The effect of left ventricular pressure or volume overload on ventricular dimension in children. Left ventricular volume determination from one or two ventricular dimensions

Regional functional depression immediately after ventricular septal defect closure

Left ventricular ejection is depressed immediately after repair of ventricular septal defect (VSD). Postrepair functional depression seen after VSD closure could result from a reduction in preload. However, other mechanisms could be at work. Functional depression could also be caused by closure of a low-impedance path for left ventricular ejection, the introduction of a stiff akinetic patch, or the operation itself. We reasoned that functional depression mediated by changes in preload or afterload should symmetrically affect end-diastole and end-systole, whereas depression resulting from changes in septal mechanics should be localized. We, therefore, performed segmental wall-motion analysis on intraoperative echocardiograms from patients undergoing VSD and atrial septal defect repair. After VSD closure, there was an asymmetric change in left ventricular end-systolic segment length and a decrease in fractional segment shortening localized to the septal and lateral walls, whereas patients with atrial septal defect had a symmetric increase in fractional shortening. These results suggest that acute functional depression after VSD repair is a result of localized impairment of septal function.

Evaluation of left ventricular volume using automatic border detection in children: a comparison with conventional off-line echocardiographic quantification

BACKGROUND

Evaluation of the clinical usefulness of the one-line automatic border detection system for determination of left ventricular volume in children in comparison to the conventional off-line method.

METHODS

Eighty consecutive patients in whom clear images were obtained by two-dimensional echocardiography were studied. Using the Hewlett-Packard Sonos 2500 with a 3.5 or 5.5 Mhz phased array transducer, all patients were studied in the apical four-chamber imaging plane for automatic border detection and apical four-chamber and two-chamber imaging planes for manual tracing. Left ventricular end-diastolic and end-systolic volumes were measured and compared using the bi-plane Simpson method.

RESULTS

Left ventricular end-diastolic volumes obtained by automatic border detection correlated well but were slightly underestimated compared to those obtained by manual tracing (r = 0.98). Left ventricular end-systolic volumes obtained by automatic border detection also correlated well with those obtained by manual tracing (r = 0.96). Left ventricular ejection fractions compared favorably. However, left ventricular volumes obtained using the classical Pombo M-mode echocardiography showed poorer correlation with those obtained by manual tracing methods.

CONCLUSIONS

Automatic border detection is a promising method for real-time estimation of left ventricular volume. In patients with good endocardial tracking, automatic border detection can be used for routine studies of cardiovascular disease, even in children.

Estimation of stroke volume using Doppler echocardiography and left ventricular echocardiographic dimensions in infants and children

To evaluate the accuracy of noninvasive determination of stroke volume in infants and children, 28 patients (age range 4 weeks to 19 years) were studied. Stroke volume was calculated according to Teichholtz from M-mode echocardiographic tracings of left ventricular dimensions in 8 subjects. Agreement with thermodilution performed within 60 min of echocardiography was good (r = 0.995, y = 0.91x + 1.59, SEE = 1.8 ml). Since stroke volume correlated to body size we corrected for (height)3. After this correction there was still good agreement to thermodilution (r = 0.88, y = 1.29x-7.13, SEE = 7.1 ml/H3). M-mode echocardiography was then used as a reference method for evaluating two different Doppler methods in the remaining 20 subjects. Continuous wave Doppler stroke distance, calculated from the mean velocity, was combined with aortic root area (Method I), and stroke distance calculated from maximum velocity was combined with the aortic interleaflet area (Method II). Good agreement was found with Method I (r = 0.95, y = 1.01x-0.14, SEE = 8.1 ml) and Method II (r = 0.95, y = 1.04x-1.14, SEE = 8.4 ml). However, when stroke volume was normalized for (height)3, Method I was found to be superior to Method II.

Mucocutaneous lymph node syndrome: clinical, hemodynamic and angiographic features of coronary obstructive disease

Clinical, hemodynamic and angiographic features of coronary obstructive disease (greater than or equal to 90% diameter reduction) in Kawasaki disease were evaluated in 30 patients. The mean age at the onset of Kawasaki disease was 2.9 +/- 1.9 years and that at cardiac catheterization was 6.3 +/- 2.8 years. Obstructive lesions were observed in the right coronary artery in 12 patients (group 1), in the left anterior descending coronary artery (LAD) in 6 (group 2), in both right coronary artery and LAD in 10 (group 3) and in the left main coronary artery in 4 (group 4). Twenty-two patients (73%) had cardiac symptoms, including myocardial infarction in 10 (33%). Cardiac symptoms were observed in 41% in group 1, 100% in group 2, 80% in group 3 and 100% in group 4. Left ventricular (LV) end-diastolic pressure, end-diastolic volume and ejection fraction were abnormal in 32% of the patients in group 1, a frequency less than that in other groups (83% in group 2, 78% in group 3 and 100% in group 4). Fifty percent had mitral regurgitation and 73% had left ventricular wall motion abnormalities. No patient in groups 1 or 2 has died, but 8 of 14 patients in groups 3 and 4 have died. These observations indicate that coronary obstruction owing to Kawasaki disease can cause depressed LV function, mitral regurgitation and LV wall motion abnormalities in children.(ABSTRACT TRUNCATED AT 250 WORDS)