Biomedical subjects

Sharon L Mulvagh

Publications and source records attributed to Sharon L Mulvagh.

9 recordsLinked to original sources

PubMed2006

Relationship between coronary artery calcification detected by electron-beam computed tomography and abnormal stress echocardiography: association and prognostic implications.

OBJECTIVES: The purpose of this study was to compare the results and prognostic value of electron-beam computed tomography (EBCT) and exercise echocardiography. BACKGROUND: Although patients with elevated coronary artery calcium scores (CACS) might be referred for exercise echocardiography, the association of EBCT CACS with wall motion score index (WMSI) is not known. METHODS: Patients without known coronary artery disease who underwent both clinically indicated EBCT and exercise echocardiography within a 3-month period were identified. Exercise WMSI was based on a 16-segment model (normal = 1; abnormal >1). The EBCT CACS was derived with the Agatston scoring system. Follow-up was obtained for the combined end point of death and myocardial infarction. RESULTS: The study population included 556 patients (age 54 +/- 10 years; 65% male). Correlation between EBCT CACS and exercise WMSI was limited (r = 0.17, p < 0.0001) but statistically significant. The proportion of patients with abnormal exercise WMSI increased with increasing CACS severity (chi-square = 19.1, p < 0.001). However, even in those with CACS >400, 66% had normal exercise WMSI. Age, CACS, and chest pain were independently associated with abnormal exercise WMSI. Events occurred in 12 (2%) patients. Wall motion score index (risk ratio [RR] 3.7, p = 0.023) and age (RR 1.9, p = 0.019) were associated with events. CONCLUSIONS: Electron-beam computed tomography CACS was predictive of abnormal exercise WMSI, but the majority of patients with elevated CACS had normal WMSI. Wall motion score index and age were the best predictors of events. Prospective studies are indicated to establish the relative roles of these tests in risk stratification.

Aged↗

PubMed2006

Determining myocardial viability in chronic ischemic left ventricular dysfunction: a prospective comparison of rest-redistribution thallium 201 single-photon emission computed tomography, nitroglycerin-dobutamine echocardiography, and intracoronary myocardial contrast echocardiography.

BACKGROUND: Detection of viable myocardium (VM) has important therapeutic implications for chronic ischemic left ventricular (LV) systolic dysfunction. We compared the ability of nitroglycerin-dobutamine echocardiography (NTG-DE), intracoronary myocardial contrast echocardiography (MCE), and rest-redistribution thallium 201 single-photon emission computed tomography (RRT-SPECT) to detect VM in this setting. METHODS: Patients with LV ejection fraction (LVEF) <40% and multivessel coronary disease suitable for revascularization underwent NTG-DE, MCE, RRT-SPECT, and radionuclide ventriculography to determine baseline LVEF. Myocardial contrast echocardiography was performed using intracoronary injection of Albunex. Patients who underwent revascularization had 3-month postprocedural radionuclide ventriculography and transthoracic echocardiography to assess functional recovery. RESULTS: Of 512 myocardial segments in the 32 patients studied, 309 were akinetic or dyskinetic at baseline. Nitroglycerin alone increased regional thickening in 20% of segments with contractile reserve. By RRT-SPECT, 93% of nitroglycerin-responsive segments were viable. Myocardial contrast echocardiography had up to 85% sensitivity and 74% specificity for detection of VM diagnosed by RRT-SPECT. In the 23 patients who underwent revascularization, 54% of akinetic segments showed improved contractility, and mean LVEF increased from 32% to 37% (P = .04). Sensitivities and specificities for detecting functional recovery were 95% and 37% for RRT-SPECT, up to 87% and 48% for MCE, and 63% and 83% for a biphasic response during NTG-DE. CONCLUSIONS: In patients with chronic ischemic LV dysfunction, RRT-SPECT had the highest sensitivity, and NTG-DE, the best specificity for detection of VM. Nitroglycerin facilitated detection of VM and may be a useful adjunct to dobutamine stimulation.

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PubMed2006

Rationale and design: the VALsartan In Diastolic Dysfunction (VALIDD) Trial: evolving the management of diastolic dysfunction in hypertension.

BACKGROUND: Although 50% of hypertensive patients in the community are estimated to have diastolic dysfunction, there is no specific guideline for diastolic dysfunction therapy at present despite the condition's clear association with increased cardiovascular risk. Although the efficacy of angiotensin II receptor blockers (ARBs) in hypertension and left ventricular hypertrophy regression has been established, the effect of angiotensin II receptor blockade on intrinsic parameters of diastolic function has not been evaluated in large-scale studies. METHODS: The VALIDD Trial is an investigator-initiated randomized, controlled, double-blind clinical trial on approximately 350 patients designed to explore whether antihypertensive therapy with the ARB valsartan, in addition to standard therapy, would improve intrinsic diastolic properties of the myocardium in patients with hypertension and evidence of diastolic dysfunction. The result of such therapy will be compared with placebo after 38 weeks of treatment. The primary efficacy variable is change in early diastolic lateral mitral annular relaxation velocity measured by tissue Doppler imaging on week 38. CONCLUSIONS: We expect the VALIDD Trial to provide novel insights into the specific effects of ARBs on diastolic dysfunction, as assessed by tissue Doppler imaging, in hypertensive patients. The trial may provide clinically useful data on whether such therapy can directly improve diastolic function in patients with hypertension.

Angiotensin II Type 1 Receptor Blockers↗

PubMed2006

Echocardiographic indices of increased left ventricular filling pressure and dilation after acute myocardial infarction.

The relationship between echocardiographic indicators of acute and chronic left ventricular (LV) filling pressure and LV dilation after acute myocardial infarction was assessed in 47 patients. The ratio of early transmitral flow velocity to early mitral annulus velocity (E/e') reflects acute LV filling pressure and the indexed volume of the left atrium is an indicator of chronic LV filling pressure. E/e' was higher (19 vs 10, P = .001) among patients who experienced a greater than 15% increase in indexed LV end-diastolic volume (remodeling group, n = 10). Receiver operating characteristic curve analysis confirmed that E/e' was a predictor of remodeling (area under the curve 0.83, P = .002). Patients with E/e' greater than 15 had a mean increase in indexed LV end-diastolic volume of 9.3 versus 1.7 mL/m2 in patients with E/e' 15 or less (P = .01). Multivariable regression analyses confirmed that E/e' was the strongest independent predictor of remodeling in this cohort (odds ratio 1.39, P = .01). There was no relationship between indexed volume of the left atrium and LV dilation. These data suggest that the E/e' ratio may be a useful predictor of LV dilation after acute myocardial infarction. In particular, an E/e' ratio greater than 15 identifies patients at increased risk.

Aged↗

PubMed2005

Usefulness of real-time intravenous myocardial contrast echocardiography in predicting left ventricular dilation after successfully reperfused acute myocardial infarction.

The ability of real-time intravenous myocardial contrast echocardiography to predict left ventricular remodeling after reperfused acute myocardial infarction was assessed in 47 patients. Intravenous myocardial contrast echocardiography was an independent predictor of left ventricular dilation after acute myocardial infarction. In particular, normal contrast opacification within dyssynergic segments indicated a very low risk of remodeling.

Acute Disease↗

PubMed2004

Advances in myocardial contrast echocardiography and the role of adenosine stress.

Advances in contrast echocardiography hold promise for the routine assessment of myocardial perfusion. Continued progress may ultimately position myocardial contrast echocardiography (MCE) as an imaging modality that can provide comprehensive cardiac assessment-anatomic, physiologic, and pathophysiologic. Vasodilator stress with adenosine can play an important role in conjunction with MCE, particularly as it relates to the noninvasive evaluation of myocardial perfusion and coronary blood flow reserve. Adenosine pharmacologic stress testing may provide improved test performance through perfusion detection when compared with traditional use of dobutamine assessments of regional wall motion abnormalities.

Adenosine↗

PubMed2004

Transient constrictive pericarditis: causes and natural history.

OBJECTIVES: This study was designed to elucidate the causes and natural history of transient constrictive pericarditis (CP). BACKGROUND: In some patients with acute CP, the symptoms and constrictive physiologic features resolve with medical therapy alone, a phenomenon that has been labeled "transient constrictive pericarditis." No large studies have examined the causes or natural history of transient CP. METHOD: Review of the Mayo Clinic echocardiogram database identified 212 patients who had echocardiographic findings of CP from 1988 through 1999. Demographic, clinical, and echocardiographic findings were identified in all patients. In 36 of these patients, follow-up echocardiograms showed resolution of the constrictive hemodynamics without pericardiectomy. RESULTS: The average age of the patients was 49 +/- 21 years, and 72% were men. The causes for the CP were diverse, the most common being prior cardiovascular surgery (25%). In a subset of 22 patients who were followed serially during the course of their illness, resolution of the constrictive physiologic features occurred at an average of 8.3 weeks after diagnosis. CONCLUSIONS: A subset of patients with CP experience resolution of the disorder without requiring pericardiectomy.

Adolescent↗

PubMed2003

Comparison of intravenous myocardial contrast echocardiography and low-dose dobutamine echocardiography for predicting left ventricular functional recovery following acute myocardial infarction.

Akinesia after acute myocardial infarction (AMI) may be reversible or irreversible. Distinguishing these 2 entities early after AMI is difficult, but clinically important. Previous studies have shown that myocardial contrast echocardiography (MCE) and low-dose dobutamine echocardiography (DE) may both be useful in this setting. However, there are few data regarding the relative and combined value of these techniques. The aim of this study was to compare the utility of real-time intravenous MCE and low-dose DE in the early prediction of functional recovery of akinetic myocardium after AMI. Thirty-seven patients were studied 3 +/- 2 days after an AMI. Each subject underwent real-time MCE using an intravenous infusion of perflutren microbubbles. Immediately after this, low-dose DE was performed. Contrast opacification and wall motion were determined by experienced observers blinded to clinical data. Repeat echocardiograms were obtained 51 +/- 19 days later and wall motion at rest was scored by an observer blinded to clinical data. Normal contrast opacification predicted functional recovery with a positive predictive value of 63%, a negative predictive value of 73%, and an accuracy of 66%. Residual contractility during low-dose DE had a positive predictive value of 82%, a negative predictive value of 72%, and a predictive accuracy of 76%. When the 2 tests were concordant (64%), they had a positive predictive value of 81%, a negative predictive value of 85%, and a predictive accuracy of 83%. Low-dose DE was superior to intravenous MCE in the prediction of functional recovery of akinetic myocardium after AMI, but the combination of both maximizes predictive accuracy.

Aged↗

PubMed2003

Contrast echocardiography using intravenous octafluoropropane and real-time perfusion imaging predicts functional recovery after acute myocardial infarction.

Akinesia after acute myocardial infarction (MI) may be reversible, secondary to stunning, or irreversible, as a result of extensive myocyte necrosis. Distinguishing these 2 entities soon after MI is difficult, but has important clinical implications. The current study assessed the use of intravenous myocardial contrast echocardiography (MCE) in this setting. A total of 35 patients were studied 2 (+/- 1) days after an acute MI. Of these, 31 (91%) underwent myocardial revascularization. Perfusion was assessed using real-time MCE and an intravenous infusion of octafluoropropane microbubbles. Repeated echocardiograms were obtained 56 (+/- 29) days later. Normal perfusion predicted functional recovery with a positive predictive value of 66% and a negative predictive value of 81%. The accuracy of the technique was superior in myocardial segments supplied by the left anterior descending coronary artery (positive and negative predictive value: 70% and 90%, respectively). In multivariable analysis, the mean MCE perfusion score in akinetic segments was the most powerful independent predictor of functional recovery (odds ratio 8.6, P =.02). These data suggest that real-time intravenous MCE is a useful predictor of functional recovery of akinetic myocardium after acute MI.

Aged↗