[Hyperthyroidism, eosinophilia, and fever in a 64-year-old patient]. / Hyperthyreose, Eosinophilie und Fieber bei einem 64-jährigen Patienten.

We report on a male patient suffering from loss of weight, fatigue, fever, eosinophilia, and hyperthyreoidism. The echocardiogram revealed a left atrial mass originating from the posterior mitral leaflet. In combination with the constitutional symptoms a left atrial myxoma was diagnosed. The tumor was surgically removed. Postoperatively therapy with corticosteroids and thiamazole was stopped. During follow-up, eosinophilia and hyperthyreodism could no longer be detected.

[Surgical atrial fibrillation ablation therapy and postoperative monitoring]. / Rhythmuschirurgie des Vorhofflimmerns und postoperatives Monitoring.

Atrial fibrillation represents the most common atrial arrhythmia seen in clinical practice. The surgical treatment of atrial fibrillation is recommended in symptomatic patients as well as in asymptomatic patients at low postoperative risk. As a "stand alone" procedure, surgical ablation therapy is indicated after failed catheter ablation therapy, which occurs increasingly due to the high number of catheter-based ablation techniques. In order to gain acceptance among patients as well as referring cardiologists, the surgical ablation procedure ought to be performed in a minimally invasive fashion and with a very high success rate. When applied in an interdisciplinary approach by cardiologists/electrophysiologists and cardiothoracic surgeons, both ablative techniques have the potential to treat atrial fibrillation effectively and in the long-term. In order to document the true heart rhythm after ablation therapy, intermittent "snapshot" ECG documentation ought to be avoided. Small leadless devices that can be implanted subcutaneously enable full heart rhythm disclosure with documentation of atrial arrhythmias. The modern technique of implantable loop recorders permits individualized treatment for each patient.

[Diagnostic pathways and pitfalls in acute thoracic aortic dissection: practical recommendations and an awareness campaign]. / Diagnostische Wege und Irrwege der akuten thorakalen Aortendissektion: Praktische Empfehlungen und Aufklärungskampagne.

Despite significant improvements in the surgical therapy of acute aortic dissection (AAD), mortality rates in the initial phase remain unacceptably high. Early diagnosis and therapy are essential to improving prognosis in these patients. A prerequisite of prompt and correct diagnosis is"thinking of it". Delayed or incorrect diagnosis can often have catastrophic results.The reported acute chest and back pain of a tearing, stabbing nature combined with the physiognomy of Marfan syndrome often arouse the clinical suspicion of AAD, prompting immediate imaging of the thoracic aorta and therapy. For less clear cases, additional hints drawn from the patient history and special findings from the medical examination are presented schematically in a diagnostic pathway. As an innovative form of diagnosis, preventive echocardiographic screening in high risk groups is discussed.To heighten awareness of AAD and the importance of its correct diagnosis, the poster campaign "Thinking of it can save lives" has been initiated. The poster depicts AAD schematically, indicates Marfan syndrome as a risk factor for AAD in young people and illustrates a CT scan as the most frequently performed imaging technique with high sensitivity and specificity.

Transmyocardial laser revascularization combined with intramyocardial endothelial progenitor cell transplantation in patients with intractable ischemic heart disease ineligible for conventional revascularization: preliminary results in a highly selected small patient cohort.

OBJECTIVE: Transmyocardial laser revascularization for angina relief and intramyocardial autologous endothelial progenitor cell injection for neoangiogenesis may offer a new treatment strategy for patients with intractable ischemic heart disease. METHODS: Transmyocardial laser revascularization and intramyocardial injection of bone marrow-derived CD133+ cells was performed in six highly symptomatic patients. Transmyocardial laser channels were created and isolated CD133+ cells were injected intramyocardially. All patients were followed up for a minimum of 6 months postoperatively. RESULTS: One patient died shortly after the operation due to refractory heart failure. In the five survivors, CCS class improved as well as left ventricular ejection fraction. Left ventricular end-diastolic volume and myocardial perfusion varied between the patients. All patients described a considerable improvement in quality of life postoperatively. Repeated 24-hour Holter monitoring revealed no significant arrhythmias. CONCLUSIONS: In this small patient cohort, intramyocardial CD 133+ cell injection combined with transmyocardial laser revascularization led to an improvement in clinical symptomatology in all patients and in left ventricular function in 4 out of 5 patients, with an unclear effect on myocardial perfusion. Caution is advised when employing this therapy in patients with severely depressed left ventricular function.

Impact of graft size and commissural resuspension height on aortic valve competence in valve-sparing aortic replacement under physiological pressures.

BACKGROUND: Valve competence in valve-sparing aortic root replacement has been described as being influenced by commissural height as well as graft size. The aim of this study was to investigate the impact of a gradual reduction of commissural height and graft diameter on aortic insufficiency under physiological conditions in an IN VITRO model. METHODS: Porcine aortic valves were reimplanted into a tubular graft and a native commissural height was obtained. Subsequently the height was reduced by 10 % and 20 %, respectively. To investigate the impact of graft size, a 30 % reduction of the prosthesis diameter was carried out in valves with both native and reduced commissural heights. All conditions were investigated under pulsatile flow simulation and static pressure exposure. RESULTS: Reduction of commissural height caused regurgitation at both 10 % and 20 % lower heights, which was more pronounced in grafts with 20 % reduction. Graft undersizing resulted in significant reflux, with regurgitation even occurring with valves in a native commissural position. CONCLUSIONS: Valve competence is impaired both by the reduction of commissural height and by reduced graft size. In particular, reimplantation of aortic valves into undersized grafts promotes valve insufficiency even if commissural height is well adjusted.

Types of reconstructive surgery of the aortic valve.

The aortic valve is part of the aortic root which is wedged between the heart and the ascending aorta, maintaining a directional flow throughout life-span. Beside different types of aortic valve replacements, reconstructive techniques are increasingly performed to restore normal aortic valve function. To apply these operations, understanding of normal and pathological valve anatomy and physiology is of basic importance. In addition, a widely accepted uniform aortic valve and root terminology is desirable for a proper scientific communication. Reconstructive techniques themselves can be divided into isolated reconstruction of aortic valve/root structures and the isolated replacement of one or more structures. Examples for the former ones are commissurotomy, cusps plication, decalcification or extension as well as plications of other aortic root structures (i.e. the intercusp triangles or the basal annulus). Examples for the latter ones are the remodeling and reimplantation techniques and their modifications. Replacement of the ascending aorta at the sinotubular level for the adjustment of the commissures to restore aortic root geometry also belongs to this group of techniques for aortic valve reconstruction. In this review article a systematic description of the current reconstructive techniques to restore adequate aortic valve function as well as clinical data are presented.

Autonomously contracting human cardiomyocytes generated from adult pancreatic stem cells and enhanced in co-cultures with myocardial biopsies.

Myocardial regeneration with artificially applied cardiomyocytes is emerging as a promising issue of significant scientific and clinical impact. Nevertheless the source of cells for human cardiomyocyte differentiation especially from adult tissue is still unclear. We hypothesized that human pancreatic stem cells may differentiate into cardiomyocyte-like cells and may increase in number when co-cultured with myocardial tissue. Adult stem cells were harvested from pancreatic tissue of patients undergoing operative procedures including the pancreas. The cells were selected, cultured and passaged. To promote self-differentiation into cardiomyocytes, human pancreatic stem cells were co-cultered with biopsies of human myocardium. After co-culture and breeding, cells were phenotyped as well with respect to RNA, protein and cardiomyocyte specificity at the electron-microscopic level.Pancreatic stem cells have already differentiated spontaneously into cardiomyocyte-like cells performing netlike cell clusters with rare but distinct multilocular cellular autonomous contractions with a frequency of about 20 beats per minute. The number of contracting areas however could be enhanced by co-culture with human myocardial biopsies. On RNA and protein levels as well as in electron-microscopy, evidence for cardiomyocyte specificity is shown. To the best of our knowledge this is the first report demonstrating the feasibility of generating autonomously contracting cardiomyocyte-like cells from adult human pancreatic stem cells and their enhancement by myocardial co-culture. This procedure might prove to be an alternative source and method for myocardial regenerative medicine.

Time course of aortic valve function and root dimensions after subcoronary ross procedure for bicuspid versus tricuspid aortic valve disease.

BACKGROUND: The freestanding aortic root, which is the currently preferred operative technique for pulmonary autografts, is reported to dilate and potentially promote aortic insufficiency, which has led to a controversial debate on the appropriate surgical technique, especially for congenital bicuspid aortic valve disease. Desirable data on the time course of valve function and root dimensions for the alternative subcoronary technique comparing bicuspid and tricuspid aortic valve disease are scarce. METHODS AND RESULTS: Echocardiographic examinations of 31 patients with congenital bicuspid aortic valve disease (group A; age 50.5+/-11.0 years) and 51 patients with acquired tricuspid aortic valve disease (group B; age 48.1+/-15.7 years) who were operated on between June 1994 and August 1998 were performed twice postoperatively. At first and second follow-up, respectively, maximum (mean) pressure gradients were 6.0+/-2.0 (3.6+/-1.0) and 5.1+/-2.1 (2.9+/-1.1) mm Hg in group A and 6.5+/-3.5 (3.9+/-1.9) and 5.0+/-1.7 (2.9+/-1.0) mm Hg in group B (P>0.05 between groups). In group A, grade 0 aortic insufficiency at first and second follow-up occurred in 8 and 7 patients, respectively, grade 0-I in 12 and 9 patients, grade I in 9 and 11 patients, grade I-II in 1 and 0 patients, and grade II in 1 and 4 patients; in group B, grade 0 aortic insufficiency occurred in 16 and 18 patients, grade 0-I in 16 and 8 patients, grade I in 17 and 21 patients, grade I-II in 0 and 1 patient, and grade II in 0 and 1 patient (P>0.05). Aortic insufficiency decreased in 10 patients (17%). However, there was an overall tendency for aortic insufficiency to increase over time (n=23, 38%), although it remained subclinical. Aortic root dimensions did not differ between groups and were constant during follow-up. CONCLUSIONS: This study provides some evidence that the function of the subcoronary pulmonary autograft in bicuspid aortic valve disease is excellent, with stable root dimensions, and is not different from that of tricuspid aortic valves at least up to 5.5 years postoperatively, which suggests the subcoronary technique should be reconsidered.

Opening and closing characteristics of the aortic valve after different types of valve-preserving surgery.

BACKGROUND: The surgical approach to aortic root aneurysm and/or dissection remains controversial. The use of valve-sparing operations, which are thought to have many advantages, is increasing. We hypothesized that the particular technique and type of surgery could influence valve motion characteristics and function. Therefore, we studied the instantaneous opening and closing characteristics of the aortic valve after the main 2 types of valve-sparing surgery. METHODS AND RESULTS: In 20 patients (10 with tube replacement of the aortic root, group A; and 10 with separate replacement of the sinuses of Valsalva, group B) and 10 controls (group C), transthoracic and transesophageal studies on aortic valve dynamics were performed. Three distinct phases of aortic valve motion were identified. They were as follows: (1) a rapid opening, with a velocity of 20.9+/-4.2 cm/s in group C, 27.1+/-10.9 cm/s in group B (P=NS), and 58.3+/-18.4 cm/s in group A (group A versus group C, P<0. 001; group A versus group B, P=0.001); (2) a slow systolic closure, with 12.5+/-6.6% and 10.8+/-2.2% of maximal opening in groups C and B, respectively (P=NS), and 3.8+/-1.6% in group A (group A versus group C, P=0.001; group A versus group B, P<0.001); and (3) a rapid closing movement, with a velocity of 26.3+/-5.6 cm/s in group C, 32. 4+/-11.4 cm/s in group B (P=NS), and 21.8+/-3.5 cm/s in group A (group A versus group C, P=NS; group A versus group B, P=0.008). The pressure strain of the elastic modulus was different in groups C and B only at the commissures (682+/-145 g/cm(2) versus 1896+/-726 g/cm(2), respectively; P<0.001). At all root levels, the distensibility was reduced in group A (P<0.001). Systolic contact of aortic cusps and wall occurred only in group A. CONCLUSIONS: Near-normal opening and closing characteristics can be achieved by a technique that preserves the shape and independent mobility of the sinuses of Valsalva.

Clenbuterol-supported dynamic training of skeletal muscle ventricles against systemic load: a key for powerful circulatory assist?

BACKGROUND: The profound loss of power that occurs in skeletal muscle after electrical conditioning has been the major limiting factor in its clinical application. This study investigates a 3-fold approach for chronic conditioning of skeletal muscle ventricles (SMVs) combining electrical transformation, dynamic training against systemic load, and pharmacological support with clenbuterol. METHODS AND RESULTS: In 10 adult male goats, SMVs were constructed from latissimus dorsi muscle wrapped around an intrathoracic training device with windkessel characteristics. SMVs were stimulated electrically and trained dynamically by shifting volume against systemic load. Group 1 goats were controls (n=5), and group 2 goats (n=5) were supported with clenbuterol (150 microg 3 times a week). SMV dynamics were recorded weekly over 5 to 8 months: peak pressure (P(max)), stroke volume (SV), volume displacement per minute (VD), stroke work per day (SW/d), and maximum rates of pressure generation, +dP/dt(max), and decay, -dP/dt(max). In group 1, after 149.5+/-2.7 days (n=4), data were P(max)=70.8+/-4.7 mm Hg, SV=3.2+/-1.2 mL, VD=62.3+/-21.1 mL/min, SW/d=0.8+/-0.4 kJ, +dP/dt(max)=64+/-13 mm Hg/s, and -dP/dt(max)=156+/-32 mm Hg/s. These parameters were significantly improved (P<0.007) in the clenbuterol-treated group 2 after 151+/-2.7 days: P(max)=176.2+/-43.8 mm Hg, SV=23.3+/-6.1 mL, VD=568.2+/-186.1 mL/min, SW/d=9.1+/-2.2 kJ, +dP/dt(max)=1134+/-267 mm Hg/s, and -dP/dt(max)=1028+/-92 mm Hg/s. In 2 SMVs of group 2, VD increased to 1090 and 1235 mL/min after 202 and 246 days of training, respectively. At termination, myosin heavy chains were totally transformed into myosin heavy chain-1 in all SMVs. CONCLUSIONS: This clenbuterol-supported dynamic training provides powerful SMVs that may have important clinical implications for the treatment of end-stage heart failure by muscular blood pumps.

Does histocompatibility affect homograft valve function after the Ross procedure?

BACKGROUND: Homograft valves have been shown to be immunogenic, but it is unknown whether this affects valve function. Therefore, we prospectively studied the degree of histoincompatibility (defined as the number of human leukocyte antigen [HLA] mismatches between valve donor and recipient) and the response of the recipient (measured by antibodies against HLA) in relation to echocardiographic parameters of homograft valve function after the Ross procedure. METHODS AND RESULTS: Twenty-six patients (mean age 41+/-14 years; 20 males, 6 females) and the cryopreserved pulmonary homograft valves that were implanted during a Ross procedure were typed for HLA-A, HLA-B, and HLA-DR. After a mean follow-up of 15+/-6 months, 14 (54%) of the patients were anti-HLA class I antibody positive. In all but 1 patient, these antibodies were shown to be donor specific. During follow-up, there was a significant increase of the maximal (+6.2+/-7.1 mm Hg) and mean (+3.2+/-4.3 mm Hg) transhomograft pressure gradients but not of homograft regurgitation. Neither the number of HLA mismatches nor antibody status was found to have significant impact on homograft valve function. In a multivariate analysis, smaller homograft size (P=0.001) and younger recipient age (P=0.044) were shown to be significantly associated with increased transhomograft pressure gradients. CONCLUSIONS: Implantation of a cryopreserved pulmonary homograft during the Ross procedure can induce a specific humoral response. We observed a significant increase of the transhomograft pressure gradients within 15+/-6 months after surgery. For this period, we were unable to demonstrate a relationship between this increase and the degree of histoincompatibility.

Association of serology with the endovascular presence of Chlamydia pneumoniae and cytomegalovirus in coronary artery and vein graft disease.

BACKGROUND: Chemotherapeutic treatment for patients with symptomatic coronary artery disease to reduce cardiovascular events may be initiated in response to elevated antibody titers against Chlamydia pneumoniae or cytomegalovirus. How antibody titers are associated with the endovascular presence of these microorganisms is still unclear. METHODS AND RESULTS: Antibody titers against C pneumoniae (microimmunofluorescence) and cytomegalovirus (ELISA) in patients undergoing primary (coronary desobliterates, n=80) or repeated CABG (occluded vein grafts, n=45) were correlated with the endovascular presence of the 2 microorganisms. C pneumoniae was detected by means of a nested polymerase chain reaction (PCR) and by culturing. Both conventional PCR and quantitative PCR were applied for detection of cytomegalovirus. C pneumoniae (PCR/culture) was detected in 19/9% (15/80 and 7/80) of coronary desobliterates and in 18/11% (8/45 and 5/45) of occluded vein grafts. There was no statistical evidence that IgG values differed between patients with or without C pneumoniae detection who were undergoing primary CABG. In contrast, repeated-CABG patients with a positive PCR (P=0.0027) or C pneumoniae culture (P=0.0018) had distinctly elevated IgG titers compared with patients in whom C pneumoniae was not detected. Cytomegalovirus could not be detected in the examined specimens. CONCLUSIONS: Cytomegalovirus infection does not seem to be associated with advanced coronary artery lesions. C pneumoniae antibody titers are not associated with the endovascular presence of C pneumoniae in patients with coronary artery disease. The observed strong association between elevated IgG titers and the detection of C pneumoniae in occluded vein grafts warrants further investigation.

Biomechanical hearts: muscular blood pumps, performed in a 1-step operation, and trained under support of clenbuterol.

BACKGROUND: As shown previously in goats, clenbuterol increased the power of electrically conditioned skeletal muscle ventricles (SMVs) of clinically relevant size (150 mL), which were constructed around a mock system. They pumped against a pressure of 60 to 70 mm Hg immediately during surgery and up to several months after, finally at >1 L/min. SMVs without clenbuterol administration failed. Thus, we expected that clenbuterol-supported SMVs might become integrated into the circulation by a 1-step operation instead of the 2-step procedure required up to now. METHODS AND RESULTS: In adult Boer goats (n=5), latissimus dorsi muscle was wrapped around a polyurethane chamber of 150 mL that was connected to the descending aorta. This muscular flow-through pumping chamber containing a stabilizing inner layer (called a biomechanical heart [BMH]) was formed and immediately made to work against a systemic load with the support of clenbuterol (5x150 microg/wk). During surgery, the mean stroke volume of BMHs was 53.8+/-22.4 mL. One month after surgery, in peripheral arterial pressure, the mean diastolic (P(MD)) and minimal diastolic (P(min)) pressures of BMH-supported heart cycles differed significantly from unsupported ones (P(MD)=+2.9+/-1.1 mm Hg [P<0.04], P(min)=-2.4+/-0.9 mm Hg [P<0.04]). After BMH-supported heart contractions, the subsequent maximal rate of pressure generation, dP/dt(max), increased by 20.5+/-8.1% (P<0.02). One BMH, catheterized 132 days after surgery, shifted a volume of 34.8 mL per beat and 1.4 L/min with a latissimus dorsi muscle of 330 g. Depending on duration of training, the percentage of myosin heavy chain type 1 ranged between 31% and 100%. CONCLUSIONS: Under support of clenbuterol, BMHs of a clinically relevant size can be trained effectively in the systemic circulation after a 1-step operation and offer the prospect of a sufficient volume shift and probably unloading of the left ventricle.

Endovascular presence of viable Chlamydia pneumoniae is a common phenomenon in coronary artery disease.

OBJECTIVES: We sought to examine coronary arteries for the presence of viable bacteria of the fastidious species Chlamydia pneumoniae. BACKGROUND: The respiratory pathogen C. pneumoniae has been implicated in the pathogenesis of coronary artery disease (CAD). Previous studies have demonstrated an antichlamydial seroresponse to be a cardiovascular risk factor and coronary atheromata to contain chlamydial components in varying proportions. Endovascular demonstration of replicating bacteria is required to provide evidence for an infectious component in CAD and a rationale to discuss antimicrobial therapy. METHODS: Myocardial revascularization was performed in 70 patients. Atherosclerotic lesions from 53 coronary endarterectomy and 17 restenotic bypass samples were cultured and subjected to nested polymerase chain reaction (PCR) for C. pneumoniae. Antichlamydial immunoglobulin G (IgG), IgA and IgM was examined by microimmunofluorescence. RESULTS: Viable C. pneumoniae was recovered from 11 (16%) of 70 atheromata, and chlamydial deoxyribonucleic acid (DNA) was detected in 21 (30%) of 70 atheromata; 17 nonatherosclerotic control samples were PCR-negative (p < 0.01). Fifteen (28%) of 53 endarterectomy and 6 (35%) of 17 bypass samples were PCR-positive. DNA sequencing of six different PCR products did not reveal differences between coronary isolates and respiratory reference strains, suggesting that common respiratory strains gain access to the systemic circulation. Serologic results did not correlate with direct detection results and did not identify individual endovascular infection. CONCLUSIONS: A significant proportion of atherosclerotic coronary arteries harbor viable C. pneumoniae. This finding supports the hypothesis of a chlamydial contribution to atherogenesis. Whether chlamydiae initiate atherosclerotic injury, facilitate its progression or colonize atheromata is unknown. However, the endovascular presence of viable bacteria justifies a controlled clinical investigation of antimicrobial treatment benefit in the therapy and prevention of CAD.

Up to seven years of experience with the Ross procedure in patients >60 years of age.

OBJECTIVES: The objective of this study was to compare the outcome of patients >60 years of age with younger patients after the Ross procedure. BACKGROUND: Currently, the Ross procedure is performed predominantly in young patients. Main arguments against the Ross procedure in the elderly are the complexity of the operation and related risks. Experience with the Ross procedure in patients >60 years of age is scarce. METHODS: Between February 1990 and August 1998, the Ross procedure was performed in 27 patients (15 men and 12 women) >60 years of age (mean 64.2 +/- 3.1 years, range 60.5 to 70.6; group A) and in 84 patients (68 men, 12 women) <60 years of age (mean 43.8 +/- 12.4 years, range 15.2 to 59.4; group B). Echocardiography was applied at a mean follow-up of 28.4 +/- 21.0 and 25.2 +/- 21.4 months, respectively, to determine hemodynamic variables (ejection fraction, fractional shortening, stroke volume, cardiac output), cardiac dimensions and autograft and homograft valve function. RESULTS: There was one early and one late (esophageal bleeding) death in group B; the mortality rate was 0% in group A. One autograft was replaced because of a subvalvular aneurysm, and one patient was lost to follow-up (group B). There were no significant differences in cardiac dimensions, grade of insufficiencies across homografts and autografts and hemodynamic variables, except for a higher pressure gradient across the homograft in group B (maximal pressure gradient 11.3 +/- 5.6 vs. 7.7 +/- 4.6 mm Hg in group A). The median New York Heart Association functional class was I in both groups. CONCLUSIONS: Our seven years of experiences (mean follow-up 28 months) indicate that the Ross procedure may be performed in selected patients >60 years of age without increased risk for mortality or complications in experienced centers.

Quality of life in aortic valve replacement: pulmonary autografts versus mechanical prostheses.

OBJECTIVES: We sought to determine whether the quality of life (QoL) is different in patients after aortic valve replacement with mechanical prostheses or pulmonary autografts. BACKGROUND: Quality of life after mechanical valve replacement may be affected by the risk of thromboembolism and anticoagulation, and after autograft implantation, by the risk of degeneration and re-operation especially of the homograft. METHODS: Two groups of 40 patients each--one after the autograft procedure (group I) and one after mechanical valve implantation (group II)--were matched for age, gender and length of follow-up. At latest follow-up, all patients underwent routine echocardiography, the short-form health survey (SF-36) QoL survey and an extensive psychological investigation. RESULTS: Patients with an autograft showed better QoL scales, as compared with mechanical valve recipients. The difference was significant for both the physical (72.72+/-20.00 vs. 60.27+/-26.07, p = 0.021) and psychological health sum scores (74.71+/-21.03 vs. 64.71+/-23.49, p = 0.046) and for the subtests of physical functioning (73.72+/-22.44 vs. 62.77+/-25.42, p = 0.049), physical pain (88.39+/-19.13 vs. 73.36+/-27.08, p < or = 0.006), general health perception (64.37+/-17.88 vs. 51.86+/-22.86, p < or = 0.008) and health change (61.89+/-18.94 vs. 50.11+/-24.37, p = 0.02). The QoL variables did not correlate to pressure gradients, ejection fraction and New York Heart Association functional class. Psychometric tests revealed no meaningful differences between the groups. CONCLUSIONS: This study provides some evidence that patients with pulmonary autografts have greater benefit in terms of QoL, as compared with recipients of mechanical valve substitutes.

Effects of angiocardiographic contrast media on the pulmonary circulation in pigs.

In 12 open-chest pigs, mean weight 18 kg, simultaneous beat-to-beat measurements of pressure in the right and left atria and right and left ventricles, and of pressure and flow in the pulmonary artery, were performed before, during and after the injection of 0.8 ml/kg with 10 to 15 ml/s of diatrizoate, ioxaglate and iopamidol as well as mannitol, normal saline solution and own blood into the right atrium, right ventricle and pulmonary artery. Within 5 beats after injection, all determined hemodynamic values reached their maxima of change independent of site of injection and kind of injectate. After 10 to 20 beats, pulmonary resistance diminished, and the reduction was more pronounced and longer lasting the higher the osmolality of the injectate. Hemodynamic changes during the first beats were a result of the rapidly injected volume; longer lasting hemodynamic changes were associated with an osmolality-dependent decrease in pulmonary resistance.

Influence of the two-stage anatomic correction of simple transposition of the great arteries on left ventricular function.

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great arteries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = 11), and compared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 +/- 10) and between 13 and 47 months (mean 24 +/- 10), respectively. The interval between anatomic correction and the investigation ranged from 10 to 29 months (mean 20 +/- 7). After banding, LV ejection fraction decreased (p less than 0.01) and LV peak systolic pressure (p less than 0.01) as well as LV end-diastolic pressure (p less than 0.05) increased. After anatomic correction, these variables and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 patients after anatomic correction was within control range. The highest values were found in the youngest patients at banding and at anatomic correction. In contrast to measures of global myocardial function, such as LV ejection fraction and LV end-diastolic pressure data, the LV end-systolic stress-ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.

Catheter evaluation of left ventricular shape and function 1 or more years after anatomic correction of transposition of the great arteries.

Twenty-eight children were reinvestigated by cardiac catheterization and angiography greater than 1 year after anatomic correction of transposition of the great arteries (TGA). Seventeen patients with simple TGA underwent banding of the pulmonary trunk plus or minus systemic to pulmonary artery shunt to prepare the left ventricle for anatomic correction. In addition to TGA, 10 of the remaining 11 patients had a large ventricular septal defect and 1 had an aorticopulmonary window. They required no preparation of the left ventricle. Age at repair ranged from 2 to 120 months (mean 26). Catheterization 12 to 48 months after anatomic repair revealed a left ventricular end-diastolic pressure of 4 to 14 mm Hg (mean 9.5 +/- 2.5 [+/- standard deviation]). Ejection fraction ranged from 52 to 75% (mean 66 +/- 8). Frame-by-frame computer-assisted analysis of left ventricular (LV) contraction and relaxation was performed in 14 patients and compared with normal left ventriculograms. Shape index, derived as 4 pi X cavity area/perimeter2 X 100, was measured in 24 patients and showed a mean index of 89 +/- 3% at end-diastole and 79 +/- 8% at end-systole. A control group had a mean diastolic index of 86 +/- 6% and mean systolic index of 73 +/- 8%. It is concluded that LV shape after anatomic correction tends to be more globular than normal and changes little during systole. LV ejection fraction and end-diastolic pressure are normal.

Atrial natriuretic peptide release at rest and with exercise after cardiac transplantation with bicaval anastomoses.

Bicaval anastomoses in orthotopic cardiac transplantation offer the advantage of preserving the right atrial geometry. To elucidate the impact of this anastomotic technique on atrial natriuretic peptide plasma levels at rest and with exercise, nine patients were submitted to a symptom-limited supine exercise test. Atrial natriuretic peptide plasma levels in samples obtained from the right atrium were elevated at rest (274.4 +/- 60.4 pg/ml), at peak exercise (438.1 +/- 71.7 pg/ml), and thereafter (328.1 +/- 71.2 pg/ml) with respect to normal reference values of 21 +/- 1 pg/ml at rest and 92 +/- 14 at peak exercise. Renin, angiotensin, and aldosterone plasma levels were almost normal and did not indicate any pathologic processes in volume homeoostasis. Right-sided hemodynamic parameters were not correlated with atrial natriuretic peptide secretion. An adverse relationship between cold ischemic time of the donor organ and atrial natriuretic peptide release was found (r = 0.88, p < 0.0008), indicating that endocrine cardiocytes are sensitive to prolonged ischemia. Atrial natriuretic peptide release may thus be independent of the surgical approach, and other unique characteristics of the transplanted heart, such as denervation, are more likely to be responsible for elevated atrial natriuretic peptide plasma concentrations after orthotopic heart transplantation.