Stress-induced wall motion abnormalities with low-dose dobutamine infusion indicate the presence of severe disease and vulnerable myocardium.
ABSTRACT Patients with left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) may develop stress-induced wall motion abnormalities (SWMA) with low-dose (10 microg/kg/min) dobutamine infusion. The clinical significance of low-dose SWMA is unknown.
We investigated the clinical, hemodynamic and angiographic correlates of low-dose SWMA in patients with chronic ischemic LV systolic dysfunction.
Seventy patients with chronic ischemic LV systolic dysfunction who had dobutamine stress echocardiography were studied. Clinical, hemodynamic, and angiographic parameters at rest and low-dose were compared between 38 patients (mean ejection fraction (EF) of 30 +/- 8%) with low-dose SWMA and 32 patients (EF 30 +/- 11%) without low-dose SWMA.
Multivariate analysis showed that the number of coronary territories with severe disease (stenosis > or =70%)(P = 0.001, RR = 6.3) was an independent predictor of low-dose SWMA. An increasing number of collateral vessels protected patients from low-dose SWMA (P = 0.011, RR = 0.25). A higher resting heart rate was a negative predictor of low-dose SWMA (P = 0.015, RR = 0.92) but no other hemodynamic variables were predictors. In the patients with low-dose SMA, regions with low-dose SWMA were more likely to be supplied by vessels with severe disease than regions without low-dose SWMA (92% vs 58%, P < 0.001).
In patients with ischemic LV systolic dysfunction, the extent of severe disease and a lower numbers of collaterals predict the occurrence of low-dose SWMA. Low-dose SWMA is a highly specific marker for severe disease.
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ABSTRACT: Agents that increase cardiac contractility (positive inotropes) have beneficial hemodynamic effects in patients with acute and chronic heart failure but have frequently led to increased mortality when given on a long-term basis. Despite this fact, inotropes remain commonly used in the management of heart failure. We reviewed the available data on short- and long-term inotrope use in heart failure, emphasizing high-quality evidence on the basis of randomized trials that were powered to address clinical end points. Available data suggest that long-term inotropic therapy has a negative impact on survival in patients with heart failure, regardless of the agent used. The data that inotropic therapy improves quality of life are mixed. High-quality randomized evidence is lacking for the use of inotropes for other heart failure indications, such as for acute decompensations or as a "bridge to transplant." On the basis of the available evidence, the routine use of inotropes as heart failure therapy is not indicated in either the acute or chronic setting. Potentially appropriate uses of inotropes include as temporary treatment of diuretic-refractory acute heart failure decompensations or as a bridge to definitive treatment such as revascularization or cardiac transplantation. Inotropes also may be appropriate as a palliative measure in patients with truly end-stage heart failure. A model of heart failure pathophysiologic features that combines an understanding of both hemodynamic and neurohormonal factors will be required to best develop and evaluate novel treatments for advanced heart failure.American Heart Journal 10/2001; 142(3):393-401. · 4.50 Impact Factor
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ABSTRACT: Evaluation of collateral vascular circulation according to hemodynamic variables and its relation to myocardial ischemia. There is limited information regarding the hemodynamic quantification of recruitable collateral vessels. Angiography of the donor coronary artery was performed before and during balloon coronary occlusion in 63 patients with one vessel disease. Patients were divided into groups of those with an absence of collateral vessels (group 1, n = 10), those with recruitable collateral vessels (group 2, n = 23) and those with spontaneously visible collateral vessels (group 3, n = 30). During balloon inflation the coronary wedge/aortic pressure ratio (Pw/Pao) was determined as were collateral blood flow velocity variables, using a 0.014" Doppler guide wire. Myocardial ischemia was defined as > or =0.1 mV ST-shift on a 12 lead electrocardiogram at 1 min coronary occlusion. Myocardial ischemia was present in all patients of group 1, in 14 patients of group 2 and in 3 patients of group 3. Recruitable collateral flow without ischemia showed similar hemodynamic values as in group 3 while these values were similar to group 1 in regard to the presence of recruitable collateral vessels showing ischemia. Logistic regression analysis revealed both Pw/Pao and Vi(col) as independent predictors for the function of collateral vessels. Hemodynamic variables of collateral vascular circulation are better markers of the functional significance of collateral vessels than is coronary angiography. The total collateral blood flow velocity integral and coronary wedge/aortic pressure ratio are good and independent predictors of the function of collateral vessels producing complementary information.Journal of the American College of Cardiology 03/1999; 33(3):670-7. · 14.09 Impact Factor
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ABSTRACT: Myocardial hibernation is a condition of chronic left ventricular dysfunction associated with severe coronary artery disease whereby significant recovery of function occurs after revascularization. Identification of hibernating myocardium has important prognostic and therapeutic implications. The presence of contractile reserve as assessed by dobutamine echocardiography may be promising in the detection of hibernation. We designed a prospective study to evaluate the accuracy and optimal dose of dobutamine echocardiography for predicting recovery of ventricular function after angioplasty in patients with stable coronary artery disease and ventricular dysfunction. Twenty patients with stable coronary artery disease and segmental ventricular dysfunction scheduled for coronary angioplasty underwent dobutamine echocardiography before revascularization using incremental doses of 2.5, 5, 7.5, 10, 20, 30, and 40 micrograms/kg per minute every 3 minutes. Digital images of all eight stages were displayed simultaneously (two quad screens side by side) and interpreted using a 16-segment ventricular model and a 6-grade scoring system. Serial resting echocardiograms before, early (< 1 week), and late (> or = 6 weeks) after angioplasty were digitized and randomized in a quad-screen format for the assessment of recovery of function. Wall motion score index in the revascularized regions decreased from 2.86 +/- 0.76 before angioplasty to 2.12 +/- 1.03 late after angioplasty (P < .05). Of 320 ventricular segments, 148 had abnormal wall motion at baseline and 114 were revascularized. Recovery of function (> or = 2 grades) occurred in 25% of revascularized segments early and in 33% late after angioplasty. Of the 34 abnormal segments not revascularized, recovery of function occurred in only 1. During dobutamine echocardiography, abnormal segments exhibited one of four responses: biphasic (improvement at low dose and worsening at high dose) in 28% of segments, sustained improvement (persistent improvement till peak dose) in 18%, worsening in 15%, and no change in 39%. A biphasic response had the highest predictive value (72%) for recovery of function followed by worsening only (35%), while the lowest was seen with a "no-change" or sustained improvement response (13% and 15%). Combining biphasic and worsening responses resulted in a sensitivity of 74% and specificity of 73% for assessment of recovery of individual segments and 90% and 60%, respectively, for functional recovery of individual patients (n = 10). In segments with a biphasic response, the low dose at which improvement in wall motion was most prevalent (84%) was 7.5 micrograms/kg per minute and increased to 94% when the 5 and 7.5 micrograms/kg per minute doses were displayed. The reworsening phase of the biphasic response was usually seen with doses > or = 20 micrograms/kg per minute but was also observed as early as the 7.5 micrograms/kg per minute dose. The wall motion response during dobutamine echocardiography is useful in the prediction of recovery of ventricular function after revascularization in patients with stable coronary artery disease and ventricular dysfunction. The administration of low as well as high doses of dobutamine is needed for optimal evaluation.Circulation 03/1995; 91(3):663-70. · 15.20 Impact Factor