OBJECTIVES: This study examined the effects of early long-term monotherapy with enalapril on the severity of functional mitral regurgitation in dogs with moderate heart failure. BACKGROUND: Functional mitral regurgitation often develops in patients with heart failure and, depending on its severity, can have a marked adverse impact on the stroke output of the failing left ventricle and contribute to progressive deterioration of the heart failure state. METHODS: Left ventricular dysfunction (ejection fraction 30% to 40%) was produced in 14 dogs by multiple sequential intracoronary microembolizations. Dogs were randomized to 3 months of therapy with enalapril (10 mg twice daily, n = 7) or no therapy at all (control, n = 7). The severity of functional mitral regurgitation was quantified by Doppler color flow mapping in seven control and six enalapril-treated dogs. Mitral annular diameter was assessed by echocardiography and left ventricular volumes and shape by ventriculography. Measurements were made before initiation and after completion of therapy. RESULTS: In control dogs, the severity of mitral regurgitation increased during the follow-up period ([mean +/- SEM] 14 +/- 4 vs. 23 +/- 4%, p < 0.001) and was associated with increased left ventricular end-systolic and end-diastolic volumes. In contrast, the severity of regurgitation was not significantly changed in dogs treated with enalapril (18 +/- 3 vs. 16 +/- 6%, p < 0.59) and was associated with preservation of left ventricular volumes. CONCLUSIONS: In dogs with moderate heart failure, early long-term therapy with enalapril prevents progressive worsening of functional mitral regurgitation. This beneficial effect is most likely achieved by prevention of progressive left ventricular dilation.
OBJECTIVES: This study examined the effects of early long-term monotherapy with enalapril on the severity of functional mitral regurgitation in dogs with moderate heart failure. BACKGROUND:Functional mitral regurgitation often develops in patients with heart failure and, depending on its severity, can have a marked adverse impact on the stroke output of the failing left ventricle and contribute to progressive deterioration of the heart failure state. METHODS:Left ventricular dysfunction (ejection fraction 30% to 40%) was produced in 14 dogs by multiple sequential intracoronary microembolizations. Dogs were randomized to 3 months of therapy with enalapril (10 mg twice daily, n = 7) or no therapy at all (control, n = 7). The severity of functional mitral regurgitation was quantified by Doppler color flow mapping in seven control and six enalapril-treated dogs. Mitral annular diameter was assessed by echocardiography and left ventricular volumes and shape by ventriculography. Measurements were made before initiation and after completion of therapy. RESULTS: In control dogs, the severity of mitral regurgitation increased during the follow-up period ([mean +/- SEM] 14 +/- 4 vs. 23 +/- 4%, p < 0.001) and was associated with increased left ventricular end-systolic and end-diastolic volumes. In contrast, the severity of regurgitation was not significantly changed in dogs treated with enalapril (18 +/- 3 vs. 16 +/- 6%, p < 0.59) and was associated with preservation of left ventricular volumes. CONCLUSIONS: In dogs with moderate heart failure, early long-term therapy with enalapril prevents progressive worsening of functional mitral regurgitation. This beneficial effect is most likely achieved by prevention of progressive left ventricular dilation.
Authors: Sharad Rastogi; Victor G Sharov; Sudhish Mishra; Ramesh C Gupta; Brent Blackburn; Luiz Belardinelli; William C Stanley; Hani N Sabbah Journal: Am J Physiol Heart Circ Physiol Date: 2008-09-26 Impact factor: 4.733