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A total of six Maryland community college presidents were guided through conversations to identify the organizational challenges and uncertainties that have forced organizational changes in their respective colleges. Another thrust of the research was to discover what organizational change processes these presidents have implemented to overcome the challenges and to describe what leadership approaches they have used to lead change. Seven challenges, two general change process categories consisting of 12 different steps, and three leadership approaches emerged using a qualitative ethnomethodological research technique. The presidents' definitions of leadership and its essence, along with their leadership development experiences, are also presented.

The purpose of the present study is to quantitate the contribution of the thebesian veins to the total physiologic shunt in anesthetized man. The subjects were adults, free of septal defects, who were undergoing a variety of open-heart procedures for the correction of diseased valves. The studies were completed following thoracotomy but prior to the placement of catheters. Subjects were anesthetized, intubated, and ventilated with a constant-volume respirator. Prior to blood sampling 100% oxygen was administered for at least 3 min. Samples were simultaneously drawn from the left atrium and the aorta and analyzed for Po2 with a microelectrode which had been calibrated with tonometered blood. Only studies in which aortic Po2 exceeded 150 mm Hg were accepted. Pco2 and pH were also measured. From the difference in Po2 between left atrium and aorta the contribution of left ventricular thebesian veins to the physiologic shunt was calculated using a modification of the shunt equation. Values found ranged from 0.12 to 0.43% of the aortic flow. Mixed thebesian oxygen content was assumed to be 6 vol % in this calculation, but the value chosen can be shown not to be critical. physiologic shunt; A-a difference Submitted on November 30, 1964

DURING the past ten years there have been reports of a significant incidence of psychiatric symptoms after cardiac surgery using closed-heart technics. The incidence of psychosis has clearly been greater than the 1:1500 reported by Knox1 in his study of a large group of general-surgery patients. These cardiac-surgery reports2 3 4 5 indicated an overall incidence of psychosis ranging from 1 to 19 per cent. A particularly high incidence of psychotic symptoms has now been noted during the recovery period after open-heart surgery at the Columbia–Presbyterian Medical Center. The aims of this study were as follows: to elucidate the nature and incidence of . . .

Deep median sternotomy wound infection is a significant source of morbidity after cardiac operations. Accepted approaches in treating this complication include debridement with either sternal closure over an irrigation system or open dressings and closure by secondary intention. Muscle flaps are often used in subsequent procedures for wound closure. A single-stage procedure was developed to eliminate irrigation, open wound management, or reoperation for muscle flap closure. This approach consists of debridement and immediate closure with a pectoral musculocutaneous flap. The following report describes 31 patients treated by such a method. Compared with results of previous techniques in treating sternal wound infections, hospital study is decreased, fewer reoperations are needed, and patient management is simplified.

Twelve patients with cor triatriatum sinistrum were treated over a 28-year period. Their ages ranged from 1 month to 7.5 years. Congestive heart failure was the most common presentation. Cardiac catheterization was performed on six of the 12 patients and a correct diagnosis of cor triatriatum was made on angiography in only four of the six. Of the remaining six patients, three were diagnosed as having cor triatriatum by echocardiography and three by autopsy. Echocardiography is now considered to be the diagnostic modality of choice in our institution. Seven patients were operated on and five died prior to diagnosis or treatment. Associated cardiac anomalies included persistent left superior vena cava, atrial septal defects, coarctation of the aorta, and total anomalous pulmonary venous drainage. A right atrial, transseptal approach to the common pulmonary chamber and excision of the left atrial membrane was found to be the treatment of choice and was used in six of the seven patients operated on. One patient died in the postoperative period. Thus, cor triatriatum sinistrum, a rare and potentially lethal congential cardiac anomaly, can be diagnosed by echocardiography and successfully treated surgically with a low operative mortality.

Recent reports have shown that it is possible to record extracellular electrograms from the rabbit and dog sinoatrial (SA) node. We applied similar techniques to record SA nodal activity in 23 patients who underwent cardiac surgery for various forms of heart disease. Both a bipolar technique, using pairs of electrodes at various interelectrode distances, and a unipolar technique, using an exploring and an indifferent electrode, were used. To record SA nodal electrograms, polarity was reversed from the conventional electrocardiographic recording; high amplification (100 microV/cm) and low-pass filters (0.15-20 Hz) were used. SA nodal electrograms were recorded from eight of 12 patients using the bipolar method and from nine of 11 patients using the unipolar method. There were no significant differences in the success rate or quality of the recording between the two methods. However, the unipolar method allowed a more accurate localization of the SA node. Human SA nodal electrograms resembled those of the dog and rabbit and showed two distinct slopes: a diastolic slope and an upstroke slope preceding the P wave of the ECG, SA conduction times were 32.4 +/- 2.8 msec (mean +/- SEM) at sinus (PP) cycle lengths of 587.6 +/- 35.6 msec for the bipolar method, and 38.2 +/- 3.2 msec at sinus (PP) cycle lengths of 712.2 +/- 50.7 msec for the unipolar method. These methods for recording of extracellular SA nodal electrograms in man may prove useful in 1) localization of the SA node during open heart surgery and 2) assessment of SA nodal function in health and disease.

Hemodynamic effects of isoproterenol, dopamine, and epinephrine were studied before and after acute beta-adrenergic blockade in 16 open-chest, anesthetized mongrel dogs. Beta blockade was induced with 1 mg. per kilogram of intravenous propranolol. Cardiac output measurements were obtained by thermal dilution, and pressure recordings were obtained in the right ventricle, pulmonary artery, left atrium, left ventricle, and aorta. Derived parameters included stroke volume, pulmonary and systemic vascular resistances, and peak left ventricular dP/dt. In the presence of propranolol, epinephrine became a lethal drug in large doses and did not increase cardiac output in standard doses. Dopamine, in 25 to 50 mcg. per kilogram per minute doses, increased arterial pressure and systemic resistance; cardiac output was diminished compared with dopamine, 10 mcg. per kilogram per minute, prior to propranolol, as a result of increased resistance and decreased LV contractility. Isoproterenol, 0.6 to 0.9 mcg. per kilogram per minute, 15 to 20 times standard dosages, had moderately positive inotropic effects and increased cardiac output. Left ventricular systolic pressure with isoproterenol after propranolol was reduced when compared with effects of smaller doses prior to propranolol. These observations suggest that none of the catecholamines studied would be optimal for circulatory support in heart failure in the presence of propranolol. The present results define a pharmacologic basis for design of appropriate drug combinations for circulatory support in beta-blocked animals.

We used standard microelectrode techniques to study the effects of histamine on right atrial tissues from patients undergoing corrective cardiac surgery. In the 10(-6) to 10(-4) M range, histamine increased maximum diastolic potential, action potential amplitude, and automaticity. In some preparations, histamine also induced delayed afterdepolarizations and triggered activity. The potency of histamine in increasing automaticity was about 10 times less than that of epinephrine. Propranolol (2 x 10(-7)M), which abolished the chronotropic effect of epinephrine, did not alter the effect of histamine. Conversely, the effect of histamine but not that of epinephrine was antagonized by cimetidine (3 x 10(-6) to 1 x 10(-5) M). This suggests that H2 receptors mediate the chronotropic effects of histamine on the human heart. The slow channel blocker verapamil (2 x 10(-8) to 2 x 10(-6) M) counteracted the effects of histamine on automaticity, delayed afterdepolarizations, and triggered activity, suggesting that in human atrium histamine may act by increasing slow inward (presumably Ca2+) current. If one considers these arrhythmogenic effects of histamine and the fact that human cardiac tissue contains large amounts of histamine, our experiments lend further support to the concept that histamine release can induce arrhythmias.

To compare the hemodynamic effect of vasodilator therapy on different regurgitant lesions, we infused sodium nitroprusside intraoperatively in 12 patients with mitral regurgitation and 15 with aortic regurgitation. During the critical period preceding establishment of cardiopulmonary bypass, both groups had developed intense vasoconstriction and cardiac decompensation. All demonstrated improved cardiac function with vasodilator therapy; however, the degree of improvement with nitroprusside differed in the two groups. Stroke volume increased 10 ml. per beat per meter squared in those patients with aortic regurgitation and only 6 ml. per beat per meter squared in those with mitral regurgitation (p

Infants with ventricular septal defect (VSD) who are symptomatic despite intensive medical therapy require surgical intervention. Choice of treatment depends upon the cumulative mortality and morbidity rates of the two-stage approach of initial pulmonary artery banding followed by debanding and VSD closure as compared to the risk of primary intracardiac repair in infancy. Sixteen infants underwent pulmonary artery banding at Columbia-Presbyterian Medical Center between 1967 and 1976, with one operative death but with a significant incidence of morbidity and late death. Forty patients underwent pulmonary artery debanding and closure of VSD with three operative deaths. This second-stage procedure was frequently complicated by repair of acquired lesions. During the same 10 year period 37 infants underwent primary closure of VSD with eight operative deaths. The morbidity related to this procedure is low. With the use of profound hypothermia and circulatory arrest, results have significantly improved and the risk of early correction now compares favorably with the cumulative mortality rate of the two-stage approach. Primary intracardiac repair is the procedure of choice.

Perioperative hemodynamic changes following mitral valve replacement using the porcine heterograft prosthesis were measured in 21 patients with acquired mitral valve disease. Preoperatively, a state of compensatory cardiac failure was suggested by the following: an increased heart rate (HR) (96 beats per minute); low cardiac and stroke volume (SVI) indices (2.3 +/- 0.10 L/min/m2 and 25 +/- 2 ml/beat/m2); and increased systemic vascular resistance (SVR) (1,626 +/- 116 DYNE SEC CM-5). Bothe the mean pulmonary artery PAP) and pulmonary capillary wedge pressures (PCWP) were elevated as well (32 +/- 3 and 22 +/- 2 torr). Immediate hemodynamic improvement followed valve replacement. HR, SVR, PAP, and PCWP all decreased significantly. Twenty-four hours after valve replacement, PAP (23 +/- 1 torr) and PCWP (13 +/- 1 torr) demonstrated marked declines, SVR was reduced by one-third (1,173 +/- 87 dyne sec cm-5), HR had decreased by 10 beats per minute, and SVI had increased to 30 +/- 2 ml/beat/m2. The prompt circulatory improvement of patients soon after mitral valve replacement using the porcine heterograft compares favorably with studies in which other valve types were employed and in which postoperative cardiovascular depression was encountered frequently.

The Fontan procedure is often associated with elevated right-sided pressures and low cardiac output during the early postoperative period. A dog model was established to test the effect of pulmonary artery counterpulsation after atriopulmonary anastomosis. After exclusion of the right ventricle by a purse-string suture at the right AV orifice, placed during inflow occlusion, a valved conduit was inserted between the right atrial appendage and the pulmonary artery. This created a circulatory pattern comparable to a Fontan procedure. Counterpulsation was achieved by inserting a cannula into the conduit distal to the valve in eight dogs; alternatively, in four, counterpulsation could be achieved through a 10 mm side-arm graft connected to the conduit distal to the valve. Twenty-four observations were made. Without counterpulsation the circulatory status of the dog deteriorated rapidly. Counterpulsation resulted in a mean increase in cardiac output of 48% (p

The course of the His bundle proximal to membranous septum was electrophysiologically delineated during open-heart surgery in 80 patients: 21 patients with d-transposition of the great vessels, 19 with endocardial cushion defects, 12 with secundum atrial septal defect, 13 with tetralogy of Fallot, 7 with ventricular septal defect, and 8 with other congenital heart diseases. His bundle electrograms were found immediately adjacent to the atrioventricular (A-V) annulus in all patients. Electrograms of the His bundle were most commonly recorded along a line extending from the coronary sinus ostium toward the medial aspect of the tricuspid valve, starting 10 mm. anterior to the coronary sinus ostium on an area of 10 by 5 mm. in most patients with various forms of congenital heart disease. In most patients with endocardial cushion defects, His bundle electrograms were recorded immediately adjacent to the coronary sinus ostium, suggesting a posterior shift of the His bundle in these patients. This study correlates the anatomic location and the sites from which human His bundle electrograms are most commonly recorded. Also, because of the ease of the technique, its sensitivity, and the brief duration (3 to 5 minutes) required for the electrophysiological delineation of the His bundle, we think it prudent that this technique be used in all patients undergoing open-heart surgery in which the risk of injury to the His bundle is significant.

Fifteen patients with various congenital heart defects were studied during open heart surgery in order to establish the precise mechanism by which a right ventriculotomy causes a right bundle branch block (RBBB) pattern on the scalar electrocardiogram (ECG). All required a right ventriculotomy for the correction of their defects. In each, the right ventriculotomy was carried out in steps, with incisions (3 to 7) of approximately 1 cm in length. Six simultaneous scalar ECG leads were recorded prior to the first incision and following each incision. The QRS duration was then measured and related to the length of the ventriculotomy. Following the right ventriculotomy, 12 of the 15 patients developed an RBBB pattern; the remaining three did not. In all cases, the total increase in QRS duration occurred during one specific incision of the right ventricular free wall and was not related to the total length of the ventriculotomy or to the sequence of the incisions. The site at which incision of the right ventricle caused the RBBB pattern was located at between 40 to 73% of the distance between the pulmonary artery annulus and the inferior border of the heart in nine patients; in three patients the site was higher on the right ventricular free wall. Our results explain why some patients who had a right ventriculotomy during open heart surgery do not develop an RBBB pattern on the scalar ECG. Also, since no relation was found between the length of the incision and the QRS duration, our results suggest that the ventriculotomy-induced RBBB pattern is unlikely to be due to disruption of a continuous Purkinje network but is probably due to disruption of a distal branch or branches of the right bundle.

Clinical applications of counterpulsation and, in particular, of intra-aortic balloon pumping (IABP) have been successful in the management of refractory left ventricular power failure. Synchronous external counterpulsation has emerged as an appealing noninvasive form of temporary cardiac assistance. To evaluate this modality, we performed 30 experiments in 6 dogs by inducing hypo- and hypervolemic cardiogenic shock with propranolol (1.5 mg. per kilogram) and ligation of the left anterior descending coronary artery (LAD). Unidirectional dual-chambered balloons were positioned in the inferior vena cava (IVCBP) and in the descending thoracic aorta (IABP) of the same animal to simulate external counterpulsation, and two assist consoles were synchronized to the electrocardiogram. The results indicate that IVCBP is detrimental in hypovolemic cardiogenic shock and that these results can be reversed with the addition of IABP. In contrast, IVCBP alone in hypervolemic cardiogenic shock resulted in significant hemodynamic improvement. It is concluded that the primary hemodynamic effects of these experiments, in which the venous hemodynamics of external counterpulsation have been simulated, may be related in great part to venous diastolic augmentation and to the state of hydration.

Between 1971 and 1982, 249 patients received right heart extracardiac conduits. The 173 patients who survived 30 days were reviewed retrospectively; 72 had antibiotic-sterilized aortic homografts, 97 had xenografts of various types, and four had valveless tubes. Reoperation for conduit obstruction was required as early as 13 months after the original operation, but actuarial analysis showed no differences in overall performance of homograft and heterograft conduit groups with respect to late death or survival free of conduit obstruction. More important risk factors for late death or the need for reoperation were the severity of the underlying cardiac lesions and the influence of early postoperative complications. When analyzed statistically, the performance of conduits bearing homografts was disappointing, influenced sometimes by complications in the Dacron extension tubes. Repairs dispensing with conduits entirely should be evaluated.

Ultrastructural studies were performed on portions of the operatively resected right atrium from six patients with a ventricular septal defect and six patients with an endocardial cushion defect. The six patients with a ventricular septal defect had normal right atrial mean pressure and no evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients appeared normal and measured 6 to 12 mu in diameter. The six patients with an endocardial cushion defect had elevated right atrial mean pressure and evidence of right atrial volume overload. Ultrastructurally, the atrial muscle cells in these patients were generally larger than 12 mu in diameter. The cells were irregular and had multiple and occasionally widened intercalated discs. In addition, there were degenerative changes in two patients with markedly increased atrial pressure. These changes included extensive loss of contractile elements, aggregation of small irregular mitochondria and proliferation of tubules of the sarcoplasmic reticulum. The structural changes suggest that hypertrophy of the right atrium may be secondary to volume overload of the atrium, whereas degenerative changes may be secondary to increased right atrial pressure.

A method for signal enhancement of electrograms of the specialized atrioventricular conduction system is presented. This method allows a single, electrogram to replace the three tracings of bipolar electrograms previously required to ensure recognition of the specialized conduction system and yet maintains the safety afforded by use of three pairs of recording electrodes. In addition, this new signal is enhanced in magnitude and is always unidirectional (positive). These features are desirable for automated signal recognition. This method therefore provides an important step toward future automation and signal recognition of specialized conduction system electrograms during open-heart surgery.

Infants with pulmonary atresia and intact ventricular septum (PA-IVS) usually require urgent surgical intervention. Thirty patients with this anomaly, seen at the Columbia-Presbyterian Medical Center between 1962 and 1978, had palliative operations, 26 within the first 3 days of life. Six underwent a closed pulmonary valvotomy alone, with no survivors; six had only a systemic–pulmonary artery shunt, with three early survivors. Because of this experience, 17 had a combined procedure of valvotomy and shunt, with 14 early survivors. One patient recently underwent a definitive right ventricular outflow patch procedure with cardiopulmonary bypass. Eight patients subsequently have had corrective open-heart procedures, with five patients surviving from 2 to 10 years. A unicusp aortic homograft was used for repair in five and a Hancock valved conduit in three. Four patients are presently awaiting operation. We conclude that the initial surgical management of these critically ill infants must not only increase pulmonary blood flow but in addition provide an opportunity for right ventricular growth. Thus we continue to advocate the combined procedure of a valvotomy plus a shunt to provide adequate palliation. Repeat catheterization should be performed within a year to confirm the adequacy of the valvotomy, since this is essential to maximal right ventricular enlargement and to allow for definitive correction at a later date.

Ninety-four children ranging from 3 months to 19 years of age underwent cardiac valve replacement at Columbia Presbyterian Medical Center from 1965 to 1985. The overall operative mortality was 12%, but mortality was higher among patients less than 2 years of age, patients who had had previous cardiac operations, and patients requiring double-valve replacement. Seven of 11 patients who received mechanical valves and no anticoagulation experienced major thromboembolic events. An episode of gastrointestinal hemorrhage that was easily controlled represents the only bleeding complication in the entire series. Valve replacement in children continues to be a high-risk procedure, and efforts to preserve native valve function should be attempted when technically feasible. Our data also suggest that anticoagulation can be safely accomplished in the pediatric age group and should be employed in patients requiring placement of a mechanical prosthesis, especially in the mitral position.

Insertion of extracardiac right ventricular (RV)-pulmonary artery (PA) conduits for repair of severe forms of RV-PA discontinuity has become a widely used technique. During a 10-year period, 76 patients had open heart repair with a porcine-valved RV-PA external conduit. The most common diagnoses were truncus arteriosus (15%) and pulmonary atresia with ventricular septal defect (15%). The patients were 18 days to 37 years old (median 7 years). The postoperative median follow-up period was 4 years. Four patients (8%) have been lost to follow-up. Nineteen patients (25%) died in the early postoperative period and there were 10 late deaths (13%). Calculated probability of survival was 66% at 8 years. Thirty-six patients have undergone late hemodynamic studies. A residual shunt was present in 14% of the patients; moderate to severe PA hypertension was present in 25% and significant RV-PA gradients (greater than 30 mm Hg) in 50%. The mean RV pressure for the group was 78.5 +/- 38 mm Hg. The severity of the gradients appeared to be greater in patients who had been followed longer. Ten patients have undergone reoperation because of conduit obstruction or residual shunting; 6 are alive and well. Of the surviving patients, 95% are acyanotic and without significant exercise intolerance and only 5% have cardiovascular symptoms. Thus, open heart repair using an external RV-PA conduit provides a marked improvement in the quality of life in patients who survive.

In 31 dogs chronically beta blocked with oral propranolol (12 to 14 mg/kg/day), glucagon (20 ug/kg) and combined dopamine (10 ug/kg/min) and isoproterenol (0.2 ug/kg/min) were given intravenously and tested for hemodynamic efficacy. Dogs were divided into four groups. Basal hemodynamics were obtained in Group I (n = 8) without cardiopulmonary bypass. In Group II (n = 8), hemodynamics were studied after 15 minutes of global ischemia during cardiopulmonary bypass. In Group III (n = 8), hemodynamics were studied after regional ischemia produced by ligation of the proximal left anterior descending coronary artery. In Group IV (n = 7), myocardial oxygen consumption and left ventricular mechanics were studied before and after 1 hour of cardiopulmonary bypass. Our results indicate the following: (1) Dopamine-isoproterenol improves hemodynamics in basal, post-global ischemic, and post-regional ischemic states. Glucagon improves hemodynamics either insignificantly or to a lesser extent than dopamine-isoproterenol. Furthermore, glucagon produces a larger increase in heart rate, which is not desirable. (2) Both dopamine-isoproterenol and glucagon increase myocardial oxygen consumption in comparison with control.

Intra-aortic balloon pumping (IABP) is currently the supportive treatment of choice for the management of refractory left ventricular power failure. However, in the extremely low output state, IABP may be hemodynamically ineffective, and a more direct left ventricular assist is desirable. Left ventricular balloon pumping (LVBP) is an effective cardiac assist device in the experimental low output state. LVBP both alone and in combination with IABP was evaluated in an experimental canine cardiogenic shock preparation. With LVBP alone, significant improvement was seen in the following: mean aortic flow (AoF), +46.2 per cent; aortic pressure (AoP), +15.1 per cent; left ventricular stroke work (LVSW), +147.0 per cent; left ventricular dp/dt (LVdp/dt), +52.9 per cent; coronary sinus flow (CSF), +24.6 per cent; and myocardial oxygen consumption +25.2 per cent. There was a concomitant decrease in left ventricular end-diastolic pressure (LVEDP) -71.6 per cent and left atrial pressure (LAP) -62.7 per cent. The combination of LVBP and IABP showed further improvement in CSF (+6.1 per cent) and further decreases in LVdp/dt (-8.7 per cent), LVEDP (-48.0 per cent), LAP (-28.9 per cent) and myocardial oxygen consumption (-33.3 per cent). The results indicate that LVBP may be a promising circulatory assist and that, in the extremely low output state, the addition of IABP decreased myocardial oxygen consumption and offered a transition in mechanical cardiac support which was initiated with LVBP.

Chronic beta adrenergic blockade was induced in eight dogs with 240 to 360 mg of oral propranolol daily for 2 to 6 weeks. Beta blockade was confirmed by a minimal heart rate response to isoproterenol, 0.06 μg/kg/min, in a pentobarbital-anesthetized, open-chest preparation. Subsequent to confirmation of beta blockade, hemodynamic effects of isoproterenol and dopamine were examined individually and in combination. A desirable balance of arterial pressure and cardiac output was achieved by combining isoproterenol, 0.2 to 2.0 μg/kg/min, with dopamine, 5 to 20 μg/kg/min. This combination increased mean arterial pressure (109 ± 9 versus 81 ± 7), cardiac output (4.3 ± .5 versus 2.8 ± .3 L/min) and heart rate 156 ± 4 versus 120 ± 7) (p

A pulsatile assist device (PAD) has been developed to convert roller pump flow to pulsatile flow in a simple fashion. The device can also be used as an arterial counterpulsator before and after cardiopulmonary bypass. The PAD has been used in 125 adult patients undergoing open-heart operations for coronary artery or valvular heart disease or the combination. Ninety-two patients were in New York Heart Association Functional Class III or IV or had ejection fractions of less than 0.3. The PAD functioned as a hemodynamically effective arterial counterpulsator before and after perfusion. All patients were successfully weaned from bypass with the PAD. There has been 1 intraoperative death and 2 late deaths. Only 1 patient had a perioperative myocardial infarction, and this person was successfully treated with intraaortic balloon pumping. We believe the PAD is a simple and reliable device for intraoperative counterpulsation and for the creation of pulsatile cardiopulmonary bypass. More important, use of the PAD may decrease both the incidence of perioperative myocardial infarction and the need for postoperative intraaortic balloon pumping.

In recent years the development of modern direct techniques for revascularization surgery has resulted in a multitude of critically ill patients undergoing open heart surgery. To deal with the increasing numbers of patients who both require urgent open heart surgery and present with many complicated patterns of disease, a spectrum of cardiac assist measures, ranging from simple pharmacological interventions to mechanical cardiac assist techniques, has been developed. Those temporary mechanical cardiac assist devices which employ the principle of couterpulsation and balloon pummping have met with the most consistent clinical success. We now report our experience and progress in this field since early 19729

Two-dimensional ultrasound was employed for qualitative and quantitative studies during cardiac operations in 74 patients. A gas-sterilized phased-array transducer applied directly to the anterior surface of the heart produced high-quality images without a water path or other special manipulations. The techniques employed were successful in demonstrating alterations in cardiac anatomy associated with valve disease and cardiac tumors. Continuous clouds of microbubbles ejected from the left ventricle immediately following cardiopulmonary bypass were detected in 42% of 45 patients studied. Measurement of short-axis area change during systole proved useful for evaluation of intraoperative changes in left ventricular function. In the perioperative period, with the chest closed, the method detected increasing left ventricular mass during transplant rejection and was useful for monitoring changes in left ventricular performance when image quality was sufficient. The capabilities and limitations of this technique for special studies during cardiac operations should be familiar to surgeons with access to the method.

Previous reports have indicated an incidence of right bundle branch block (RBBB) and left anterior hemiblock (LAH) pattern varying from 8-22% following corrective surgery in patients with tetralogy of Fallot. Among 207 patients with tetralogy of Fallot operated on at our institution, 8.7% developed an ECG pattern of RBBB and LAH. These patients were followed for 1-13 years (mean 6.2 years) for a total of 111 patient years. All patients are alive and none have had documented late atrioventricular dissociation, syncope, or other symptoms. Transient heart block was present in one patient in the immediate postoperative period but has not recurred. This group of patients differs significantly from other series in which such an ECG pattern was associated with a marked increase in morbidity and mortality. These data and the experimental evidence suggest that two distinct groups of patients exist: 1) a group in which this ECG pattern is secondary to lesions within the bundle of His and 2) a group in which the pattern is caused by lesions in the peripheral conduction system. It is postulated that these two groups which demonstrate the same ECG pattern may carry significantly different prognoses. Analysis of H-V intervals postoperatively may help identify patients at risk.

Green dye measurements of cardiac index (in liters per minute per square meter) were compared in 32 infants and 58 children, 6 and 24 hours after normothermic cardiopulmonary bypass. Cardiac index was significantly lower in infants under one year of age, as compared to older infants and children. This parameter was also lower in patients with total anomalous pulmonary venous drainage, truncus arteriosus, and tetralogy of Fallot. Five infants who died had 6-hour cardiac index determinations of 2.0 L./min./sq. M. Only 2 of 27 survivors had cardiac indices below this level. Simultaneously recorded heart rate and central venous pressure did not correlate with cardiac index. Systolic blood pressure was significantly lower in infants in whom the cardiac index was less than 2.0 L./min./sq. M. (p

We determined the effects of epinephrine on automaticity and action potential characteristics of right atrial specialized fibers (RAF) from human atria obtained during cardiac surgery. RAF were studied with standard microelectrode techniques during superfusion with Tyrode's solution at 37 degrees C. A biphasic response to epinephrine was seen, rate slowing at low agonist concentrations and increasing at high concentrations. The epinephrine-induced slowing of spontaneous rate was due to a decrease in the slope of phase 4 depolarization. At the high epinephrine concentrations RAF hyperpolarized. The alpha-adrenergic blocker, phentolamine, shifted the dose-response curve upward and to the left and enhanced the hyperpolarization of RAF. The beta blocker, propranolol, shifted the curve to the right and decreased the degree of hyperpolarization. Our study suggests the presence of alpha and beta receptors in RAF. The alpha response consists of a slowing of rate, the beta response of an acceleration of rate and hyperpolarization of RAF.

Population characteristics and survival factors are presented for 89 reoperations (eight referrals) from 1,445 valve replacements performed over 17 years at the Columbia-Presbyterian Hospital. There were three basic categories of indications leading to reoperation: valve-related systemic disease (infection, embolism, hemolysis), valve-related insufficiency (paravalvular leak, ball variance, homograft retraction), and valve-related stenosis (thrombosis, pannus, homograft obstruction). The leading indication for reoperation among aortic, mitral, and double valves was systemic disease (43 of 83—52 percent); tricuspid reoperations were most frequently performed (five of six—83 percent) for valve-related stenosis. The over-all early mortality rate was 19 percent (17 of 89) and varied with the reoperative site, indication, and urgency. In general, survival was lower in atrioventricular than aortic prosthetic reoperations. High-risk reoperations (N = 37, mortality rate 43.2 percent) occurred in the presence of prosthetic infection or prosthetic stenosis. When reoperations were performed urgently in the high-risk group, the mortality rate increased to 67 percent (16 of 24). However, in the absence of infection or stenosis, regardless of the urgency of reoperation, the mortality rate was only two percent. Five-year survival rates for low-risk reoperations were—aortic 69 percent and mitral 55 percent. Morbidity parameters among survivors did not differ from initial valve replacements. It appears that prosthetic valve reoperations can be performed with risks equal to the original operation except in the presence of subacute prosthetic infection or end-stage prosthetic stenosis.

Although previous studies have described the electrophysiological and ultrastructural characteristics of human cardiac fibers, no attempt has been made as yet to describe quantitatively the relationship between the ultrastructural and cellular electrophysiological derangements occurring with cardiac disease, and their clinical manifestations. In this study, we used standard microelectrode techniques to record the action potential characteristics of human atrial fibers obtained during cardiac surgery and correlated the electrophysiological parameters with clinical and ultrastructural data. Ultrastructure was studied by optical and electron microscopy. We found a multiple linear regression among maximum diastolic potential, atrial size and pressure, P wave duration and ultrastructure changes. Proliferations of Z band material, widening of intercalated discs, and degenerative changes were quantified and correlated with electrophysiological and clinical data. These studies emphasize the relationship between hemodynamic anomalies and resultant changes in both human atrial fiber structure and electrical function. Finally, the likelihood of occurrence of arrhythmias can be predicted using the analytic method described.

Statistical data on surgery for congenital and acquired heart disease in New York City in the 17 years from 1961 through 1977 and in New York State in 1977 document trends in volume and types of operations. The ratio of open heart surgery for congenital versus acquired heart disease of 2:1 in 1961 was reversed to 1:6 by 1977 as the number of procedures for valvular and coronary heart disease increased. The case load for surgery for congenital heart disease using the open heart technique gradually increased until 1974 and then decreased. The number of closed heart operations was relatively constant. Observations suggest a finite number of open and closed heart operations for congenital cardiac malformations; the total of 1,381 cardiac operations in New York State in 1977 may continue to diminish if the decreasing birth rate persists. The number of operations for valvular heart disease has stabilized, but the number of operations for coronary artery disease has increased 7-fold since 1970. In 1977, coronary arterial bypass grafting in New York State accounted for 63 percent of operations for acquired heart disease (6,407) and the mortality rate was less than 3 percent.

This study compares the effect of pulsatile (Group C, Fib/P) and nonpulsatile (Group B, Fib/NP) coronary perfusion on myocardial performance during 2 hours of normothermic ventricular fibrillation. Group A (BH/NP), used as a base-line observation, consisted of 2 hours of nonpulsatile coronary perfusion in beating hearts. The assessment of ventricular performance included diastolic ventricular compliance, myocardial oxygen consumption and lactate extraction, regional myocardial blood flow, and histology. After 120 minutes of ventricular fibrillation, Group C showed normal ventricular diastolic compliance as compared to a 50 per cent decrease in Group B (p

Twenty-two patients underwent aortic valve replacement for acquired valvular heart disease with the porcine heterograft prosthesis. In the immediate postoperative period, a transient decrease in the cardiac index (CI) (preoperative 3.0 ± 0.14 to 2.45 ± 0.16 L. per minute per square meter, p 0.05) were seen; these values returned to preoperative levels by the first postoperative day. After valve replacement, an elevation in the heart rate (HR) (preoperative 75 ± 2 to 87 ± 4 beats per minute, p

Unidirectional intra-aortic balloon pumping (IABP) was applied to 28 adult patients undergoing open-heart surgery over a 35 month period. The patients were divided into three groups according to the temporal sequence of initiating IABP. Group A consisted of 4 patients who were in a low output state or in cardiogenic shock prior to study. All patients survived cardiac catheterization and surgery, and 3 (75 per cent) were long-term survivors. Group B included 15 patients who could not be weaned from cardiopulmonary bypass with the usual supportive measures. Twelve patients (80 per cent) were weaned from bypass with IABP, and 11 (73 per cent) were discharged from the hospital. Group C was composed of 9 patients who manifested a low cardiac output syndrome within the first 24 hours following surgery. IABP was initiated in the recovery room. Six patients (67 per cent) were discharged. The total experience with these 28 patients therefore includes 24 patients (86 per cent) who were weaned from IABP, 20 (71 per cent) who were discharged, and 18 (64 per cent) who were long-term survivors. The present criteria for the use of IABP in the cardiac surgical patient are defined.

The clinical, hemodynamic, and angiographic observations, as well as the surgical approach used for repair in three patients with congenitally corrected transposition of the great arteries and ventricular membranous septal aneurysms, are presented. In two of the three patients the membranous septal aneurysm caused subpulmonary obstruction, with 94 and 125 mm Hg systolic gradients. In each patient the aneurysm was demonstrated by angiocardiography, which also showed differences in size and shape with cardiac systole and diastole. Review of the previously described reports indicates that patients with congenitally corrected transposition often display various forms of pulmonary outflow obstruction and when a ventricular membranous septal aneurysm exists, a significant subpulmonary obstruction is present in most patients. The unique anatomic relationship between the pulmonary artery and a ventricular membranous septal aneurysm in patients with transposition of the great arteries with and without atrioventricular discordance explains why subpulmonary obstruction sometimes develops.

Downstream and upstream pumping with unidirectional intra-aortic balloons was compared in 8 open-chest normal mongrel dogs anesthetized with pentobarbital. Downstream pumping effected a 32 per cent increase in cardiac index, a 24 per cent decrease in systemic resistance, and a 2 per cent decrease in heart rate. Upstream pumping did not significantly affect these parameters. Mean aortic pressure proximal and distal to the balloon was not altered significantly by pumping in either direction. This unique observation of increased cardiac output may have important implications for the treatment of low output cardiac failure. Preliminary studies including baroreceptor denervation suggest that a reflex mechanism may be involved.