Navin C. Nanda

Three-dimensional reconstruction of echocardiographic images using the rotation method☆

We describe a method for three-dimensional reconstruction of real time two-dimensional echocardiographic images using a rotation method. Seven tissue specimens were studied in a water bath and two-dimensional images were recorded by rotating the transducer every 30 degrees, from 0 to 180 degrees. Angular reconstruction of areas was obtained at different axial locations and volumes calculated by a Sigma 9 computer using axial summation without geometric assumptions. Using spatial coordinate data, three-dimensional perspective images could be plotted by the computer in any desired view. The volumes obtained by this method (range 90-231 ml) corresponded closely (R = 0.96) with volumes measured directly by water displacement (range 95-200 ml). Two patients were also studied with this technique by placing the transducer at the cardiac apex to record two-dimensional left ventricular and diastolic and end systolic images. Three-dimensional reconstructed volumes closely correlated with those obtained by left ventricular angiography. Ejection fraction in one patient was 52% by three-dimensional reconstruction, 47% by angiocardiography. In the other patient, the ejection fraction was 76% by three-dimensional imaging, 69% by angiocardiography. This preliminary study demonstrates the feasibility and simplicity of three-dimensional reconstruction using the rotation method.

Doppler Echocardiographic Studies in Sequential Atrioventricular Pacing

Six patients with sequential atrioventricular pacemakers were studied by Doppler echocardiography. A commercially available continuous wave system (transcutaneous aortovelography) was used and the transducer was placed in the suprasternal notch and angled to obtain peak aortic arch blood flow velocity. Changes in Doppler peak velocity have been previously shown to correlate closely and reliably with changes in hemodynamically measured stroke volume/cardiac output in the same patients following interventions, In all patients, the pacemaker was programmed from DVI mode to VVI (heart rate was kept constant) and then back to DVI, with the Doppler transducer held in a fixed position all the time, and peak velocities measured after the patient had been in any particular mode for at least 1 minute. Five of 6 patients showed reduction in peak velocities ranging from 13–25% (mean 18.4%) when the pacing mode was switched from DVI to VVI. Doppler peak velocity remained unchanged in 1 patient. Doppler echocardiography represents a simple, noninvasive method for estimating increments in stroke volume/cardiac output obtained with sequential AV pacing.

Doppler Echocardiography and Cardiac Pacing

There is a need for a non‐invasive method to evaluate the hemodynamic consequences of pacing. The value of Dop pler echocardiography in assessing relative changes in stroke volume and cardiac output is reviewed. We present preliminary observations illustrating the potential value of Doppler echocardiography in cardiac pacing. (PACE, Vol. 5, July‐August, 1982)

Pericardiocentesis induced intrapericardial thrombus: Detection by two-dimensional echocardiography☆

2. Cohen LS, Friedman WF, Braunwald E: Natural history of mild congenital aortic stenosis elucidated by serial hemodynamic studies. Am J Cardiol 30:1, 1972. 3. Bogart DB, Murphy BL, Wong BYS, Pugh DM, Dunn MI: Progression of aortic stenosis. Chest 76:391, 1979. 4. Cheitlin MD, Gertz EW, Brundage BH, Carlson CJ, Quash JA, Bode RS Jr: Rate of progression of severity of valvular aortic stenosis in the adult. AM HEART J 98:689, 1979.

Two-dimensional echocardiographic identification of pacing catheter-induced thrombosis.

We describe a case in which pacing catheter‐induced thrombosis of ihe great veins is demonstrated by two‐dimensional real‐time echocardiography

Evaluation of Bicuspid Aortic Valves by Two-Dimensional Echocardiography

M-mode echocardiography has proved useful in the identification of congenital bicuspid aortic valves. Characteristically, marked eccentricity of the cusp echoes within the aortic lumen in diastole is observed. This results in asymmetry of the systolic images of the aortic valve so that one leaflet appears to be larger than the other. An additional frequent finding in patients with bicuspid aortic valves is the presence of multilayered echoes in diastole in the absence of fluoroscopic or pathological evidence of valvular calcification. Redundant leaflet tissue normally present in bicuspid aortic valves probably produces folds whose diastolic position may vary in different cardiac cycles giving rise to asymmetry and variability of diastolic cusp position. Asymmetric leaflet images may also be due to the unequal size of the leaflets. However, both false positive and false negative diagnoses have been made. A midline aortic valve diastolic cusp position may be obtained from a single transducer position and false positives have been obtained in conditions with abnormal position or distortion of the aortic root, such as sinus of Valsalva aneurysm.

Two-dimensional echocardiographic identification of multiple cardiac tumors in a newborn☆

Abstract We describe identification of multiple intracardiac tumors in a newborn by real time two-dimensional echocardiography. All three tumors were successfully resected.

Left ventricular inflow obstruction and atrial septal deffect: Diagnosis by real time two-dimensional echocardiography☆

This report describes the usefulness of real time two-dimensional echocardiography in the diagnosis of left ventricular inflow obstruction associated with atrial septal defect. Echocardiographically, left ventricular inflow obstruction was at the level of the mitral valve in case one, mitral and subvalvular in cases 2 and 3 and supravalvular in case 4 (left atrial membrane). In all patients the defect was of the secundum variety and was seen as a constant discontinuity in the atrial septal image. The diagnosis was confirmed in all patients by cardiac catheterization, surgery or autopsy.

Right sided endocarditis following swan-ganz catheterization: detection by two-dimensional echocardiography

Two-dimensional echocardiography was found useful in detecting vegetations on both tricuspid and pulmonary valves in a patient who developed staphlococcus right sided endocarditis following Swan-Ganz catheterization.