[Automatic display of epicardial mapping of right atrium: experimental and clinical uses].
Explore the source record for details and available documents.
Action Potentials↗
SEARCH · Search PubMed
Results for “Atrial Function, Right”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Biventricular pacing and atrioventricular junction ablation as treatment of low output syndrome due to refractory congestive heart failure and chronic atrial fibrillation.
A 71-year-old male patient with end-stage heart failure, atrial fibrillation, congestive and low output symptoms, underwent biventricular pacing and atrioventricular junction ablation while anuric and hypotensive. Following atrioventricular junction ablation blood pressure increased by 20 mmHg during biventricular but not during right ventricular apical pacing. A rapid clinical improvement was observed and the patient was discharged from the hospital in NYHA functional class III.
Aged↗
Primary hypothyroidism in severe chronic heart failure.
Thyroid function was studied in 40 patients with chronic heart failure. Thyroid antibodies and microsome antibodies were negative in all cases. Serum T4, and T3 concentrations showed significant inverse correlation with cardiothoracic ratio, mean right atrial pressure, pulmonary artery systolic pressure, and peripheral venous pressure. Serum T4, T3 concentrations showed significant correlation with PaO2, serum albumin, and serum cholinesterase. Serum TSH concentrations increased with increasing cardiothoracic ratio. Histological examinations showed fibrosis and atrophy of the thyroid gland in 2 cases. These findings suggest the possible development of primary hypothyroidism as a result of chronic heart failure.
Adult↗
Atrial granules in the dog heart after cardiac denervation.
Because the increase in sodium excretion during left atrial distension in conscious dogs is abolished after chronic cardiac denervation, we have investigated whether this is a result of the disappearance of specific atrial granules. Electron microscopy and light-microscopical and ultrastructural immunohistochemistry of canine atria show that atrial granules displaying immunoreactivity for cardiac hormones of the cardiodilatin/atrial natriuretic polypeptide (CDD/ANP) family are still present in denervated left and right atria, although reduced in quantity. It is concluded that the "atrial-induced natriuresis" is not only related to the existence of specific atrial granules. The functional link between atrial-induced natriuresis provoked by atrial distension and the release of atrial polypeptide hormones remains uncertain because the denervated heart can secrete CDD although the diuretic-natriuretic effect is altered.
Animals↗
Paroxysmal atrial fibrillation with and without primary atrial vulnerability. Clinical and electrophysiological differences.
Primary atrial vulnerability defined as induction of repetitive atrial firing by a single atrial extrastimulus cannot always be demonstrated in patients with paroxysmal atrial fibrillation. The authors studied the electrophysiological differences between paroxysmal atrial fibrillation with and without primary atrial vulnerability. In 14 of 31 patients with documented history of atrial fibrillation, single extrastimulation at the high right atrium initiated repetitive atrial firing defined as rapid disorganized atrial activity continuing longer than 1 second. In the 14 patients with vulnerable atrium, the atrial effective and functional refractory were periods significantly shorter and the duration of the local atrial electrogram of the premature beat was longer and was fractionated. The % sinus node recovery time was longer in patients without vulnerability. Nine of the 17 patients without atrial vulnerability had sinus node dysfunction, and 4 of the remaining 8 patients had a repetitive type of atrial automatic tachycardia. In contrast, only 3 (21%) of the 14 patients with vulnerability had sinus node dysfunction, and none showed repetitive atrial tachycardia. The high prevalence of sinus node dysfunction or repetitive type of atrial automatic tachycardia in patients without primary atrial vulnerability suggests that these transient electrophysiological modifications which are not dealt with in the basic conditions may have a role in the enhancement of atrial vulnerability.
Adolescent↗
Regional myocardial blood flow in patients with sick sinus syndrome randomized to long-term single chamber atrial or dual chamber pacing--effect of pacing mode and rate.
OBJECTIVES: This study aimed to evaluate regional myocardial blood flow (MBF) and global left ventricular ejection fraction (LVEF) during chronic pacing in patients with sick sinus syndrome (SSS) randomized to either single chamber atrial (AAI) or dual chamber (DDD) pacing. BACKGROUND: Experimental studies indicate that chronic pacing in the right ventricular apex changes regional MBF, thereby compromising left ventricular function. METHODS: Thirty patients (age 74 +/- 10 years) were randomized to AAI (n = 15) or DDD (n = 15) pacemakers. After 22 +/- 7 months of pacing, MBF was quantified with 13N-labeled ammonia positron emission tomography scanning at 60 beats per min and 90 beats per min. Patients in the DDD group furthermore underwent MBF measurement at temporary AAI pacing, 60 beats per min. Myocardial blood flow was assessed in the anterior, lateral, inferior and septal regions, and the global mean MBF was calculated. Left ventricular ejection fraction was determined by echocardiography at pacemaker implantation and at the time of MBF measurements. RESULTS: Myocardial blood flow at rates 60 and 90 beats per min did not differ between the AAI and DDD groups. During temporary AAI pacing in the DDD group, MBF was significantly higher than during DDD pacing in both the inferior (p = 0.001) and septal (p = 0.004) regions and also globally (0.61 +/- 0.15 vs. 0.53 +/- 0.13 mL x g(-1) x min(-1), p = 0.005). In the DDD group, LVEF decreased from pacemaker implantation to time of MBF measurements (0.61 +/- 0.09 vs. 0.56 +/- 0.07, p = 0.013). Left ventricular ejection fraction during temporary AAI pacing at time of MBF measurements was not different from LVEF at pacemaker implantation. CONCLUSIONS: In patients with SSS, chronic DDD pacing reduced inferior, septal and global mean MBF as well as LVEF, as compared with temporary AAI pacing. The LVEF reversed to baseline level during temporary AAI pacing despite 22 months of permanent ventricular pacing preceding it. Augmenting pace rate to 90 beats per min increased MBF equally in the two treatment groups.
Aged↗
Electropharmacodynamics of N-acetylprocainamide in the immature mammalian heart--evidence for a prominent class III effect in the newborn.
The electrophysiologic effects of N-acetylprocainamide (NAPA), a metabolite of procainamide reported to exert significant Class III antiarrhythmic effects in the adult heart, were evaluated in 12 neonatal mongrel canines (ages 7-14 days). Following transvascular placement of quadripolar electrical catheters in the right atrium and ventricle, and a tripolar catheter in the region of the His bundle, electrophysiologic assessments were made of sinus and AV nodal function and atrial and ventricular refractoriness utilizing intracardiac stimulation and recording techniques following cumulative intravenous doses of 20 and 40 mg/kg of NAPA (serum concentrations 13.1 +/- 1.9 and 25.6 +/- 3.4 micrograms/ml). NAPA resulted in an overall increase in sinus cycle length of 18%. No changes were observed in the paced cycle length resulting in AV nodal Wenckebach. Consistent with NAPA's reported Class III action, NAPA increased the effective and functional refractory periods of the ventricle by 35 and 34%, respectively (p less than 0.001). Even larger increases were observed in atrial refractoriness (effective 75%, functional 57%, p less than 0.001). In separate experiments (n = 6), the effects of intravenous NAPA (40 mg/kg) on the duration of the monophasic action potential recorded from the neonatal atrium and ventricle were determined. NAPA increased APD90 of the atrium by approximately 50% and that of the ventricle by 60%, thus confirming a significant effect on myocardial repolarization in the neonate.
Acecainide↗
CD62 expression during thrombus formation.
A large right atrial mass was discovered in a 16-year-old female patient receiving chemotherapy treatment for Hodgkin disease. The patient was participating in a platelet function research study. During laboratory examination of platelet activation, increasing CD62 and CD63 expression were found to mirror the clot formation. Further investigation of platelet expression of CD62 and CD63 by flow cytometry might reveal it to be a valuable tool in predicting impending thrombus formation.
Adolescent↗
Computer simulations of activation in an anatomically based model of the human ventricular conduction system.
Simulations of the electrical activity during excitation were performed in an anatomically based model of the human ventricular conduction system. Each of the 33,000 elements of this model represented a unit bundle of Purkinje or atrioventricular nodal tissue. The Ebihara-Johnson model for sodium defined the active membrane characteristics. Using a combination of new and existing modeling techniques, simulations of excitation were completed in approximately 5 min CPU time on an IBM 3090 at the Cornell National Supercomputer Facility. Activation times at sites in the model were compared to experimental measurements for the excitation of the ventricular myocardium on the endocardial surface. These "literature-based" times were estimated from a number of reported human heart mapping studies. Initially, the times fit poorly. The major factor for the discrepancy was the conduction velocities of the elements, which were a result of the physical and electrical parameters derived from a review of histologic and electrical properties studies. In addition, there was a latency between activation of the system in the left ventricle of the model and that in the right ventricle when compared to the experimental work. When the times were scaled to adjust for the conduction velocity and ventricular latency effects, the match between the simulation and literature-based times was much improved. Quantitative comparison between normalized times resulted in correlation coefficients CCF = 0.76 for the right ventricle and CCF = 0.64 for the left ventricle.
Atrial Function↗
Bacterial endocarditis in a child with a Broviac catheter.
Broviac and Hickman catheters facilitate the care of children with cancer but provide a source of potential infection. We describe a child with a Broviac catheter who developed left-sided bacterial endocarditis in whom right-to-left atrial shunting was documented following catheter flushing. Following removal of the catheter and administration of prolonged intravenous antibiotics, recovery was complete and cardiac function returned to normal.
Antineoplastic Combined Chemotherapy Protocols↗
One 25 day survivor with total artificial heart.
One calf, which weighed 87 kilograms, survived for 25 days with a total artificial heart (TAH) implanted orthotopically. All hemodynamic parameters stayed normal except the right atrial pressure (RAP), which increased gradually toward the end of the experiment. The cardiac output was maintained between 8.0 and 11.0 L. per minute. Kidney function was well maintained, and no pulmonary insufficiency was noted. Infection became obvious after 2 weeks of pumping although it was controlled to the extent that the calf was able to eat, to several factors, amont them mechanical damage to red blood cells, infection, malnutrition, and liver damage. The calf was standing until 30 minutes before its sudden death from cerebral thromboembolism. The calf's activity throughout the postoperative course convinced us of the feasibility of clinical application and of immediate application to studies of cardiovascular physiology and pharmacology.
Animals↗
The isoprenoid pathway in lone atrial fibrillation with embolic stroke.
BACKGROUND: The isoprenoid pathway was assessed and compared in patients of lone atrial fibrillation with embolic stroke as well as in patients with right hemispheric, left hemispheric and bihemispheric dominance to determine the role of hemispheric dominance in its pathogenesis. METHODS AND RESULTS: The activities of hydroxyl methyl glutaryl-CoA reductase and RBC sodium-potasium ATPase as well as serum levels of plasma magnesium, digoxin, dolichol and ubiquinone were measured. The tyrosine/tryptophan catabolic patterns, glycoconjugate metabolism, free radical metabolism and RBC membrane composition were also assessed. In patients with lone atrial fibrillation with embolic stroke, there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, and low ubiquinone and elevated free radical levels. There was also an increase in tryptophan catabolites and a reduction in tyrosine catabolites: and an increase in the cholesterol: phospholipid ratio with a reduction in the glycoconjugate levels of the RBC membrane. The same biochemical patterns were obtained in individuals with right hemispheric dominance whereas the patterns were reversed in patients with left hemispheric dominance. CONCLUSIONS: Lone atrial fibrillation with embolic stroke is associated with an upregulated isoprenoid pathway and elevated digoxin secretion from the hypothalamus. This occurs in right hemisphere-dominant individuals.
Aged↗
[Advanced sequelae of apical hypertrophic cardiomyopathy: report of two cases with wall motion abnormalities].
In view of the paucity of reports describing symptoms of increased degree, and deterioration of left ventricular systolic function in patients with apical hypertrophic cardiomyopathy (apical HCM), two cases with congestive heart failure and progressive thinning of previously hypertrophied apical portions of the left ventricle are reported. These were among 13 patients observed from eight to 10 years. Case 1: A 56-year-old man was diagnosed as having apical HCM at the age of 49 years. Severe left ventricular hypertrophy and prominent ST-T changes were observed on ECG during his first admission. His left ventricular end-diastolic pressure (LVEDP) was 24 mmHg and a left ventriculo-gram revealed a decrease in the left ventricular cavity in the apex and marked hypertrophy of the apical wall. Moderate interstitial fibrosis without hypertrophy or disarray of myocytes was observed in a left ventricular endomyocardial biopsy specimen. In two episodes of cardiac arrest he was successfully resuscitated at the age of 50 years. At the age of 55 years, two-dimensional echocardiography revealed thinning and abnormal motion in the apical wall, and a defect in 201T1 accumulation was observed in the same region by perfusion scintigraphy. This patient was readmitted with a diagnosis of cerebral embolism at the age of 56 years. Cardiac catheterization revealed normal LVEDP (8 mmHg), and a left ventriculogram revealed an aneurysm in the left ventricular apex with normal major epicardial coronary arteries. He has been under treatment with antiarrhythmic medications, calcium antagonists and anticoagulants, and has become relatively asymptomatic. Case 2: A 69-year-old-man was diagnosed as having apical HCM after a complete evaluation, including cardiac catheterization, at the age of 59 years. His LVEDP was elevated (17 mmHg), and a left ventricular angiogram revealed marked hypertrophy localized to the apex. Ejection fraction was 64%. A left ventricular endomyocardial biopsy revealed interstitial fibrosis without hypertrophy of myocytes. Thereafter, he has been followed as a New York Heart Association functional class III to IV with occasional elevation of cardiac enzymes but without chest pain or acute changes in his ECGs. However, atrial fibrillation with complete right bundle branch block developed at the age of 60 years. Apical wall thinning and dyskinesis were diagnosed by 2D echocardiography and a defect in the 201T1 accumulation was observed at about 65 years of age. He was readmitted in severe cardiac failure at the age of 69 years, and he was diagnosed as having cardiac asthma with pulmonary capillary wedge pressure of 35 mmHg.(ABSTRACT TRUNCATED AT 400 WORDS)
Aged↗
Electrophysiological effects of intravenous dantrolene on canine heart.
The electrophysiological effects of an intravenous dantrolene infusion (10 mg kg-1) were evaluated in healthy, anaesthetized dogs by intracardiac electrophysiological study. Dantrolene administration resulted in a significant prolongation of the refractory periods of the right atrium and ventricle, while the functional refractory period of the AV node was not altered. A slight increase of AV nodal conduction, measured as atrial-His bundle interval, without any change in infranodal conduction, measured as His bundle-ventricular interval, was observed during sinus rhythm. Dantrolene had no significant effects on surface ECG parameters. We conclude that intravenously administered dantrolene, at the maximal recommended doses, has primary effects on electrophysiological parameters. These findings support the hypothesis that the beneficial effects of dantrolene on cardiac arrhythmias associated with malignant hyperthermia may be related to its intrinsic activity on the electrophysiological properties of the heart, but confirmation requires further investigations on induced arrhythmias in experimental models.
Animals↗
[The usefulness of transesophageal echocardiography in the follow-up of patients operated on for replacement of the ascending aorta with a tubular-valvular prosthesis (Cabrol's intervention)].
OBJECTIVES: The usefulness of transesophageal echocardiography (TEE) in assessing the postoperative results of aortic root replacement (Cabrol's procedure) was evaluated. METHODS: Between 1986 and 1993, 31 patients underwent replacement of the aortic valve and ascending aorta by a composite graft using the Cabrol procedure. Twenty-six patients had annuloaortic ectasia, two type I DeBakey dissection and four type II dissection. Hospital mortality was 9.7%. Studies were performed in 18 patients, two to 70 months (mean 27.5 months) after composite graft replacement. The following features were examined: prosthetic aortic valve function, coronary graft morphology and function, tubular graft and aneurysm wrapped around morphology and dimensions, presence of intimal flap, false lumen and thrombus in the false lumen and persistence of right atrial fistula. RESULTS: Periprosthetic leakage with significant regurgitation was detected by TEE in 3 (16.6%) of 18 patients. In one patient with infected aortic graft a fistula between the periprosthetic space and the right ventricle was detected (confirmed at reoperation). In another patient occlusion of the graft for left coronary artery was noted. In three patients (16.6%) an aneurysm of the periprosthetic space with perivalvular leakage and persistence of the fistula with the right atrium was visualized. In the two patients operated for DeBakey type I dissection an intimal flap persisted distal to the graft and in one patient flow was detected in the false lumen, while it was totally obliterated in the other. CONCLUSIONS: 1) Complications after Cabrol's procedure are not infrequent; although the real importance of some of them (periprosthetic aneurysm, persistence of dissection) is uncertain, a careful follow-up may be essential to improve the long term survival. 2) TEE is a useful and well-tolerated procedure for postoperative follow-up of patients who underwent aortic root replacement with Cabrol's procedure.
Adult↗
Accelerated cardiac growth and abnormal cardiac flow in fetuses of type I diabetic mothers.
OBJECTIVES: To determine the growth patterns of the fetal heart and the development of cardiac function during gestation in fetuses of diabetic mothers, and to compare these findings with those of normal fetuses. METHODS: Serial M-mode and Doppler echocardiographic recordings were made at 4-week intervals in 14 fetuses of well-controlled type I insulin-dependent diabetic mothers and in ten control fetuses at 20-36 weeks' gestation. The following variables were measured: interventricular septal thickness, left ventricular wall thickness, right ventricular wall thickness, ratio between the peak velocities during early passive ventricular filling and active atrial filling at the level of the atrioventricular valves, peak velocities, and time to peak velocity at the level of the ascending aorta and pulmonary artery. RESULTS: In both groups of fetuses, all of the indices increased linearly with gestation. However, fetuses of diabetic mothers showed significant differences in the slope and intercept values for the function describing the growth of the interventricular septum (P less than or equal to .001) and the right and left ventricular wall thicknesses (P less than or equal to .01), resulting in accelerated cardiac growth. The function describing the development of the ratios between early and active ventricular filling showed differences in slope and intercept values at the level of both the mitral (P less than or equal to .001) and tricuspid valves (P less than or equal to .001), resulting in a lower rate of increase during diabetic pregnancy when compared with control fetuses. Significantly higher intercept values were found in the functions describing the increase of peak velocities in the aorta and pulmonary artery in fetuses of diabetic mothers (P less than or equal to .01), whereas the slopes were similar to those of control fetuses. No differences were found in the time to peak values between the groups of fetuses. No relationships were found between the echocardiographic results and the metabolic control of pregnancy or fetal characteristics. CONCLUSIONS: This study suggests that strict maternal diabetes control does not exclude accelerated fetal cardiac growth and abnormal development of cardiac function.
Adult↗
Use of transesophageal echocardiography for postoperative evaluation of right ventricular function.
BACKGROUND: No method has been available to assess the right ventricular (RV) pressure-volume relation in the operating room or intensive care unit. Left ventricular cross-sectional area measured by echocardiography using the technology of automated border detection has been used to construct left ventricular pressure-area (P-A) loops. In the human right ventricle, however, this approach has not been validated. METHODS: We recorded RV P-A loops in 14 patients in the intensive care unit using transesophageal echocardiography. Multiple RV P-A loops were obtained by reducing preload with intravenous nitroglycerin, thereby elucidating the end-systolic P-A relation. RESULTS: With an incremental dose of dobutamine, the slope of the RV end-systolic P-A relation increased (from 4.56+/-2.42 to 7.34+/-3.62 mm Hg/cm2, p<0.01), with no change in the x-axis intercept, which implied increased contractility. Furthermore, in the operating room we validated the use of RV cross-sectional area as a surrogate for RV volume by demonstrating the close correlation between the stroke area (maximal RV area minus minimal RV area) and stroke volume (r = 0.962; p<0.0001). CONCLUSIONS: Transesophageal echocardiography with automated border detection is a promising tool for elucidating RV function through the analysis of RV P-A loops.
Adult↗
Simultaneous left and right atrial pressure curves during Valsalva's experiment.
Explore the source record for details and available documents.
Atrial Pressure↗