Effects of hydralazine on pressure-volume and stress-volume relations in congestive heart failure secondary to idiopathic dilated cardiomyopathy.

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 less than 0.01) and decreased systemic vascular resistance from 1,603 +/- 619 to 810 +/- 317 dynes s cm-5, p less than 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 less than 0.01), LV end-diastolic volume index (184 +/- 24 vs 149 +/- 7 ml/m2, p less than 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 less than 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.

Correlation of scintigraphy and angiography for ventricular volume determinations using realistic cardiac phantoms: the unimportance of self-attenuation.

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.

Measurement of aortic root size by biplane angiography before cardiac valve replacement.

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.

Echocardiography in unstable angina.

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).

Dissecting aortic aneurysm manifested as fever of unknown origin.

A patient with a dissecting aneurysm of the ascending aorta had fever of unknown origin. Although his clinical picture included a number of classical features of his disorder, these were initially misinterpreted, largely because fever was the patient's chief complaint. Polymorphonuclear leukocytes sequestered within the aortic hemagen as they disintegrated. This case emphasizes the protean nature of the dissecting aortic aneurysm, adding yet another distinct clinical manifestation, fever of unknown origin, with which it may be associated.