The degree and effectiveness of compensatory changes in the distal coronary vascular bed during progressive proximal coronary stenosis have not been described. In this study, coronary vascular bed resistance and pressure gradient-flow relationships were determined for 157 different stenoses in nine opened-chest dogs by measuring coronary flow, aortic pressure, and coronary pressure distal to a coronary

To test the hypothesis that single-photon emission computed tomography (SPECT) could actually determine left ventricular LV mass in humans, SPECT measurements of LV mass were compared with LV mass determined by cineangiography in 12 patients with normal coronary arteries and LV function. Repeat SPECT determinations of LV mass were carried out in 5 patients. Projection images of the left ventricle were acquired after intravenous injection of thallium-201 (TI-201) using a rotating gamma camera. Transverse sections were reconstructed by filtered backprojection. The boundary of LV uptake of TI-201 in each transverse section was defined using a 3-dimensional threshold detector. Scintigraphic LV mass (total number of voxels demonstrating LV TI-201 uptake X voxel volume X specific gravity of myocardium) was compared with angiographic LV mass. There was good correlation between LV mass determined by SPECT and that determined by cineangiography. Mean angiographic LV mass was 208 +/- 45 g (+/- standard deviation). Mean SPECT LV mass was 204 +/- 42 g. Linear regression analysis revealed the following relation: SPECT LV mass = 0.76 X angiographic LV mass + 46.1 (r = 0.82, root-mean-square deviation from regression = 24.7). The SPECT values of LV mass varied an average of 10.4 +/- 4.6% (+/- standard deviation) in the 5 patients in whom 2 determinations were made. Thus, SPECT of TI-201 can accurately measure LV mass in humans.

The mechanism by which hydralazine improves cardiac function in patients with heart failure is not well characterized. Hydralazine may improve left ventricular (LV) function by decreasing afterloading wall stress or by increasing myocardial contractility. The effect of intravenous hydralazine was assessed in 8 patients with severe idiopathic dilated cardiomyopathy. Hydralazine increased stroke volume index (from 24 ± 8 to 40 ± 9 ml/m2, p < 0.01) and decreased systemic vascular resistance (from 1,603 ± 619 to 810 ± 317 dynes s cm−5, p < 0.01) and peak LV wall stress (from 476 ± 118 to 410 ± 68 kdynes/cm2, p = 0.02). Two groups were defined by normal or high LV wall stress. Patients with high LV stress had higher LV end-diastolic pressure (38 ± 12 vs 17 ± 8 mm Hg, p < 0.01), LV end-diastolic volume index (184 ± 24 vs 149 ± 7 ml/m2, p < 0.01) and systemic vascular resistance (1,423 ± 686 vs 846 ± 293 dynes s cm−5, p = 0.01). Hydralazine decreased stress more in these patients (−101 ± 57 vs −6 ± 9 kdynes/cm2, p = 0.02), LV end-diastolic pressure (−12 ± 7 vs 2 ± 2 mm Hg, p = 0.02), systolic pressure (−15 ± 13 vs 3 ± 4 mm Hg, p = 0.03) and systemic vascular resistance (−1,053 ± 247 vs −363 ± 83 dynes s cm−5, p < 0.01) than in patients with normal LV stress. Decreased LV stress was caused by decreased systolic and diastolic pressures and/or volumes. Late systolic pressure-volume relations in patients with normal LV stress suggested increased myocardial contractility, but this was not confirmed by LV dP/dt. Hydralazine improves LV function in patients with dilated cardiomyopathy by reducing elevated LV wall stress, with little inotropic effect.

The volumes of the left ventricle (LV) and right ventricle (RV) were determined by scintigraphy, radiography, and weight, using hollow, morphologically accurate cardiac phantoms that ranged from 99-415 ml (RV) and 72-364 ml (LV). Self-attenuation within these simulated ventricles appeared negligible in view of the nearly linear correlation between scintigraphic and weight determined volumes. Scintigraphy compared favorably with radiography for estimating clinically encountered volumes of the RV and LV.

Transseptal left heart catheterization was performed in 106 instances in 101 patients using right anterior oblique fluoroscopy to define septal boundaries during interatrial septal puncture, and using a preshaped guide wire to catheterize the left ventricle. By using these two modifications of the classic transseptal technique, the left atrium was entered in 105 instances (99%) and the left ventricle was catheterized in all 87 attempts (100%), including attempts in eight patients with mitral stenosis (valve area 1.29 +/- 0.39 cm2 [mean +/- standard deviation] ). No deaths occurred as a direct result of transseptal catheterization; nonfatal complications occurred in 2.8% of patients (hemopericardium in one patient, ventricular fibrillation in one patient and transient vagal reaction in one patient). The use of the right anterior oblique projection to adequately visualize both the interatrial septum and the intended point of puncture, the use of a pigtail catheter positioned in the ascending aorta to define the relation of the puncture site to the aorta in this projection and the utilization of a flexible preshaped guide wire to catheterize the left ventricle are the major factors contributing toward this improved success rate and low incidence of complications.

This study describes the postpartum course of asymptomatic parturient women who had greater than or equal to 10(2) cfu of high-virulence (HV) bacteria per milliliter of amniotic fluid. Of 60 asymptomatic parturient women with greater than or equal to 10(2) cfu of HV bacteria per milliliter of amniotic fluid, 27 (48%) remained asymptomatic in the puerperium, 16 (27%) developed fever only, and 17 (28%) developed endometritis. In asymptomatic versus symptomatic women, there were no statistically significant differences in number or type of isolates or in length of membrane rupture or labor-to-collection interval. However, there were significant differences in the intervals from collection to delivery and in the rate of cesarean section delivery. For comparison, 40 of these patients were matched with women in whom only low-virulence organisms were detected in the amniotic fluid. In the HV group, 16 women (40%) remained asymptomatic, 15 (37.5%) developed fever only, and nine (22.5%) had endometritis. In the low-virulence group, 27 women (67.5%) remained asymptomatic, 10 (25%) developed fever only, one (2.5%) developed endometritis 10 days post partum, and two (5%) had other infections (p less than 0.01). Clinically evident uterine infection depends upon type and numbers of bacteria in utero, duration of bacteria in utero, and route of delivery.

This study was performed to assess the accuracy of qualitative angiographic grading in persons with aortic regurgitation (AR) or mitral regurgitation (MR) and to determine the factors that may influence the reliability of such grading. In 230 patients (152 men, 78 women, aged 52 +/- 14 years) with AR or MR, forward cardiac index was measured by the Fick and indicator dilution techniques and left ventricular (LV) angiographic index by the area-length method, from which the regurgitant volume index was calculated. In 124 other patients (89 men, 35 women, aged 52 +/- 11 years) without regurgitation, there was good agreement between forward and angiographic cardiac indexes (r = 0.87, p less than 0.001). In the 83 patients with AR, the regurgitant volume indexes in those with 1+ (0.87 +/- 0.57 liters/min/m2) and 2+ (1.72 +/- 1.19 liters/min/m2) angiographic regurgitation were not significantly different from one another, but were significantly different from those with 3+ (3.0 +/- 1.42 liters/min/m2) and 4+ (4.80 +/- 2.25 liters/min/m2) regurgitation; at the same time, the regurgitant volume indexes of patients with 3+ and 4+ AR were not significantly different from one another. In the 147 patients with MR, the regurgitant volume indexes in patients with 1+ regurgitation (0.61 +/- 0.64 liters/min/m2) were significantly lower than other grades, but the regurgitant volume indexes of 2+ (1.14 +/- 0.85 liters/min/m2) vs 3+ (2.14 +/- 1.37 liters/min/m2) and of 3+ vs 4+ (4.60 +/- 2.31 liters/min/m2) were not significantly different. With AR and MR, regurgitant flow within each angiographic grade varied widely, especially in grades 3+ and 4+, and there was considerable overlap of regurgitant volume indexes between grades.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic valve replacement (AVR) in the patient with a small aortic root demands special consideration because the hemodynamic function of artificial valves with a small external diameter is often poor. In this study, the internal diameter of the aortic root was measured from biplane ventriculography. This measured root diameter was then used to predict the external diameter of the artificial valve. Twelve patients underwent biplane ventriculography followed by AVR with Carpentier-Edwards bioprostheses. The artificial valve diameter was predicted with a correlation coefficient of 0.93, a standard error of estimate of 0.89 mm, and an average absolute difference between preoperative measurement and valve diameter of 0.69 mm. Therefore, the aortic root diameter can be accurately measured from the ventriculogram, thus detecting the patient with a small aortic root before surgery.

The proper position of a catheter to measure pulmonary wedge pressure is usually confirmed by measuring the oxygen saturation of withdrawn blood. However, this method of confirmation is tedious and frequently unsuccessful. A fluoroscopic method to confirm proper catheter position to measure wedge pressure was tested. Between 2 and 5 ml of contrast medium was injected into the artery distal to the catheter tip. Lack of movement for 15 seconds after injection indicated proper catheter position. As judged by the saturation of withdrawn blood and by comparison of wedge and left atrial or ventricular pressure, the fluoroscopic method of confirmation was correct in 71/75 attempts. Thus the fluoroscopic method of confirmation of proper catheter position is simple, rapid, and reliable.

This study was undertaken to determine whether abnormalities on the echocardiograms of patients with unstable angina have any prognostic significance. 27 male patients, mean age 53 years, who fulfilled criteria for unstable angina and who responded to medical therapy, had echocardiograms within 48 h of admission and at discharge. Follow-up data were obtained from 7 patients during a postdischarge period of 6-26 weeks. 13 patients had mild exertional angina or were pain-free (group I) and 14 patients had either severe, stable angina pectoris or recurrence of their unstable angina (group II) during the follow-up period. When admission and discharge values were compared, the echocardiographic ratio of left ventricular end-diastolic dimension to mitral valve closure time (EDD/PR-AC) showed significant differences for both group I and group II (p less than 0.05). An abnormal EED/PR-AC ratio was present at discharge in 8 of 14 group II patients compared to only 1 of 13 group I patients (p less than 0.05). The mean values for end-diastolic dimension, mitral valve closure time, and amplitudes of interventricular septal and posterior left ventricular wall motion were not significantly different in comparisons between admission and discharge studies and between group I and group II patients. In 19 patients who had cardiac catheterization druing the follow-up period, the discharge EED/PR-AC ratio correlated inversely with the angiographic ejection fraction (r = 0.79; p less than 0.001).

Biplane cineradiography is a potentially powerful tool for precise measurement of intracardiac dimensions. The most systematic approach to these measurements is the creation of a three-dimensional coordinate system within the x-ray field. Using this system, interpoint distances, such as between radiopaque clips or coronary artery bifurcations, can be calculated by use of the Pythagoras theorem. Alternatively, calibration factors can be calculated in order to determine the absolute dimensions of a structure, such as a ventricle or coronary artery. However, cineradiography has two problems that have precluded widespread use of the system. These problems are pincushion distortion and variable image magnification. In this paper, methodology to quantitate and compensate for these variables is presented. The method uses radiopaque beads permanently mounted in the x-ray field. The position of the bead images on the x-ray film determine the compensation factors. Using this system, measurements are made with a standard deviation of approximately 1% of the true value.