Radiocardiographic assessment of dobutamine and isosorbide dinitrate therapy in patients with mitral stenosis and pulmonary congestion.

Simultaneous hemodynamic and radiocardiographic measurements were performed on 10 patients with mitral stenosis and pulmonary congestion for evaluating the acute effects of dobutamine (DB, 5 micrograms/kg/min), isosorbide dinitrate (ISD, 10 mg sublingually) or a combination of the two. DB alone produced a significant increase of the cardiac index (CI) from 2.9 +/- 0.1 to 3.7 +/- 0.2 L/in/m2 (p less than 0.01), but a modest increase in pulmonary artery diastolic pressure (PADP) and in pulmonary blood volume by approximately 15%, respectively. ISD alone caused a decline in PADP from 26 +/- 2 to 18 +/- 1 mmHg (p less than 0.001), in right heart volume from 300 +/- 36 to 215 +/- 18 ml/m2 (p less than 0.05) and in left heart volume from 321 +/- 28 to 248 +/- 20 ml/m2 (p less than 0.05), but no change in the CI. Combined administration of the two agents resulted in favorable alterations in both hemodynamic variables: PADP decreased from 26 +/- 2 to 20 +/- 1 mmHg (p less than 0.01) and the CI increased from 2.9 +/- 0.1 to 3.3 +/- 0.1 L/min/m2 (p less than 0.05). Thus, DB alone had a tendency to aggravate pulmonary venous congestion in our patients, while ISD is effective in reducing the congestive manifestations of heart failure due to its venodilating effects but less beneficial in increasing the CI. The combined therapy of DB and ISD appears to be extremely effective in restoring an adequate cardiac output and in relieving the symptoms of pulmonary vascular congestion in the presence of mitral stenosis.

2,3-Bisphosphoglycerate in developing rabbit erythroid cells.

Rabbits were made anemic to different extents by phenylhydrazine injections so as to vary the developmental stages of the erythroid cells in their peripheral blood and bone marrow. It was found that the more severe the anemia, the lower the concentration of glycerate-2,3-P2 in the bone marrow cells and in the circulating erythroid cells. The glycerate-2,3-P2 level was shown to rise during erythroid differentiation in a linear relationship to the hemoglobin level, corresponding to the equation Y = 0.03x + 0.29, where y is the concentration of glycerate-2,3-P2 (micromoles per ml packed cells) and x is the concentration of hemoglobin (milligrams per packed cells). The bone marrow cells were fractionated on a size (i.e. maturity) basis and enzyme activities in the fractionated cells were measured. The accumulation of glycerate-2,3-P2 was found to be primarily attributable to the increase in glycerate-2,3-P2 synthase activity. Glycerate-2,3-P2 phosphatase and phosphofructokinase increased as the cells matured from the polychromatic stages to become reticulocytes while pyruvate kinase and phosphoglyceromutase decreased. The changes in phosphofructokinase and pyruvate kinase appear to be advantageous for glycerate-2,3-P2 accumulation. The two enzyme activities directly responsible for the synthesis and the breakdown of glycerate-2,3-P2 are probably manifested by a single protein, glycerate-2,3-P2 synthase-phosphatase.

Role of endocrine factors in chronic congestive heart failure, with emphasis on catecholamines.

Changes in endocrine activity in response to tilting of the body were studied in 16 in-patients with various degrees of chronic congestive heart failure and one healthy subject. Norepinephrine and epinephrine excretion, plasma renin activity and plasma cortisol concentration were determined first in recumbency and then during 45 degree head-up tilting. The subjects were divided into three groups depending on the severity of heart failure. In recumbency urinary norepinephrine averaged 31.6 (standard deviation 12.7) ng/min in group 1 (controls), 54.9 +/- 25.3 ng/min in group 2 (NYHA class II--III) and 79.5 ng/min in group 3 (NYHA class IV). Thus the level of urinary norepinephrine increased with the degree of heart failure. In recumbency epinephrine excretion and plasma cortisol concentration were not different among three groups. Plasma renin activity was elevated in group 3. There was a significant positive correlation between the changes in plasma renin activity and epinephrine secretion (r = 0.67, p less than 0.01). The present study revealed that patients with slight to moderate congestive heart failure have a normal endocrine response to tilting while those in severe failure have only a slight response. It is probable that the augmented sympathetic nerve activity and increased circulating blood volume, already present in severe failure, allow for less hemodynamic change upon tilting.

Left atrial infarction with saddle embolism.

Left atrial and left ventricular infarction with various atrial arrhythmias, multiple systemic arterial thromboembolism, and a large mural thrombus over the left atrial infarction is reported. In ischemic heart disease, systemic arterial thromboembolism may develop due to atrial infarction which is often overlooked in antemortem as well as in postmortem examinations. When a clinical diagnosis of atrial infarction is made, the possibility of a Stokes-Adams syndrome, thromboembolism, and rupture of the atrium should also be investigated.

Paroxysmal atrial fibrillation with asystole and syncope: report of a case of sinus node dysfunction with hypokalemia and hypertension.

A patient is presented who developed syncope due to asystole following paroxysmal atrial fibrillation. Suppression of intrinsic cardiac pacemakers during tachycardia is postulated as the mechanism for asystole. This patient might have sinus node dysfunction. The episodes of tachycardia occurred more often when the serum potassium level was low.