Publications (13)52.68 Total impact
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Article: Echocardiography in chronic thromboembolic pulmonary hypertension.
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ABSTRACT: Chronic thromboembolic pulmonary hypertension (CTEPH) is a significant complication of venous thromboembolism and is caused by incomplete resolution of pulmonary emboli. The persistent chronic pulmonary hypertension leads to right-ventricle pressure overload. As a result, there is often significant functional and morphological alteration of both the right and the left ventricle. Transthoracic echocardiography, which allows for the estimation of pulmonary arterial pressures, not only plays an important role in the diagnosis of pulmonary hypertension but also provides insights in the pathophysiology of CTEPH. This article reviews the echocardiographic techniques and findings in CTEPH patients.Seminars in Thoracic and Cardiovascular Surgery 02/2006; 18(3):230-5. -
Article: The effects of enhanced external counterpulsation on myocardial perfusion in patients with stable angina: a multicenter radionuclide study.
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ABSTRACT: Enhanced external counterpulsation (EECP) reduces angina and extends time to exercise-induced ischemia in patients with symptomatic coronary disease. One- and two-center studies and a retrospective case series reported that EECP improves myocardial perfusion in stable angina pectoris. We sought to critically evaluate and quantify the effect of EECP on myocardial perfusion. In 6 US university hospitals, EECP was performed for 35 hours in patients with class II to IV angina who had exercise-induced myocardial ischemia. Symptom-limited quantitative gated technetium Tc 99m sestamibi single photon emission computed tomography exercise perfusion imaging was performed at baseline and 1 month post-EECP. Sestamibi was injected at the same heart rate in both stress tests. Single photon emission computed tomography images were read at a blinded core laboratory. Thirty-seven patients were enrolled, 34 of whom completed pre- and post-EECP stress testing. The mean age was 61 +/- 10 years, 81% were male, 78% had prior revascularization, and 68% had 3-vessel disease. The mean angina class decreased from 2.7 +/- 0.7 at baseline to 1.7 +/- 0.7 after EECP (P < .001). Exercise duration increased from 9.1 +/- 3.7 minutes at baseline to 10.2 +/- 3.6 minutes post-EECP (P = .03). The average percentage of tracer uptake, magnitude of reversibility, average thickening fraction, and the left ventricular ejection fraction remained unchanged after EECP. We confirm previous report that EECP reduces angina and improves exercise capacity. There were no significant changes in mean defect magnitude, amount of reversibility, thickening fraction, and ejection fraction measured using myocardial quantitative single photon emission computed tomography imaging when compared at identical pre- and post-EECP heart rates.American heart journal 11/2005; 150(5):1066-73. · 4.65 Impact Factor -
Article: A 39-year-old man with anasarca.
Chest 11/2004; 126(5):1683-6. · 5.25 Impact Factor -
Article: Does lowering pulmonary arterial pressure eliminate severe functional tricuspid regurgitation? Insights from pulmonary thromboendarterectomy.
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ABSTRACT: Because pulmonary thromboendarterectomy (PTE) can result in an immediate reduction in pulmonary artery (PA) pressure, we sought to evaluate the effect of PTE on severe tricuspid regurgitation (TR) without tricuspid annuloplasty. Few data exist regarding the frequency and magnitude of functional TR improvement after reduction in PA pressure. We identified 27 patients with severe TR, defined by a regurgitant index (RI) >33%, who underwent PTE. The RI, tricuspid annular diameter (TAD), apical displacement of leaflet coaptation, and estimated PA systolic pressure were determined on pre- and post-PTE echocardiograms. Patients were stratified based on resolution (RI < or =33%) or persistence (RI >33%) of severe TR. Comparing pre- and post-PTE echocardiography results, severe TR resolved in 19 of 27 (70%) patients. This group had a more effective PA systolic pressure reduction after PTE (49 +/- 20 mm Hg vs. 32 +/- 16 mm Hg by echocardiography, p = 0.075, and 37 +/- 16 mm Hg vs. 16 +/- 13 mm Hg by catheter measurement, p = 0.004). No difference was observed in TAD, apical displacement of the tricuspid valve, or other features compared with the group with persistent severe TR. There was a trend toward longer hospital stays in the group with persistent severe TR (19 +/- 15 days vs. 14 +/- 9 days; p = 0.55). After significant PA pressure reduction by PTE, severe functional TR with a dilated annulus may improve without annuloplasty despite dilated tricuspid annulus diameters.Journal of the American College of Cardiology 07/2004; 44(1):126-32. · 14.16 Impact Factor -
Article: Microbubble contrast agents for echocardiography: rationale, composition, ultrasound interactions, and safety.
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ABSTRACT: Imaging the small blood vessels within the myocardium, which contains only a small fraction of the total coronary blood volume, is a significant challenge for ultrasound imaging. Recent advances in microbubble design and ultrasound technology have improved our ability to image the microcirculation. It is essential to understand the fundamentals of microbubble behavior in an ultrasound field and how it impacts technology and safety.Cardiology Clinics 06/2004; 22(2):171-80, v. · 1.36 Impact Factor -
Article: Myocardial contrast echocardiography (MCE) with triggered ultrasound does not cause premature ventricular complexes: evidence from PB127 MCE studies.
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ABSTRACT: Previous studies suggest that myocardial contrast echocardiography using high mechanical index triggered ultrasound can be associated with increased frequency of the premature ventricular complex (PVC). However, this association has not been systematically examined. PB127 (Point Biomedical Corp, San Carlos, Calif) is a novel microsphere designed for evaluation of myocardial perfusion with ultrasound. PB127 myocardial contrast echocardiography was performed with triggered harmonic power Doppler in early/mid diastole (mechanical index </= 1.0). A total of 71 patients (cohort A) were studied at rest and another 64 (cohort B, age 62 +/- 12.6 years) were allocated to stress. Continuous electrocardigraphy was recorded. The study evaluated premature ventricular complex frequency at baseline, during, and after infusion of PB127 (dose < 0.175 mg/kg, <60-minute duration). Proportions of triggered and nontriggered intervals associated with premature ventricular complex were determined. PVC frequency did not increase with PB127 infusion in either cohort (P =.572, P =.263). Proportion of triggered intervals after QRS associated with PVC was similar to proportion of untriggered intervals in cohort A (P >.999) and was lower than untriggered intervals (P =.001) in B, suggesting that triggers do not cause PVC. PB127 does not cause increase PVC frequency during or after imaging with triggered ultrasound at mechanical index of 1.Journal of the American Society of Echocardiography 10/2003; 16(10):1037-42. · 3.71 Impact Factor -
Article: Physical principles of microbubble ultrasound contrast agents.
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ABSTRACT: Early contrast agents could not achieve left-sided cardiac opacification because these microbubbles could not traverse the pulmonary circulation and remain intact. The specific shell material and gas used determine the properties of individual microbubbles, including fragility, persistence, and resonance. Persistence, perhaps the most important property of a microbubble, has been achieved by second-generation agents through the use of shells or surfactants and by substituting high-density, high molecular weight gas for air. Today's agents readily achieve opacification, not only of the cardiac chambers but also of the myocardium. Refinements in contrast agents and in the instrumentation for their detection are primarily responsible for these improvements.The American Journal of Cardiology 12/2002; 90(10A):3J-7J. · 3.37 Impact Factor -
Article: Correlation of left ventricular diastolic filling characteristics with right ventricular overload and pulmonary artery pressure in chronic thromboembolic pulmonary hypertension.
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ABSTRACT: This study was designed to determine a quantitative relationship between right ventricular (RV) pressure overload and left ventricular (LV) diastolic filling characteristics in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Right ventricular pressure overload in patients with CTEPH causes abnormal LV diastolic filling. However, a quantitative relationship between RV pressure overload and LV diastolic function has not been established. We analyzed pre- and postoperative diastolic mitral inflow velocities and right heart hemodynamic data in 39 consecutive patients with CTEPH over the age of 30 (55 +/- 11 years) with mean pulmonary artery pressure >30 mm Hg who underwent pulmonary thromboendarterectomy (PTE). After PTE, mean pulmonary artery pressure (mPAP) decreased from 50 +/- 11 to 28 +/- 9 mm Hg (p < 0.001) while cardiac output (CO) increased from 4.4 +/- 1.1 to 5.7 +/- 0.9 l/m (p < 0.001). Mitral E/A ratio (E/A) increased from 0.74 +/- 0.22 to 1.48 +/- 0.69 (p < 0.001). E/A was < 1.25 in all patients pre-PTE. After PTE, all patients with E/A >1.50 had mPAP <35 mm Hg and CO >5.0 l/min. E/A correlated inversely with mPAP (r = 0.55, p < 0.001) and directly with CO (r = 0.53, p < 0.001). E/A is consistently abnormal in patients with CTEPH and increases post-PTE. Moreover, E/A varies inversely with mPAP and directly with CO. Following PTE, E/A >1.5 correlates with the absence of severe pulmonary hypertension (mPAP >35 mm Hg) and the presence of normal cardiac output (> 5.0 l/m).Journal of the American College of Cardiology 07/2002; 40(2):318-24. · 14.16 Impact Factor -
Article: Paradoxical inferior-posterior wall systolic expansion in patients with end-stage liver disease.
The American Journal of Cardiology 04/2002; 89(5):626-9. · 3.37 Impact Factor -
Article: Role of cardiac ultrasound in heart failure.
Journal of Nuclear Cardiology 9(5 Suppl):53S-59S. · 2.67 Impact Factor -
Article: Dilation of the Coronary Sinus on Echocardiogram: Prevalence and significance in patients with chronic pulmonary hypertension
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ABSTRACT: Background:Although rarely seen in healthy patients,the coronary sinus (CS) is often visualized on echo-cardiography in patients with right-sided heart disease. However, the prevalence of this finding and its relation to right-sided heart structure and pressure remains undefined.Methods:We examined the transthoracic echocardiograms of 43 consecutive patients referred for the evaluation of pulmonary hypertension (26 men, 17 women) with a mean age of 53 ± 15 years (range 21 to 82 years). Structural abnormalities of the tricuspid valve were absent. All patients underwent right heart catheterization within 48 hours of their echocardiogram, which revealed the following pressures: mean pulmonary artery (50 mm Hg, range 31 to 84 mm Hg) and right atrial (RA) (mean 10, range 1 to 24 mm Hg). Echocardiograms were analyzed for CS size (identified as the smallest diameter of a circular structure in the left atrioventricular groove in the parasternal long-axis view), as well as RA and right ventricular (RV) sizes. The presence and severity (grades 1 through 3) of tricuspid regurgitation (TR) were also recorded.Results:The CS was visualized in 35 (81%) of 43 patients, and measurements ranged from 0.4 to 1.6 cm (mean 0.8 cm). No difference in RA size, RV size, TR grade, RA pressure (RAP), RV pressure (RVP), mean pulmonary artery pressure (PAP), or pulmonary vascular resistance (PVR) was observed between patients with a visualized and nonvisualized CS. Coronary sinus size correlated significantly with RA size (r = 0.60, P < .001) and pressure (r − 0.59, P < .001), but not with RV size, degree of TR, RVP, PAP, or PVR. Nineteen of 35 patients with a visualized CS underwent pulmonary artery thromboendarterectomy (PTE), and their CS size and RAP were unchanged (0.8 cm and 12 mm Hg, respectively, pre- and post PTE; both P = NS [not significantD, though a decrease was observed in other measurements: RA size (4.2 versus 4.8 cm, P = .02), RV size (4.2 versus 5.1 cm, P = .0004), mean PAP (37 versus 72 mm Hg, P < .0001), and PVR (230 versus 899 min Hg, P < .0001).Conclusions:Coronary sinus dilation was observed in 81% of a selected group of patients with pulmonary hypertension in the absence of structural disease of the tricuspid valve. Coronary sinus dilation is related to RAP and RA size, but not to RV size, degree of TR, RVP, PA pressure, or PVR. Once dilated, CS size does not change shortly after decreases of RA size, RV size, or PA pressure produced by PTE.Journal of the American Society of Echocardiography. -
Article: Correlation of left ventricular diastolic filling characteristics with right ventricular overload and pulmonary artery pressure in chronic thromboembolic pulmonary hypertension
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ABSTRACT: ObjectivesThis study was designed to determine a quantitative relationship between right ventricular (RV) pressure overload and left ventricular (LV) diastolic filling characteristics in patients with chronic thromboembolic pulmonary hypertension (CTEPH).BackgroundRight ventricular pressure overload in patients with CTEPH causes abnormal LV diastolic filling. However, a quantitative relationship between RV pressure overload and LV diastolic function has not been established.MethodsWe analyzed pre- and postoperative diastolic mitral inflow velocities and right heart hemodynamic data in 39 consecutive patients with CTEPH over the age of 30 (55 ± 11 years) with mean pulmonary artery pressure >30 mm Hg who underwent pulmonary thromboendarterectomy (PTE).ResultsAfter PTE, mean pulmonary artery pressure (mPAP) decreased from 50 ± 11 to 28 ± 9 mm Hg (p < 0.001) while cardiac output (CO) increased from 4.4 ± 1.1 to 5.7 ± 0.9 l/m (p < 0.001). Mitral E/A ratio (E/A) increased from 0.74 ± 0.22 to 1.48 ± 0.69 (p < 0.001). E/A was < 1.25 in all patients pre-PTE. After PTE, all patients with E/A >1.50 had mPAP <35 mm Hg and CO >5.0 l/min. E/A correlated inversely with mPAP (r = 0.55, p < 0.001) and directly with CO (r = 0.53, p < 0.001).ConclusionsE/A is consistently abnormal in patients with CTEPH and increases post-PTE. Moreover, E/A varies inversely with mPAP and directly with CO. Following PTE, E/A >1.5 correlates with the absence of severe pulmonary hypertension (mPAP >35 mm Hg) and the presence of normal cardiac output (> 5.0 l/m).Journal of the American College of Cardiology. -
Article: Does lowering pulmonary arterial pressure eliminate severe functional tricuspid regurgitation?: Insights from pulmonary thromboendarterectomy
[show abstract] [hide abstract]
ABSTRACT: ObjectivesBecause pulmonary thromboendarterectomy (PTE) can result in an immediate reduction in pulmonary artery (PA) pressure, we sought to evaluate the effect of PTE on severe tricuspid regurgitation (TR) without tricuspid annuloplasty.BackgroundFew data exist regarding the frequency and magnitude of functional TR improvement after reduction in PA pressure.MethodsWe identified 27 patients with severe TR, defined by a regurgitant index (RI) >33%, who underwent PTE. The RI, tricuspid annular diameter (TAD), apical displacement of leaflet coaptation, and estimated PA systolic pressure were determined on pre- and post-PTE echocardiograms. Patients were stratified based on resolution (RI ≤33%) or persistence (RI >33%) of severe TR.ResultsComparing pre- and post-PTE echocardiography results, severe TR resolved in 19 of 27 (70%) patients. This group had a more effective PA systolic pressure reduction after PTE (49 ± 20 mm Hg vs. 32 ± 16 mm Hg by echocardiography, p = 0.075, and 37 ± 16 mm Hg vs. 16 ± 13 mm Hg by catheter measurement, p = 0.004). No difference was observed in TAD, apical displacement of the tricuspid valve, or other features compared with the group with persistent severe TR. There was a trend toward longer hospital stays in the group with persistent severe TR (19 ± 15 days vs. 14 ± 9 days; p = 0.55).ConclusionsAfter significant PA pressure reduction by PTE, severe functional TR with a dilated annulus may improve without annuloplasty despite dilated tricuspid annulus diameters.Journal of the American College of Cardiology.
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2002–2006
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University of California, San Diego
- Division of Cardiology
San Diego, CA, USA
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