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 1,153 records · Page 64Linked to original sources
PubMed2006

[Percutaneous mitral commissurotomy and Lutembacher syndrome].

INTRODUCTION: Lutembacher syndrome refers to the rare combination of congenital atrial septal defect and acquired mitral stenosis. This condition is usually treated surgically by mitral valve operation with concomitant closure of the atrial septal defect. MATERIALS AND METHODS: Between 1993 and 2003, 4 patients with congenital Lutembacher syndrome had percutaneous mitral commissurotomy without closure of the atrial septal defect at our institution. The 4 patients were very symptomatic with right-sided heart failure signs and NYHA functional class III-IV. RESULTS: The procedure was carried out successfully for the four patients. Mitral valve area increased from 0.87 to 1.97 cm2 at mean; left atrial pressure decreased from 28.2 to 12.7 mmHg and the mean valve mitral gradient was reduced from 15.5 to 3.9 mmHg. Functional and clinical improvement was observed in all the cases. During a mean follow up of 55 +/- 29 months, our 4 patients remain pauci symptomatic under medical treatment. CONCLUSION: The percutaneous treatment of the Lutembacher syndrome is currently a possible alternative to the surgery among patients having an anatomy favourable to the procedure.

Adult↗
PubMed1975

Sequential atrioventricular pacing as a stress test. Evaluation of left ventricular function in second-degree AV heart block developing during atrial pacing.

Advanced or second-degree atrioventricular (AV) heart block pre-existing or developing during atrial pacing (AP) at low heart rates of smaller than 130 per minute, limits the value of AP to stress the left ventricle. When Wenkebach type AV block is present, the heart rate can be increased by administration of atropine before atrial pacing or by right ventricular pacing. Atropine, however, occasionally may cause serious supraventricular or ventricular arrhythmias, and high rate right ventricular pacing is not tolerated by many patients with left ventricular dysfunction because of the absence of the atrial contribution. Twenty-eight out of 101 patients with angina pectoris (27.7 percent) developed second degree AV heart block during atrial pacing studies performed for evaluation of left ventricular function. In 8 of the 28 patients, sequential AV pacing (SP) was performed successfully, with the heart rate being increased to 150-167 per minute. In 4 of the 8 patients, left ventricular dysnfunction was demonstrated during and immediately after SP. Typical angina pectoris developed in two of the four patients during SP, one of whom proved to have normal coronary arteriogram. Sequential AV pacing is an alternative method to increase the heart rate for the purpose of stressing the left ventricle when advanced degree or second-degree AV heart block pre-exists or develops during right atrial pacing. In some patients the method of SP might be preferable to administration of atropine or to ventricular pacing.

Adult↗
PubMed1988

Beneficial effect of atrial natriuretic factor on ischemically injured kidneys in the rat. A new approach to improve early renal function.

In a rat experimental study we investigated whether the atrial natriuretic peptide by itself is able to improve early renal function after an ischemic injury. Two groups of Wistar male rats underwent a right nephrectomy and a left renal artery occlusion for 30 min and were infused for 2 hr after ischemia with isotonic saline or rat atrial natriuretic peptides (alpha ANF: 28 amino acids (AP 28) and atriopeptin III (AP 24): 24 amino acids). ANF infusion increased the urinary flow (P less than 0.001), the urinary sodium concentration (P less than 0.001), the sodium excretion rate (P less than 0.0001), and improved the glomerular filtration rate (GFR) recovery (P less than 0.02) determined at the end of the 2-hr infusion period. AP 24 exhibited higher natriuretics activities than AP 28. The effect of both peptides upon GFR recovery was equivalent. These effects of ANF observed after acute ischemia suggest that this peptide may be beneficial on the resumption of renal function in the early phases following transplantation.

Animals↗
PubMed1984

Right atrial thrombus and superior vena cava syndrome in a child.

Complications of central venous catheterization are well described. They include right atrial thrombosis and superior vena cava syndrome resulting from impaired venous drainage. Such complications are normally observed while the catheter is in place. They are often transient, resolving upon catheter removal. A patient with recurrent signs of superior vena caval obstruction 1 1/2 years after removal of the central venous catheter is described. The obstruction was determined to be intermittent and functionally related to elevated cardiac output due, in turn, to anemia. This patient was also found to have a calcific right atrial thrombus which was not obstructive.

Catheters, Indwelling↗
PubMed1992

Activation patterns in experimental canine atrial flutter produced by right atrial crush injury.

OBJECTIVES: This study was designed to localize and characterize the atrial flutter reentrant circuit and the electrophysiologic effects of right atrial crush injury in a new canine model. BACKGROUND: In previous studies sustained atrial flutter was induced in the canine heart by rapid atrial pacing after a linear crush injury was placed in the right atrial free wall. METHODS: Eight dogs (group 1) with three electrode plaques on the right and left atria and Bachmann's bundle and seven dogs (group 2) with a single high density electrode plaque on the right atrium were studied with use of a 64-channel computerized mapping system. RESULTS: At baseline, during sinus rhythm and right and left atrial pacing, activation spread uniformly without areas of slow conduction. Crush injury produced marked conduction delay or complete block during sinus rhythm, increasing the mean difference in activation times across the injury compared with control values (group 1, 31 +/- 4 vs. 14 +/- 5 ms, p less than 0.01; group 2, 28 +/- 10 vs. 7 +/- 2 ms, p less than 0.01). Rapid atrial pacing (S1S1 200 ms) above and below the crush injury revealed a line of complete block across which adjacent electrodes recorded markedly different activation times (33 +/- 5 and 38 +/- 12 ms difference, respectively) and around which activation wave fronts proceeded, colliding opposite the stimulating electrodes. The mean atrial flutter cycle length of 11 episodes induced in group 1 and 14 episodes in group 2 was 157 +/- 16 and 140 +/- 16 ms, respectively (p = NS). Activation mapping revealed a reentrant circuit in the right atrium around the crush injury in all episodes. Although the reentrant circuit did not contain a discrete area of slow conduction, activation time below was longer than that above the crush injury (92 +/- 14 vs. 66 +/- 8 ms and 82 +/- 12 vs. 59 +/- 9 ms in groups 1 and 2, respectively, p less than 0.01 for both). Rapid atrial pacing or premature stimuli produced progressive conduction delay and unidirectional block between the crush injury and the tricuspid anulus, inducing atrial flutter directly in 9 of 25 episodes. In 16 episodes, atrial flutter developed after transient induction of atrial fibrillation. CONCLUSIONS: 1) Atrial flutter in this model is due to reentry in the right atrium; 2) the crush injury functions as an anatomic obstacle around which reentry may occur; and 3) the reentrant circuit does not contain a discrete area of slow conduction but, rather, generally slower conduction below the crush injury.

Animals↗
PubMed1980

Inlet and intrachamber concentration distributions in tracer studies of the canine central circulation and their relation to the isotope dilution residue function.

We analyzed the isotope dilution residue function from a single cardiac chamber for an arbitrary inlet distribution of tracer and arbitrary mixing within the chamber, and established a general relationship between cardiac output and the chamber residue function. In our experiments, we made simultaneous temperature measurements in three left ventricular chamber subregions of the dog subjected to left and right atrial injections of chilled saline. Flow-proportional tracer labeling always occurred at the left ventricular inlet when injection was into the right atrium. This state almost never obtained, however, with direct left atrial injection, although it was approximated most closely when multiple side hole cathers were used. We also demonstrated that imperfect tracer mixing in the normal ventricle can lead to significant regional temperature inequalities during tracer passage. These inequalities are more pronounced in the ventricle with compromised function, but in both normal and compromised ventricles they are minimal several beats after tracer concentration peaks if injection is into the right atrium.

Animals↗
PubMed1981

Sympathetic neural effects on regional atrial recovery properties and cardiac rhythm.

The functional distribution of the cardiac sympathetic nerves to the atria and their arrhythmiogenic effects were determined in 16 open-chest pentobarbital-anesthetized dogs. Shortening of refractory periods at four right and two left atrial sites during stimulation of the nerves was taken as a criterion of their distribution. Stimulation of right stellate ganglion, craniovagal, and right stellate cardiac nerves produced localized shortening on the right atrium, particularly at the sinus node area, and invariably induced sinus tachycardia. The recurrent cardiac nerve produced little shortening at all sites and less arrhythmiogenic effect. The left stellate ganglion and ventrolateral cardiac nerve affected only left atrial sites and induced atrioventricular junctional rhythm. The ventromedial cardiac nerve affected all sites and had no consistent arrhythmiogenic effect. The innominate nerve had no substantial effect. We concluded that the functional distribution of the cardiac sympathetic nerves is localized, and that rate, rhythm, and refractory period changes induced by stimulation of these nerves are characteristic of the area of distribution.

Animals↗
PubMed2002

Noninvasive estimation of both systolic and diastolic pulmonary artery pressure from Doppler analysis of tricuspid regurgitant velocity spectrum in patients with chronic heart failure.

BACKGROUND: Noninvasive estimation of pulmonary artery systolic and diastolic pressures usually requires the investigation of both tricuspid and pulmonary regurgitant jets and an estimate of right atrial pressure. A new, noninvasive method to obtain pulmonary diastolic pressure (based on the hemodynamic demonstration that right ventricular systolic pressure and pulmonary artery diastolic pressure are equal at the time of pulmonary valve opening) from the analysis of tricuspid regurgitation alone has been described in a small cohort of patients. We sought to verify the accuracy of this method in a large population of patients with heart failure. METHODS: An estimate of pulmonary artery diastolic pressure was obtained by transposing the pulmonary opening time (from the onset of the R wave on the electrocardiographic tracing to the beginning of pulmonic forward flow on Doppler examination) onto the tricuspid regurgitant velocity curve and calculating the pulmonary artery diastolic pressure value as the pressure gradient between the right ventricle and right atrium at this time. The study group included 86 consecutive patients (64 men, aged 52 +/- 11 years) with heart failure (New York Heart Association class > or =II, 94%) who were in stable clinical condition with a chiefly idiopathic (57%), ischemic (24%), or other form (13%) of dilated cardiomyopathy. Noninvasive, right-sided pressures were compared with invasive measurements obtained during right heart catheterization performed within 24 hours. The Bland and Altman graphic method was used together with the calculation of the Lin concordance correlation coefficient and its 95% CI to assess the agreement between hemodynamic and echocardiographic measurements. RESULTS: Catheter-derived pulmonary artery systolic pressure ranged from 8 to 119 mm Hg (mean 42 +/- 21 mm Hg), pulmonary artery diastolic pressure from 1 to 59 mm Hg (mean 20 +/- 11 mm Hg), and right atrial pressure from -5 to 20 mm Hg (mean 6 +/- 5 mm Hg). Tricuspid regurgitation was detected in 75 of 86 patients (87%). Pulmonary artery systolic pressure ranged from 13 to 110 mm Hg (mean 44 +/- 21 mm Hg); the pressure gradient between the right ventricle and right atrium at time t of the pulmonary valve opening on the tricuspid regurgitation velocity curve was measurable in 70 of 75 (93%) cases and ranged from 3.5 to 64 mm Hg (mean 22 +/- 11 mm Hg). Good agreement was observed not only for pulmonary artery systolic pressure but also for pulmonary artery diastolic pressure, based on the analysis of the tricuspid regurgitation velocity jet, with a slight difference between measurements (-1.8 and 0.1, respectively), no evident pattern of point scattering, and a high concordance correlation coefficient that was elicited by the virtually total overlapping of lines on the graph. Overall results were not significantly different whether patients with depressed right ventricular function (right ventricular ejection fraction < or =35%), with a tricuspid regurgitation grade > or =2 and atrial fibrillation were included in the analysis. CONCLUSIONS: The narrow paired difference for the estimate of pulmonary artery systolic pressure and the even better difference for pulmonary artery diastolic pressure using the tricuspid regurgitation velocity curve analysis indicates that this new method reliably estimates invasive right-sided pressures over a wide range of pressure values in patients with heart failure. The overall good correlation with invasive values indicates that Doppler examination of tricuspid regurgitation alone may provide a simple and comprehensive new method for the noninvasive evaluation of right ventricular and pulmonary hemodynamics in patients with heart failure.

Blood Pressure↗
PubMed1986

Postoperative evaluation of endomyocardial fibrosis.

25 patients with angiographic features suggestive of endomyocardial fibrosis underwent endocardiectomy and atrioventricular valve replacement. There were 8 deaths. 17 survivors were reevaluated after a mean follow-up of 13.5 months. 8 had right ventricular endomyocardial fibrosis (RVEMF) 5 had left ventricular endomyocardial fibrosis (LVEMF) and 4 had biventricular disease (BVEMF). The survivors showed a significant improvement in their clinical features and functional status. There was a significant reduction in atrial size in X-ray. Hemodynamic data showed a significant fall in right heart filling pressure, right ventricular systolic pressure and pulmonary artery mean pressure, and a significant fall in left heart filling pressure in patients with left ventricular disease either alone or as a part of biventricular disease. In ventriculogram, while there was no change in right ventricular shape after endocardiectomy, left ventricular shape was restored to near normal. The significant improvement is mostly due to the correction of the regurgitant lesion and to some extent due to restoration of ventricular compliance.

Adolescent↗
PubMed1996

Radiofrequency catheter ablation of atrial flutter circuits.

Common atrial flutter is due to reentrant activation of the right atrium, rotating around anatomic structures and areas of functional block, in counterclockwise direction in the frontal plane. The myocardium between the inferior vena cava and the tricuspid valve is critical to close the activation circuit, and ablation of this isthmus by catheter-delivered radiofrequency can interrupt flutter, and eventually destroy the circuit, preventing recurrence of the arrhythmia. Flutter interruption does not mean complete isthmus ablation, and the procedure endpoint is to attain flutter non-inducibility, and isthmus block. Despite non-inducibility, flutter may recur, and new procedures may be needed for complete ablation. Atrial fibrillation can occur in up to 35% of the cases during follow-up but is generally well controlled with drugs that were ineffective against flutter before ablation. Some atypical atrial flutters show circular right atrial activation, using the same circuit in a clockwise direction, and these can also be interrupted by ablation of the inferior vena cava-tricuspid valve isthmus. Other atypical flutters can have different anatomic substrates in the right or left atrium, and mapping has to define specific isthmuses as ablation targets in each case. Left atrial flutter remains inaccessible to ablation.

Atrial Flutter↗
PubMed2004

Regional right and left ventricular function after the Senning operation: an ultrasonic study of strain rate and strain.

BACKGROUND: Systemic right ventricular dysfunction is a major concern in the follow-up of patients who underwent an atrial redirection procedure for transposition (concordant atrio-ventricular and discordant ventriculo-arterial connections). No good non-invasive method is currently available for quantifying right ventricular function. AIMS: We have used ultrasonically based imaging of strain rate and strain to quantify regional deformation in the right ventricle after the Senning operation, comparing properties of regional deformation of the right ventricle with right ventricular ejection fraction as measured using magnetic resonance imaging. METHODS: In 20 asymptomatic patients who had undergone the Senning procedure, we measured peak systolic strain rate and systolic strain values in the right ventricular free wall, the septum and the left ventricular lateral wall using colour Doppler myocardial imaging, comparing the data with findings obtained in 30 healthy subjects. Global right ventricular ejection fraction was assessed using magnetic resonance imaging. RESULTS: Properties of deformation of the right ventricular free wall were reduced and homogeneous after the Senning procedure compared to normals, with significantly lower values for peak systolic strain rate and systolic strain (-1.1 +/- 0.4 vs. -2.5 +/- 0.9 s(-1); p < 0.05 and -16 +/- 7% vs. -38 +/- 13%; p < 0.05, respectively). There was a significant correlation between regional longitudinal right ventricular systolic strain values and right ventricular ejection fraction (r = -0.87, p < 0.001). In the septum, peak systolic strain rate was again reduced and homogeneous (-1.2 +/- 0.4 vs. -1.8 +/- 0.5 s(-1); p < 0.05 vs. normals). Also in the left ventricle, the lateral wall peak systolic strain rate and systolic strain values were reduced (-1.5 +/- 0.5 vs. -2.1 +/- 0.9 s(-1); p < 0.05 and -20 +/- 6% vs.-25 +/- 9%; p < 0.05, vs. normals, respectively). CONCLUSIONS: Properties of regional longitudinal deformation of the systemic right ventricle are reduced after the Senning procedure compared to normal controls, and correlate well with global right ventricular performance. These findings suggest that ultrasonic strain rate and strain imaging could be used in the non-invasive follow-up of ventricular function in these patients.

Adolescent↗
PubMed2001

Effect of different location of atrial lead position on nearfield and farfield electrograms in dual chamber pacemaker-defibrillators.

The normal functioning of dual chamber pacemaker-cardioverter defibrillator (AV pacer/ICD) may be affected by oversensing of the farfield R wave (FFRW) by the atrial channel. This study aimed to investigate whether placement of the AV pacer/ICD's atrial lead at a lateral (LAT) wall location compared to a medial (MED) location i.e. the appendage of the right atrium, would reduce the amplitude of FFRWs but not the nearfield atrial electrograms (AEGMs) during sinus rhythm (SR) and ventricular fibrillation (VF). In 17 patients, real time electrograms were recorded during SR and induced VF through the atrial lead initially at the MED and subsequently at the LAT location. In 10 patients the electrograms in SR were also recorded on a computerized data acquisition and recording system at different band-pass filter settings. Although FFRWs were recorded both at MED and LAT locations, they were much smaller, 3.5+/-4.1mm during SR and 1.7+/-2.2mm during VF at the LAT location. At 30-500Hz band-pass filter, lower amplitudes of FFRWs 0.14+/-0.09 mV were recorded at the LAT location. The V/A ratios of the amplitudes of FFRWs and AEGMs were smaller at the LAT location during SR and VF. The nearfield AEGMs were of similar amplitudes at the MED and LAT locations. These data indicate that lower amplitudes of FFRWs are recorded by placement of the atrial lead at the lateral wall of the right atrium. Oversensing of FFRWs may be prevented to improve functioning of the AV pacer-ICD.

Aged↗
PubMed1987

Atrial septal defect: attenuation of respiratory variation in systolic and diastolic time intervals.

The effects of pathologic states on right and left ventricular function have been studied extensively. However, there have been few studies on the interrelations between right and left ventricular function in normal human subjects and in patients with disease. Respiratory effects on ventricular interrelations reflected by diastolic time, right or left ventricular systolic time and ventricular performance (pre-ejection period/ejection time ratio) were studied in 12 normal subjects and 15 patients with a normal pressure-large shunt atrial septal defect. Simultaneous pulmonary artery (intracardiac manometer recordings) and left ventricular external recordings were performed in both groups. Left ventricular diastolic time increased with inspiration in the normal subjects and decreased in the patients with atrial septal defect (12.6 +/- 2.39 [1 SE] versus -13.4 +/- 3.48 ms, p less than 0.001). Left ventricular systolic time and ejection time decreased with inspiration in the normal group and remained unchanged in the patient group (-7.6 +/- 0.95 versus -0.9 +/- 0.77 ms, p less than 0.001 and -10.4 +/- 1.09 versus -1.7 +/- 0.80 ms, p less than 0.001, respectively). Left ventricular pre-ejection period/ejection time ratio increased with inspiration in the normal subjects and remained unchanged in the patients with atrial septal defect (0.03 +/- 0.008 versus 0 +/- 0.01, p less than 0.01). Right ventricular diastolic time decreased with inspiration in normal and patient groups (-8.8 +/- 1.6 versus -17 +/- 3.87 ms).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2003

Fetal anatomic and functional echocardiography: a 5-year review.

OBJECTIVE: To assess the concordance of fetal and postnatal echocardiography when congenital heart disease is suspected prenatally. METHODS: The perinatology and pediatric cardiology ultrasound databases were searched for fetal echocardiograms obtained between June 1995 and June 2000. All cases with abnormal fetal echocardiographic findings in which postnatal echocardiography was performed were included. A perinatologist, pediatric cardiologist, or both interpreted all fetal echocardiograms; a pediatric cardiologist interpreted all postnatal echocardiograms. The fetal and postnatal echocardiograms were compared for the presence of 25 specific components. The kappa statistic was calculated to evaluate concordance between fetal and postnatal studies. Positive and negative predictive values for fetal studies were calculated under the assumption that the postnatal study yielded the correct diagnosis. RESULTS: Sixty-five patients were included. Congenital heart disease ranged from an isolated atrial septal defect to complex disease. Images adequately showed all 25 components in more than 85% of the fetal studies. Concordance between fetal and postnatal echocardiograms was excellent (kappa > 0.75) for 20 of the 25 components evaluated. Four of the remaining 5 components had fair concordance (kappa = 0.4-0.75) between fetal and postnatal studies. Structural abnormalities without excellent concordance included partial anomalous pulmonary venous return, secundum atrial septal defects, and heart malposition. Concordance between fetal and postnatal right and left ventricular function was fair; however, differences may have been due to physiologic changes that occurred after birth rather than to inferior diagnostic accuracy of fetal echocardiography. CONCLUSIONS: Fetal echocardiography is an extremely useful and accurate clinical tool for prenatal and postnatal evaluation of congenital heart disease.

Female↗
PubMed1999

Ventricular Septal Defect.

Ventricular septal defects (VSDs) are the most common congenital heart malformations seen in children. Because spontaneous closure occurs frequently, patients with small VSDs should be followed clinically with no limitations except endocarditis prophylaxis. Surgical closure is recommended for only small defects with significant associated lesions such as aortic regurgitation, aortic valve prolapse, right or left ventricular outflow obstruction, tricuspid regurgitation, left ventricle to right atrial shunt, or recurrent endocarditis. Enlarging left ventricular size or deteriorating left ventricular function would also be an indication for surgical repair. Moderate and large VSDs in infancy often require treatment of congestive heart failure with diuretics, digitalis, and afterload reduction. Surgical closure before 9 months of age is indicated for large VSDs and by 2 years of age for moderate shunts to prevent pulmonary vascular obstructive disease and the consequences of long-standing volume overload. Device closure of VSD is still in the investigational stage but holds promise for treatment of apical or multiple muscular VSDs.

Journal Article↗
PubMed1988

Systolic and diastolic alterations of left ventricular function: prevalence in ischaemic heart disease and importance in the management of individual patients.

Myocardial perfusion and contractile performance are strictly interrelated. Conclusive experimental data show that changes in perfusion cause immediate changes in function, and conversely, that changes in contraction affect both total and regional myocardial blood flow. In ischaemic heart disease, both transient and permanent changes in global and/or regional left ventricular (LV) function have been described. In myocardial ischaemia, an impairment of LV relaxation, as indicated by a reduction of negative dP/dt, is the first appreciable haemodynamic event. When ischaemia is sustained, impairment of LV contraction follows, as indicated by a drop of positive dP/dt, reduction of systolic LV pressure, rise of end-diastolic LV pressure. Unrestricted reperfusion, as in experimental coronary occlusion and in Prinz-Metal angina, is associated with a transient rebound in regional systolic function. Spontaneous and/or induced changes of regional ventricular function provide relevant information for the management of the individual patient. In PTCA candidates monitoring regional contractile performance by mono and two-dimensional echocardiography during dypiridamole infusion has proven to be a sensitive and specific test for (1) assessing the haemodynamic significance of a coronary stenosis in patients with single-vessel disease, (2) identifying the 'culprit' lesion in patients with multiple-vessel disease. During PTCA, right and left ventricular function assessed by radionuclide angiography both at rest and during atrial pacing appears to be a sensitive method for the immediate evaluation of the efficacy of the procedure.

Angioplasty, Balloon↗
PubMed1987

Vasodilator properties of prostacyclin after coronary artery bypass surgery.

The vasodilatory properties of prostacyclin were studied in 12 intubated patients who underwent coronary artery bypass surgery. When infused in doses of 2.5, 5, 10, and 20 ng/kg/min, prostacyclin produced a dose-dependent decrease in systemic vascular resistance from 2,702 +/- 143 to 1,654 +/- 106 dynes/cm5/m2 (p less than 0.05). Heart rate, right atrial pressure, and pulmonary arterial and capillary wedge pressures did not change. Cardiac function was improved, since stroke volume index increased from 29.5 +/- 1.4 to 35.5 +/- 2.0 ml/min/m2 (p less than 0.05) and the rate pressure product decreased from 13.3 +/- 1.3 to 10.9 +/- 0.9 X 10(3) mm Hg/beats/min (p less than 0.05), while stroke work index remained unchanged. These hemodynamic changes were associated with a dose-dependent decrease in arterial oxygen tension which occurred from 278 +/- 25 to 133 +/- 22 mm Hg; however, oxygen transport increased as a result of the prostacyclin-induced increase in cardiac index. This study demonstrates that prostacyclin is a potent arterial vasodilator that may be of interest in the treatment of postoperative vasoconstriction occurring after coronary artery bypass surgery.

Adult↗
PubMed1990

Chronic supraventricular tachycardia causes ventricular dysfunction and subendocardial injury in swine.

Chronic supraventricular tachycardia has been associated with ventricular dysfunction in humans and animals. However, this ventricular failure is poorly characterized, and the ultrastructural consequences of supraventricular tachycardia are unknown. We serially examined right and left ventricular function, endomyocardial ultrastructure, and creatine kinase activity in eight pigs at base line and again at 1, 2, and 3 wk following rapid atrial pacing. Left and right ventricular ejection fractions fell significantly from base line after 1 wk of chronic tachycardia. Three weeks of chronic pacing resulted in further deterioration in ejection fractions. Significant biventricular chamber dilatation developed and was associated with a reduction in end-diastolic wall thickness after 2 wk of tachycardia. Mitochondrial injury and diminished mitochondrial cytochrome oxidase staining of subendocardial myocytes were observed after 2 wk of tachycardia. Endomyocardial creatine kinase activity fell from control levels following 2 wk of pacing. Postmortem examination revealed a reduction in left ventricular wall thickness compared with 14 control animals. Fibrosis occurred along the subendocardial layer in paced animals, and glycogen content was also reduced. In summary, chronic supraventricular tachycardia resulted in severe biventricular pump dysfunction and chamber dilatation that were associated with ultrastructural alterations and reduced enzyme activity of the subendocardial myocytes. These ultrastructural and metabolic changes may be potential mechanisms responsible for the ventricular dysfunction and dilatation observed in this model.

Animals↗