Search PubMed⌕ Search

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.

At least 1,009 records · Page 56Linked to original sources
PubMedDate not supplied

Right ventricular size and function as assessed by echocardiography and angiography in patients with different volume load.

A comparative study of right ventricular (RV) function, assessed by echocardiography and angiography, undertaken in 20 patients, 10 of whom had atrial septal defects (ASDs) and 10 had various other heart diseases. All of the measured echocardiographic variables of RV size, apart from RV length, were larger in the patients with ASD. When assessed by multiple regression analysis, the RV M-mode dimension was an independent variable of RV angiographic end-diastolic volume (EDV) in patients without RV volume load (R = 0.92, R2 = 0.85, p < 0.001). In the patients with ASD, echocardiographic RV end-diastolic area was an independent variable of angiographic RVEDV (R = 0.75, R2 = 0.55, p < 0.05), whereas M-mode dimension had a weaker correlation (r = 0.29). The agreement between RV ejection fraction (RVEF) obtained by echocardiography and angiography was moderate in both patient groups. However, fractional area change and fractional length change could not estimate RVEF better. Thus care should be taken to use single measurements and derivatives as the only parameters of RV size and function.

Adolescent↗
PubMed1978

Human atrial noradrenaline content, hypothermic ischaemic arrest and parameters of left ventricular function.

The noradrenaline (NA) content in tissue excised from the right atrium before and after hypothermic ischaemic arrest and subsequent coronary reperfusion was estimated biochemically and histochemically. The series consisted of 22 patients suffering from aortic valve disease. The NA concentration in the preoperative and postoperative samples was similar in all instances and it was clear that the right atrial myocardial NA content remained unchanged under conditions typical of an aortic valve replacement operation. The mean NA contents (microgram/g +/- SD) of the whole series before and after procedure were 2.0 +/- 1.1 and 2.2 +/- 1.5, respectively (p greater than 0.1 NS). Additionally, left heart catheterization was performed preoperatively in 11 patients with aortic valve disease, and certain left ventricular cardiocirculatory variables of contractility and failure were recorded. No statistically significant correlation could be found between the right atrial myocardial NA content and the left ventricular contractile state. However, left ventricular end-diastolic pressure presented a significant positive correlation with the NA content of right atrial myocardium (r = 0.65, p less than 0.02, n = 11). The problems encountered in weaning the heart off perfusion after aortic surgery can hardly be explained in terms of altered myocardial NA stores.

Adult↗
PubMed1994

Recovery of the right ventricle after single-lung transplantation in pulmonary hypertension.

Single-lung transplantation has been successfully performed in patients with pulmonary fibrosis and emphysema. In contrast, patients with end-stage pulmonary hypertension (either primary or secondary to Eisenmenger's syndrome) have conventionally been offered heart-lung transplantation. The rationale underlying this approach is that chronic pulmonary hypertension results in irreversible right ventricular dilatation and failure. Recovery of the right ventricle has previously been reported after thromboendarterectomy for chronic large-vessel pulmonary embolism, correction of atrial septal defect or mitral valve replacement. The evolution of right ventricular morphology and function after lung transplantation has not been previously described. This study examines the reversibility of right ventricle dysfunction following normalization of pulmonary artery pressure after single-lung transplantation in 4 patients with pulmonary hypertension. Cardiac function was assessed using electrocardiography, echocardiography and radionuclide angiography. Pulmonary hemodynamic measurements, including pulmonary artery pressure and pulmonary vascular resistance, decreased in all patients after single-lung transplantation. Electrocardiographic changes observed were leftward shift in the QRS axis, and a decrease in P-wave amplitude and in right ventricular force. Echocardiographic examination revealed decreased right atrial, right ventricular and tricuspid valve annular dimensions, normalization of septal motion, and decreased tricuspid regurgitation. Thus, improved pulmonary hemodynamics after single-lung transplantation for pulmonary vascular disease results in reversal of right heart dilatation and dysfunction, and improved myocardial performance. The extent of right ventricular dysfunction beyond which recovery is unlikely to occur has yet to be determined.

Adult↗
PubMed1993

[Length method in evaluating right ventricular volume in children with congenital heart disease: a comparison with two dimensional echocardiographic method].

The accuracy and reliability of two-dimensional echocardiographic length method in right ventricular volume measurement were assessed by three-dimensional echocardiographic method in 10 normal children, 10 patients with atrial septal defect, and 10 patients with pulmonary stenosis. Their age and sex were matched. Right ventricular end diastolic, end systolic, mid-systolic volume, and ejection fraction evaluated by length method were correlated very well with the values obtained by three-dimensional echocardiographic method in normal and pulmonary stenosis group (r = 0.71-0.95, P < 0.01). In atrial septal defect group, right ventricular volume obtained by the two methods was correlated well (r = 0.86-0.95, P < 0.01). Although the correlation in right ventricular ejection fraction was lower, it was still significant. The shortening rate of X, Y, Z parameters required by length method were similar in each group: delta Z % > delta X % > delta Y %. We conclude that right ventricular volume and function could be assessed accurately by two-dimensional echocardiographic length method in children with right ventricular volume or pressor overloaded, and that right ventricular systolic pattern is similar in those situations.

Child, Preschool↗
PubMed2003

Single versus dual chamber pacing in the young: noninvasive comparative evaluation of cardiac function.

The advantages of atrial synchrony over asynchronous ventricular pacing remain unclear in the young, chronically right ventricular (RV) - paced patient. This is in contrast to the older patient with inherent diastolic dysfunction who has been shown to benefit from atrial synchrony with dual chamber (DDD,R/VDD), over single chamber rate response (VVI,R) ventricular pacing. The goal of this study was to noninvasively assess cardiac function in a group of young, RV-paced patients before and after establishment of atrial synchrony. Echocardiographic data were retrospectively analyzed from 10 patients with congenital or acquired complete AV block, who were VVI,R paced for 10.2 +/- 2 years (mean age at study 19.2 +/- 8.9 years), and were subsequently converted to DDD,R/VDD pacing (mean age at study 20.7 +/- 9.5 years). Paired t-test analysis of left ventricular (LV) systolic and diastolic function during VVI,R versus DDD,R/VDD pacing did not result in any short-term difference in LV short axis fractional area of change or FAC (53% +/- 7.5% vs 56.8% +/- 8.7%) or mitral maximal velocity (E) normalized to mitral flow velocity time integral (VTI) (5.2/s +/- 1.5 vs 4.4/s +/- 1.5). A decrease in mitral flow E/A ratio was observed after short-term DDD,R/VDD pacing (2.2 +/- 0.5 vs 1.9 +/- 0.3). Atrial synchronous dual chamber pacing in young patients with complete AV block does not lead to any appreciable early change in global LV function over single-site RV pacing. Therefore, early establishment of atrial synchrony in the young asymptomatic VVI,R-paced patient with normal intrinsic ventricular function may not be warranted.

Adolescent↗
PubMed1997

Effects of atrial dilatation on refractory period and vulnerability to atrial fibrillation in the isolated Langendorff-perfused rabbit heart.

BACKGROUND: Atrial fibrillation (AF) is frequently observed under conditions that are associated with atrial dilatation. The aim of this study was to investigate the effects of atrial dilatation on the substrate of AF. METHODS AND RESULTS: In 15 Langendorff-perfused rabbit hearts, the interatrial septum was perforated, and after occlusion of the caval and pulmonary veins, biatrial pressure was increased by raising the level of an outflow cannula in the pulmonary artery. Right and left atrial effective refractory periods (AERPs), monophasic action potentials (MAPs), and inducibility of AF by single premature stimuli were measured as a function of atrial pressure. Increasing the atrial pressure from 0.5+/-0.7 to 16.2+/-2.2 cm H2O resulted in a progressive shortening of the right AERP from 82.2+/-9.8 to 48.0+/-5.1 ms. In the left atrium, an increase in pressure up to 7.4+/-0.3 cm H2O had no effect on the AERP. At higher pressures, however, the left AERP also shortened, from 67.5+/-7.5 to 49.3+/-2.0 ms. The duration of MAPs also decreased by an increase in atrial pressure, showing a high correlation with the shortening in AERP (r=.94, P<.01). All these changes were completely reversible within 3 minutes after release of the atrial stretch. Dilatation of the atria was a major determinant for the vulnerability to AF. The inducibility of AF increased from 0% at low pressures to 100% when the atrial pressure was >10 cm H2O. Release of the atrial wall stress resulted in prompt cardioversion of AF. The increased vulnerability for AF was highly correlated with the shortening in AERP (logistic regression r=.97). No correlation was found with the spatial dispersion between right and left AERPs. CONCLUSIONS: Increased atrial pressure in the isolated rabbit heart resulted in a significant increase in vulnerability to AF that was closely correlated to shortening of the AERP. These changes were completely reversible within 3 minutes after release of the atrial stretch, resulting in prompt termination of AF.

Animals↗
PubMed1990

Cardiac allograft function with corticosteroid-free maintenance immunosuppression.

Potent prophylactic immunosuppressive protocols promote the safe withdrawal of corticosteroid maintenance. The benefits of corticosteroid-free maintenance immunosuppression include the absence of the cushingoid habitus, fewer infections, less obesity, and lower serum cholesterol. The incidence of allograft coronary artery disease is not increased by corticosteroid-free maintenance. To assess the long-term effects of corticosteroid-free immunosuppression on allograft function, we compared results of hemodynamic study and noninvasive evaluation over the 2-year follow-up of 57 patients on corticosteroid-free maintenance to 40 patients who required corticosteroid. Age and pretransplantation diagnoses were similar, but a greater percentage of those who required corticosteroid maintenance were female (28% versus 2%, p less than 0.001). Indexes of allograft function were similar in both groups and these indexes included ejection fraction, right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index, left ventricular end-diastolic dimension, and posterior wall thickness. Patient survival was identical in the two groups (98%). These data indicate that corticosteroids can be safely withdrawn with the subsequent early benefits and without compromising long-term allograft function.

Antibodies, Monoclonal↗
PubMed2006

Inositol-1,4,5-trisphosphate and ryanodine-dependent Ca2+ signaling in a chronic dog model of atrial fibrillation.

Ca2+ signaling regulation plays an important role in triggering and/or maintaining atrial fibrillation (AF). Little is known about the relationship of the inositol-1,4,5-triphosphate receptors (InsP3Rs) and ryanodine receptors (RyRs) in left atrium to chronic AF. In this study, we investigated the expression and function of InsP3R1, InsP3R2 and RyR2 in a chronic dog model of AF. AF was induced in 6 dogs by rapid right atrial pacing for 24 weeks, and a sham procedure was performed in 5 dogs (control group). The intact left atrial myocytes were used to examine the expression and function of InsP3Rs, RyRs by BODIPY(O,R) TR-X ryanodine, heparin-fluorescein conjugate, and were stimulated by caffeine, ATP to release Ca2+ through RyRs, InsP3Rs separately. We also assessed the molecular components of left atrial tissue underlying the amount of RyR2, InsP3R1 and InsP3R2 determined by RT-PCR, immunohistochemistry and Western blot analysis. In the chronic AF group, the Ca2+ released through RyRs is not altered, but the Ca2+ released through InsP3Rs increased significantly. RyR2 distributed in cytosol of myocytes, cellular membrane; its expression significantly decreased in AF group compared to controls. InsP3R1 distributed in cytosol, InsP3R2 distributed not only in cytosol, cellular membrane, but also in nuclear envelope and intercalated discs. The InsP3R1 and InsP3R2 expression significantly increased in chronic AF group compared to controls. These results indicated that in a chronic dog model of AF, the expression and function of RyR2 down-regulated; on the contrary, the expression and function of InsP3R1, InsP3R2 up-regulated, and InsP3R2 may be the major InsP3Rs, which regulate intracellular or even intercellular Ca2+ signal transmission.

Animals↗
PubMed2004

Effect of biventricular pacing therapy in patients with dilated cardiomyopathy with severe congestive heart failure.

OBJECTIVES: Biventricular pacing (BVP) therapy has recently emerged as an effective treatment for patients with moderate to severe congestive heart failure (CHF) and ventricular asynchrony all over the world. However, this therapy is not yet available in Japan. We evaluated the effects of BVP in patients with severe CHF due to dilated cardiomyopathy (DCM). SUBJECTS: Four patients with medically refractory severe CHF due to DCM in New York Heart Association functional class III or IV heart failure underwent BVP therapy. We combined the implantation of the left ventricular (LV) epicardial lead via small thoracotomy following right atrial and ventricular intravenous leads under general anesthesia. We evaluated to determine whether improvements of ventricular function, ventricular size, mitral regurgitation, functional status, frequency of hospitalization, and quality of life were associated with BVP therapy. RESULTS: BVP improved LV systolic function, decreased LV size and mitral regurgitation, and shortened prolonged QRS interval. The patients' symptoms, exercise tolerance, frequency of hospitalization, and quality of life were also dramatically improved by BVP. Furthermore, combination of BVP and oral administration of amiodarone significantly prevented recurrence of ventricular tachycardia and paroxysmal atrial fibrillation, and maintained sinus rhythm for a long period. CONCLUSIONS: In view of these findings, BVP therapy may contribute to the development of new therapeutic method for patients with severe CHF due to DCM.

Administration, Oral↗
PubMedDate not supplied

Phentolamine as a treatment for poor mixing in transposition of the great arteries with adequate intraatrial communication.

Patients with transposition of the great arteries often show poor mixing for different reasons, even after adequate balloon atrial septostomy. We present a patient with such a lesion whose clinical status improved dramatically after phentolamine was applied. We believe this improvement is due to reduction in afterload caused by the alpha(2) blocker and also possibly as a response to a presumptive effect of the drug on the diastolic function of the right ventricle, allowing more left-to-right shunt across the atrial septal defect. Both phenomena can improve cardiac output in such a situation.

Abnormalities, Multiple↗
PubMed2000

Right ventricular volume unloading evaluated by tangential magnetocardiography.

OBJECTIVE: The evaluation of right ventricular volume overload in the presence of a right bundle branch block based solely on the results of an electrocardiogram is difficult. The purpose of this study was to purify acute right ventricular volume unloading from the tangential magnetocardiography. METHODS: We measured the tangential (x-y plane) magnetocardiogram and electrocardiogram simultaneously in nine patients with a secundum atrial septal defect. The magnetocardiograms were obtained before surgical closure and during the immediate postoperative period using the 32-channel superconducting quantum interference device system in a magnetically shielded room. RESULTS: The QRS duration on the surface electrocardiogram decreased significantly (p < 0.05) in the immediate postoperative period. The right ventricular depolarization time as measured by the magnetocardiogram was shortened from 40.3 +/- 6.1 to 25.3 +/- 7.4 milliseconds (p < 0.0005). The maximum peak amplitude during right ventricular depolarization decreased from 17.9 +/- 4.8 to 11.1 +/- 4.9 pT (p < 0.01). CONCLUSIONS: We conclude that acute volume unloading of the right ventricle was indicated quantitatively by shortening of the right ventricular depolarization time and a reduction in the amplitude of current vectors originating from the right ventricular depolarization on the tangential magnetocardiography.

Adolescent↗
PubMed2001

[Intracardiac hemodynamics after closure of atrial septal defects with the endovascular device, Amplatzer septal occluder].

Changed size and forms of the right and left ventricles of the heart and intraventricular hemodynamics were studied in 5 patients after closing the defects of the interventricular septum with an intravascular device. It was found that after occlusion of the defects by the safe and atraumatic endovascular device the right ventricular myocardium of the heart relaxed, the stroke index became less, the ejection fraction became greater, the diastolic diameter of the right ventricle decreased, and of the left ventricle increased. The indices of the regional contraction function of the tri-cuspid and output sectors of the input part and external and pulmonary output sectors of the right ventricle were found to normalize.

Adolescent↗
PubMed1995

Efficacy of a skeletal muscle-powered dynamic patch: Part 2. Right ventricular assistance.

The purpose of this study was to assess the feasibility of using a skeletal muscle-powered dynamic patch to assist the failing right ventricle. Seven adult mongrel dogs were used in the study. The proximal portion of the left latissimus dorsi muscle was harvested and reattached to the actuator to serve as a skeletal muscle energy convertor. The right ventricular free wall was fully excised and the dynamic patch was implanted under cardiopulmonary bypass. After weaning from cardiopulmonary bypass, the latissimus dorsi muscle was stimulated using a burst frequency of 33 Hz, a burst duration of 200 ms, and 1:2 synchronous mode stimulation with the native R wave. Latissimus dorsi muscle stimulation increased systolic aortic pressure (78 versus 91 mm Hg; p < 0.01), mean aortic pressure (56 versus 62 mm Hg; p < 0.05), aortic blood flow (0.73 versus 0.97 mL; p < 0.01), and systolic right ventricular pressure (41 versus 56 mm Hg; p < 0.01). The mean right atrial pressure decreased from 14 to 9.6 mm Hg (p < 0.01). Our results demonstrate that the use of a right ventricular dynamic patch powered by a skeletal muscle linear-type actuator can not only function as a right ventricular free wall substitute but also lead to the augmentation of right ventricular and global cardiac function.

Animals↗
PubMed2005

A mystery featuring right-to-left shunting despite normal intracardiac pressure.

The cause of right-to-left atrial shunting despite normal intracardiac pressures and normal or near-normal pulmonary function through a patent foramen ovale has still not been completely clarified. It is probably responsible for several linked diseases, such as paradoxical embolism, platypnea-orthodeoxia syndrome, migraine with aura, transient global amnesia, and decompression sickness in sport divers. Despite modern diagnostic methods, the underlying anatomophysiologic and pathogenic mechanisms of right-to-left atrial shunting without abnormal intracardiac pressures remain a matter of debate and controversy. Holistically speaking, a return to a direct study of embryology, gross anatomy, and physiology may help us elucidate the real mechanism of this paradoxical shunting.

Heart Atria↗
PubMed1992

Mechanism of immunoreactive atrial natriuretic factor release in an ovine model of endotoxemia.

We have previously reported an increase in plasma levels of atrial natriuretic factor (ANF) in an ovine model of endotoxemia. The purpose of this study was to determine if this IR-ANF release was mediated by the increase of right atrial pressure (RAP) and right heart volumes concomitantly observed following endotoxin (LPS) administration. We studied right ventricular function, renal blood flow (RBF), urinary output (UO), urinary clearance of free water (CH20), urinary osmolality (UOSM), sodium excretion (UENA), and the plasma IR-ANF concentration (radioimmunoassay), following the administration of an E. coli LPS bolus (1 microgram/kg) with (group O, n = 8) and without (group E, n = 10) pretreatment with OKY-046, a selective thromboxane synthetase inhibitor. LPS induced early increases in RAP, right ventricular end-systolic (RVESV) and end-diastolic (RVEDV) volumes, heart rate (HR), and IR-ANF, and delayed increases in RBF, UO, and CH20. OKY-046 prevented the elevation of RAP, RVEDV, and RVESV; however, both groups showed virtually identical increases in IR-ANF (E: 20.03 +/- 3.8 to 192.33 +/- 35.47 pg/ml, O: 17.9 +/- 4.1 to 159.5 +/- 23 pg/ml) as well as an increase of HR, RBF, UO, and CH20. The increase in IR-ANF release noted following the administration of LPS in an ovine model does not appear to be related to the early elevations in right heart volumes or atrial distension.

Animals↗
PubMed1992

Usefulness of right ventricular indices in early diagnosis of cardiac tamponade.

Early diagnosis of postoperative cardiac tamponade is impeded by its clinical similarity to left ventricular failure. Moreover, the hemodynamic changes necessary to diagnose cardiac tamponade are detected by conventional monitoring technique only after clinical compromise. Early signs of cardiac tamponade and left ventricular failure were studied with emphasis on right ventricular function in anesthetized dogs. One group (n = 20) had cardiac tamponade produced by incrementally increasing pericardial pressure (2 to 20 mm Hg), and another group (n = 20) had acute left ventricular failure produced by successive ligation of the anterior descending coronary artery at the lower, middle, and upper thirds. Besides standard hemodynamic measurements, right ventricular function was examined with a rapid-response thermodilution catheter. During cardiac tamponade, cardiac output, right ventricular ejection fraction, right ventricular stroke volume, and right ventricular end-diastolic volume were significantly decreased from baseline values after a pericardial pressure of 8 mm Hg or more (p less than 0.05). Right atrial and pulmonary arterial pressures were not significantly elevated until 14 and 20 mm Hg of pericardial pressure, respectively. Although cardiac function in the left ventricular failure group was reduced after each ligation, right ventricular ejection fraction remained unchanged. This study suggests that right ventricular indices may facilitate earlier diagnosis of cardiac tamponade with greater accuracy.

Animals↗
PubMed1992

Right latissimus dorsi cardiomyoplasty for left ventricular failure.

Recent experimental studies have shown that cardiomyoplasty using the right latissimus dorsi provides excellent hemodynamic augmentation. Based on these experimental findings, this procedure was performed in a 40-year-old man with a dilated cardiomyopathy after a large myocardial infarction. The patient tolerated the procedure well and has had marked functional improvement. Examination 6 months after operation demonstrated decreases in right atrial pressure, pulmonary capillary wedge pressure, and left ventricular end-diastolic volume. In addition, increases were noted in cardiac output, stroke volume, left ventricular stroke-work, right ventricular ejection fraction, and left ventricular ejection fraction. Because of this promising clinical result, we have started a series of right latissimus dorsi cardiomyoplasties for left ventricular failure.

Adult↗