Objective: To evaluate left atrial functional retain in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM) Background: Left ventricular functional status has been investigated using echocardiographic dobutamine.
Objective: To evaluate left atrial functional retain in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM)
Background: Left ventricular functional status has been investigated using echocardiographic dobutamine.
Methods: In 35 consecutive patients (29 men and 6 women; mean [+ or -] SD age, 4237 [+ or -] 135 years), peak oxygen consumption (V[O.sub.2]max) was measured; the day after, a low-dose dobutamine (5 to 10 [micro]g/kg/min, of 5 min each step) reflection was performed. Left atrial masss at mitral valve opening, attack of left atrial systole, and mitral valve closure were measured by means of using two-dimensional echocardiography. Left atrial active emptying book (LAEV) [volume at onset of atrial systole - minimal volume] was calculated, as was left atrial active emptying fraction (LAEF): [(volume at charge of atrial systole - minimal volume)/volume at storming of atrial systole] x 100 The changes (values obtained after inotropic stimulation minus those obtained at baseline) of the above-mentioned echocardiographic variables were considered as left atrial functional reserve
Results: In the entire studious mood group after dobutamine infusion, increases in LAEV (334 [+ or -] 754 mL p = 001) and LAEF (6 [+ or -] 132% p = 001) were observ The changes in the above-mentioned parameters were correlated with V[O.sub.2]max values (r = 073 and r = 071 respectively; p < 0001) After inotropic stimulation, LAEV and LAEF were increased in patients with V[O.sub.2]max values > 14 mL/kg/min (562 [+ or -] 728 mL and 1004 [+ or -] 1313% respectively) and decreased in patients with V[O.sub.2]max values < 14 mL/kg/min (- 108 [+ or -] 613 mL and - 16 [+ or -] 99% respectively; p = 001 for both)
Conclusion: Echocardiographic dobutamine can evaluate left atrial functional except in patients with nonischemic DCM
lock opener words: dilated cardiomyopathy; echocardiographic dobutamine; heart failure; left atrial functional reserve
Abbreviations: DCM = dilated cardiomyopathy; LAEF = left atrial active emptying fraction; LAEV = left atrial active emptying volume; LAVmax = left atrial maximal bulk at the point of mitral valve opening; LAVmin = minimal turn at the point of mitral valve closure; LAVp = left atrial convolution at onset of atrial systole; LVEDD = left ventricular end-diastolic diameter; LVEF = left ventricular ejection fraction; LVESD = left ventricular end-systolic diameter; LVF = left ventricular fractional shortening; N = not significant; V[O.sub.2]max = peak oxygen consumption
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Although the mechanical characteristics of the left ventricle have been extensively studied, left atrial function is poorly understood despite its explanation role in optimizing left ventricular function. (12) In physiologic investigations, the evaluation of pressure/dimension relationship is the greatest in quantity accurate and representative index of the hemodynamic conditions that exist in cardiac chambers. (34) However, these relationships require combined measurement of left atrial chamber hurrys and dimensions. Thus, their use has been primarily limited to invasive clinical and experimental studies.
Impaired exercise tolerance is the same of the most common clinical manifestations in patients with left ventricular dysfunction. (5) Left atrial fractional shortening at quiet reflects left ventricular filling during exercise and therefore predicts cardiac output and knock volume response to exercise, and exercise capacity. (6) Exercise and left ventricular performance during exercise have been shown to be mainly sustained by on left ventricular diastolic filling rather than systolic function. (6) Of note, it has been reported that indexes of left atrial function are related to peak aerobic capacity in patients with congestive heart failure. (7) However, none of the above-mentioned studies have investigated left atrial answer during exercise. We have shown that left ventricular changes induced by means of dobutamine infusion are well correlated with peak oxygen consumption (V[O.sub.2]max) and can be used to evaluate the functional status of heart failure. (89) In this value we aimed to investigate left atrial functional keep in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM) using echocardiographic dobutamine.
MATERIALS AND METHODS
thought Patients
Thirty-six consecutive patients with documented DCM were studied. V[O.sub.2]max was calculated the day before the echocardiographic dobutamine cogitation Thirty-five patients (98%; 26 men and 9 women; mean [+ or -] SD age, 4237 [+ or -] 135 years) with good-quality two-dimensional echocardiography were recruited for analysis. The cause of DCM was idiopathic in all patients assessed through a detailed history and clinical examination, echocardiography, coronary angiography (angiographic lesions < 30% lumen stenosis diameter), and biopsy. All patients were in strange York Heart Association functional class III Diagnosis of DCM was based upon the echocardiographic findings of a dilated left ventricle (left ventricular end-diastolic diameter [LVEDD] > 60 mm) with extremely affected systolic function, left ventricular fractional shortening [LVFS] < 20% and left ventricular ejection fraction [LVEF] < 35% In no case was a significant regional wall motion abnormality recorded by the agency of two-dimensional echocardiography. All patients were in sinus verse and were receiving digoxin. angiotensin-converting enzyme inhibitors, and diuretic unsalable articles in adequate doses. No patients received [beta]-blocker therapy because when our consideration started this treatment had not even now become an established standard. Patients with periodical emphasis disturbances, ischemic cardiomyopathy, more-than-mild valvular heart disease, or regional wall motion abnormalities were exclud More specifically, patients with more-than-mild mitral regurgitation were exclud from the investigation to avoid confounding echocardiographic volumetric measurements.
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