Search PubMed⌕ Search

Biomedical subjects

D B Doty

Publications and source records attributed to D B Doty.

At least 73 records · Page 4Linked to original sources

Does visual interpretation of the coronary arteriogram predict the physiologic importance of a coronary stenosis?

To assess visual interpretation of the coronary arteriogram as a means of predicting the physiologic effects of coronary obstructions in human beings, we compared caliper measurements of the degree of coronary stenosis with the reactive hyperemic response of coronary flow velocity studied with a Doppler technique at operation, after 20 seconds of coronary arterial occlusion. In 39 patients (44 vessels) with isolated, discrete coronary lesions varying in severity from 10 to 95 per cent stenosis, measurement of the percentage of stenosis from coronary angiograms was not significantly correlated (r = -0.25) with the reactive hyperemic response. Results were the same for obstructions in the left anterior descending, diagonal, and right coronary arteries. Underestimation of lesion severity occurred in 95 per cent of vessels with greater than 60 per cent stenosis of the diameter by arteriography. Both overestimation and underestimation of lesions with less than 60 per cent stenosis were common. These results, together with the high interobserver and intraobserver variability of standard visual analysis of angiograms, suggest that the physiologic effects of the majority of coronary obstructions cannot be determined accurately by conventional angiographic approaches. The need for improved analytical methods for the physiologic assessment of angiographically detected coronary obstructions is apparent.

Angiography↗

Repair of pectus excavatum by sternal eversion.

Pectus excavatum was repaired by the sternal eversion (turnover) technique in 26 patients over a 7-year period. Vascular supply to the sternal graft was maintained by preservation of one internal mammary vascular pedicle. Good results were obtained in 21 (81%) patients followed for periods ranging from 2 to 76 months (mean, 32 months) postoperatively. Four patients (15%) had fair results; 2 patients with Marfan's syndrome had partial recurrence, as did 1 patient with skin necrosis and 1 with hypertrophic scar. One patient (4%) had a poor early result due to wound infection and distal sternal necrosis requiring reoperation. Other complications were minor: superficial wound seroma in 2 patients and pneumothorax in 1. The sternal eversion technique for repair of pectus excavatum utilizes the concave shape of the sternum when turned over to create a cosmetically acceptable convex anterior chest wall contour. Judicious tailoring of the costal cartilages and shaping of the anterior sternum corrects asymmetrical deformities. The chest wall is very stable after repair. Since no prosthetic struts or pins are used, a second operation for removal is avoided. Preservation of the vascular supply to the sternum should allow normal growth of the anterior chest wall. The results have been sufficiently encouraging for us to recommend sternal eversion as the primary method for repair of pectus excavatum.

Adolescent↗

The value of lesion cross-sectional area determined by quantitative coronary angiography in assessing the physiologic significance of proximal left anterior descending coronary arterial stenoses.

The results of previous work from this laboratory have shown a poor correlation between percent stenosis (determined visually with calipers) and the coronary reactive hyperemic response (an index of maximal coronary vasodilator capacity) determined during cardiac surgery. This study was performed to determine whether other parameters of lesion severity could predict the reactive hyperemic response and thus the hemodynamic significance of coronary stenoses in human beings. Twenty-three patients with lesions in the proximal left anterior descending coronary artery were studied. To account for differences in expected vessel size, patients with large diagonal branches (greater than one-half the diameter of the left anterior descending artery) arising before the lesion were excluded. Computer-assisted quantitative coronary angiography was used to measure percent diameter stenosis, percent area stenosis, and minimal stenosis cross-sectional area. With a pulsed Doppler velocity probe, reactive hyperemic responses were recorded after a 20 sec coronary occlusion of the left anterior descending artery at cardiac surgery before cardiopulmonary bypass and were quantified by the peak/resting velocity ratio (normal greater than 3.5:1). Percent area stenosis ranged from 7% to 54% for vessels with normal reactive hyperemic responses and from 27% to 94% for vessels with abnormal reactive hyperemic responses. With both percent diameter stenosis and percent area stenosis there was substantial overlap between vessels with normal and abnormal reactive hyperemic responses. In contrast, nine of nine vessels with normal reactive hyperemic responses had lesion minimal cross-sectional areas of greater than 3.5 mm2 and 13 of 14 vessels with abnormal reactive hyperemic responses had minimal cross-sectional areas of less than 3.5 mm2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Aortic atresia: morphologic characteristics affecting survival and operative palliation.

A quantitative anatomic study of 54 cardiac specimens with aortic atresia is related to surgical treatment of patients with aortic atresia and hypoplastic left heart syndrome. Coarctation of the aorta was present in 80% of patients with aortic atresia and should influence the extent of aortic arch reconstruction when present. Other associated cardiac defects were uncommon but, when present, may be contraindications to operative palliation because of added complexity of the operation. Anatomic abnormalities of the tricuspid or pulmonary valve were present in 7% of cases and could be important in the outcome of palliative procedures. Natural survival was related to thickness of the right ventricular wall so that selection of those infants with thicker and better functioning right ventricles may improve short-term and long-term operative results in aortic atresia.

Aortic Coarctation↗

Coarctation of the aorta in infants.

Repair of coarctation of the aorta in the first year of life by resection and end-to-end anastomosis has been reported to have a high rate of recurrence, and recent studies favor angioplasty techniques. Forty-seven consecutive infants less than 1 year of age who were operated upon over a 20 year period were analyzed. The hospital mortality was analyzed in three groups: Group I--two of 11 patients (18%) with coarctation; Group II--one of nine patients (11%) with coarctation and ventricular septal defect; Group III--12 of 27 patients (44%) with coarctation and major intracardiac anomalies. There was no difference in age or body surface area between survivors and nonsurvivors. Repair was performed by a resection and end-to-end anastomosis to the distal aortic arch in 43 and by patch angioplasty in four. Anastomosis was performed with 5-0 silk suture prior to 1972. Since then, 7-0 polypropylene suture has generally been used. Arm/leg pressure gradient was assessed at rest by the Doppler technique in 31 long-term survivors of the end-to-end anastomosis technique; 24 of them had polypropylene suture used and seven had silk suture. Recurrence of coarctation was defined as arm/leg gradient greater than or equal to 20 mm Hg. Actuarial freedom from recurrence at 5 and 10 years was 91% in the polypropylene group versus 57% and 44% in the silk group. Good long-term results with low incidence of recurrent coarctation achieved by end-to-end anastomosis with fine polypropylene suture justify continued use of this technique in preference to angioplasty techniques, which sacrifice the left subclavian artery or introduce prosthetic materials. Techniques chosen for coarctation repair should be compared with current operative techniques and not older studies.

Age Factors↗

Abnormalities in the coronary circulation that occur as a consequence of cardiac hypertrophy.

Myocardial ischemia is frequently observed in patients with cardiac hypertrophy even when the conduit coronary arteries are normal. Recent studies indicate that impaired coronary reserve in hypertrophied hearts probably occurs because growth of the coronary bed does not keep pace with increases in cardiac mass. The imbalance between vascular proliferation and muscle growth is probably most severe when cardiac hypertrophy is produced by pressure overload. Experimental studies also suggest that abnormalities intrinsic to pressure-hypertrophied heart muscle (decreased capillary density; decreased coronary reserve; electrophysiologic abnormalities) adversely affect the response of the enlarged heart to sudden coronary occlusion. When animals with hypertension and left ventricular hypertrophy are subjected to sudden coronary occlusion, the incidence of sudden cardiac death is increased severalfold and infarct size is substantially augmented. These observations suggest that abnormalities in the coronary microcirculation that accompany cardiac hypertrophy play a significant role in the pathogenesis of the complications associated with cardiac hypertrophy.

Animals↗

Coronary artery bypass surgery in the elderly.

One hundred fifteen patients over 65 years of age were operated on at our institution for coronary artery bypass grafting (CABG). The operative mortality was 5% compared with an overall operative mortality of 2.5% in the last five years for 1,500 persons with CABG. Increased risk factors included qualification for New York Heart Association (NYHA) class IV, ejection fraction of less than 35%, diffuse disease requiring more than five grafts, and age over 75 years. At one year after operation, 81% of the patients were clinically improved, and the survival rate was 91%. Patients over 65 years of age in NYHA classes II and III with good left ventricular function requiring four or less bypass grafts appeared to have an excellent prognosis both acutely and during a one-year follow-up period.

Age Factors↗

Total anomalous pulmonary venous connection.

Total anomalous pulmonary venous connection (TAPVC) was repaired by operation in 20 infants during a 101/2-year period (1972 to 1983). Five patients died following operation. Factors that most affected mortality were the condition of the patient prior to repair, the year of operation, and the technique used for repair. Operative mortality before 1976 was significantly different from that after 1976 (57% [4/7] versus 8% [1/13], respectively; p less than 0.04). Prior to 1976, the several techniques used for anastomosis of the left atrium to the common pulmonary vein involved displacement of the heart from its anatomical position. After 1976, a standard approach using a right atriotomy for access was adopted for all such repairs. Intracardiac type of TAPVC was repaired by pericardial patch to direct blood flow through the atrial septal defect to the left atrium. Supracardiac and infracardiac types were repaired by enlarging the atrial septal defect so that a transverse incision through the back of the left atrium was exactly overlying the pulmonary vein posteriorly. A large anastomosis of the left atrium and common pulmonary vein was made with the heart in its natural anatomical position, which eliminates the possibility of distortion of the anastomosis. A pericardial patch was used to close the atrial septal defect. This experience suggests that the right transatrial approach of creating an anatomically correct anastomosis of the left atrium to the common pulmonary vein is an important factor in reducing operative mortality in patients with TAPVC.

Cardiac Catheterization↗

Techniques to avoid injury of the conduction tissue during the surgical treatment of corrected transposition.

Sequential atrioventricular conduction may be maintained during surgery in most patients with corrected transposition of the great arteries by operative techniques that include: (1) closure of the ventricular septal defect to the left side of the ventricular septum through a right atrial-right atrioventricular valve exposure, and (2) spiral pulmonary outflow patch (with or without pulmonary valve replacement), which enlarges the outflow tract posteriorly combined with posterior subvalvular resection of fibromuscular outflow tract obstruction. These techniques place operative manipulation posterior to the pulmonary anulus and on the left side of the septum so as to preserve the conduction tissue, which is located anterior to the pulmonary anulus and on the anterior rim of the ventricular septal defect in corrected transposition of the great arteries.

Adolescent↗

Decreased coronary reserve: a mechanism for angina pectoris in patients with aortic stenosis and normal coronary arteries.

The pathogenesis of angina pectoris in patients with aortic stenosis and normal coronary arteries remains uncertain. Using a specially designed Doppler probe, we measured the maximal velocity of coronary blood flow in the left-anterior descending coronary artery at the time of elective open-heart surgery in 14 patients with aortic stenosis and left ventricular hypertrophy (13 had angina) and in 8 controls without left ventricular hypertrophy. The ratio peak velocity of coronary blood flow, after a 20-second occlusion, to resting velocity was decreased by more than 50 per cent (P less than 0.05) in the patients with aortic stenosis. In 7 of the patients this ratio was decreased by more than 75 per cent. Studies of the velocity of coronary blood flow in vessels perfusing the right ventricle in these patients showed only mild abnormalities. These data demonstrate a selective and marked decrease in coronary reserve to the hypertrophied left ventricle in patients with severe aortic stenosis. The impairment in coronary reserve is probably an important contributor to the pathogenesis of angina pectoris in these patients.

Aged↗

Communicating hydrocephalus secondary to venous complications following intraatrial baffle operation (mustard procedure) for d-transposition of the great arteries.

A 39-month-old male had macrocephaly and communicating hydrocephalus secondary to superior vena cava (SVC) obstruction which was a postoperative complication of an intraatrial baffle operation (Mustard procedure) performed at age 10 months. Computerized tomography revealed progressive hydrocephalus. Cardiac catheterization showed an SVC pressure of 24 mm Hg. IVC and systemic vein atrium pressures were 5 mm Hg. Cineangiograms showed huge azygos collaterals from SVC to IVC. The operation was revised using a Dacron baffle instead of the original pericardial baffle. Nine months postoperatively, the head circumference was 55.0 cm and there was no clinical evidence of SVC obstruction.

Child, Preschool↗

Repair of large ventricular septal defects in infants and small children.

It is possible to achieve excellent results for primary closure of ventricular septal defects regardless of the age of the patients when surgical intervention is required. Thirty-two severely symptomatic patients, age 1-24 months, with large ventricular septal defects (m Qp/Qs = 3.4, m R VSD = 4.0), had primary repair of the defects with one (3%) hospital death. Seven patients (22%) had increased pulmonary vascular resistance ranging from 5.4 to 12 units/m2. It was possible to close the ventricular septal defect through the right atrium in 26 patients (81%). Pulmonary artery banding was not performed in any patient with isolated ventricular septal defect during the period of this study. The 31 survivors have been followed an average of four years, and 30 of them are remarkably improved and remain New York Heart Association Class I or II. Only one patient, with obstructive pulmonary vascular disease (pulmonary resistance = 12 U/m2), died suddenly 16 months after operation. Follow-up catheterization was offered to all patients, and to date, 18 (60%) have been restudied. These hemodynamic data show that pulmonary vascular resistance after surgery is usually normal or only minimally elevated; except for one patient with a large residual ventricular septal defect, functionally significant left to right shunts were eliminated. These results and the analysis of results of combined series reported in the literature for primary and staged operations for the continued practice of primary repair of isolated large ventricular septal defects in infants and children who require surgery.

Age Factors↗

Vasomotor dynamics associated with cardiac operations. I. Venous tone and the effects of vasodilators.

Vasomotor dynamics were studied in 52 patients undergoing direct coronary revascularization or mitral valve replacement utilizing cardiopulmonary bypass. Emphasis was placed on the study of venous tone. Operation resulted in a general vasoconstrictive response with increased arterial resistance and reduced venous capacitance. These changes were magnified in patients who underwent mitral valve replacement for mitral valve stenosis related or partially related to reduced cardiac performance before and after operation. Nine patients became hypertensive following coronary artery bypass and were treated with nitroprusside; eight patients were given nitroglycerin to reduce venous tone and prevent hypertension. A comparison of these two vasodilators, with their somewhat different actions on the vascular bed, reveals that afterload reduction and increase of cardiac output were equivalent with both. However, nitroglycerin had the effect of increasing venous capacitance, while nitroprusside had little effect on the venous circulation. In addition, nitroglycerin was especially effective in reducing venous tone and left ventricular preload following mitral valve replacement. Relative merits of pharmacologic reduction of venous tone as a part of overall relief of increased vascular resistance following cardiac operation should be considered when attempting to obtain an optimal hemodynamic state.

Adult↗