William Gill

Publications (2)4.61 Total impact

• Article: Stress-induced wall motion abnormalities with low-dose dobutamine infusion indicate the presence of severe disease and vulnerable myocardium.

  Stephen G Sawada, Anas Safadi, Rajdeep S Gaitonde, Nisha Tung, Jothiharan Mahenthiran, William Gill, Waqas Ghumman, Irmina Gradus-Pizlo, Masoor Kamalesh, Naomi Fineberg, Harvey Feigenbaum
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  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.
  Echocardiography 09/2007; 24(7):739-44. · 1.24 Impact Factor
• Article: Usefulness of rest and low-dose dobutamine wall motion scores in predicting survival and benefit from revascularization in patients with ischemic cardiomyopathy.

  Stephen G Sawada, Stephen J Lewis, Judy Foltz, Agota Ando, Samer Khouri, Shawn Kaser, Irmina Gradus-Pizlo, William Gill, Naomi Fineberg, Douglas Segar, Harvey Feigenbaum
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  ABSTRACT: This study examined the value of wall motion scores at rest and with low- and high-dose dobutamine infusion for prediction of outcome and benefit from revascularization in patients with ischemic cardiomyopathy. Follow-up was obtained in 139 patients with ischemic cardiomyopathy who had echocardiography at rest, and during low- (10 microg/kg/min) and high-dose dobutamine (maximal dose 50 microg/kg/min) infusion. Both rest and low-dose wall motion scores were multivariate predictors of cardiac death, but ischemia and peak dose scores were not predictors. Rest scores risk stratified patients into 3 groups: score (1.00 to 1.99) with 11% cardiac death; score (2.00 to 2.49) with 30% death; and score > or =2.50 with 47% death. One third of patients with rest scores > or =2.50 had improvement in scores to < 2.50 with low-dose dobutamine. Their frequency of cardiac death was reduced to 23% compared with 60% (p = 0.04) in those who remained with low-dose scores > or =2.50. Low-dose scores also identified those who benefited from revascularization. In patients with low-dose scores (1.00 to 1.99), the frequency of cardiac death was marginally lower in revascularized than nonrevascularized patients (10% vs 21%, p = 0.28). In patients with scores (2.00 to 2.49), revascularized patients had a significantly lower frequency of cardiac death than nonrevascularized patients (15% vs 41%, p < 0.05). The frequency of death in those with low-dose scores > or =2.50 was very high in both revascularized (75%) and nonrevascularized (56%, p = 0.42) patients. Thus, rest and low-dose wall motion scores enable risk stratification of patients with ischemic cardiomyopathy and identify those who do and do not benefit from revascularization.
  The American Journal of Cardiology 04/2002; 89(7):811-6. · 3.37 Impact Factor