumors allowed more confidence in narrowing the differential diagnosis of the etiology of the mass. In addition, 3D TTE allowed us to identify precise location of the attachments of the masses as well as to determine whether there were mobile components to the mass. Another noteworthy advantage of 3D TTE was that the volumes of the masses could be calculated. Additionally, the findings by 3D TTE correlated well with pathologic examination of RV tumors, and some of the masses measured larger by 3D TTE than by 2D TTE, which was also validated in one case by surgery. As in the case of RV fibroma, another advantage was that 3D TTE actually identified more masses than 2D TTE. RV noncompaction was also well studied, and the assessment with 3D TTE helped to give a more definitive diagnosis in these patients.

Evolving role of platelet function testing in coronary artery interventions

The substantial reduction in ischemic events provided by the dual antiplatelet regimen with aspirin and clopidogrel is well documented in patients with acute coronary syndrome and patients undergoing percutaneous coronary intervention. Recently the variable response to the antiplatelet agents has received considerable attention after several “boxed warnings” on clopidogrel. This led to intense controversy on pharmacokinetic, pharmacodynamic, and pharmacogenomic issues of antiplatelet drugs, especially clopidogrel. Research use of platelet function testing has been successfully validated in identifying new antiplatelet drugs like prasugrel and ticagrelor. These platelet function assays are no longer regarded just as a laboratory phenomenon but rather as tools that have been shown to predict mortality in several clinical trials. It is believed that suboptimal response to an antiplatelet regimen (pharmacodynamic effect) may be associated with cardiovascular, cerebrovascular, and peripheral arterial events. There has been intense controversy about this variable response of antiplatelet drugs and the role of platelet function testing to guide antiplatelet therapy. While the importance of routine platelet function testing may be uncertain, it may be useful in high-risk patients such as those with diabetes mellitus, diffuse three vessels coronary artery disease, left main stenosis, diffuse atherosclerotic disease, and those with chronic renal failure undergoing percutaneous coronary intervention. It could also be useful in patients with suspected pharmacodynamic interaction with other drugs to assure the adequacy of platelet inhibition. While we wait for definitive trials, a predictive prognostic algorithm is necessary to individualize antiplatelet therapy with P2Y12 inhibitors based on platelet function assays and genetic testing.

Live three-dimensional transthoracic echocardiographic assessment of aortic dissection.

In the present study, we report our experience of using live three‐dimensional transthoracic echocardiography in the assessment of aortic dissection in ten adult patients. To our knowledge, this has not been reported previously. (ECHOCARDIOGRAPHY, Volume 20, August 2003)

Platelet function testing to predict hyporesponsiveness to clopidogrel in patients with chest pain seen in the emergency department

Background A dual antiplatelet regimen has been shown to reduce the risk of major adverse cardiovascular events after percutaneous coronary intervention. However, there is little information available on inhibition of platelet aggregation in patients with a prior coronary stent presenting with chest pain. This study evaluated the prevalence of hyporesponsiveness to clopidogrel and factors associated with this in patients presenting to our emergency department with chest pain who had previously undergone coronary stent placement and were prescribed dual antiplatelet therapy. Methods Responsiveness to clopidogrel was evaluated in a cohort of 533 consecutive stented patients presenting to the emergency department with chest pain. P2Y12 reaction units (PRU) and percent P2Y12 inhibition with clopidogrel were measured in all patients. Of 533 patients, 221 (41.6%) had PRU ≥ 230. A multivariate logistic regression model was used to determine the relationship between hyporesponsiveness to clopidogrel (defined as PRU ≥ 230) and several potential risk factors, ie, gender, age, race, type 1 or type 2 diabetes, hypertension, smoking, chronic renal failure, and obesity. Results There was a greater risk of hyporesponsiveness in African Americans than in non-African American patients (adjusted odds ratio [OR] = 2.165), in patients with type 2 diabetes than in those without (adjusted OR = 2.109), and in women than in men (adjusted OR = 1.813), as well as a greater risk of hyporesponsiveness with increasing age (adjusted OR = 1.167 per decade). Conclusion There was a high prevalence of hyporesponsiveness to clopidogrel in patients presenting with chest pain and a prior coronary stent. Non-insulin-dependent diabetes mellitus and African American race were the strongest predictors of hyporesponsiveness to clopidogrel, followed by gender and age.

Embolization of Atrial Septal Occluder Device into the Pulmonary Artery: A Rare Complication and Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography

Percutaneous closure of atrial septal defects (ASD) in adults has emerged as an alternative to surgery. We report a rare complication of an atrial septal occluder device embolization into the pulmonary artery which was detected by fluoroscopy and echocardiography. The potential usefulness of live/real time three‐dimensional transthoracic echocardiography in the management of patients undergoing percutaneous ASD occlusion is described. (ECHOCARDIOGRAPHY, Volume 26, July 2009)

Left ventricular noncompaction: A rare disorder in adults and its association with 1p36 chromosomal anomaly†

We report on a case of a 25‐year‐old male with 1p36 deletion syndrome, who was diagnosed with left ventricular noncompaction (LVNC). The association of this rare chromosomal abnormality with LVNC is reported in the pediatric literature, but it has not previously been specifically reported in adults. It is important to diagnose this unclassified cardiomyopathy in the adult population with this chromosomal abnormality for appropriate management and treatment as highlighted in our case.