Right Atrium In Patients Research Articles

Electro-Anatomical Characteristics of Typical Atrial Flutter

Type 1 atrial flutter (AFL) is a macroreentrant tachycardia in the right atrium; the anterior barrier of the common AFL circuit is located at the tricuspid annulus (TA) and the posterior border is functional line of block at the posteromedial (sinus venosa region) right atrium. The upper turnover site of the wave front is mainly located at the anterior to the superior vena cava. Conduction property across the posteromedial (sinus venosa region) right atrium in patients with and without AFL is different. i.e., functional conduction block occurs at the lower pacing rate in patients with AFL, and the majority of patients with chronic AFL demonstrate conduction block across the posteromedial (sinus venosa region) right atrium even during sinus rhythm. Catheter ablation therapy for AFL is creation of linear lesion between tricuspid annulus and inferior vena cava. Changes in activation sequence around the tricuspid annulus are used to confirm bidirectional block. However, it is difficult to demonstrate the bidirectional block in the presence of transverse conduction around the inferior vena cava. In such a case, bidirectional block should be confirmed by differential pacing or 3‐dimensional mapping system.

The Nonselective β-Blocker Carvedilol Suppresses Apoptosis in Human Cardiac Tissue: A Pilot Study

Cardioplegia and reperfusion of the myocardium may be associated with cardiomyocyte apoptosis and subsequent myocardial injury. To establish a pharmacologic strategy for the prevention of these events, this study aimed to verify the reliability of our human cardiac model and to evaluate the antiapoptotic properties of the nonselective beta-blocker carvedilol during simulated cardioplegia and reperfusion ex vivo. Cardiac biopsies were retrieved before induction of cardiopulmonary bypass from the auricle of the right atrium of patients undergoing elective coronary artery bypass grafting. Biopsies were exposed to ex vivo conditions of varying periods of cardioplegia/reperfusion (30/10 minutes, 60/20 minutes, 120/40 minutes). Group I was the untreated control (n = 15), group II was the treated control (cardioplegia/reperfusion, n = 15), and group III was the experimental group (cardioplegia/reperfusion plus carvedilol, n = 15). Immunostaining for antibodies to activated caspase 3 and poly(ADP-ribose) polymerase 1 (PARP-1) cleavage was used to detect apoptosis. The percentage of apoptotic cardiomyocytes was significantly lower (P < .05) in group I than in group II, revealing a time-dependent increase. In group III, carvedilol treatment suppressed apoptosis significantly (P < .05). Carvedilol significantly suppresses apoptosis in our ex vivo setting. This finding warrants further studies to evaluate the potential beneficial effects of carvedilol in suppressing ischemia/reperfusion injury in clinical settings.

Study of the shape and function of right atrium in patients with chronic pulmonary hypertension and the influencing factors

Objective To assess the volume and function of right atrium(RA) in patients with chronic pulmonary hypertension(PH) by echocardiography and explore the influencing factors of these changes.Methods The study include 20 healthy participants as the control group and 57 patients with chronic PH as the case group.The patients were divided into three groups: low-grade PH, midrange PH and severe PH.Maximal RA volume index(VmaxI), minimal RA volume index(VminI), pre-atrial contraction RA volume index( VpreI), reservoir volume index(RVI), conduit volume index(CVI), contraction-chamber volume index (CCVI) were measured and calculated.The diameter of tricuspid valve and the late-diastole peak velocity of the bloodstream(Va) were measured,and then RA ejection force(RAEF) could be calculated.Systolic strain rate(RASRs), early diastolic strain rate (RASRe), and late diastolic strain rate (RASRa) of RA free wall were measured respectively.The correlation between pulmonary arterial systolic pressure (PASP), right ventricular ejection fraction(RVEF),the tissue Doppler of RV free wall(Ea/Aa) and the parameters of RA were analysed,and the main factors influencing the volume and function of RA were exploxed.Results With the rising of PASP, the RA volume changed obviously.And CCVI, RAEF, RVI, RASRs and the absolute value of RASRa increased gradually, but CVI decreased gradually.PASP, RVEF and Ea/Aa correlated with the parameters of RA.The main factors influencing the Vprel were EDVI, Ea/Aa and the course of disease,and VpreI and PASP mainly influenced the RAEF.Conclusions In patients with chronic PH the volume and function of RA changed,and some index of which was infuenced by PASP, RVEF, Ea/Aa and so on. Key words: Echocardiography; Atrial function, right; Hypertension, pulmonary

Assessment of nociceptin/orphanin FQ and μ-opioid receptor mRNA in the human right atrium

BackgroundThe expression of µ (mu: MOP) and nociceptin/orphanin FQ (NOP) receptors in the human myocardium is controversial. In this polymerase chain reaction (PCR)-based study using human right atrial biopsies, we have (i) probed for mRNA encoding NOP receptor and its endogenous peptide precursor, ppN/OFQ, and mRNA encoding MOP and (ii) attempted to correlate expression with cardiac function. MethodsmRNA encoding MOP, NOP, and the precursor for NOP (ppN/OFQ) was assessed by quantitative real-time PCR (Q-PCR) using validated TaqMan® primers and compared with a housekeeper (glyceraldehyde-3-phosphate dehydrogenase, GAPDH). Q-PCR data are expressed as the difference in cycle threshold (ΔCt=CtGene of interest−CtGAPDH: high value, low expression) and patients were grouped according to left ventricular ejection fraction (LVEF). ResultsForty patients were recruited; NOP, MOP, and ppN/OFQ mRNA were measured in 38, 29, and 10 patients, respectively. ΔCt (median and range) values for NOP and MOP were 10.9 (7.8–13.7) and 16.0 (12.3–18.9), respectively, representing low expression of MOP and ∼34-fold more NOP. MOP mRNA was not detected in seven samples and with ΔCt values of ∼20, ppN/OFQ was considered absent. When patients were grouped into normal (>50%) and impaired (<50%) LVEF, there was no difference between the groups for either NOP or MOP. In some patients, intraoperative LVEF was estimated using transoesophageal echocardiography, and there was no correlation with either NOP or MOP. ConclusionsThe human right atrium of patients with coronary artery disease and heart failure expresses mRNA encoding NOP and possibly low levels of MOP. This does not correlate with degree of cardiac dysfunction. In addition, the atrium does not express ppN/OFQ mRNA.

Urotensin II receptor expression in human right atrium and aorta: effects of ischaemic heart disease

Urotensin II (UII) and its receptor UT are involved in control of the cardiovascular system and are implicated in heart failure. We measured UT expression by quantitative PCR (Q-PCR) in atrial and aortic tissue, and plasma UII while simultaneously assessing cardiac function in 40 patients undergoing coronary artery bypass surgery. RNA extracted from atrial and aortic samples was probed with specific Q-PCR UT and housekeeper (glyceraldehyde-3-phosphate dehydrogenase, GAPDH) TaqMan primers. Plasma UII was measured using radioimmunoassay. Left ventricular ejection fraction (LVEF) was measured using preoperative trans-thoracic echocardiography and ventriculography, and intraoperatively using transoesophageal echocardiography. Q-PCR data are expressed as difference in cycle threshold (DeltaC(t)=C(tUT)-C(tGAPDH): high number indicates low expression). There was no difference in DeltaC(t) in either atrium or aorta between patients with normal (LVEF >50%) or those with impaired (LVEF <50%) preoperative systolic function. There was a weak negative correlation (r(2)=0.245, P=0.031) between intraoperative LVEF and DeltaC(t) in 19 patients possibly indicating down-regulation of UT with worsening LVEF. Atria expressed significantly more UT than aorta (P=0.011). In the absence of non-diseased controls, plasma UII was higher than a historical control group. This is the first study to simultaneously measure UT (mRNA), UII, and cardiovascular function. Collectively, these pilot data may suggest a down-regulation of UT within the right atrium of patients with heart failure.

Activated nuclear factor-κB and increased tumor necrosis factor-α in atrial tissue of atrial fibrillation

Objectives. To depict the interaction between atrial fibrillation (AF) and inflammatory reaction, studies were taken to measure the activity of NF-κB in myocardium, the concentration of regional inflammatory factors and the pathological process of the right atrium in patients with AF. Design. Patients with valvular disease with AF or sinus rhythm (SR) were recruited and compared. Before the extracorporal circulation, about 250 mg tissue of right atrium was collected for pathological examination. The activity of NF-κB in myocardium was measured by electrophoretic mobility shift assay (EMSA), and the concentration of cardiac tissue interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) was determined by radioimmuoassay. Results. Patients with valvular disease with AF exhibited higher NF-κB activity, higher concentration of TNF-α and IL-6, severe lymphomonocyte infiltration, and more fibrosis than those patients with valvular disease with SR. There were significant positive correlations among NF-κB activity and levels of TNF-α and IL-6 and collagen volume fraction. Conclusions. This study proved the presence of inflammation in atrial myocardium by triggering inflammatory reaction.

Prevalence of conduction delay of the right atrium in patients with SSS: implications for pacing site selection

To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS). Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos > 60 ms and group B if < 60 ms. Each Group was randomized to RAA/IAS pacing and algorithms ON/OFF. Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes. Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

Stimulated release of calcitonin gene-related peptide from the human right atrium in patients with and without diabetes mellitus

Calcitonin gene-related peptide (CGRP), a potent vasodilator released during activation from a subset of sensory Aδ- and C-fiber afferents, has been suggested to play a beneficial role in myocardial ischemia. Variations in CGRP release can possibly be correlated with diseases that involve changes in activity or degeneration of cardiac afferent fibers. The aim of the present study was to examine basal and stimulated CGRP release from cardiac tissue in patients who underwent cardiopulmonary bypass surgery and to compare patients with and without known history of diabetes mellitus. Small pieces of the right atrium routinely excised during the bypass operations were passed through series of oxygenated solutions. The TRPV1 receptor agonist capsaicin and the nitric oxide donor NONOate were added for stimulation of cardiac afferent fibers. The eluates were processed using an enzyme immuno-assay (EIA) for measurement of CGRP concentrations. Both capsaicin and NONOate caused significant increases in CGRP release. No significant differences in CGRP release between patients with and without diabetes mellitus were examined. The present study evaluates a simple and reproducible model for measuring stimulated CGRP release from the human right atrium.

AB24-1: Electrophysiological and anatomical characteristics of the posterior right atrium in patients with and without atrial flutter: Intracardiac echocardiography analysis

AB24-1: Electrophysiological and anatomical characteristics of the posterior right atrium in patients with and without atrial flutter: Intracardiac echocardiography analysis

Application of cardiopulmonary bypass for resection of renal cell carcinoma and adrenocortical carcinoma extending into the right atrium

The application of cardiopulmonary bypass to atrial involvement represents an important advance that has improved the safety and technical efficacy of a difficult surgical undertaking. Our experiences of the management of extended thrombi into the right atrium in patients with retroperitoneal malignancy using a cardiopulmonary bypass were discussed. Data were reviewed for five patients (two men and three women; mean age, 60.4 years; range, 49-79 years) with retroperitoneal tumors displaying intracardiac tumor extension. Tumors originated in the right kidney in four patients, and in left adrenal gland in one patient. Cardiopulmonary bypass was used in all cases. Mean total blood loss was 6059 mL. Mean operative time was 14.7 h. No intra- or postoperative complications due to surgical technique were encountered, and no significant bleeding occurred during incision of the inferior vena cava or after removal of tumor thrombus. The follow-up period ranged from 3 to 20 months with a mean of 12.6 months. Of the five patients, three died of metastatic diseases, one died of liver dysfunction and one remains disease free as of 18 months postoperatively. Our experience indicates that this procedure can be safely used for atrial involvement. Although superior long-term survival cannot be shown yet, favorable early results and a lack of perioperative complications were identified.

Myocardial Preconditioning Against Ischemia-Induced Apoptosis and Necrosis in Man

Ischemic preconditioning (IPC) protects against apoptosis and necrosis but the contribution of the two forms of cell death and whether the beneficial effects are mediated by similar or different signal transduction pathways remains unclear. Here we have investigated the effect of IPC on the type of cell death in the human heart and whether the inhibition of apoptosis and necrosis by IPC requires the opening of mitoK(ATP) channels and the activation of PKC and p38MAPK. Free-hand tissue sections (n = 6/group) obtained from the right atrium of patients at the time of coronary bypass surgery were subjected to 90-min simulated ischemia followed by 120-min reoxygenation (SI/R) with or without IPC (5 min SI/5 min R) prior to SI/R. IPC reduced apoptosis from 30.0 +/- 3.8 to 11.0 +/- 1.5% (P < 0.05) by TUNEL technique and necrosis from 11.6 +/- 2.4 to 4.2 +/- 1.7% (P < 0.05) by propidium iodide staining. When inhibitors of mitoKATP channels (1 mm 5-hydroxydecanoate), PKC (10 microm chelerythrine), and p38MAPK (10 microm SB203580) were added for 10 min before SI, the protection against necrosis was abolished. However, whereas 5-hydroxydecanoate and chelerythrine also abolished the protection of IPC against apoptosis, SB203580 did not. The activation of mitoKATP channels (100 microm diazoxide), PKC (1 microm PMA), and p38MAPK (1 nm anisomycin) were a mirror image of the findings with blockers. IPC protects the human myocardium against both apoptosis and necrosis. The anti-necrotic effect is mediated by the opening of mitoKATP channels and activation of PKC and p38MAPK; however, the anti-apoptotic effect requires opening of the mitoKATP channels and PKC activation but is p38MAPK-independent.

945 Electroanatomic features of right atrium in patients affected by myotonic dystrophy type 1

945 Electroanatomic features of right atrium in patients affected by myotonic dystrophy type 1

945 Electroanatomic features of right atrium in patients affected by myotonic dystrophy type 1

945 Electroanatomic features of right atrium in patients affected by myotonic dystrophy type 1

Relationship Between Connexins and Atrial Activation During Human Atrial Fibrillation

Gap junctional connexin proteins (connexin40 [Cx40], connexin43 [Cx43]) are a determinant of myocardial conduction and are implicated in the development of atrial fibrillation (AF). We hypothesized that atrial activation pattern during AF is related to connexin expression and that this relationship is altered by AF-induced remodeling in the fibrillating atria of chronic AF. Isochronal activation mapping was performed during cardiac surgery on the right atria of patients in chronic AF (n = 13) using an epicardial electrode array. The atrial activation pattern was categorized using a complexity score based on the number of propagating wavefronts of activation and by grouping atria into those capable of uniform planar activation (simple) and those that were not (complex). The activation pattern was correlated with the levels of Cx43 and Cx40 signal measured by immunoconfocal quantification of biopsies from the mapped region. We studied the impact of electrical remodeling by comparing these findings with the unremodeled atria of patients in sinus rhythm during pacing-induced sustained AF (n = 17). In chronic AF, atria with complex activation had lower Cx40 signal than atria showing simple activation (0.013 +/- 0.006 microm(2)/microm(2) vs 0.027 +/- 0.009 microm(2)/microm(2), P < 0.02), with the relative connexin signal (Cx40/Cx40+Cx43) correlating with complexity score (P = 0.01, r =-0.74). This relationship did not occur in the unremodeled atria, and increased heterogeneity of distribution of Cx40 labeling in chronic AF was the only evidence of connexin remodeling that we detected in the overall group. The pattern of atrial activation is related to immunoconfocal connexin signal only in the fully remodeled atria of chronic AF. This suggests that intercellular coupling and pattern of atrial activation are interrelated, but only in conjunction with the remodeling of atrial electrophysiology that occurs in chronic AF.

Temperature of blood in the coronary sinus and right atrium in patients with and without coronary artery disease

We measured the blood temperature of the coronary sinus and the right atrium in control subjects and patients with significant stenoses in the right or left coronary arteries. Coronary sinus temperature was increased in patients with coronary artery disease compared with the control group and was found to be a prognostic factor for mid-term clinical outcome.

Comparison of culprit lesions showing negative remodeling between acute coronary syndrome and stable angina pectoris

between RCA and control group (p=O.lO). Conclusions: Coronary sinus blood temperature measurement is increased compared to that of right atrium in patients with significant lesions in LCA. This technique may prove useful in identifying patients with enhanced inflammatory involvement and additional studies are required for evaluating the clinical significance of coronary sinus thermography in risk stratification and prognosis.

Electroanatomic mapping of transseptal conduction during coronary sinus pacing in patients with paroxysmal atrial fibrillation

Objective—To delineate the electrophysiological properties of transseptal conduction from the left to the right atrium in patients with paroxysmal atrial fibrillation (AF).Design and results—Right atrial mapping using the electroanatomic mapping technique was performed at 111 ± 16 sites in 16 patients with paroxysmal AF during pacing from distal coronary sinus (CS). A single transseptal breakthrough near the CS ostium was observed in all patients. The activation time from the pacing site to the earliest septal activation site was 47 ± 13 ms. The total septal activation time (68 ± 16 ms) was markedly longer but the total right atrial activation time (118 ± 17 ms) was similar to that in patients without AF in a previous observation.Conclusion—During distal CS pacing, a preferential site of transseptal conduction near the CS ostium was demonstrated in patients with paroxysmal AF. This has clinical implications when surgical dissection or catheter ablation is considered to eliminate interatrial connection in patients with AF.

Flow Pattern of the Superior Caval Vein in Children After Closure of Atrial Septal Defect: A Comparison of Catheter Therapy with Open-Heart Surgery

To compare the flow pattern of the superior caval vein (superior vena cava; SVC) after catheter therapy with that after open-heart surgery, we examined the flow velocity curves of the SVC in 10 pediatric patients who underwent catheter closure of atrial septal defect (ASD) and in 20 pediatric patients who underwent open-heart surgery. We used pulsed Doppler examinations to record the velocity curves. On the velocity curve of the SVC in children after open-heart surgery, the velocity in systole was lower than that in diastole, which is contrary to the normal pattern. The velocity in systole increased more than that in diastole during inspiration, which also differs from the normal pattern. In contrast, the velocity curve of the SVC in patients after catheter therapy showed a normal pattern. The change of flow velocity during respiration became smaller after treatment in the surgery group, although it did not change after treatment in the catheter group. These results might indicate less reserve ability in the right atrium in patients who undergo open-heart surgery. ASD closure by catheter is useful not only for its economy and noninvasiveness but also for its potential to contribute conservation of right atrial function.

Mapping the organization of atrial fibrillation with basket catheters. Part II: Regional patterns in chronic patients.

The aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter in a population of 17 patients with persistent AF. The number of occurrences (NO) (i.e., the number of points laying on the baseline) was used as an objective measure of organization. This parameter significantly matches Wells' criteria for the classification of bipolar recordings during AF. The anatomic correspondence of the splines with eight atrial regions (namely anterior free wall, lateral free wall, posterolateral free wall, posterior free wall, posterior atrial septum, atrial septum, tricuspid valve, and anterior tricuspid valve) was assessed by fluoroscopic projections and electrogram morphology. Each region was further divided into high, mid-high, mid-low, and low segments. It was observed that individual and well-defined patterns of organization characterize the electrical activity of the right atrium in patients with persistent AF. When observed over 10 minutes, these patterns are rather stable in time. In each patient, the NO measurements were significantly different in the various right atrium regions (P < 0.0001 for all patients, Friedman test). The NO averaged over the population was significantly different among the regions (P < 0.001, Kruskal-Wallis test), owing to a common disorganized pattern observed in the tricuspid valve and anterior tricuspid valve regions. When these regions were removed from the analysis, the differences among the remaining regions were not statistically significant (P = 0.77). In conclusion, the quantitative assessment of organization in the entire right atrium showed an individual rather than common distribution. This may have implications in the choice of regions candidate for ablation.

Correlation of right atrial pressure and blood flow velocities in the common femoral vein obtained by duplex Doppler sonography

Purpose The purpose of this study was to correlate the right atrial pressure with the blood flow velocity and pulsatility index (PI) values obtained with duplex Doppler sonography of the common femoral vein. Methods Thirty consecutive patients with suspected right-sided heart failure who had right atrial pressure measurements for correlation were included in the study. The common femoral veins were examined with duplex Doppler sonography. Irrespective of the presence or absence of clinical right-sided heart failure, patients were divided into 2 groups on the basis of their right atrial pressures. The mean flow velocities and PIs in the common femoral veins of the 2 groups were compared. Results In patients with elevated right atrial pressure (≥G8 mm Hg), the mean minimum flow velocity ± standard deviation (−0.15 ± 0.11 m/second) in the common femoral vein was significantly lower than that in patients with normal right atrial pressure (< 8 mm Hg) (0.01 ± 0.10 m/second) (p < 0.001). There was no significant difference in the mean maximum flow velocities in the common femoral vein between the patients with elevated right atrial pressure (0.25 ± 0.08 m/second) and the patients with normal right atrial pressure (0.21 ± 0.09 m/second). The mean PI in patients with elevated right atrial pressure (7.75 ± 3.19) was significantly higher than the mean PI in patients with normal right atrial pressure (1.55 ± 1.30; p < 0.001). There was a weak negative correlation between the minimum flow velocity and the pressure in the right atrium in patients with elevated right atrial pressure (p = 0.05; r = −0.4760). The amplitude of retrograde waves seen in patients with normal right atrial pressure was significantly smaller than in patients with elevated right atrial pressure (p < 0.05). Conclusions The association of a decreased minimum velocity, especially a negative value, and an increase in PI in the common femoral vein may indicate an elevated right atrial pressure. Sonographic assessment of retrograde flow velocity in the common femoral vein may be useful in monitoring the response to medical treatment to decrease atrial pressure. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:87–91, 2001.