Lewis Dexter

Resolution Rate of Acute Pulmonary Embolism in Man

Abstract In 15 patients with definite angiographic evidence of embolism involving both lungs, and treated with heparin or venous ligation or both, sequential studies showed only minimal angiographic and hemodynamic signs of resolution at seven days. By 10 to 21 days, pressures in the right side of the heart had decreased to near normal levels, and there was unmistakable angiographic evidence of resolution. Complete resolution, with normal angiograms and hemodynamics, was noted in three patients at 14, 15 and 34 days. In other patients angiographic and hemodynamic abnormalities persisted weeks after embolism.

Pulmonary angiography in acute pulmonary embolism: Indications, techniques, and results in 367 patients☆

Abstract Pulmonary angiography is the most specific test available for the diagnosis of acute pulmonary embolism. This technique can safely be performed in critically ill patients. In 367 consecutive studies our incidence of complications has been 4 per cent, and there has been only one death. Hemodynamic studies done as part of the procedure permit evaluation of the severity and the pathophysiology of acute pulmonary embolism. The two diagnostic angiographic findings of pulmonary embolism are intraluminal filling defects and cutoff arteries. Oligemia and asymmetry of blood flow are frequently seen in pulmonary embolism, but are not specific. These latter two abnormalities may occur in chronic lung disease or congestive heart failure without pulmonary embolism. Using these diagnostic criteria in 247 patients studied because of a clinical diagnosis of acute pulmonary embolism, a definitive diagnosis (either definite pulmonary embolism or negative) was established by angiography in 74 per cent. In 9 per cent the diagnosis was probable pulmonary embolism, and in 17 per cent the findings were equivocal for pulmonary embolism. Application of these diagnostic criteria results in minimal false posiive angiographic diagnoses. False negative diagnoses may occur if embolism is limited to peripheral branches of the pulmonary vasculature that are not visualized by current angiographic techniques. The incidence of symptomatic pulmonary embolism limited to these small arteries is uncertain. The primary limitation of this technique is, that in patients with underlying heart disease or chronic lung disease, the results of angiography may be equivocal. The application of new techniques of magnification angiography and/or selective cineangiography offer promise in enhancing the recognition of embolism in this group of patients.

Diagnostic Sensitivity of Laboratory Findings in Acute Pulmonary Embolism

Abstract Many different laboratory tests have been used to screen patients for pulmonary embolism. The sensitivity of certain laboratory tests was assessed in a prospective study of 50 patients wit...

Occult Cancer in Patients with Acute Pulmonary Embolism

An association between venous thrombosis and cancer was first suggested by Trousseau, and has been confirmed by multiple postmortem studies. Clinical studies have shown that thrombophlebitis migrans may occur before malignancies become clinically evident, and therefore serves as a clue to occult cancer. A relation between occult cancer and the commoner deep venous thrombosis and pulmonary embolism has not been established. We ascertained the incidence of cancer before and after pulmonary embolism was diagnosed by pulmonary angiography in 128 patients. The incidence of cancer before pulmonary embolism (12%) was essentially the same as that in a comparison group of patients without pulmonary embolism (10%). In the 2 years after pulmonary angiography, however, cancer was diagnosed in 13 patients with pulmonary embolism in contrast to no patients in the comparison group (p less than 0.001). The most frequent cancers involved the lung, gastrointestinal tract, breast, and uterus. The malignancies were nearly always occult when pulmonary embolism occurred. These findings indicate that pulmonary embolism with or without overt deep venous thrombosis should alert the clinician to consider occult cancer.

The hemodynamic and respiratory effects of diazepam (Valium).

Diazepam, 5–10 rag, was given intravenously to treat anxiety occurring during cardiac catheterization in 15 patients. Anxiety was effectively relieved in 11 patients. Hemodynamic and ventilatory parameters were assessed before, and ten and 30 minutes after diazepam. The cardiac index decreased significantly in only three patients, each of whom had a control cardiac index in the high-normal range. No significant changes occurred in patients whose control cardiac indexes were below normal. Systolic blood pressure decreased by more than 10 mm Hg in eight patients. Pulmonary arterial pressure, heart rate, stroke volume and pulmonary and systemic resistance did not change significantly. Hypoventilation occurred in all patients. Ten minutes after diazepam minute ventilation had decreased by 28 per cent and tidal volume by 23 per cent. Paco2 increased by 5 mm Hg and Pao2 decreased by 10 mm Hg. The observed changes in blood pressure and ventilation were without clinical correlates and did not require therapy.

Paradoxical embolism: Diagnosis during life☆

Abstract Of 128 reported cases of paradoxical embolism, only twelve have been diagnosed during life. However, five cases of paradoxical embolism have been detected during life at this hospital in two years. These five cases are presented to illustrate the pathophysiologic features that allow detection of paradoxical embolism during life. All five patients had unexplained arterial embolism. None had associated atrial fibrillation, mitral stenosis or myocardial infarction. Each had venous thrombosis. Two patients had congenital heart disease, whereas in three the defect permitting paradoxical embolism was a patent foramen ovale. Each patient was treated to prevent further embolism. Three did well and were discharged. Two died, and at postmortem examination, the clinical diagnosis was confirmed. The detection of five cases in two years indicates that this treatable cause of systemic embolism is substantially more frequent than indicated by the literature.

Late Prognosis of Acute Pulmonary Embolism

Abstract Sixty consecutive patients who survived an episode of acute pulmonary embolism documented by pulmonary angiography were assessed one to seven years later (average follow-up period, 29 mont...

Studies of Congenital Heart Disease IV. Uncomplicated Pulmonic Stenosis

Congenital pulmonic stenosis is indicated by cardiac catheterization by the finding of a higher systolic pressure in the right ventricle than in the pulmonary artery. Eight cases of uncomplicated pulmonic stenosis are studied. The findings on history, physical examination, x-ray and fluoroscopy, and electrocardiogram have been analyzed and the variations in circulatory dynamics encountered in these individuals are described in detail.

Studies of the circulatory dynamics in mitral stenosis. II: Altered dynamics at rest

Abstract 1. 1. Twenty-one patients with mitral stenosis have been studied by the technique of cardiac catheterization. These patients were classified clinically and also according to the size of the orifice of the mitral valve. Six patients were in pulmonary edema during the study. 2. 2. As a consequence of mitral valvular stenosis, a balance develops between pulmonary vascular pressures and peripheral blood flow (tending toward an increase in pulmonary pressure and a decrease in blood flow). 3. 3. Cardiac and stroke indices were decreased at rest, although a wide range of values was seen. Patients with auricular fibrillation had slightly lower cardiac indices than patients with normal sinus rhythm. Tissue oxygen extraction per cubic centimeter of blood was increased so that oxygen consumption was maintained within the normal range in all. 4. 4. Pulmonary “capillary” pressures were increased above normal as a result of the increase in left atrial pressure proximal to the mitral stenosis. 5. 5. Pulmonary arterial pressures were increased above normal as a result of (a) the increase in pulmonary “capillary” pressure and (b) increased pulmonary arteriolar resistance. 6. 6. The presence of an elevated pulmonary arteriolar resistance was roughly related to the level of pulmonary “capillary” pressure and the degree of valvular stenosis. 7. 7. An inverse logarithmic relationship was observed between total pulmonary resistance and stroke output per square meter. 8. 8. As a result of the increased pulmonary vascular pressures, the pressure work of the right ventricle was greatly increased. 9. 9. Right ventricular incompetency, as judged by an elevated filling pressure, was seen in over one-half of the patients studied. Incompetence was believed due to (a) the increased pulmonary pressure load and (b) underlying myocardial damage from rheumatic fever.

Early Reduction of Pulmonary Vascular Resistance after Mitral-Valve Replacement

PULMONARY-artery pressure rises out of proportion to the left atrial, pulmonary venous and pulmonary capillary pressure in some patients with elevated left atrial pressure secondary to mitral steno...