Comparison of single-plane and biplane contrast analyses of right ventricular function and size

Risk assessment in nonischemic ventricular arrhythmia by left and right ventriculography

Ventricular fibrillation and sudden death are rare phenomena in nonischemic ventricular arrhythmia, particularly in arrhythmogenic right ventricular cardiomyopathy. In most instances electrophysiologic studies help to assess the risk of sudden death, but sometimes programmed ventricular stimulation is unsuccessful. Among 48 patients with ventricular fibrillation (n = 9) and sustained (n = 25) and nonsustained (n = 19) ventricular tachycardia, invasive and noninvasive diagnostic tests (coronary angiography, biventricular angiography, programmed ventricular stimulation, and echocardiography) were performed to obtain more information about the underlying heart disease. In 43 patients (90%) arrhythmogenic right ventricular cardiomyopathy was diagnosed with segmental hypokinesia (n = 31) and diffuse hypokinesia (n = 12) of the right ventricle. In patients with documented ventricular fibrillation, the right ventricular ejection fraction was lower (30.8% vs 47.8% and 45.9%, respectively) and multisegmental contraction impairment of the right ventricle was significantly more frequent (p less than 0.001). Additional left ventricular abnormalities and right ventricular dilatation were not significant parameters for identifying high-risk patients. In addition to programmed ventricular stimulation, quantitative analysis of the results of right and left ventricular angiography contributes to risk assessment in patients with nonischemic ventricular arrhythmia.

Correlation of right ventricular volume using axial angulated ventriculography to known right ventricular cast volumes in infants and children with congenital heart disease

To calculate right ventricular (RV) volumes from biplane cineangiography obtained in nonstandard views, regression equations were developed from RV casts of known volume. Volumes were calculated using Simpson's rule from casts ranging from 2 to 42 ml from 25 postmortem specimens with various congenital heart diseases. The casts were divided into 2 groups: group 1 (n = 15) with abnormal or group 2 (n = 10) with normal RV hemodynamic measurements. Biplane cinegrams were taken in the anterolateral, anterior and long axis oblique, hepatoclavicular and sitting up projections. The true volume of each cast was determined from its weight and specific gravity. Excellent correlations were obtained between measured and true volumes (r = 0.92 to 0.96) in all projections, although each projection overestimated the true volume (slope value less than 1). The regression equations obtained from group 1 were not statistically different from those in group 2 in any view. Although the application of different regression equations is required in measuring RV volumes by multiple angulated angiography, these regression equations appear not to be affected by the hemodynamic state of the ventricle. These results are important in assessing RV volume in pediatric patients with congenital heart disease using axial angulated ventriculography.

Validation of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volume: comparison with cast-validated biplane cineventriculography

To determine the accuracy of attenuation-corrected equilibrium radionuclide angiographic determinations of right ventricular volumes, we initially studied 14 postmortem human right ventricular casts by water displacement and biplane cineventriculography. Biplane cineventriculographic right ventricular cast volumes, calculated by a modification of Simpson's rule algorithm, correlated well with right ventricular cast volumes measured by water displacement (r = .97, y = 8 + 0.88x, SEE = 6 ml). Moreover, the mean volumes obtained by both methods were no different (73 +/- 28 vs 73 +/- 25 ml). Subsequently, we studied 16 patients by both biplane cineventriculography and equilibrium radionuclide angiography. The uncorrected radionuclide right ventricular volumes were calculated by normalizing background corrected end-diastolic and end-systolic counts from hand-drawn regions of interest obtained by phase analysis for cardiac cycles processed, frame rate, and blood sample counts. Attenuation correction was performed by a simple geometric method. The attenuation-corrected radionuclide right ventricular end-diastolic volumes correlated with the cineventriculographic end-diastolic volumes (r = .91, y = 3 + 0.92x, SEE = 27 ml). Similarly, the attenuation-corrected radionuclide right ventricular end-systolic volumes correlated with the cineventriculographic end-systolic volumes (r = .93, y = - 1 + 0.91x, SEE = 16 ml). Also, the mean attenuation-corrected radionuclide end-diastolic and end-systolic volumes were no different than the average cineventriculographic end-diastolic and end-systolic volumes (160 +/- 61 and 83 +/- 44 vs 170 +/- 61 and 86 +/- 43 ml, respectively). Comparison of the uncorrected and attenuation-corrected radionuclide right ventricular volumes demonstrated narrower 95% confidence intervals for the attentuation-corrected right ventricular volume determinations over a wide range of cineventriculographic volumes. Thus we conclude that: (1) attenuation-corrected radionuclide right ventricular end-diastolic and end-systolic volumes compare closely with those obtained by a cast-validated biplane cineventriculographic method and (2) attenuation-corrected radionuclide right ventricular volumes correspond more closely to determinations of biplane cineventriculographic right ventricular volumes and are thus likely to be more accurate than uncorrected radionuclide right ventricular volumes.

Method for estimating right ventricular volume by planes applicable to cross-sectional echocardiography: correlation with angiographic formulas

Right ventricular (RV) volumes determined by echocardiography were compared with those measured using established angiographic formulas. RV cast displacement volumes were first correlated with data derived from radiographic images of the casts corresponding to standard angiographic RV views. Four established angiographic formulas (Ferlinz, Boak, Fisher and Thilenius) correlated well with cast volume, with the corrected prism method of Fisher showing a best fit (r = 0.98, y = 1.1 + 0.9 x, standard error of the estimate = 3.6). Cast volumes calculated using our echocardiographic formula were then examined relative to the volumes derived from radiographic images of the RV casts. Volumes calculated using the corrected area-length Thilenius formula correlated best with those obtained using our derived 2-dimensional echocardiographic formula (r = 0.96, y = 4.6 + 1.0 x, standard error of the estimate = 6.8). These data confirm that volume calculated using the suggested optimal echocardiographic formula correlates well with volume obtained using derived angiographic data. Accordingly, confirmation in humans by the use of angiography is a rational step.

Single versus biplane right and left ventricular volumetry: a cast and clinical study

True volume (y) and measured volume (x) determined from 23 right and 22 left normal human casts in four biplane angiographic positions and in their eight single-plane components were used to find the correction factor (b) by regression through the origin (y = bx). The correction factors were applied to human studies to assess the validity of the various biplane and single-plane modalities in vivo. The casts studies yield excellent correlations in both right and left biplane methods (right volumetry: 0.555 less than or equal to b less than or equal to 0.708, 0.917 less than or equal to r less than or equal to 0.954, 4.10 less than or equal to SEE less than or equal to 6.01 left volumetry: 0.748 less than or equal to b less than or equal to 0.825, 0.974 less than or equal to r less than or equal to 0.982, 4.81 less than or equal to SEE 5.79). Good results were obtained with single-plane volumetries as well (right volumetry: 0.316 less than or equal to b less than or equal to 0.887, 0.750 less than or equal to r less than or equal to 0.917, 10.75 less than or equal to SEE less than or equal to 18.96; left volumetry: 0.728 less than or equal to b less than or equal to 0.881, 0.897 less than or equal to r less than or equal to 0.976 5.73 less than or equal to SEE less than or equal to 11.97). The correction factors for the single-plane studies depend much more strongly on the spatial position relative to the radiographic system, particularly in the case of the right ventricular volumes. Thus, the application of the appropriate correction factors is mandatory. The human studies (141 left and 60 right volumetric studies in various single-plane and biplane projections) showed a larger scatter of single-plane values, more pronounced for the right ventricle. In certain disease conditions, single plane volumetric studies using cast-derived correction factors cannot be used to obtain meaningful results. Correction factors for the following single or biplane mode volumetry are presented for the first time: biplane hepatoclavicular view (right and left ventricle), biplane long axial oblique view (right ventricle), and their single-plane components; lateral and 60 degree Left Anterior Oblique (LAO) single plane for the left-sided measurements, Postero-Anterior (PA), lateral, and 60 degree LAO for the single-plane right-sided calculations.

Effects of acute incremental volume overload on cardiac chamber size, function, and the pulmonary circulation: analysis by digital intravenous angiography

To assess the effects of acute incremental volume overload on cardiac size, function, and the pulmonary circulation, we studied six anesthetized dogs using intravenous digital angiography. Aortocaval (AC) fistulas were placed in four dogs, and fistulas in both a carotid and iliac artery were placed in two dogs. Data were obtained at four points: (1) control stage; (2) partial shunt (PS, where either AC partially open or iliac fistula was open and carotid fistula was closed); (3) full shunt (FS, AC shunt open or both iliac and carotid shunts open); and (4) control stage 2. Little change in heart rate (HR) or arterial pressure occurred. With FS, both mean pulmonary artery and wedge pressures increased (p less than 0.05); however, systemic and pulmonary vascular resistances declined. Cardiac output rose (1.54 +/- 0.42 L/min at control) to 2.44 +/- 0.84 L/min at PC (P less than 0.05 vs control) and to 3.13 +/- 0.89 L/min at full shunt (p less than 0.01 vs control). Both left (0.40 +/- 0.09 to 0.55 +/- 0.10 to 0.66 +/- 0.10, p less than 0.05 and p less than 0.01 vs control, respectively) and right (0.34 +/- 0.10 to 0.40 +/- 0.10 to 0.51 +/- 0.09, the latter p less than 0.01 vs control) ventricular ejection fractions rose, as did left (30.7 +/- 13 ml to 35.1 +/- 13 ml to 37.8 +/- 13 ml, the latter p less than 0.05 vs control) and right (37.4 +/- 6.1 ml to 44.2 +/- 16.6 ml to 51.4 +/- 17 ml, the latter p less than 0.01 vs control) ventricular end-diastolic volumes. Atrial volume (determined at ventricular end-systole) also increased (9.4 +/- 3.6 ml to 11 +/- 3.5 ml to 12.9 +/- 4.3 ml, the latter p less than 0.05 vs control). These increases in cardiac function and size occurred in association with a shortening of pulmonary transit time (5.4 +/- 0.8 to 3.5 +/- 0.7 seconds to 2.9 +/- 0.5 seconds, the latter two p less than 0.05 and p less than 0.01 vs control, respectively), with no significant change in pulmonary blood volume. We conclude that acute volume overload produces cardiac chamber dilatation, along with increases in systolic function. Both pulmonary and systemic vascular resistance declined, and the transit time in the pulmonary circulation shortened. Digital intravenous ventriculography is a useful technique for the analysis of the central circulation during acute hemodynamic manipulations.