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At least 73 records · Page 4Linked to original sources
PubMed1984

Echocardiographic evaluation of atrial function after Senning and Mustard correction for transposition of the great arteries.

Two groups of six children who had undergone either Senning or Mustard repair for uncomplicated transposition of the great arteries were studied with M mode echocardiography derived from a phased array sector scanner picture. The newly created atria were visualised from the subxiphoid region and the upper systemic venous inflow was selected for a simultaneous M mode registration with a subsequent wall motion analysis with a commercially available computer. In the Mustard group of patients the atrial walls seemed to move passively with the overall heart movements, while abrupt atrial wall excursions of both atria synchronous with heart action were noted in all patients after Senning repair. In this group also slow cyclic changes followed respiration. The atrial wall movements were significantly superior (p = 0.001) in the Senning group of patients. It is concluded that, in contrast to the Mustard method, the Senning operation seems to lead to a viable atrium with the capability of increasing and diminishing atrial diameter and with subsequent potential for growth.

Adolescent↗
PubMed1993

Human small cell lung cancer cell lines express functional atrial natriuretic peptide receptors.

Small cell lung cancer cell (SCLC) lines, NCI-H82, NCI-H660, and NCI-H1284, and HeLa cells were analyzed for the presence of atrial natriuretic peptide (ANP) receptors. In these SCLC cell lines and HeLa cells, ANP A receptor mRNA was identified by Southern blot analyses of polymerase chain reaction products and RNase protection assays using poly(A)(+)-selected RNA. Saturable binding assays revealed that HeLa cells had 2000 to 5000 high affinity atrial natriuretic peptide receptors per cell with a dissociation constant of 140 pM. In the SCLC cell lines, the binding was saturable but too low to accurately estimate the number of binding sites. After addition of human ANP, radioimmunoassays revealed accumulation of cyclic GMP in SCLC cells as well as HeLa cells in a dose-dependent fashion. The half-maximal stimulation concentration of cyclic GMP accumulation in HeLa and these SCLC cell lines was approximately 2 nM. Tetrazolyl blue assays and tritiated thymidine incorporation did not show any remarkable growth inhibition or growth stimulation of SCLC cell lines after addition of human ANP up to 3.3 microM, more than 1000-fold greater than the half-maximal stimulation concentration of cyclic GMP accumulation. Our results indicate that human SCLC cells express functional ANP receptors but ANP addition produced no detectable change in their growth pattern.

Atrial Natriuretic Factor↗
PubMed1976

Functionally atrialized parchment-like right ventricle with extensive myocardial fibrosis of left ventricle.

A 18-year-old female with unusual type of parchment-like right ventricle died of intractable congestive heart failure was reported. A catheter study revealed the absence of systolic contraction of the right ventricle. The pressure tracing curve in the right ventricle was virtually the same as in the right atrium. At autopsy, there was an extensive myocardial fibrosis of the left ventricle in addition to the almost total absence of the myocardium of the right ventricle. The case was considered to be a unique type of idiopathic cardiomyopathy.

Adolescent↗
PubMed1991

Effects of hyperglycaemia on kidney function, atrial natriuretic factor and plasma renin in patients with insulin-dependent diabetes mellitus.

In normoalbuminuric patients with insulin-dependent diabetes mellitus, plasma atrial natriuretic factor (ANF), cyclic GMP and active renin and the renal clearances of [99Tcm]-diethylenetriaminepentaacetic acid (DTPA) lithium and sodium were studied on a hyperglycaemia day and a euglycaemia day. Baseline euglycaemia was achieved by an overnight variable insulin infusion, which during study days was fixed at the rate necessary to maintain euglycaemia in the morning. After a baseline euglycaemic clearance period of 90 min, measurements were repeated in a new 90-min period beginning 150 min later. On the hyperglycaemia day i.v. infusion of 20% glucose was started at the end of the euglycaemic baseline period, increasing blood glucose (5.3 +/- 1.3 vs 12.1 +/- 1.2 mmol l-1, p less than 0.01). On the euglycaemia day blood glucose declined (5.1 +/- 1.0 vs 4.2 +/- 1.0 mmol l-1, p less than 0.02). Glomerular filtration rate (GFR) was unchanged by acute hyperglycaemia (127 +/- 16 vs 129 +/- 24 ml min-1, NS), but nearly normalized during maintained euglycaemia on the euglycaemia day (124 +/- 17 vs 105 +/- 16 ml min-1, p less than 0.01). When comparing the hyperglycaemic study period with the similarly timed period on the euglycaemia day, GFR was elevated by hyperglycaemia (129 +/- 24 vs 105 +/- 16 ml min-1, p less than 0.01), while the renal clearances of lithium and sodium were similar. Consequently, the calculated absolute proximal reabsorption rate of sodium and water was elevated during hyperglycaemia. Hyperglycaemia reduced the slight decline in plasma concentrations of ANF and cyclic GMP observed on the euglycaemia day. Active renin, glucagon and plasma osmolality were unchanged. In conclusion, marked changes in glomerular filtration rate are induced by changes in blood glucose concentration, but the effect is delayed and thus not directly related to renal tubular transport of glucose. Hyperglycaemia does not affect renal clearances of lithium and sodium, while proximal tubular reabsorption is markedly stimulated. These changes are not related to changes in ANF, renin, glucagon or plasma osmolality.

Adult↗
PubMed1989

Functional atrial natriuretic peptide receptor in human adrenal tumor.

The effects of synthetic human atrial natriuretic peptide (ANP) on the release of catecholamines, aldosterone, or cortisol were observed in human adrenal tumors obtained surgically from patients with pheochromocytoma, primary aldosteronism, or Cushing's syndrome, respectively. Each tumor tissue or adjacent normal cortical tissue was sectioned into slices, which were incubated in medium-199 in the presence or absence of adrenocorticotrophin (ACTH) and ANP. The amounts of epinephrine, norepinephrine, aldosterone, or cortisol released into the medium were measured. Existence of ANP receptors on the adrenal tissues was examined by binding assays, affinity labeling, and immunohistochemistry. Release of catecholamines from pheochromocytoma tissues was inhibited by ANP, and the presence of the ANP receptor on pheochromocytoma was further demonstrated by both binding assays and affinity labeling; Scatchard analysis revealed a single class of binding sites for ANP with a Kd of 1.0 nM and a Bmax of 0.4 pmol/mg of protein and the molecular size was estimated as 140 and a 70 kDa under nonreducing and reducing conditions, respectively. The presence of ANP receptors in pheochromocytoma was demonstrated by immunohistochemistry. ANP inhibited both basal and ACTH-stimulated aldosterone secretion in the slices of normal cortex, and localization of ANP receptors in zona glomerulosa cells was also demonstrated. However, ANP did not inhibit basal and ACTH-stimulated aldosterone and cortisol secretion in both tissue slices from aldosteronoma and Cushing's adenoma. Consistent with these observations, the absence of ANP receptors in adenoma tissues was determined by binding assays, affinity labeling, and immunohistochemistry.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex↗
PubMed1995

Clinical significance of fibrillatory wave amplitude. A clue to left atrial appendage function in nonrheumatic atrial fibrillation.

Seventy-eight patients with chronic nonrheumatic atrial fibrillation were studied by transesophageal echocardiography with regard to the left atrial appendage function and its relation to the coarseness of atrial fibrillation on electrocardiogram. These 78 patients (52 men and 26 women; mean age, 66 +/- 10 years; range, 40 to 94 years) were classified into two groups according to the presence of coarse (group 1, n = 46; those with the greatest amplitude of fibrillatory wave in lead V1 > or = 1 mm) or fine (group 2, n = 32; those without the coarse fibrillatory wave in lead V1) atrial fibrillation on a standard 12-lead electrocardiogram within 1 month of echocardiographic studies. There were no significant differences in age, sex, mean duration of atrial fibrillation, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, left ventricular ejection fraction, and left atrial dimension between the two groups. In group 1, however, the left atrial appendage ejection fraction (24.4 +/- 14.2% vs 32.6 +/- 14.8%; p < 0.05) and the peak emptying velocity (21.7 +/- 12.6 cm/s vs 30.4 +/- 14.3 cm/s; p < 0.01) were lower than those in group 2. There were higher incidences of left atrial appendage spontaneous echo contrast (26/46 vs 7/32; p < 0.005) and thrombus (8/46 vs 0/32; p < 0.05) in group 1 patients. The coarse atrial fibrillation revealed a sensitivity of 80.0%, a specificity of 58.1%, a positive predictive value of 60.9%, and a negative predictive value of 78.1% for the presence of left atrial appendage spontaneous echo contrast and/or thrombus formation. In conclusion, in patients with coarse nonrheumatic atrial fibrillation, the left atrial appendage function is usually poor and the incidence of spontaneous echo contrast and thrombus formation appears to be higher in these patients.

Adult↗
PubMed1990

Comparative values of the precordial and transesophageal approaches in the echocardiographic evaluation of atrial baffle function after an atrial correction procedure.

Previous methods used to assess atrial baffle function after correction of transposition of the great arteries have included precordial echocardiography and cardiac catheterization. To evaluate whether single plane transesophageal echocardiography might provide additional information, its findings were correlated with information derived from both precordial echocardiography and cardiac catheterization in 15 patients (14 Mustard procedures, 1 Senning procedure) aged 4.2 to 33 years (mean 16.3). Precordial ultrasound with combined imaging, color flow mapping and pulsed Doppler ultrasound visualized the supramitral portion of the common systemic venous atrium in every case but could identify only superior limb obstruction in three of six patients, mid-baffle obstruction in zero of two and inferior limb obstruction in zero of two patients. Transesophageal studies with use of the same range of ultrasound methods demonstrated superior limb obstruction (severe in four, mild in two) in six of six patients, mid-baffle obstruction in two of two and inferior limb obstruction in two of two patients. The entire pulmonary venous atrium was equally well interrogated by either ultrasound approach, with both identifying three cases (two mild, one moderate) of mid-pulmonary venous atrium obstruction. However, individual pulmonary vein velocity profiles could only be recorded by transesophageal pulsed Doppler ultrasound. Precordial studies identified baffle leaks (1 large, 2 small) in only three patients, whereas transesophageal studies identified 11 such baffle leaks (1 large, 10 small), which were multiple in two patients. It is concluded that transesophageal echocardiography provides a more detailed and accurate assessment of atrial baffle morphology and function than is provided by either precordial ultrasound or cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Left atrial appendage contractile function in atrial fibrillation. Influence of heart rate and cardioversion to sinus rhythm.

BACKGROUND: A high incidence of embolic phenomena is associated with atrial fibrillation (AF) and the left atrial appendage (LAA) is frequently the source of the emboli. Thrombus formation may be due to stasis within the fibrillating and inadequately emptying LAA. Because LAA emptying in AF may be the result of mechanical compression by the adjacent left ventricle, it is possible that left ventricular diastolic filling duration will importantly influence passive emptying of the LAA. We hypothesized that the magnitude of emptying of the LAA in AF is related to the duration of left ventricular diastolic filling which is determined by the ventricular response rate in AF. OBJECTIVE: The objective of our study was to determine the relationship of ventricular response rate in AF to LAA emptying and to assess the influence of sinus rhythm and heart rate on LAA emptying immediately after direct current cardioversion to sinus rhythm. METHODS: To study this, we used transesophageal echocardiography to measure LAA ejection fraction ([LAAmax-LAAmin]/LAAmax x 100%) and evaluated its relationship to left ventricular response rate (VRR) in 26 patients with AF (mean age, 65 +/- 7 [1 SD] years). RESULTS: There was a strong inverse relationship between LAA ejection fraction and VRR in AF (r = -0.73; p < 0.001). LAA ejection fraction during AF was 26 +/- 10%, and immediately after successful cardioversion, it increased to 46 +/- 12% (p < 0.001). However, during sinus rhythm there was no relationship between LAA ejection fraction and VRR (r = 0.06; p = NS) in the subgroup of patients who were successfully converted to sinus rhythm. There were poor relationships between LAA ejection fraction and peak transmitral flow velocity (r = -0.41; p = NS) or pulmonary venous flow velocity (r = -0.03; p = NS) in AF. CONCLUSION: These results indicate that the magnitude of LAA emptying in AF is strongly and inversely influenced by ventricular rate. Direct current cardioversion to sinus rhythm is associated with an increase in the magnitude of LAA emptying that is not influenced by heart rate. The magnitude of LAA emptying may be an important factor in the formation of thromboemboli in AF. The extent to which controlling the VRR in chronic AF will prevent stasis and LAA thrombus formation remains to be determined.

Aged↗
PubMed1991

Does atrial appendectomy aggravate secretory function of atrial natriuretic polypeptide?

The present study was designed to clarify how atrial appendectomy affects hemodynamics and secretory function of atrial natriuretic polypeptide in the failing heart. Eleven mongrel dogs were prepared for the experimental model of high-output heart failure by creation of arteriovenous fistulas between femoral arteries and veins. Two months after the first operation, effects of bilateral atrial appendectomies on basal and pacing-induced secretions of atrial natriuretic polypeptide were investigated in five dogs with simultaneous measurement of various hemodynamic indices. In the remaining six dogs, used as a control group, pacing-induced secretion of atrial natriuretic polypeptide was examined in the same way as in the appendectomy group. After excision of the atrial appendages, neither systolic blood pressure nor either atrial pressure changed, but plasma atrial natriuretic polypeptide level was decreased (292 +/- 54 to 188 +/- 47 pg/ml, p less than 0.01) and cardiac output fell (3.7 +/- 0.9 to 3.0 +/- 0.8 L/min, p less than 0.01). During pacing-induced tachycardia, the peak level of plasma atrial natriuretic polypeptide was lower in the appendectomy group than in the control groups (593 +/- 213 versus 1170 +/- 324 pg/ml, p less than 0.05), despite similar left atrial pressures in the two groups. The excised appendages contained approximately 30% of the total amount of atrial natriuretic polypeptide. These results demonstrate that atrial appendectomy decreases secretory function of atrial natriuretic polypeptide and reduces cardiac output in dogs with experimental high-output heart failure.

Animals↗