Effects of chronic atrial fibrillation on gap junction distribution in human and rat atria.

OBJECTIVES: To elucidate the structural basis for the electrophysiologic remodeling induced by chronic atrial fibrillation (AF), we investigated connexin40 and connexin43 (Cx40 and Cx43) expression and distribution in atria of patients with and without chronic AF and in an animal model of AF with additional electrophysiologic investigation of anisotropy (ratio of longitudinal and transverse velocities). BACKGROUND: Atrial fibrillation is a common arrhythmia that has a tendency to become persistent. Since gap junctions provide the syncytial properties of the atrium, changes in expression and distribution of intercellular connections may accompany the chronification of AF. METHODS: Atrial tissues isolated from 12 patients in normal sinus rhythm at the time of cardiac surgery and from 12 patients with chronic AF were processed for immunohistology and immunoblotting for the detection of the gap junction proteins. The functional study of the cardiac tissue anisotropy was performed in rat atria in which AF was induced by 24 h of rapid pacing (10 Hz). RESULTS: Immunoblotting revealed that AF did not induce any significant change in Cx43 content in human atria. In contrast, a 2.7-fold increase in expression of Cx40 was observed in AF. Immunohistologic analysis indicated that AF resulted in an increase in the immunostaining of both connexins at the lateral membrane of human atrial cells. A similar spatial redistribution of the Cx43 signal was seen in isolated rat atria with experimentally-induced AF. In addition, AF in rat atria resulted in decreased anisotropy with slightly enhanced transverse conduction velocity. CONCLUSIONS: This experimental study showed that AF is accompanied by spatial remodeling of gap junctions that might induce changes in the biophysical properties of the tissue.

Predictive value of low dose dobutamine transesophageal echocardiography and fluorine-18 fluorodeoxyglucose positron emission tomography for recovery of regional left ventricular function after successful revascularization.

OBJECTIVES: This study was designed to assess the predictive value of myocardial viability diagnosed by dobutamine transesophageal echocardiography and fluorine (F)-18 fluorodeoxyglucose positron emission tomography for left ventricular functional recovery after revascularization in patients with chronic left ventricular dysfunction. BACKGROUND: The identification of akinetic but viable myocardium is of particular importance for the selection of patients with a compromised left ventricle who will benefit from coronary revascularization. METHODS: Multiplane rest and dobutamine transesophageal echocardiography (dobutamine, 5 and 10 microg/min per kg) studies and F-18 fluorodeoxyglucose positron emission tomographic studies at rest were performed in 2 patients with 1) previous myocardial infarction and regional akinesia, 2) a stenosed infarct-related coronary artery, and 3) a patent infarct-related vessel after revascularization. A basally akinetic segment was considered viable by transesophageal echocardiography if dobutamine-induced contractile reserve could be observed. Viability by positron emission tomography was defined as F-18 fluorodeoxyglucose uptake > or = 50% of the maximal uptake in a region with normal wall motion. Recovery of regional left ventricular function 4 to 6 months after revascularization was diagnosed by transesophageal echocardiography if > or = 50% of segments akinetic at baseline had improved wall thickening. RESULTS: Dobutamine transesophageal echocardiography identified viable infarct regions in 25 (59%) of 42 patients, and F-18 fluorodeoxyglucose positron emission tomography in 30 (71%) of 42 patients, yielding diagnostic agreement in 86% of patients. Sensitivity and specificity for prediction of left ventricular functional recovery in individual patients was 92% and 88%, respectively, for dobutamine transesophageal echocardiography versus 96% and 69% for F-18 fluorodeoxyglucose positron emission tomography. Segments remaining akinetic after revascularization had a significantly lower (p < 0.001) F-18 fluorodeoxyglucose uptake (48 +/- 15%) than that (73 +/- 15%) of segments with recovery of regional left ventricular function. CONCLUSIONS: Both dobutamine transesophageal echocardiography and F-18 fluorodeoxyglucose positron emission tomography were highly sensitive in predicting functional recovery of chronically kinetic or dyskinetic myocardium after successful revascularization. Thus, dobutamine transesophageal echocardiography is a clinically valuable alternative to F-18 fluorodeoxyglucose positron emission tomography for assessing residual viability and predicting functional recovery after revascularization.

Long-term results after Fontan procedure and its modifications.

The Fontan procedure is an effective method of treatment for patients with tricuspid atresia, univentricular heart, and other complex lesions. Modifications of the Fontan procedure have been developed to treat various anatomic malformations. From 1975 to 1984, 31 patients (17 male and 14 female) have undergone 35 Fontan operations. The youngest patient was 4 and the oldest 26 years of age (average 12.2 years). Sixteen patients had tricuspid atresia, and 15 univentricular heart. Twenty-three patients had undergone 37 palliative operations before the Fontan procedure. The original Fontan procedure was performed in 10 patients until 1977, and there were three early deaths (30%). After that time, the operative technique was modified and the early mortality dropped to 12% (3/25 patients). A valved prosthetic conduit was used in 11 patients (right atrium to pulmonary artery in five; right atrium to right ventricle in six), a valveless conduit in 14 patients (right atrium to pulmonary artery in nine; right atrium to right ventricle in five), and direct anastomosis (right atrium to pulmonary artery) in 10 patients. Postoperative cardiac catheterization was performed in 20 patients and revealed excellent results in 15. The remaining five had reduced oxygen saturation; three of them had had a Glenn anastomosis 8 and 10 years before the Fontan procedure, and one had an anomaly of the coronary sinus with a shunt to the left atrium. This patient required reoperation. Three other patients underwent reoperation because of calcified stenotic and/or outgrown conduits. Postoperative mean right atrial pressure varied from 10 to 20 mm Hg. The hemodynamic ventricular parameters were within the normal range. We conclude that in patients with tricuspid atresia, univentricular heart, and other complex cardiac lesions, inactivating the right ventricular pump function by means of the Fontan procedure does not adversely affect the systemic ventricle. Although the response to exercise was abnormal, the clinical condition of these patients was good to excellent.

Cardiac surgery in patients with end-stage renal disease: 10-year experience.

BACKGROUND: End-stage renal disease is known to be an important risk factor complex for cardiac operations performed with cardiopulmonary bypass. METHODS: To investigate the influence of preoperative status on perioperative mortality and morbidity, we retrospectively analyzed data from 65 patients (20 women and 45 men with a mean age of 58.8+/-10.0 years [+/-standard deviation]) with end-stage renal disease who were on dialysis and who underwent a cardiac surgical procedure between 1988 and 1998. RESULTS: Fifty-one percent of the patients had isolated coronary artery bypass grafting, 35% had replacement or reconstruction of one valve or two valves, and 14% underwent combined coronary artery bypass grafting and valve replacement. The perioperative mortality rate was 13.8% with 78% (7 of 9) of deaths occurring in patients having a valve procedure. Six of the 9 patients who died had compromised left ventricular function preoperatively, and all 9 were in New York Heart Association class III or IV. Mean preoperative duration of dialysis was longer (80+/-70 months) in the 9 patients who died compared with that in the surviving 56 patients (45+/-49 months) (p = 0.05). We found dyspnea at rest, duration of dialysis of 60 months or more, combined procedures (coronary artery bypass grafting and valve operation), and New York Heart Association class IV to be associated with a higher relative risk for perioperative death. Neither angina pectoris nor isolated coronary artery bypass grafting was associated with increased relative risk for perioperative death. However, after a cardiac operation, mortality in patients with end-stage renal disease was substantially higher than in those with normal renal function. CONCLUSIONS: These data are comparable with those in the literature and possibly suggest that both indications and referral for surgical intervention have been delayed in patients who have end-stage renal disease combined with coronary artery disease, valve disease, or both. The delay may contribute to the relatively high perioperative mortality.

Cooling gradients and formation of gaseous microemboli with cardiopulmonary bypass: an echocardiographic study.

BACKGROUND: Previous studies demonstrated gas emboli formation during rewarming from hypothermia on cardiopulmonary bypass when the temperature gradient exceeded a critical threshold. It also has been suggested that formation of arterial gas emboli may occur during cooling on cardiopulmonary bypass when cooled oxygenated blood exiting the heat exchanger is warmed on mixture with the patient's blood. The purpose of this study was to determine under what circumstances gas emboli formation would occur during cooling on cardio-pulmonary bypass. METHODS: Eight anesthetized mongreal dogs were placed on cardiopulmonary bypass using a roller pump, membrane oxygenator, and arterial line filter. For emboli detection, we positioned a transesophageal echocardiographic probe at the aortic arch distal to the aortic cannula and Doppler probes at the common carotid artery and the arterial line. Cooling gradients between normothermic blood and cooled arterial perfusate of 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 0 degree C (isothermal controls) were investigated. In addition to preestablished temperature gradients, we investigated the effect of rapid cooling (maximal flow through the heat exchanger at a water bath temperature of 4 degrees C) after the initiation of normothermic cardiopulmonary bypass. RESULTS: Minimal gas emboli were detected at the aortic arch at gradients of 10 degrees C or greater. The incidence of emboli was related directly to the magnitude of the temperature gradient (p < 0.01). No emboli were detected at the carotid artery. During rapid cooling, no emboli were observed either at the aorta or at the carotid artery. CONCLUSIONS: Cooling gradients of 10 degrees C or greater may be associated with gas emboli formation, but they may be of limited clinical significance because no emboli were detected distal to the aortic arch. During the application of rapid cooling, no emboli formation was observed.

Left ventricular geometry and function before and after mitral valve replacement.

Left ventricular geometry and function were assessed in 20 patients with mitral stenosis (MS) and in another 20 patients with mitral insufficiency (MI) five days before and 12 days after mitral valve replacement by transthoracic (TTE) and transesophageal (TEE) echocardiography, as well as late postoperatively (mean: 194 days) by TTE. The continuity of the subvalvular apparatus could not be preserved in any of these patients. In mitral stenosis the area ejection fraction (AEF) in the short axis of the left ventricle (LV) did not change significantly early or late postoperatively. There was a significant lengthening of the left ventricular longitudinal axis in the apical four chamber view whereas the transverse axis remained unchanged. This was likely the result of the discontinuity between the mitral valve and the papillary muscles. AEF and ejection fraction (EF) determined in the four chamber view showed a slight tendency to decrease in the postoperative phase. Patients with mitral insufficiency likewise showed a significant increase of the LV longitudinal diameter postoperatively. In the short axis of the left ventricle and in the apical four chamber view a significant reduction of the AEF was observed. Furthermore, left ventricular EF dropped significantly postoperatively. This decrease was caused by the extension of the LV longitudinal axis accompanied by an enlargement of the transverse diameter as well as by an afterload increase, and a masked impairment of left ventricular function preoperatively. Wall motion analysis of the LV in both groups documented new postoperative hypokinesis especially in the septal segments. At late postoperative examination the hypokinesis disappeared in about 50% of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary closure of median sternotomy with interposition of hydroxyapatite blocks. A new approach in pediatric cardiac surgery.

Chest closure after correction of congenital heart disease with subsequent enlargement of the heart has been a problem encountered throughout departments performing pediatric cardiac surgery. Present techniques using Rehbein struts or an open chest with a Gore-Tex patch skin closure have not solved this issue satisfactorily. Between January 1989 and September 1990, median sternotomies could not be closed primarily due to hemodynamic consequences in nine patients age 3 months to 19 years operated upon in our department. In three children, a conduit exchange, in two a Mustard correction, in two a correction of Fallot's tetralogy, in one a prosthetic valve exchange and in one, a new implantation of a homograft was performed. Primary chest closure was achieved by interposing hydroxyapatite blocks (50 mm x 15 mm x 6 mm) without hemodynamic consequences. In a follow-up period of 10 +/- 8 months, all children are alive and well. There was no complication resulting from the implanted blocks. Due to the excellent functional and cosmetic results of this technique and the outstanding histomorphological characters of hydroxyapatite, we regard the implantation of hydroxyapatite blocks as a superb method for primary sternotomy closure especially in pediatric cardiac surgery.

Risk stratification in heart surgery: comparison of six score systems.

OBJECTIVE: Risk scores have become an important tool in patient assessment, as age, severity of heart disease, and comorbidity in patients undergoing heart surgery have considerably increased. Various risk scores have been developed to predict mortality after heart surgery. However, there are significant differences between scores with regard to score design and the initial patient population on which score development was based. It was the purpose of our study to compare six commonly used risk scores with regard to their validity in our patient population. METHODS: Between September 1, 1998 and February 28, 1999, all adult patients undergoing heart surgery with cardiopulmonary bypass in our institution were preoperatively scored using the initial Parsonnet, Cleveland Clinic, French, Euro, Pons, and Ontario Province Risk (OPR) scores. Postoperatively, we registered 30-day mortality, use of mechanical assist devices, renal failure requiring hemodialysis or hemofiltration, stroke, myocardial infarction, and duration of ventilation and intensive care stay. Score validity was assessed by calculating the area under the ROC curve. Odds ratios were calculated to investigate the predictive relevance of risk factors. RESULTS: Follow-up was able to be completed in 504 prospectively scored patients. Receiver operating characteristics (ROC) curve analysis for mortality showed the best predictive value for the Euro score. Predictive values for morbidity were considerably lower than predictive values for mortality in all of the investigated score systems. For most risk factors, odds ratios for mortality were substantially different from ratios for morbidity. CONCLUSIONS: Among the investigated scores, the Euro score yielded the highest predictive value in our patient population. For most risk factors, predictive values for morbidity were substantially different from predictive values for mortality. Therefore, development of specific morbidity risk scores may improve prediction of outcome and hospital cost. Due to the heterogeneity of morbidity events, future score systems may have to generate separate predictions for mortality and major morbidity events.

Activation of myocardial constitutive nitric oxide synthase during coronary artery surgery.

OBJECTIVE: The role of nitric oxide (NO) in myocardial ischemia/reperfusion is controversial. While some studies have shown cardioprotective effects of NO, others suggested that increased myocardial NO release secondary to ischemia may contribute to reperfusion injury. However, the impact of cardioplegia-induced myocardial ischemia/reperfusion on the activity of the NO-producing enzyme constitutive NO-synthase (cNOS or NOS-III) has not been investigated. METHODS: Twenty elective CABG patients were randomized to receive myocardial protection using either intermittent cold blood cardioplegia with 'hot-shot' (CBC; n=10) or continuous warm blood enriched with the ultra-fast-acting beta-blocker esmolol (WBE; n=10). We collected transmural LV biopsies prior to cardiopulmonary bypass (CPB), at the end of the cross-clamp period, and at the end of CPB. Specimen were subjected to immunocytochemical staining against myocardial NOS-III and cGMP using polyclonal antibodies. NOS-III activity was determined using TV-densitometry (gray units) and cGMP content using a semiquantitative score. Global myocardial metabolism was assessed by arterio-coronary sinus lactate concentration difference (a-csD(LAC)). For LV function determination we measured the fractional area of contraction (FAC) using TEE. RESULTS: In CBC hearts a-csD(LAC) was significantly decreased following cross-clamp removal as compared to pre-CPB indicating global ischemia during cross-clamp. In contrast, a-csD(LAC) was unchanged in WBE hearts indicating absence of relevant ischemia in this group. In CBC hearts NOS-III activity did not change from pre-CPB (35.6+/-11.1 U) to the end of the cross-clamp period (38. 0+/-8.1 U; P=0.2), but increased significantly to 48.5+/-12.1 U at the end of CPB following initial warm blood reperfusion (P=0.026). In WBE hearts NOS-III activity remained unchanged throughout (29. 2+/-10.8, 35.1+/-11.8, and 32.2+/-14.7 U, respectively; 0.3). At the end of CPB, nine CBC hearts, but only one WBE heart showed increased cGMP content (P=0.002). Compared to pre-CPB, FAC in the CBC group was 109+/-25% following weaning off CPB (P=0.26), but was slightly decreased to 87+/-22% at 4 h post-CPB (P=0.03). In the WBE group FAC remained unchanged compared to pre-CPB throughout (103+/-21 and 96+/-37%, respectively; 0.5). CONCLUSIONS: Our data show that global myocardial ischemia and reperfusion induced by CBC is associated with myocardial NOS-III activation and increased cGMP content suggesting increased NO release. In contrast, avoidance of ischemia by use of WBE prevented NOS-III and c-GMP increase. As LV function was decreased at 4 h post-CPB in the CBC group, these data suggest that increased NO release secondary to NOS-III activation may have contributed to ischemia-reperfusion injury as has been shown experimentally.

Coronary oxygen persufflation combined with HTK cardioplegia prolongs the preservation time in heart transplantation.

BACKGROUND: One of the most restricting factors remaining in heart transplantation is the limited myocardial ischemia time. A new approach towards the prolongation of this time is the combination of primary cardioplegic arrest followed by continuous coronary oxygen persufflation (COP) with gaseous oxygen. METHODS: This technique was applied in pig hearts, which we transplanted orthotopically after cardioplegic arrest by original (n = 5) and modified (addition of hyaluronidase: n = 11) Bretschneider HTK solution and 14 h of hypothermic preservation. Depending on the different preservation techniques, we created four groups: (1), original HTK (HTK), n = 5; (2), modified HTK (mHTK), n = 5; (3), modified HTK solution plus COP (mHTK + COP), n = 6; and (4), as a control five hearts were transplanted after cardioplegic arrest by the original HTK solution and a cold ischemia time of 3 h comparable to clinical routine procedure. RESULTS: After 14 h of preservation and orthotopic transplantation, cardiac functional recovery in mHTK + COP hearts was similar to control hearts, and improved compared to hearts of both other groups. Hemodynamics were significantly better in hearts preserved by mHTK + COP and in the control group compared to the HTK-hearts (P < 0.05), not significant compared to mHTK hearts (dp/dt(max) in % of preoperative +/- standard error of mean (SEM): mHTK + COP, 85 +/- 9; control, 85 +/- 10.5; mHTK, 59 +/- 14; HTK, 50 +/- 4). The cardiac output (CO) in % of preoperative was: mHTK + COP, 68 +/- 5.4; control, 64 +/- 4; mHTK, 44 +/- 2.7; HTK, 25 +/- 11. The ATP of left ventricular myocardium in mHTK + COP hearts at 14.7 +/- 1 micromol/g dry weight (DW) and in the control at 14.59 +/- 1.8 was higher compared to that in mHTK at 12.2 +/- 2.8 (P is non-significant (n.s.) versus mHTK + COP and control) and in HTK-hearts at 7.0 +/- 0.5 (P < 0.05 versus mHTK + COP and control). CK-MB in percent of CK showed no increase in either group. CONCLUSIONS: These data show that COP combined with a mHTK solution represents a potential alternative to complement currently used cold storage techniques for prolonged preservation periods.

Acute coronary occlusion with impending infarction as an angiographic complication relieved by a guide-wire recanalization.

In a 45 year old male patient with a history of previous inferior myocardial infarction and unstable angina pectoris, coronary angiography revealed two-vessel disease: a 60-70% lesion in the middle third of the LAD, and a 90% lesion in the middle third of the very large RCA. There was only a small akinetic segment in the posterobasal region of the left ventricle. During angiography total occlusion of the RCA occurred followed the clinical and electrocardiographic signs of impending inferior reinfarction. Recanalization of the occluded vessel was accomplished by using a guide-wire, which was passed through a Sones catheter, placed in the RCA. The patient's symptoms subsided and the electrocardiographic signs of acute ischemia reverted within eight minutes. Aortocoronary bypass surgery with revascularization of the LAD and RCA was performed within 3 hours after recanalization. Postoperatively there was no evidence of major tissue loss by enzyme or electrocardiographic criteria. Control angiography, performed on the ninth day postoperatively, revealed the graft to the RCA to be widely patent. Left ventricular function was unchanged. It is concluded, that the combined approach of early transluminal recanalization of the acutely occluded RCA followed by successful construction of a graft to this vessel, has averted necrosis of a major portion of the left ventricle. However, general use of this technique does not seem advisable at the present time.

Aortoventriculoplasty for different types of left ventricular outflow tract obstructions.

Since the first clinical application of aortoventriculoplasty for tunnel subaortic stenosis in 1974 the indication for this method was extended to other types of left ventricular outflow tract stenoses (LVOTO). The operative technique consists of enlarging both the left and right ventricular outflow tracts and inserting an aortic prosthetic valve. 47 operations have been performed in patients with various types of LVOTO: 8 narrow annulus, 23 diffuse subaortic stenosis (multiple level stenosis), 9 complex forms of tunnel subaortic stenosis (Shone complex) 3 outgrown prosthesis, 4 obstructive idiopathic hypertrophic subaortic stenosis. Patients ages ranged from 4 to 35 years. Overall mortality was 13%, there were no late deaths, in the last 34 patients there was no death. In 25 patients there had been 1, and in 13 patients 2 previous procedures. As a result of the operation 9 patients developed complete right bundle branch block or left anterior hemi-block; 2 patients developed total a-v block with the need of a permanent pacemaker 25 patients had catheterization postoperatively. The mean gradient across the left ventricular outflow tract was significantly reduced from 91.5 +/- 21 mm Hg to 13.1 +/- 15 mm Hg. According to our experience aortoventriculoplasty can be used routinely in all forms of diffuse subaortic stenosis, narrow aortic annulus, reoperation in HOCM, multiple level stenosis and outgrown aortic prosthesis.

The durability of bioprostheses in young people. Long-term results with intra- or extracardiac implanted porcine valves.

Forty two children and two young adults who were long term survivors of either intracardiac or extracardiac valve replacement with glutaraldehyde porcine valves form the basis of this report. The follow-up period varied from 6 months to 9 years. Ten of eleven intracardiac valves developed some dysfunction--the eleventh patient died from other causes. Of a total of 36 extracardiac valved conduits in the Rt side of the heart, four have needed replacement and an additional four will require replacement in due course. The probability of an event free performance of an intracardiac porcine valve is zero at 5 years. Four extracardiac valves there is in an 80% expectancy at 5 years and a 12% at 8 years of trouble free existence.

[Homograft implantation in heart surgery]. / Homograftimplantationen in der Herzchirurgie.

In order to fulfill in the field of cardiothoracic surgery the obligations of patient-care and research in a university facility according to the international standard it is nowadays absolutely necessary to run a homograft bank. Implantation of an allograft is a preferable choice for a number of different operations, i.e. in aortic valve endocarditis, complex congenital heart disease, Ross' operation and others. Furthermore, in children, women of childbearing age and patients in whom anticoagulation is contraindicated, heart valve replacement with allografts has become routine. The most important advantages of allografts are the excellent hemodynamic qualities and the low risk endocarditis. Anticoagulation is not necessary, because there is no risk for thromboembolism or hemolysis. For the patients mentioned above, these factors are decisive for their quality of life and their prognosis. Because of the shortage of donor organs and the priority of heart transplantation over allograft harvesting, the use of allografts should be limited to the above mentioned indications, mechanical and bioprothetic valves and, just lately available, bioprothetic valves from autogenous pericardium are appropriate.

[Surgical myocardial revascularization: indications, perioperative risk constellation and prognosis]. / Die chirurgische Myokardrevaskularisation: Indikation, perioperative Risikokonstellation und Prognose.

Since the inception of coronary artery bypass grafting, refinements in surgical technique, myocardial preservation, anesthesia and in pre- and postoperative care, reduced the perioperative mortality and improved the long-term results in patients with chronic coronary artery disease. Large-scale, multicentre randomized and a multitude of non-randomized clinical trials of surgical versus medical treatment have set therapeutic standards for quality and refined the indications for bypass surgery. In summary, these studies clearly indicate that surgery is superior to medical therapy in symptom relief, decreased antianginal drug use and improved exercise performance, but does not improve the likelihood of return to employment, non-fatal myocardial infarction prevalence or hospitalization rates. After surgery, survival is prolonged in those subsets of patients who are considered at high risk, i.e. patients with left main disease (greater than 70%), with two-vessel disease with severe left anterior descending artery stenosis or with three-vessel disease with signs of significant ischemia on exercise or left ventricular dysfunction present. Specific individual risk profiles during coronary artery surgery were evaluated by a multicentre retrospective analysis of 8363 patients (QuaDRA-study) documenting a significantly higher perioperative letality and incidence of postoperative complications (low output syndrome, infection, renal dysfunction, psychosyndrome) in the elderly (greater than 65 years).

[Late results following Rastelli corrective operations in transposition of great vessels]. / Spätergebnisse nach Korrekturoperationen bei Transposition der grossen Gefässe nach Rastelli.

From 1974 to 1985, 19 patients with transposition of the great arteries, ventricular septal defect and pulmonary valve stenosis or atresia underwent Rastelli correction. The mean age of the patients at operation was 9.7 years. Four patients died on the day of operation (early mortality: 21%). One patient died 7 years later due to dysrhythmias (overall mortality: 26%). Cardiac catheterization was performed on average 1.8 and 6.7 years after the operation. Gradients above 40 mm Hg were registered in 70% of the conduits, 6 years after the operation. Five patients underwent six reoperations for conduit stenosis. The actuarial survival rate was 75%; the event-free survival rate was only 20% after 12 years.

Reduction of the left-ventricular outflow-tract obstruction by aortoventriculoplasty--long-term results of 96 patients.

The aortoventriculoplasty (AVP) is an established surgical procedure for enlargement of different types of congenital and acquired obstruction of the left-ventricular outflow tract (LVOTO), especially with narrowing of the aortic valvular and subvalvular segment. Between 1974 and 1992, 96 patients underwent AVP. There were 32 female and 64 male patients, aged 3 to 32 years (mean 11.2 +/- 2.7 years) at operation. Indications for the procedure were as follows: 1. narrowing of the aortic annulus (19 patients), 2. multi-level stenosis (26 patients), 3. "outgrown"-prosthesis (8 patients), 4. recurrent hypertrophic obstructive cardiomyopathy (HOCM) (5 patients), and 5. subaortic stenosis of different origins (38 patients; out of these 19 patients had a "tunnel-like" stenosis, 7 of them with a "Shone-complex"). Seventy-six patients had previous operations at different levels of the left-ventricular tract. The mean preoperative peak transvalvular gradient was 88 +/- 27 mmHg (range 50-160 mmHg) and could be reduced by AVP to 14 +/- 13 mmHg. The early mortality was 8.3% (8/96). Among the last 58 patients there were no deaths. Three patients underwent subsequent reoperations: one for ascending aortic aneurysm, one for right-ventricular outflow tract obstruction (RVOTO), and one for "outgrown" prosthesis. Three patients required pacemaker implantation for a permanent a-v block, 71 of 96 patients had sinus rhythm postoperatively. The long-term results are similar to those of standard aortic valve replacement in childhood and adolescents. The advantages and disadvantages of the AVP in comparison to the other alternative surgical methods for relief of LVOTO are discussed.

Absence of hemodynamic and ECG changes in a patient with traumatic left ventricular injury and puncture of the left anterior descending branch.

Patients with penetrating cardiac injury usually present with cardiac tamponade and shock upon hospital arrival. However, absence of hemodynamic depression does not exclude a potentially fatal injury of the heart. This article reports on a patient who developed neither hemodynamic depression nor ECG changes for several hours, despite two left ventricular lacerations with puncture of the LAD. Echocardiography is advocated as the diagnostic tool of choice, and it is emphasized that no penetrating objects should be removed from the wound before surgical access to the heart is established, as this may result in the sudden development of cardiac tamponade.

A case of an intramural coronary artery associated with transposition of the great arteries.

One case of an intramural coronary artery in association with transposition of the great arteries is presented. A 16-month-old infant was admitted for the second-stage operation of complete transposition after a subclavian patch plasty for the aortic isthmus stenosis, division of the persisting arterial duct, and pulmonary artery banding had been performed in the first-stage operation soon after birth. The primarily planned arterial switch operation was, however, not performed because of an unusual coronary artery morphology and pattern--a separated origin of both coronary arteries from the posterior, "facing" sinus of Valsalva and an intramural course of the left anterior descending artery. This very rare case of coronary artery variation is presented from the surgical point of view.