Protein phosphatase mRNA expression in Purkinje cells of staggerer and reeler mutant mice

Orthotopic heart transplantation (OHT) with bicaval and pulmonary venous anastomoses avoids the large atrial anastomoses of the standard biatrial technique. To determine whether the bicaval technique improves atrial performance, we used Doppler echocardiography to study 13 patients with bicaval OHT, 15 with biatrial OHT, and 8 normal subjects. All were in sinus rhythm and free of rejection. Left atrial size, transmitral (M) and late diastolic (A) mitral flow velocity integrals were measured. Atrial transport (A/M, %) and atrial ejection force (kilodynes, calculated from peak A-wave velocity and mitral orifice area) were assessed. Left atrial dimensions in the bicaval (4.3 +/- 0.5 cm) and biatrial groups (4.9 +/- 0.9 cm) were larger than in controls (3.3 +/- 0.8 cm, p < 0.05). Left atrial transport (37% +/- 12% and 35% +/- 12%) and ejection force (14.1 +/- 6.9 kdyne and 10.2 +/- 7.8 kdyne) were similar in the bicaval group and controls (p not significant) but were significantly lower in the biatrial group (20% +/- 19% and 3.6 +/- 4.0 kdynes, p < 0.05). The bicaval and pulmonary venous technique of OHT produces more physiologic atrial function compared with the biatrial technique as evidenced by greater atrial ejection force and more normal atrial transport.     

The bicaval anastomosis technique for orthotopic heart transplantation yields better atrial function than the standard technique: an echocardiographic automatic boundary detection study

BACKGROUND: Atrial function is an important determinant of cardiac performance. In patients who undergo operation by standard heart transplantation atrial enlargement, distortion of geometry and asynchronous contraction resulting from the donor/recipient atrial connections may affect atrial function. The bicaval anastomosis technique should be free from these limitations. METHODS: We used the echocardiographic automatic boundary detection technique to obtain on-line time/volume curves of right and left atria from patients who had undergone bicaval (n = 22) or standard (n = 27) heart transplantation and from 15 control subjects. Maximal, middiastolic, preatrial contraction, and minimal volumes of both atria were measured. Reservoir volume (defined as the difference between maximal and middiastolic atrial volumes); pump volume (defined as the difference between preatrial contraction and minimal atrial volumes); and conduit volume (defined as the difference between left ventricular stroke volume and the sum of reservoir and pump volumes) were derived for both atria. Atrial emptying fraction was calculated as the difference between maximal and minimal volumes divided by the maximal volume and expressed in percent and pump fraction as the pump volume divided by the sum of reservoir and pump volumes. Tricuspid and mitral regurgitation, evaluated by color-flow Doppler scanning, were considered significant when they were greater than grade 1. Atrial ejection force was calculated from mitral and tricuspid flow velocities at atrial contraction. RESULTS: In patients who had bicaval heart transplantation, both atria were smaller than in patients who underwent standard heart transplantation. With the bicaval technique right and left atrial emptying (right 45% +/- 9% vs 36% +/- 10%, p < .05; left 51% +/- 8% vs 39% +/- 8%, p < .001) and pump fractions (right 57% +/- 17% vs 19% +/- 13%, p < .001; left 45% +/- 28% vs 22% +/- 12%, p < .01) were greater than with the standard technique and similar to those in control subjects. Right atrial ejection force was significantly greater in bicaval (10.0 +/- 5.6 kdyne) than in standard heart transplantation (4.5 +/- 2.2 kdyne, p < .0001). Significant tricuspid or mitral regurgitation was rarely found in bicaval heart transplant recipients (3 and 1 of the 22 patients, respectively), although they were much more frequent after standard heart transplantation (13 and 8 of the 27 patients, respectively). CONCLUSIONS: Heart transplantation performed with the bicaval anastomosis technique determines smaller atrial volumes, yields better right and left atrial function and fewer atrioventricular valve regurgitation than the standard technique.     

Right ventricular function in orthotopic total atrioventricular heart transplantation

BACKGROUND: Total orthotopic heart transplantation was recently introduced into clinical practice as an alternative technique of orthotopic heart transplantation, adding bicaval and left and right pulmonary vein anastomoses to pulmonary artery and ascending aorta connection (total technique). The conventional technique (ventricular transplantation with atrioplasty) is compared with the total technique with particular emphasis on right ventricular performance. METHODS: Forty-eight mongrel dogs (23 to 31 kg) were used for 12 total and 12 standard orthotopic heart transplantations. Right ventricular (RV) function and atrial systole were analyzed with the use of micromanometry, sonomicrometry, and ultrasonic flow probes (preload-independent RV recruitable stroke work, RVPRSW). Fourier analysis was used to calculate RV power and pulmonary vascular impedance. RESULTS: There was no significant difference in cardiac ischemic and bypass times between the two groups. After transplantation, sinus rhythm was preserved after all total transplantations and after only one standard transplantation; no significant hemodynamic differences were observed. RVPRSW in the total group was conserved after transplantation; however, RVPRSW decreased by 39% (+/-8, p < .05) in the standard group. There was also a significant decrease in the rate of RV filling in the standard group after transplantation, suggesting decreased right atrial function. Pulmonary vascular impedance and RV power output were not significantly different after transplantation between the two groups. CONCLUSIONS: Total atrioventricular transplantation is a feasible alternative and conserves normal sinus rhythm. Ischemic and bypass times were not significantly different when the superior vena cava anastomosis is performed last after the release of the aortic cross-clamp. The insignificant decrease in the rate of RV filling with the use of the total technique suggests conserved RV diastolic function after transplantation with less decreased RV function in the total group.     

A rare cause of respiratory failure: Echinococcus of the pulmonary artery

To combine the advantages of the standard technique and the bicaval technique of orthotopic heart transplantation, we use a muscular flap of recipient heart right atrium for connecting the superior vena cava with the donor heart right atrium. The results in respect to the maintenance of atrioventricular valve competence as well as atrial conduction are promising.     

Staphylococcus aureus cap5O and cap5P genes functionally complement mutations affecting enterobacterial common-antigen biosynthesis in Escherichia coli

BACKGROUND: Excision of large right atrial masses requires bicaval cannulation and cardiopulmonary bypass. Safe venous cannulation can be accomplished only by knowing the exact intracavitary location and extension of the mass to avoid fragmentation. Transthoracic echocardiography and intraoperative transesophageal echocardiography, although helpful, cannot always define the exact intracavitary relationships of the tumor. METHODS: We have used both intraoperative transesophageal and epicardial echocardiography to guide venous cannulation in 4 patients with large right atrial masses. Both echo images are used by the surgeon to select the exact site and method of cannulation to avoid fragmentation of the mass. Epicardial echocardiography complemented the images obtained by transesophageal echocardiography. RESULTS: The technique of combined transesophageal and epicardial echocardiography allowed safe venous cannulation in all 4 patients. Each of the right atrial masses was safely excised using case-specific cannulation techniques guided by the echocardiographic images. CONCLUSIONS: We propose the routine use of both intraoperative transesophageal and epicardial echocardiography in guiding venous cannulation for safe excision of large right atrial masses.     

Acute bicaval obstruction as a result of intracapsular haemorrhage in a right atrial myxoma: report of a case

Right atrial myxomas are rare and presentation is characterised by the gradual onset of one or more of a triad of constitutional, obstructive, or embolic symptoms. We describe a case in which interstitial haemorrhage within a right atrial myxoma resulted in rapid expansion and presentation with features of rapidly progressing bicaval obstruction and atrial flutter. Transthoracic echocardiography failed to detect this tumour; however, transoesophageal echo clearly displayed it and gave information on its attachment and relations which proved to be valuable in the planning of its surgical excision.     

Secundum atrial septal defect. Nonoperative closure during cardiac catheterization

A 17-year-old girl had clinical and cardiac catheterization findings compatible with a secundum atrial septal defect. During cardiac catheterization, the atrial septal defect was sized and closed using a transvenous umbrella technique.     

Alterations in pulmonary artery flow patterns and shear stress determined with three-dimensional phase-contrast magnetic resonance imaging in Fontan patients

OBJECTIVE: This study compares in vivo pulmonary blood flow patterns and shear stresses in patients with either the direct atrium-pulmonary artery connection or the bicaval tunnel connection of the Fontan procedure to those in normal volunteers. Comparisons were made with the use of three-dimensional phase contrast magnetic resonance imaging. METHODS: Three-dimensional velocities, flows, and pulmonary artery cross-sectional areas were measured in both pulmonary arteries of each subject. Axial, circumferential, and radial shear stresses were calculated with the use of velocities and estimates of viscosity. RESULTS: The axial velocities were not significantly different between subject groups. However, the flows and cross-sectional areas were higher in the normal group than in the two patient groups in both pulmonary arteries. The group with the bicaval connection had circular swirling in the cross section of both pulmonary arteries, causing higher shear stresses than in the controls. The disorder caused by the connection of the atrium to the pulmonary artery caused an increase in some shear stresses over the controls, but not higher than those found in the group having a bicaval tunnel. CONCLUSIONS: We found that pulmonary flow was equally reduced compared with normal flow in both patient groups. This reduction in flow can be attributed in part to the reduced size of the pulmonary arteries in both patient groups without change in axial velocity. We also found higher shear stress acting on the wall of the vessels in the patients having a bicaval tunnel, which may alter endothelial function and affect the longevity of the repair.     

Freezing to death--the treatment of accidental hypothermia in the Scottish mountains

Ultrastructure of atrial cardiomyocytes in adrenalin myocardiodystrophy was studied in white rat experiments. Morphometrically, there was a reduced number of mitochondria and secretory granules in the atrial muscular cells, space characteristics of cardiomyocytes and their nuclei increased. The above rearrangement of the atrial cardiomyocytes indicates that adrenalin myocardiodystrophy is associated with a decline in synthetic and secretory function of the test cardiac muscular cells.     

Transient sinus node dysfunction after the Cox-maze III procedure in patients with organic heart disease and chronic fixed atrial fibrillation

OBJECTIVES: This prospective study examined types, frequency and time dependency of the electrophysiologic manifestation of the sinus node dysfunction after the Cox-maze III procedure--the technique of choice for the management of medically refractory atrial fibrillation-in patients with organic heart disease, chronic fixed atrial fibrillation and no preoperatively overt dysfunction of the sinus node. BACKGROUND: The original maze procedure was modified twice in order to reduce the high incidence of the sinus node inability to generate an appropriate sinus tachycardia in response to maximal exercise, and occasional left atrial dysfunction. Despite these modifications, postoperative disturbance of sinus node function can be frequently observed. METHODS: In 15 adult patients, standard electrocardiogram, 24-h Holter monitoring, power spectral analysis of heart variability, exercise testing, Valsalva maneuver and rapid positional changes were performed 3, 6 and 12 months after the Cox-maze III procedure and mitral valve surgery or closure of atrial septal defect. RESULTS: Electrocardiographic manifestations of sinus node dysfunction were identified in 12 patients at 3 months, in 6 patients at 6 months, and in 0 patients at 12 months after surgery. The heart rate response to exercise during the first 6 months was reduced in the maze group and became fully normal at 12 months. Power spectral analysis of heart rate variability showed very low power values at 1 month with inhibited cardiac autonomic activity and no response on sympathetic stress. A potential of recovery of cardiac autonomic activity was documented 12 months after surgery. CONCLUSIONS: The manifestations of sinus node dysfunction following the Cox-maze III procedure were time dependent and their frequency and intensity progressively decreased and disappeared within 12 months after surgery.     

Change in the hemodynamic indices under hemodilution conditions induced by the transfusion of the blood substitute geosen after acute blood loss

Cardiac performance and oxygen consumption in 30 patients undergoing surgical treatment for congenital cardiac disease were determined from intraoperative measurements. Arterial pressure, cardiac index, mean left ventricular hydraulic output power, pulmonary artery oxygen saturation were obtained at average mean left atrial pressures of 8.1 and 15.2 cm H2O after cardiopulmonary bypass in 20 patients. These same variables were measured at an average pulmonary artery saturation of 65 and 75% in 30 patients. A composite of measurements of cardiac performance was desirable to guide precise patient care intraoperatively, especially if myocardial function was compromised. It is suggested that left atrial pressure be maintained at a level that results in a pulmonary artery saturation greater than 65%.     

The age-associated alterations in late diastolic function in mice are improved by caloric restriction

Caloric restriction reduces the magnitude of many age-related changes in rodents. Cardiac function is altered with senescence in mice, rats, and healthy humans. We examined the effects of life-long caloric restriction on diastolic and systolic cardiac function in situ using Doppler techniques in ad libitum-fed 30- to 32-month-old (AL) and calorically restricted (CR) 32- to 35-month-old female B6D2-F1 hybrid mice. The heart weight to body weight ratio was similar in AL (5.74 +/- .24 mg/g) and CR (5.68 +/- .20 mg/g) mice. Two systolic functional parameters known to decrease with age in both humans and mice, peak aortic velocity and aortic acceleration, were unchanged by CR compared to AL. In contrast, diastolic function was altered by caloric restriction. Although left ventricular peak early filling velocity (E) was not different between CR and AL, peak atrial filling velocity (A) was 50% lower in CR compared to AL (p < .001). The ratio of early diastolic filling to atrial filling (E/A ratio) was 64% higher in the CR (2.74 +/- .31) than the AL (1.55 +/- .07; p = .004). The fraction of ventricular filling due to atrial systole, the atrial filling fraction, was also reduced in CR (.21 +/- .04) compared to AL (.36 +/- .02; p = .007). These changes occurred in CR without alteration in E deceleration time, which is consistent with improved diastolic function in CR. Through mechanisms that remain unknown, lifelong caloric restriction may prevent the age-related impairments in late diastolic function but does not alter the impairments in systolic or early diastolic cardiac function.     

Haemodynamics and body fluid volumes in response to fluid loading in conscious dogs: non-excretory renal influences

1. Twelve conscious, chronically instrumented dogs were subjected to rapid loading with sodium chloride solution (150 mmol/1; saline) before and 1 day after bilateral nephrectomy (six dogs) or ureterocaval anastomosis (six dogs). Measurements were performed up to 3 h after the fluid load and included cardiac output with an electromagnetic flowmeter, mean arterial pressure and right atrial pressure with chronically implanted catheters, interstitial fluid pressure with a plastic capsule, heart rate, extracellular fluid volume, erythrocyte volume, plasma volume, plasma protein concentration and other variables. 2. The increase in cardiac output in response to saline load was significantly prolonged in the anephric dogs compared with those with uretero-caval anastomosis; mean arterial pressure, right atrial pressure and heart-rate changes were similar in both groups. 3. Plasma volume appeared to increase more in the anephric dogs than in those with uretero-caval anastomosis during the first hour after the infusion, although conflicting results were obtained with different estimates of plasma volume changes. Interstitial fluid pressure increased significantly less in the anephric dogs in the early stages of the fluid load. 4. Effective vascular compliance (the ratio of the change in blood volume to the change in right atrial pressure) appeared increased in the anephric dogs. On the other hand, the change in cardiac output for a given change in right atrial pressure was found to increase after bilateral nephrectomy. 5. It is suggested that the prolonged increase in cardiac output observed in anephric dogs was not the consequence of preferential plasma volume expansion nor of decreased venous compliance, but may reflect an alteration in the cardiac function curve.     

Improved outcome after coronary bypass surgery in patients with ischemic cardiomyopathy and residual myocardial viability

BACKGROUND: Although residual myocardial viability in patients with coronary artery disease and extensive regional asynergy is associated with improved ventricular function after coronary bypass surgery, the relationship between viability and clinical outcome after surgery is unclear. We hypothesized that patients with poor ventricular function and predominantly viable myocardium have a better outcome after bypass surgery compared with those with less viability. METHODS AND RESULTS: Seventy patients with multivessel coronary artery disease and left ventricular ejection fractions < 40% who underwent preoperative quantitative 201Tl scintigraphy before coronary bypass surgery were analyzed retrospectively. 201Tl scintigrams were reviewed blindly, and each segment was assigned a score based on defect magnitude. Segmental viability scores were summed and divided by the number of segments visualized to determine a viability index. The viability index was significantly related to 3-year survival free of cardiac event (cardiac death or heart transplant) after bypass surgery (P=.011) and was independent of age, ejection fraction, and number of diseased coronary vessels. Patients with greater viability (group 1; viability index > 0.67; n=33) were similar to patients with less viability (group 2; viability index < or = 0.67; n=37) with respect to age, comorbidities, and extent of coronary artery disease. There were 6 cardiac deaths and no heart transplants in group 1 patients and 15 cardiac deaths and two transplants in group 2 patients. Survival free of cardiac death or transplantation was significantly better in group 1 patients on Kaplan-Meier analysis (P=.018). CONCLUSIONS: We conclude that resting 201Tl scintigraphy may be useful in preoperative risk stratification for identification of patients more likely to benefit from surgical revascularization.     

Laparoscopic cholecystectomy using the abdominal wall lift in a cardiac patient

We present a case report of a patient with impaired cardiac function after aortic valve replacement and open mitral commissurotomy who underwent a laparoscopic cholecystectomy for cholecystolithiasis. In preventing reduced cardiac output due to pneumoperitoneum, the laparoscopic operative procedure was performed using the abdominal wall lift. Cardiac function was continuously evaluated by transesophageal echocardiographic examination and remained stable during the surgery. Because of the patient's co-existing chronic atrial fibrillation and prosthetic aortic valve, perioperative anticoagulation management was carried out. The patient's post-operative course was uneventful, and he was discharged on the 7th post-operative day.     

Potential paracrine role of the pericardium in the regulation of cardiac function

OBJECTIVE: Both coronary and endocardial endothelium regulate cardiac contractile function via paracrine pathways. We investigated whether pericardial fluid (PF) and pericardial mesothelial cells (PMC) could exert a similar paracrine action. METHODS: Both PF and PMC were extracted from sheep pericardial space. Endothelin-1, prostaglandins and atrial natriuretic factor were measured in PF in vivo. In the other hand, PMC were grown on T-75 flasks and microcarrier beads to investigate endothelin-1, nitric oxide and prostaglandin pathways in vitro. In addition, effects of PF and PMC effluent were tested on adult rat cardiac myocyte contraction in vitro. RESULTS: In vitro, cultured PMC expressed endothelin-1 mRNA but not the endothelial nitric oxide synthase III, and released endothelin-1 and prostaglandins. Both PF and cultured PMC superfusate induced a potent, rapidly reversible decrease in the shortening of isolated rat cardiac myocytes. This effect was not associated with changes in intracellular calcium. In vivo, prostaglandins, atrial natriuretic factor and endothelin were present in PF. A greater concentration of atrial natriuretic factor was present in PF than in serum, suggesting molecular diffusion from the myocardium to PF. Preliminary results show that the instillation of vasoactive agents into the pericardial space of dogs rapidly alter coronary and systemic vascular tone, consistent with a molecular diffusion of these substances from PF into the myocardium and circulation. CONCLUSIONS: In addition to its mechanical role, the pericardium may contribute to the integration and the regulation of cardiovascular function via a paracrine mechanism.     

Clinical and echocardiographic features influencing recovery of atrial function after cardioversion of atrial fibrillation

Atrial mechanical dysfunction after cardioversion for atrial fibrillation has been widely evaluated in recent years. Nevertheless, the influence of many clinical and echocardiographic parameters is not yet understood. The aim of the present study was to evaluate the influence of clinical and echocardiographic parameters on the return of effective atrial contraction. A total of 109 patients were evaluated: 41 patients had spontaneous recovery of sinus rhythm and 68 patients were randomly treated using either direct-current (DC) shock or intravenous procainamide. Elective cardioversion was accomplished pharmacologically in 23 patients (67%) and with DC shock in 29 patients (85%). Patients underwent a complete echocardiographic examination 1 hour after the restoration of sinus rhythm and after 1 and 7 days and 1 month. The following parameters were evaluated: patient age, cardiac disease, duration and etiology of atrial fibrillation, mode of cardioversion, left ventricular diameters and function, and left atrial diameter and function assessed as atrial ejection force. The relation between these variables and atrial ejection force was tested. Atrial ejection force was greater immediately and 24 hours after cardioversion in patients who had spontaneous recovery of sinus rhythm and in patients treated with drugs than in patients treated with DC shock. The mode of cardioversion was significantly associated with the recovery of atrial mechanical function by day 1 in univariate and multivariate analyses (odds ratio 0.14; 95% confidence interval 0.02 to 1.2). The other variable associated with the recovery of function was normal left atrial size (odds ratio 0.16; 95% confidence interval 0.12 to 1.6). In conclusion, atrial ejection force is a noninvasive parameter that can be easily measured and can provide accurate information about the recovery of left atrial mechanical function. The recovery of atrial function was influenced by the mode of cardioversion and the size of the left atrium.     

Effects of propionyl-L-carnitine on cardiac dysfunction in streptozotocin-diabetic rats

The effects of orally administered propionyl-L-carnitine on cardiac dysfunction in rats with streptozotocin-induced diabetes were investigated. Wistar male rats were divided into four groups: untreated normal, propionyl-L-carnitine (daily for 4 weeks with 3 g/kg orally) -treated normal, untreated diabetic, propionyl-L-carnitine-treated diabetic. Four weeks after streptozotocin administration, plasma lipid levels were increased and myocardial carnitine content was decreased in untreated diabetic rats. These changes were significantly reversed by the propionyl-L-carnitine treatment. Assessment of cardiac function with isolated perfused working hearts revealed a depression of left ventricular developed pressure as well as both maximum positive and negative dP/dt in untreated diabetic as compared with that in normal hearts. Cardiac function at the higher left atrial filling pressures in the propionyl-L-carnitine-treated diabetic rats was improved significantly compared to that in untreated hearts. The data thus suggest that oral administration of propionyl-L-carnitine can reduce abnormalities of cardiac function, correlated with a significant increase in myocardial carnitine content and improved lipid metabolism in terms of lowered plasma lipids.     

Differential atrial filling after Mustard and Senning repairs. Detection by transcutaneous Doppler ultrasound

The dominance of Mustard's operation for transposition of the great arteries has been challenged by the recent revival of Senning's repair because it promises better long-term results in terms of venous obstruction and atrial haemodynamics. These hypotheses were tested by recording jugular venous flow waveforms transcutaneously in 24 postoperative patients with simple complete transposition using a bidirectional Doppler blood velocimeter. Eight patients had undergone Mustard's operation and 16 the Senning alternative; all had previously had a postoperative cardiac catheterisation. Both groups of patients had similar left ventricular, pulmonary arterial, and systemic venous atrial pressures. No child showed any evidence at catheterisation of either mitral regurgitation or of superior vena caval pathway obstruction. These two findings were endorsed by the transcutaneous Doppler recordings. Jugular venous flow in normal children exhibits two maxima, one of atrial filling during ventricular systole, the other of ventricular filling occurs once the tricuspid valve has opened. Both operative procedures diminished the size of the former phase, but the Mustard did so more. After Mustard's operation forward flow during the atrial filling phase was absent in approximately half the cardiac cycles recorded, and severely diminished in the rest. By contrast, there was approximately a 90 per cent appearance of atrial filling waves after Senning's operation which also provided significantly better atrial function than Mustard's procedure in terms of peak velocity of blood entering the atrium and total atrial filling. It is therefore concluded that both procedures compromise atrial volume and compliance but Senning's repair to a much lesser extent.     

Left ventricular function in asthmatic children chronically treated with theophylline evaluated by exercise Doppler echocardiography

To evaluate the chronic effects of theophylline on cardiac function, M-mode and pulsed Doppler derived variables were measured at rest and the suprasternal continuous wave Doppler measurement of ascending aortic flow was used during treadmill exercise testing. Subjects consisted of 13 children with stable asthma (mean 11.7 +/- 2.2 years) who were treated with theophylline for at least one year and 16 age-matched, untreated normal volunteers. In the resting state, the chronic administration of theophylline seemed to produce a slight increase in percent fractional shortening, outflow peak velocity and atrial contribution to ventricular filling in the asthmatic children as compared to normals, but these changes were not statistically significant. The asthmatic children showed significantly lower values than the controls in exercise induced changes in the peak velocity, stroke index and cardiac index, but not in the heart rate. Therefore, chronic administration of theophylline appears to have a minimal effect on resting cardiac function, but a possibly deleterious effect on the cardiac response to exercise testing.