Citations

A case is reported of a 20-day-old infant with origin of the right pulmonary artery from the ascending aorta. Besides its abnormal origin, the artery was stenotic in its proximal half. We believe the malformation results from persistence of the distal (instead of the proximal) part of the primitive sixth aortic arch and of a portion of the right dorsal aorta. The presence of ductal tissue in the wall of the right pulmonary artery supports this concept. The pulmonary vasculature in the two lungs showed great differences in medial and intimal characteristics. A second case of origin of the right pulmonary artery from the aorta, deseribed elsewhere, provided material for comparative study of the structure of the right main pulmonary arteries and the intrapulmonary branches.

An anatomicopathologic entity of the tetralogy of Fallot with an additional finding of an accessory flap of tricuspid valvular tissue is described. In the 3 cases reported in this paper, the outstanding hemodynamic finding was a right ventricular systolic pressure that was significantly greater than the systemic systolic pressure. The hemodynamic findings were explained by the fact that the accessory tricuspid flap partially closed the large ventricular septal defect. The clinical picture was similar to that of either severe pulmonary stenosis with an intact ventricular septum or severe pulmonary stenosis with a small ventricular septal defect and a right-to-left shunt at the ventricular level.

Necropsy studies in cases of pulmonary hypertension of unknown cause show structural changes in the pulmonary vessels that are called irreversible. Acetylcholine chloride was infused at a rate of 2 mg. per minute into the outflow tract of the right ventricle of a 48-year-old woman who had pulmonary hypertension. The mean pulmonary artery pressure decreased from 56 to 25 mm. Hg and the pulmonary flow increased slightly. These findings are consistent with the theory that so-called idiopathic pulmonary hypertension may at some stage be maintained by vasoconstriction.

Survival following surgical correction of congenital cardiovascular defects is unlikely if pulmonary hypertension cannot be decreased significantly. Infusions of acetylcholine decreased pulmonary vascular resistance in 6 of 11 patients having pulmonary hypertension associated with atrial or ventricular septal defects. When the acetylcholine was combined with the breathing of oxygen, resistance decreased further. These findings are consistent with the theory that, at some stage, the pulmonary hypertension in cases of congenital heart disease is maintained at least in part by vasoconstriction and therefore is potentially reversible.

The relative importance of organic changes and vasoconstrictive influences in the production of increased pulmonary vascular resistance in congenital heart disease is problematic. With use of a grading system previously described, a study was made of the relation between each of the grades of hypertensive pulmonary vascular disease associated with ventricular or atrial septal defects and the change of pulmonary artery blood pressure immediately following closure of the abnormal communications. The immediate reversibility of the pulmonary hypertension varies inversely with the severity of the structural changes.

Arteriovenous fistula involving the portal vein or its tributaries is a rare condition that in some cases can be treated successfully by surgery if it is recognized. The clinical manifestations and diagnostic criteria are presented.

Obstruction to pulmonary blood flow may occur in the pulmonic valve, in the infundibulum or in both. Cardiac catheterization aids in the determination of the site of obstruction. Criteria for the differentiation at operation of valvular and infundibular pulmonic stenosis are enumerated, and the usefulness of accurate pressure tracings during operation is emphasized. The accurate identification of the site or sites of obstruction to pulmonary blood flow is essential to proper surgical management. A correctly selected operation must be carried out in as complete a manner as possible.

On the thoracic roentgenograms of patients with mitral stenosis, costophrenic septal lines are frequently seen. These lines are a sign of pulmonary venous hypertension. They were not seen in a representative group of patients with pulmonary arterial hypertension but without pulmonary venous hypertension.

Background — The role of load versus angiotensin II (Ang II) and endothelin-1 (ET) in the pathogenesis of hypertensive heart disease is controversial. We sought to determine whether alterations in cardiac structure and function due to hypertension (HTN) were dependent on Ang II or ET activation. Methods and Results — Bilateral renal wrapping to produce HTN (n=12) or sham surgery (n=6) was performed in adult dogs. Weekly blood pressure, plasma renin activity, Ang II, ET, and catecholamines were measured. Systolic (end-systolic elastance, Ees) and diastolic (τ) function were assessed in sham and HTN dogs at 5 (HTN-5wk) or 12 (HTN-12wk) weeks. Ang II and ET were assayed in the left ventricle (LV) and kidney. Mean arterial pressure was higher in renal wrap dogs at week 1 (* P <0.05 versus controls: 139±4* versus 123±4 mm Hg), week 5 (174±7* versus 124±4 mm Hg), and week 12 (181±12* versus 124±4 mm Hg). LV mass index was increased in HTN-5wk (22%*) and HTN-12wk (39%*). LV fibrosis was increased in HTN-12wk. Ees was preserved in HTN-5wk and HTN-12wk. τ was increased in HTN-5wk (50±3* ms) and HTN-12wk (62±10* ms) dogs compared with sham (41±2 ms). Plasma Ang II, ET, catecholamines, and plasma renin activity were unchanged during the progressive HTN. Ang II and ET in LV and kidney were not different from controls. Conclusions — Systemic HTN induces LV hypertrophy, myocardial fibrosis, and isolated diastolic dysfunction in the absence of local or systemic activation of Ang II or ET. These findings suggest that load is the prevailing stimulus for the structural and functional changes associated with early hypertensive heart disease.

Direct surgical relief of diffuse subvalvular aortic stenosis has been accomplished in two cases by open operation through a left ventriculotomy.