Studies of blood flow in aorta-to-coronary venous bypass grafts in man.

Pressure-flow measurements were obtained from the vein graft of 57 patients undergoing a single aorta-to-coronary bypass procedure. The flow contour was similar to phasic left coronary artery flow in dogs except for a transient increase during systole possibly related to elongation of the graft. Flow was highest during bypass and decreased to a stable value 30 min after bypass. In 42 patients, flow at this time was 35+/-2 cm(3)/min (mean+/-sem).NO CORRELATIONS WERE DEMONSTRATED BETWEEN FLOW AND THE FOLLOWING: left vs. right grafts, presence or absence of collaterals, total vs. partial block, or the presence or absence of ventricular dyskinesis. In 32 patients, no correlation between these anatomic findings and the presence of reactive hyperemia was demonstrated. In 17 patients, occlusion of the graft for 10 sec resulted in a mean 51.5% flow debt repayment. In nine patients, injection of 0.3 mug of isoproterenol into the graft increased flow from 45+/-6 to 69+/-9 cm(3)/min within 4-7 sec without changes in rate, pressure, time derivative of left ventricular pressure (LV dp/dt), or left ventricular end diastolic pressure (LVEDP). Maximum increases to 87+/-10 cm(3)/min occurred 12-20 sec after injection with concomitant changes in these parameters. Intravenous infusion of norepinephrine did not change vascular resistance, whereas phenylephrine did. In six patients, injection of 0.2 mug of norepinephrine into the graft decreased flow from 49+/-6 to 25+/-5 cm(3)/min within 5-8 sec. Intravenous infusion of 0.15 mg of nitroglycerin decreased coronary vascular resistance from 2.7+/-0.4 to 2.3+/-0.3 mm Hg/cm(3) per min. In five patients, 0.12 mg of nitroglycerin injected into the graft increased flow from 46+/-7 to 71+/-13 cm(3)/min and lasted 20-40 sec.

Utility of echocardiography in the management of patients with penetrating missile wounds of the heart.

Nine consecutive patients with penetrating missile wounds of the heart were evaluated by M-mode and two-dimensional echocardiography for localization of retained missile fragments noted to be moving in synchrony with the heart by fluoroscopy. Echocardiography precisely located all 12 moving fragments: 2 in the pericardium, 5 in the anterior right ventricular wall, 3 in the free left ventricular wall, 1 in the interventricular septum and 1 in the right posterior atrioventricular groove. Five patients had echocardiographic evidence of pericardial effusion and only one manifested a wall motion abnormality, indicating that direct myocardial perforation does not always result in detectable intrapericardial bleeding or asynergy. Localization of the missile fragments to be in danger of endocardial perforation, in danger of eroding the right coronary artery and creating a clinically unsuspected membranous ventricular septal defect led directly to surgical intervention in three different patients. In all three, intraoperative echocardiography quickly localized the missile fragments and significantly reduced patient cardiopulmonary bypass time. In the remaining six patients, localization of missile fragments well within the myocardium with no danger of erosion led to decisions against surgical removal.

Effect of increases in afterload before and after coronary occlusion in awake dogs.

Ventricular function curves relating stroke work and left ventricular end-diastolic pressure were generated in awake dogs during increases in preload produced by infusion of fluid and during increases in afterload produced by administration of phenylephrine. The ventricular function curves produced by preloading were steeply upsloping whereas those produced by afterloading were essentially horizontal. Coronary occlusion produced downward displacement of these horizontal curves, but no change in slope. This increases in afterload did not help to demonstrate the functional impairment produced by coronary occlusion.

Thoracoabdominal ectopia cordis with mosaic Turner's syndrome: Report of a case.

A child was treated for thoracoabdominal ectopia cordis and an associated chromosomal defect. Contrary to most cases in which death is due to the externally situated heart and abdominal viscera, this patient died from congenital heart disease.

Relation between QRS changes and left ventricular function after coronary artery bypass grafting.

Preoperative and serial postoperative electrocardiograms (ECGs) were reviewed in 104 patients undergoing rest and exercise radionuclide angiocardiography before and 1 to 12 months after coronary artery bypass grafting (CABG). Five patient groups were defined by ECG findings before and after CABG: Group I--normal ECG before and no ECG change after CABG; Group II--prior myocardial infarction by ECG before but no QRS change after CABG; Group III--all patients with a minor QRS change (less than 0.04-second Q wave, loss of R-wave amplitude) after CABG; Group IV--all patients with a major QRS change (greater than or equal to 0.04-second Q wave) after CABG; Group V--all patients without new Q waves or loss of R-wave amplitude but with a major QRS change (conduction disturbance) after CABG. Mean resting ejection fraction changed little after CABG in all groups, although the 0.03 increase in Group I was significant (p less than 0.05). Group IV had the largest decrease in resting ejection fraction after CABG (0.04), but this was not statistically significant. Mean exercise ejection fraction increased significantly (p less than 0.0001) in Groups I, II and III but not in Groups IV and V. QRS changes do not consistently reflect impairment of left ventricular (LV) function after CABG.

Performance status and outcome after coronary artery bypass grafting in persons aged 80 to 93 years.

Although coronary artery bypass grafting (CABG) effectively eliminates or diminishes symptoms of myocardial ischemia, the overall performance status and functional outcome in elderly patients undergoing CABG is poorly documented. Therefore, 86 consecutive patients aged 80 to 93 years undergoing isolated CABG were reviewed. Preoperative, intraoperative, and postoperative characteristics and pre- and postoperative performance status (Karnofsky score) were examined. Forty patients (47%) were women, and most patients had highly symptomatic coronary artery disease with class III or IV angina in 94% and unstable angina in 90%. Significant co-morbid disease was present in 49% of patients, and cardiac catheterization revealed left main or 3-vessel disease in 74% of patients. The rate of significant in-hospital complications was 29%, with infection in 14%, stroke in 9%, and respiratory failure in 8% being most frequent. Median performance status (Karnofsky score) improved from 20 to 70% (p = 0.0001) with 89% of hospital survivors being discharged home. Factors associated with failure to achieve a successful functional outcome at discharge were presence of 1 or more preoperative co-morbid conditions (p = 0.048), preoperative myocardial infarction within 7 days of operation (p less than 0.01), and postoperative low cardiac output (p less than 0.01). Survival at 30 days, 6 months, and 3 years were 90, 78, and 64%, respectively. These data demonstrate that CABG can be offered to selected elderly patients with acceptable morbidity and mortality, marked improvement in performance status, and an acceptable quality of life.

Origin of the left coronary artery from the pulmonary artery in older adults.

Origin of the left coronary artery from the pulmonary artery is usually a serious clinical problem; untreated, it often causes death. Usually the condition becomes symptomatic early in life, but occasionally symptoms do not manifest until later in childhood. A smaller group will not have symptoms until early adulthood. Rarely, this lesion may be asymptomatic for decades. The reports in the literature and our experience with surgical correction of this condition in patients in their sixth and seventh decades of life are described. One patient is the oldest reported in the world literature to have this condition.

Management of benign and malignant lesions of the trachea and bronchi with the neodymium-yttrium-aluminum-garnet laser.

Fifty patients with lesions of the trachea or bronchi have been treated with the neodymium-yttrium-aluminum-garnet laser. Forty-three patients had advanced carcinoma of the lung with pulmonary infection or abscess distal to an obstructing bronchial lesion or else had hemoptysis. Benign lesions were seen in seven patients. A total of 72 laser treatments were administered for obstruction and/or hemoptysis. There was no significant morbidity and only one hospital death occurred, which was unrelated to the laser therapy. Among the 43 patients with malignant disease, obstructive complications and hemoptysis were controlled in 39. All those with benign lesions have been significantly improved. Presently 22 patients with malignant disease remain alive and are symptomatically improved. The longest survival after successful laser treatment has been 73 weeks, and 34 survived longer than eight weeks. This laser is a very effective means of managing patients with benign lesions and offers significant palliation for patients with hemoptysis and advanced obstructing carcinoma of the trachea or main-stem bronchus.

Extraction of intramyocardial foreign body utilizing operative ultrasonography.

Technical advances in cardiac surgery have made accessible previously remote regions within the heart and great vessels; nevertheless, limitations in the ability to locate intramyocardial foreign bodies with precision utilizing conventional radiographic techniques, together with the frequent inability to palpate a foreign body located within the walls of the heart chambers, has dampened early enthusiasm for their removal. Despite this, the recognized complications associated with nonoperative management continue to militate for an aggressive approach. The following case illustrates the use of operative high-frequency ultrasonography in the exact localization of an intramyocardial foreign body. The precision thus afforded minimizes operative time, confines the size of the necessary ventriculotomy, and greatly facilitates successful removal.

The role of bronchoplastic procedures in the surgical management of benign and malignant pulmonary lesions.

Conservative pulmonary resection is appropriate for the majority of patients with endobronchial neoplasms of low-grade malignant potential in the proximal airways and for a small but significant number of patients with carcinoma. A portion of the bronchus is removed, with or without lobectomy, as a sleeve resection and a primary bronchial reanastomosis is performed to preserve ventilatory function. Bronchoplastic techniques can also be used to repair traumatic airway injuries and benign strictures. The present series of bronchoplastic procedures consists of 28 patients undergoing operation with pathological diagnoses of carcinoma in 20, adenoma in six, hamartoma in one, and a post-traumatic laceration in one. There were minimal morbidity and no deaths. From 1947 to 1981 a total of 565 bronchoplastic procedures have been reported in the literature. Of these, 504 were sleeve resections for carcinoma. The remaining 61 bronchoplastic procedures were for either excision of endobronchial adenomas or repair of airway injuries of strictures. It appears that bronchoplastic procedures are the ideal surgical therapy for benign endobronchial lesions, tumors of low-grade malignant potential, such as adenomas, and for repair of airway injuries. This approach is also applicable to a select group of patients with carcinoma of th lung, and long-term survival periods comparable to those achieved by pneumonectomy can be demonstrated.

Noninvasive assessment of the effects of aorta-coronary bypass grafting on ventricular function during rest and exercise.

Ventricular function was measured by radionuclide angiocardiography during rest and exercise in patients before and approximately 4 months after aorta-coronary bypass grafting. The first group of seven patients continued to have symptomatic chest pain after operation. The second group of 13 patients were asymptomatic after operation but, since they had been studied before operation, consented to postoperative study. Before operation, both patient groups demonstrated similar degrees of myocardial ischemia during exercise as documented by a decrease in ejection fraction, by large increases in end-diastolic and end-systolic volumes, and by exercise-induced wall motion abnormalities. After aorta-coronary bypass grafting, ventricular function in the symptomatic patients was unchanged during rest and exercise. In contrast, ventricular function during rest and exercise in the asymptomatic patients was markedly improved. With exercise, the ejection fraction increased and the exercise-induced wall motion abnormalities seen before operation were abolished. Therefore, aorta-coronary bypass grafting can effectively reverse exercise-induced left ventricular dysfunction in patients with coronary disease. Moreover, the change in left ventricular function demonstrated by radionuclide angiocardiography correlated with the clinical status of the patient groups.

Electron microscopy in selection of patients with small cell carcinoma of the lung for medical versus surgical therapy.

Fifty-one cases of small cell carcinoma of the lung were studied by electron microscopy in order to determine if ultrastructural subsets could be found and if these subsets predicted clinical behavior. All of these cases were considered bona fide small cell carcinoma of the lung by light microscopy. Tumors with ultrastructural features of epithelial differentiation were defined by the presence of well-formed, classic desmosomes joining adjacent cells and by additional features of squamous or glandular differentiation. Thirty-one tumors (60%) were considered "typical oat cell" by electron microscopy and 20 (40%) showed features of epithelial differentiation. Fifteen (75%) tumors with epithelial features were considered operable and nine (45%) were resected with curative intent. In contrast, 26 (84%) tumors considered typical oat cell by electron microscopy presented with extensive metastatic disease. The cancer-free 5-year actuarial survival rate of patients whose tumors showed features of epithelial differentiation was 25%. The actuarial survival rate of nine patients who underwent resection of tumors with epithelial features was 38% at 5 years. Only one patient whose tumor was considered typical of oat cell carcinoma by electron microscopy survived 5 years. Our current recommendation is to remove all clinically resectable pulmonary neoplasms with the expectation that these localized small cell tumors are likely to show epithelial features by electron microscopic analysis.

Coronary collateral blood flow in acute myocardial infarction.

The evolution and transmural distribution of coronary collateral blood flow in acute myocardial infarction was determined in 24 trained, unanesthetized dogs by injection of radioactive microspheres into the coronary circulation. Acute coronary artery occlusion resulted in a greater decrease in subendocardial flow than subepicardial flow in both the central and marginal zones of the infarct. Coronary collateral blood flow was distributed primarily to the marginal zone and to the subepicardium of the central zone of the infarct. The greatest increase in collateral flow occured between 12 and 18 hours after coronary artery occlusion. By 24 hours after coronary occlusion, blood flow to all areas of the infarct except the subendocardium of the central zone had returned to near control levels. This dispropotionate distribution of coronary collateral blood flow during the early stages of myocardial ischemic injury helps to explain the apparent lack of protection of the subendocardium by collateral flow.

Noninvasive assessment of exercise cardiac function before and after pectus excavatum repair.

Surgical correction of pectus excavatum frequently results in subjective improvement of exercise tolerance. Whether or not cardiac function improves after repair remains controversial and has primarily been limited to isolated case reports. The purpose of this investigation was to assess changes in cardiac function during rest and exercise associated with the surgical correction of this deformity. First-pass radionuclide studies during upright rest and bicycle exercise were performed on 13 patients before and at least 6 months after pectus excavatum repair. Operation did not change left ventricular ejection fraction or cardiac index at rest or during exercise. However, the left ventricular end-diastolic volume index and stroke volume index increased at rest after surgical correction. The estimated resting right ventricular end-diastolic volume also increased markedly after operation and was associated with a decrease in right ventricular ejection fraction. These data show no limitation in exercise cardiac function that could be relieved by pectus repair. However, the increase in right and left ventricular volume after operation suggests that some cardiac compression is relieved by operative repair.

Coronary collateral circulation during stress and the effects of aorta-coronary bypass grafts.

The ability of coronary collateral vessels to supply an adequate volume of blood to the subendocardium during the resting state and during periods of stress was studied. Regional myocardial blood flow was determined by the radioactive microsphere technique. Ameroid constricting devices were placed around the left circumflex coronary artery in 22 adult mongrel dogs. Three months later, regional myocardial blood flow was measured in a normal area of the left ventricle as well as in the area supplied entirely by coronary collateral vessels. Collateral blood flow was sufficient in the resting state to prevent myocardial ischemia distal to a gradually occluded coronary artery. However, in 10 animals (Group I) without aorta-coronary bypass grafts (ACBG), a selective underperfusion of the collateralized subendocardium occurred during periods of stress. In 12 animals (Group II), this selective underperfusion of the collateralized subendocardium with stress was abolished by placing ACBG's distal to the site of the coronary artery occlusion.

The effect of positive end-expiratory pressure on regional ventilation and perfusion in the normal and injured primate lung.

Although positive end-expiratory pressure (PEEP) is being employed in the management of respiratory insufficiency, many of its physiological effects remain undetermined. The cardiopulmonary effects of PEEP as well as its effect on regional ventilation and perfusion were studied in 10 baboons before and after pulmonary injury with oleic acid. In the normal lung, there was significant improvement in oxygenation at a PEEP of 5 cm. of water secondary to improved ventilation and perfusion in all PEEP greater than 5 cm. of water produced increasing mismatch of ventilation and perfusion in all zones. After oleic acid was injected, hypoxemia was evident with a reversal of the normal ventilation-perfusion (V/Q) relationship between upper and lower lung zones. This mismatch of ventilation and perfusion was corrected at a PEEP of 15 cm. of water. It was reasonable to conclude that the use of PEEP in the injured lung exerts it beneficial effect by balancing regional ventilation and perfusion in addition to increasing functional residual capacity.

Intraoperative prebypass and postbypass epicardial color flow imaging in the repair of atrioventricular septal defects.

The use of intraoperative epicardial Doppler echocardiography with color flow imaging both before and after cardiopulmonary bypass to assist repair of congenital heart defects in infants and small children has not been reported. To demonstrate its simplicity and utility, we obtained immediately prebypass and postbypass examinations from 18 consecutive patients undergoing repair of atrioventricular septal defects between March 1987 and March 1988 (aged newborn to 3 years, smallest 2.4 kg, 11 patients less than 1 year old). Direct application of a sterile transducer to the epicardial surface eliminates any restriction imposed by the transesophageal approach, and the routine use of color flow imaging enables the operating surgeon to directly evaluate intracardiac anatomy and flows in a variety of orientations. Average examination time was 3.95 +/- 1.96 minutes. Prebypass studies disclosed that a short-axis inspection through the common atrioventricular valve orifice produced a unique visualization of the dynamic commitments of atrioventricular valve tissue throughout systole and diastole that was helpful in planning valve allocation during repair. In addition, echocardiography demonstrated features not previously appreciated in seven of 18 patients (39%). In all, image quality and resolution were vastly superior to preoperative chest wall studies. Postbypass studies revealed significant residual interventricular shunts in two of 18 patients (11%). Views obtained from various orientations directed specific and efficient repair immediately so that all patients left the operating room with documented, surgically acceptable results. Comparison of ventricular function between prebypass and postbypass studies enabled appropriate application of pharmacologic agents in the operating room if necessary. All patients survived their operation. There have been two late deaths, and 16 patients are alive and doing well (follow-up: 9 to 21 months). These experiences indicate that intraoperative epicardial Doppler color flow imaging (1) can be easily learned and applied by the surgeon, (2) enhances the repair of atrioventricular septal defect by providing unique spatial, anatomic, and flow information in the beating heart at the time of repair, (3) increases confidence of a surgically acceptable repair before the patients leave the operating room, (4) guides specific surgical or anesthetic adjustments to optimize results, and (5) works as a valuable aid that may help reduce poor results in the repair of complex congenital cardiac lesions.

Measurement of global ventricular function in patients during cardiac operations using sonomicrometry.

In these studies, we evaluated the applicability of pulse-transit sonomicrometry for measuring changes in global cardiac activity in patients during cardiac operative procedures. In six patients two epicardial ultrasonic crystals (8 mm) were sutured across the left ventricular minor axis. Diastolic pressure-length data were recorded as left ventricles were filled passively to transmural pressures (P) from 0 to 20 mm Hg. Data were collected at the beginning of cardiopulmonary bypass and again 15 minutes following periods of induced global ischemia (29.8 +/- 0.8 minutes). Minor axis length data were normalized to Lagrangian strain (epsilon), and best-fit regression curves were obtained from P-epsilon by computer analysis. Nonlinear elastic constants, alpha and beta, were mathematically derived as additional curve descriptors. Decreases in ventricular compliance were demonstrated as leftward shifts in both computed and measured P-epsilon curves. Global ischemia appeared to effect a decrease in overall ventricular diastolic compliance in all patients studied (p =7E 0.01 at 5, 10, 15, 20 mm Hg). Simultaneously, no statistical change occurred in lo (62.93 +/- 2.80 mm), which represented end-diastolic length (EDL) at 0 mm Hg transmural pressure. Following coronary grafting several patients showed augmented systolic excursion when compared at similar EDL. For those analyses, shortening was compared at specific minor axis EDLs rather than filling pressures. These data indicate that experimentally developed sonomicrometry may safely provide accurate indices of systolic and diastolic ventricular properties during operations necessitating cardiopulmonary bypass. Thus various cardioplegic solutions, ischemic arrest periods, and inotropic agents may be evaluated more objectively.

Calcitonin gene-related peptide enhances the recovery of contractile function in stunned myocardium.

INTRODUCTION: Calcitonin gene-related peptide, a potent vasodilating inotropic agent, increases coronary artery perfusion when administered exogenously and reduces ischemic injury in nonmyocardial tissue. However, it is unclear whether this agent improves recovery of myocardial performance after reversible myocardial ischemia. METHODS: Nine dogs underwent complete occlusion of the left anterior descending coronary artery for 15 minutes and were monitored during 24 hours of reperfusion. Calcitonin gene-related peptide (0.07 microgram. kg(-1). min(-1)), nitroglycerin (65 microgram. kg(-1). min(-1)), or saline solution placebo was infused intravenously during initial reperfusion. Ischemia/reperfusion was repeated in concurrent 24-hour periods until all animals received infusions in random order. Micromanometry and sonomicrometry determined left ventricular pressure and myocardial segment length. Myocardial performance, based on the linear relationship between stroke work and end-diastolic segment length, was estimated with the preload recruitable work area. Results were analyzed as percent control and compared statistically with the use of repeated measures analysis of variance. RESULTS: Recovery of myocardial performance was augmented during reperfusion with calcitonin gene-related peptide infusion relative to placebo

Noninvasive assessment of hemodynamic effects of mitral valve commissurotomy during rest and exercise in patients with mitral stenosis.

Noninvasive radionuclide angiocardiography (RNA) provides simple and accurate assessment of parameters of cardiac function during rest and during maximal exercise. Left ventricular function was assessed by RNA in nine patients with isolated mitral stenosis before and approximately 6 months after mitral commissurotomy. Before operation, the mean mitral valve gradient was 14.0 +/- 2.8 mm Hg, and the mean mitral valve area was 1.20 +/- 0.3 cm2. Each patient was evaluated at rest and during maximal exercise on an isokinetic bicycle ergometer before and after commissurotomy. Heart rate, ejection fraction, end-diastolic volume, stroke volume, pulmonary transit time, cardiac output, and diastolic ventricular filling rate were determined by the radionuclide technique. Before operation, patients with mitral stenosis had characteristic changes from rest to exercise which supported restriction to diastolic ventricular filling as the primary limitation in generating a cardiac output during exercise. The stroke volume was unchanged from rest to exercise. Thus the cardiac output during exercise was heart rate dependent. However, after commissurotomy the stroke volume increased from rest to exercise. Therefore, cardiac output during exercise was achieved by heart rate and an augmented stroke volume. Moreover, the pulmonary transit time was reduced during rest and exercise after operation. The maximum ventricular ejection and filling rates were markedly increased during rest and exercise after commissurotomy. These differences in hemodynamic parameters at rest and during exercise document the mechanics of increased exercise tolerance in patients with mitral stenosis after mitral commissurotomy.