George D. Davis

CLINICAL COURSE OF ATHEROSCLEROTIC RENOVASCULAR DISEASE

Abstract The clinical course of atherosclerotic renovascular hypertension was evaluated in 109 patients, and the changes in the renal artery disease were observed by serial renal arteriography in 30 patients. The estimated five year survivorship was 66.7 ± 6.4 per cent, compared to 91.7 per cent in the normal population. Associated symptomatic cardiovascular disease (angina, myocardial infarction, transient or completed stroke, intermittent claudication) was noted in 41 per cent at the initial examination, and 39 per cent of those initially free developed this during the period of observation. These episodes frequently were multiple and were not related to continued hypertension. The five year survivorship free of symptomatic cardiovascular disease was estimated to be 53.2 ± 8.0 per cent. Renovascular surgery in 46 patients did not affect survivorship. The incidence of new symptomatic cardiovascular disease was higher in the surgical group. Blood pressures were 100 mm. Hg or less at follow-up in 86 per cent of the surgically treated group and in 65 per cent in the medically treated group. Good blood pressure control appeared to improve the prognosis for life but not for symptomatic cardiovascular episodes. The serial studies of the renal vasculature in 30 patients demonstrated progression of the disease in half of the involved arteries. Three previously normal arteries became diseased. Changes for the worse were noted in the artery to one kidney in 13 patients (including 2 with prior nephrectomy) and in the arteries to both kidneys in 6. The progressive nature of renal artery atherosclerosis was reflected by impairment of function and loss of mass (clearance studies and isotopic and excretory urography); the converse was often true after successful revascularization of affected kidneys. In the presence of hypertension, atherosclerotic disease in other parts of the body should suggest the possibility of renal artery involvement. In view of the progressive nature of atherosclerosis in general, the status of the heart, brain and peripheral arteries also should be assessed initially and periodically regardless of the degree of blood pressure control.

The Effect of Angiocardiographic Contrast Medium on Circulatory Dynamics in Man Cardiac Output during Angiocardiography

The cardiovascular response to angiographic contrast medium was studied in 28 patients undergoing diagnostic angiocardiography under anesthesia. A transient phase of hypotension and tachycardia similar to that described by other authors was noted. Cardiac output was increased initially by 50 per cent and returned to the base line in 20 minutes. Peripheral blood flow increased by 100 per cent, apparently due to the direct effect of the hyperosmotic solution on the vascular smooth muscle. Hemodilution, maximal 2 to 4 minutes after injection of contrast medium, suggested a transient increase in circulating blood volume. Increased ventricular filling pressures, which were thought to be due to hypervolemia, were associated with increased left ventricular stroke work.

Clinical, angiographic, and hemodynamic assessment of late results after Mustard operation.

SUMMARYSince 1974, late results of the Mustard procedure for correcting complete transposition of the great arteries have been evaluated by cardiac catheterization, electrocardiography, roentgenography, history, and physical examination of 48 Mayo Clinic patients. Of these, 15 were studied I month to 2 years postoperatively because of clinical deterioration. The other 33 had been asymptomatic but were asked to return for hemodynamic reevaluation one-half to 1I years postoperatively. Of the asymptomatic group, 19 underwent exercise electrocardiography prior to catheterization and eight performed supine exercise during catheterization. Cardiac catheterization proved the most effective mode of study.Significant cardiovascular abnormalities (caval obstruction, residual pulmonary stenosis, etc.) were found in 35 of the 47 patients -including 20 of the 33 who were asymptomatic. Eight of the symptomatic group and three of the others have died since this restudy. These poor results warrant renewed effort to devise better methods for correcting complete transposition.

Anomalous ventricular myocardial patterns in a child with complex congenital heart disease

Abstract Unusual ventricular myocardial patterns in a child are described. These patterns, demonstrated by angiocardiography, were associated with complex, congenital heart disease. Autopsy confirmed the bizarre, spongy myocardial patterns present in both ventricles. One explanation for the abnormal myocardial pattern observed in this case is failure of the normal differentiation of the primitive ventricular wall into compact myocardium. Thus, this case may have represented persistence of an embryonal pattern.

Double outlet right ventricle: Hemodynamic and anatomic correlations

There are 16 possible variations of double outlet ventricle with regard to interrelations of the great arteries and to location of the ventricular septal defect. In a series of 62 cases, approximately two thirds of patients had the great arteries in a side by side relation, and most (28 of 41) had the ventricular septal defect in a subaortic position. In double outlet right ventricle with malposition of the great arteries, the ventricular septal defect was either subpulmonary or subaortic. Four of the 13 patients with subpulmonary ventricular septal defect had a supracristal defect with side by side relation of the great arteries (Taussig-Bing anomaly), and 9 patients had malposition of the great arteries with an infracristal ventricular septal defect. In all patients with subpulmonary ventricular septal defect, pulmonary arterial oxygen saturation was greater than systemic arterial saturation regardless of the relation of the great arteries. Forty patients had subaortic ventricular septal defect. In 24 of these patients, including 7 with malposition of the great arteries, systemic arterial oxygen saturation was greater than pulmonary arterial saturation. However, in 9 patients (25 percent) the reverse was true, as seen in complete transposition of the great arteries and in Taussig-Bing anomaly. Thus, pulmonary arterial oxygen saturation greater than systemic arterial saturation is not reliable evidence of a Taussig-Bing anomaly. Of the 25 patients with such saturation, only 4 had the Taussig-Bing anomaly.

Communication between right pulmonary artery and left atrium

Abstract The 12th case of a direct communication between the right pulmonary artery and the left atrium is reported, with special emphasis on the clinical and hemodynamic findings. The anatomic differences in the 12 cases are categorized into three general types: an anomalous vessel connecting the posterior aspect of the right pulmonary artery and draining into the left atrium with (1) normal pulmonary venous connections or (2) the pulmonary vein draining into the anomalous vessel; and (3) an anomalous communication draining into the left atrium in place of the absent right lower pulmonary vein. In patients with this anomaly, surgery should result in complete cure; early intervention is recommended because the mortality rate is higher for patients who are older at operation and because there is an increased chance that cerebral and Systemic emboli will occur if surgery is not performed.

Selection of Patients with Truncus Arteriosus for Surgical Correction Anatomic and Hemodynamic Considerations

Six years have passed since the first successful surgical correction of truncus arteriosus. A review of our experience enables some conclusions regarding the operation. Patients with mild or moderate truncal valve incompetence do not need truncal valve replacement. Patients with severe truncal valve incompetence require valve replacement, which is associated with a significantly increased surgical mortality. The surgical mortality is not increased in hemodynamically favorable patients who have only one pulmonary artery. However, these patients are especially likely to have early development of severe pulmonary vascular disease. The surgical mortality for the patient with uncomplicated disease and two pulmonary arteries, with pulmonary resistance of less than 8.0 units m2, is 10%. In patients with pulmonary resistance between 8.0 and 12 units m2, the mortality is approximately three times greater. Patients with pulmonary resistances greater than 12.0 units m2 are probably inoperable. Different hemodynamic criteria must be applied in assessing the operability of patients with a single pulmonary artery. A systemic arterial oxygen saturation less than 85% in a patient with two pulmonary arteries and without pulmonary artery stenosis or a pulmonary artery band usually indicates inoperability. Elective operation usually is deferred until a patient is four years old, but if the patients clinical condition warrants, the procedure can be done at any time after the age of one year, with a good chance of success. Follow-up on most operated patients has been encouraging.

Relation of intraoperative or early postoperative transmural myocardial infarction to patency of aortocoronary bypass grafts and to diseased ungrafted coronary arteries

Serial preoperative and postoperative electrocardiograms and vectorcardiograms were obtained in 500 patients undergoing saphenous vein aortocoronary artery bypass graft surgery. Evidence of transmural myocardial infarction was found early postoperatively in 67 patients (13 percent). Age and sex distributions, number of vessels diseased or vessels grafted, and preoperative and postoperative New York Heart Association functional classification (mean follow-up, 26 months) did not differ in the groups with and without infarction. Increased duration of cardiopulmonary bypass time (more than 120 minutes) was slightly greater in the group with infarction (P smaller than 0.05). Multivariate analysis revealed that 60 percent of patients in the group with infarction were identified by a 1st day serum glutamic oxaloacetic transaminase value greater than 100 U/liter; however, for each such patient identified, there was approximately one false positive result. Use of other values (creatine phosphokinase, cardiopulmonary bypass time and total anoxic rest time) did not improve discrimination. Twenty-five percent of all transmural infarctions occurred within the zone of myocardium supplied by a diseased ungrafted artery. In 32 patients with early evidence of transmural mycardial infarction in a zone of myocardium supplied by a grafted artery, postoperative angiography showed as many with patent as with occluded grafts. Of 154 patients in the group without infarction who had early postoperative graft angiograms, 30 (19 percent) had one graft occluded and yet no evidence of transmural infarction by our criteria. Therefore, early postoperative evidence of transmural myocardial infarction as defined in this study is an unreliable indicator of the status of the graft supplying the zone of infarction.

Regional left ventricular wall dynamics before and after sublingual administration of nitroglycerin

Regional wall dynamics of the left ventricle before and after sublingual administration of 0.6 mg of nitroglycerin were determined from left ventricular angiograms in 27 patients undergoing coronary arteriography. Regional wall dynamics were quantitatively measured from 60/sec determinations of wall thickness and derived peak rate of systolic wall thickening (peak dTw/dt) in selected sites of the left ventricle. A total of 70 regions were studied. Analysis of the same segment before and after administration of nitroglycerin revealed that the mean change in peak dTw/dt was +1.97 cm/sec in segments with an initial peak dTw/dt of less than 5 cm/sec, in contrast to a change of +0.66 cm/sec in segments with an initial control value of 5 cm/sec or greater. Akinetic or dyskinetic areas did not show improvements after nitroglycerin. In 11 left ventriculograms, an area that was initially hypokinetic manifested an increase in rate of wall thickening after nitroglycerin. The mean increase in peak dTw/dt in anterior segments with electrocardiographic evidence of myocardial infarction was 0.18 cm/sec (P less than 0.05) after nitroglycerin, compared with a mean change of 1.33 cm/sec in anterior segments without such evidence. This study presents evidence for a regional myocardial response to nitroglycerin with differing responses within the same ventricle apparently depending upon the functional state of the underlying myocardium.

Quantitative Determination of Regional Left Ventricular Wall Dynamics by Roentgen Videometry

The use of roentgen videometry as a means of studying regional left ventricular wall dynamics and performance was evaluated in 32 patients undergoing coronary arteriography. Nine patients had normal coronary arteriograms and hemodynamic findings (group 1), 8 patients had generalized decrease in left ventricular contraction and abnormal hemodynamic findings (group 2), and 15 patients with coronary artery disease had regional wall dynamics abnormalities (group 3). Sixty-per-second determinations of wall thickness were performed in selected sites of the left ventricle. Measurements performed included end-diastolic wall thickness (EDTw), mean and peak rates of systolic wall thickening (m and p dTw/dt), and fractional systolic increase in wall thickness (&Dgr;Tw/EDTw). In patients with uniformly performing ventricles (groups 1 and 2), these parameters correlated well with other parameters of ventricular function. Best distinction between the “normal’ group (group 1) and the “abnormal’ group (group 2) was achieved when the rates of thickening (m and p dTw/dt) were utilized (P < 0.001). In patients of group 3, three types of abnormal regional wall dynamics could be determined and quantified objectively: hypokinesia (decreased p dTw/dt), akinesia (p dTw/dt = 0), and dyskinesia (p dTw/dt < 0). The severity of the abnormality of the wall dynamics correlated well with the presence or absence of a previous infarction on the electrocardiogram, and the anatomic location was strongly correlated with the distribution and severity of coronary artery lesions within a given ventricle.