Pulsed Doppler echocardiographic determination of stroke volume and cardiac output: clinical validation of two new methods using the apical window.

Abstract

Two methods of measuring stroke volume and cardiac output with pulsed Doppler twodimensional echocardiography were developed and validated against the thermodilution technique in 39 patients, 33 of which were in an intensive care unit. With the use of the apical four-chamber view, a mitral inflow method combined the velocity of left ventricular inflow at the mitral anulus with the crosssectional area of the anulus calculated from its diameter at middiastole (area = z r2). From the apical five-chamber view a left ventricular outflow method combined the velocity of left ventricular outflow with the cross-sectional area of the aortic anulus calculated from its diameter during early systole (parastemal long-axis view). Measurements with the mitral inflow and left ventricular outflow methods were obtained in 35 of 39 (90%) and 39 of 39 (100%) patients, respectively. Validation of the mitral method excluded patients with mitral regurgitation (n = 11) and validation of the left ventricular outflow method excluded those with aortic regurgitation (n = 4). Good correlations were observed between thermodilution and Doppler measurements of stroke volume and cardiac output for both the mitral anulus method (R = .96 and .87, respectively) and the left ventricular outflow method (R = .95 and .91, respectively). The results of the two methods correlated well with each other in patients without regurgitant valve lesions. A greater interobserver variability was observed with the mitral anulus method, which was related solely to greater variability in measuring the annular diameter. In patients with mitral regurgitation, left ventricular inflow volume was always greater than left ventricular outflow stroke volume while the inverse was true in those with aortic regurgitation. Thus, stroke volume and cardiac output can be accurately measured from the cardiac apex with mitral inflow or left ventricular outflow methods when applicable. Comparison of volumes obtained with these two methods may prove valuable in quantitating the severity of mitral or aortic regurgitation. Circulation 70, No. 3, 425-431, 1984. RECENT technological developments have made possible the application of Doppler echocardiography to the measurement of stroke volume and cardiac output. Methods previously validated consist of measuring ascending aortic flow from the suprasternal window or pulmonary arterial flow from the parasternal window.1-' These methods work on the premise that the velocity of blood flow determined from the Doppler

Cardiac abnormalities in children with sickle cell anemia

“…The left ventricular systolic (LVSD) and diastolic (LVDD) dimensions were measured directly using M-mode echocardiography according to the recommendations of the American Society of Echocardiography [16]; these values were then used to calculate the shortening fraction (SF), a quantitative measure of systolic function. Cardiac Index (CI) was calculated from two-dimensional and Doppler echocardiography using previously described equations for volumetric flow [17]. We used two-dimensional echocardiography to determine left ventricular mass [18,19] by the arealength method [20,21].…”

Physiology of blood flow during cardiopulmonary resuscitation. A transesophageal echocardiographic study.

“…After videotape review of all Doppler signals, quantitative measurements of the forward mitral velocity time integral (stroke distance) were done by integrating the forward Doppler velocity profile over time using the Freeland system. Stroke distance is a measure of the distance an 18 studies, the mitral valve closed during compression and opened only during the release phase of cardiopulmonary resuscitation (Fig 1). There was some variability observed in the degree of mitral valve opening.…”

Role of the Mitral Valve Resistance in Evaluation of Mitral Stenosis Severity

“…Patients were classified into 3 groups according to MS severity: group I; 31 patients with severe MS (where MVA <1 cm 2 and MPG >10 mmHg), group II; 35 patients with moderate MS (MVA 1-1.5 cm 2 and MPG 5-10 mmHg) and group III; 62 patients with mild MS (MVA >1.5 cm 2 and MPG <5 mmHg) [6,9].…”