Infarction Of Right Ventricle Research Articles

Clinical significance of R-wave amplitude in lead V1 and inferobasal myocardial infarction in patients with inferior wall myocardial infarction.

To assess electrocardiogram (ECG) for risk stratification in inferior ST-elevation myocardial infarction (STEMI) patients within 24 h. Three hundred thirty-four patients were divided into four ECG-based groups: Group A: R V1 <0.3 mV with ST-segment elevation (ST↑) V7-V9, Group B: R V1 <0.3 mV without ST↑ V7-V9, Group C: R V1 ≥0.3 mV with ST↑ V7-V9, and Group D: R V1 ≥0.3 mV without ST↑ V7-V9. Group A demonstrated the longest QRS duration, followed by Groups B, C, and D. ECG signs for right ventricle (RV) infarction were more common in Groups A and B (p < .01). ST elevation in V6, indicative of left ventricle (LV) lateral injury, was more higher in Group C than in Group A, while the ∑ST↑ V3R + V4R + V5R, representing RV infarction, showed the opposite trend (p < .05). The estimated LV infarct size from ECG was similar between Groups A and C, yet Group A had higher creatine kinase MB isoform (CK-MB; p < .05). Cardiac troponin I (cTNI) was higher in Groups A and C than in B and D (p < .05 and p = .16, respectively). NT-proBNP decreased across groups (p = .20), with the highest left ventricular ejection fraction (LVEF) observed in Group D (p < .05). Group A notably demonstrated more cardiac dysfunction within 4 h post-onset. For inferior STEMI patients, concurrent R V1 <0.3 mV with ST↑ V7-V9 suggests prolonged ventricular activation and notable myocardial damage. RV infarction's dominance over LV lateral injury might explain these observations.

Is there an Electro-Angiographic Correlation in RD Infarction?

Introduction: Coronary angiography is the examination of choice in the evaluation of coronary anatomy during acute myocardial infarction, particularly of the right ventricle (RV), whose diagnosis remains difficult. The electrocardiogram reflects the pathophysiology of myocardial ischemia, thus allowing prediction of the culprit lesion.&#x0D; Objective: To investigate the correlation between electrical and coronary data and to judge the reproducibility of the electrocardiogram in identifying the culprit lesion in RV infarction.&#x0D; Materials and Methods: Retrospective study of patients hospitalized in the Cardiology Department of the Mohammed VI University Hospital in Marrakech over a period of 24 months for MDI extended to the RV.&#x0D; Results: During the study period, 120 patients were hospitalized for MI with RV extension.&#x0D; Inferior MI represented 70% of all cases of infarction extended to the RV. It is represented electrically by isolated ST-segment elevation in V3R found in 76%, as well as in association with an elevation in V4R in 45% of cases.&#x0D; Conduction disorders were noted in 38% of cases, presented essentially by first degree atrioventricular block, without any electrical specificity.&#x0D; Coronary angiography was performed in 91% of patients, half of whom underwent coronary angioplasty. A bi-truncular involvement (RC + VIA) was found in 40% of cases, the middle DC is the culprit lesion in almost half of the cases of VD infarction.&#x0D; The presence of an ST elevation in the isolated V3R shunt is a specific criterion of right middle coronary involvement, found in 48% of patients.&#x0D; Conclusion: The ECG remains an essential tool in the early prediction of the artery responsible for the infarction. Because of its complementary nature, the combination of ECG and coronary angiography is essential for a better evaluation of acute myocardial infarction.

The Incidence and Impact of Permanent Right Ventricular Infarction on Left Ventricular Infarct Size in Patients With Inferior ST-Segment Elevation Myocardial Infarction

Mounting evidence shows that right ventricle (RV) function carries independent prognostic influence in various disease states. This study aimed to investigate the incidence and impact of permanent RV infarction in patients with inferior ST-segment elevation myocardial infarction (STEMI) and culprit lesion in the right coronary artery (RCA). In this substudy of the DANAMI-3 (DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction) trial, cardiac magnetic resonance was performed in 291 patients at day 1 and follow-up 3 months after primary percutaneous coronary intervention of 674 patients with STEMI with the culprit lesion in the RCA. Final infarct was assessed using late gadolinium enhancement on cardiac magnetic resonance at 3 months. Patients with permanent RV infarction (20%) had lower ventricular function at follow-up; RV ejection fraction (EF) 47% ±6 versus 50% ± 5 (p <0.005) and left ventricular (LV) EF 56% ± 8 versus 60% ± 9 (p <0.006). Furthermore, patients with permanent RV infarction had a higher incidence of microvascular obstruction 39 (67%) versus 81 (39%) (p <0.001), larger final LV infarct size 16% ±8 versus 10% ± 8 (p <0.001) and larger LV area at risk 33% ± 10 versus 29% ± 9 (p <0.001). Permanent RV infarction was an independent predictor of final LV infarct size (p <0.001) but was not associated with LVEF (β=-0.0; p=0.13) in multivariable analyses. In conclusion, permanent RV infarction was seen in 20% of patients with inferior STEMI and culprit lesion in RCA and independently predicted final LV infarct size. However, permanent RV infarction did not predict overall LV function. LGE was used to detect infarct location and quantify infarct size.17 LGE in RV free wall on follow-up CMR was considered as permanent infarction. LGE images were obtained 10 minutes after intravenous injection of 0.1-mmol/kg body weight of gadolinium-based contrast (Gadovist; Bayer Schering, Berlin, Germany) using an electrocardiogram (ECG)-triggered inversion-recovery sequence. The inversion time was adjusted to null the signal from the normal myocardium. Short-axis images were acquired from the atrioventricular plane to the apex with adjacent 8-mm slices. The remaining protocol has been described previously.16.

FREQUENCY AND IN-HOSPITAL MORTALITY OF RIGHT VENTRICULAR MYOCARDIAL INFARCTION IN PATIENTS WITH INFERIOR WALL MYOCARDIAL INFARCTION

Objective: To determine the frequency and in-hospital mortality of right ventricular myocardial infarction, in patients with inferior wall myocardial infarction. Methods: This was a descriptive case series, conducted at Cardiology Department, Rehman Medical institute during time duration 18th Feb 2017 to 18th Aug 2017. The study was conducted after approval was obtained from the hospital ethical review committee. Sample selection was done through a non-probability consecutive sampling technique. Patients were included in the study based on inclusion and exclusion criteria. A detailed history was taken followed by a complete physical examination and ECG was done. Demographic and outcome data were noted on a predesigned Performa. Results: The mean age (SD) of patients in this study was 68±11.05 years. 94 (60.64%) patients were male while 61 (39.35%) patients were female. Among patients 142 (91.61%) were smokers, 136 (87.74%) patients were hypertensive and 123 (79.35%) patients were diabetic. A total of 155 patients were hospitalized with the diagnosis of acute inferior STEMI. Of the total 155 in-patients, 56(36.1%) were having right ventricular infarction. In-hospital mortality was recorded in 39/155(25.16%) patients during hospitalization having right ventricular myocardial infarction with inferior wall myocardial infarction. Conclusion: This study concluded that Right Ventricular Infarction can occur in patients with Inferior Wall Myocardial Infarction with certain adverse in-hospital outcomes such as mortality. Keywords: Coronary Artery Disease (CAD), Right Ventricle Infarction (RVI).

Dead man sign of ECG: An unique predicting sign of acute coronary syndrome

Coronary artery disease is the most common cause of morbidity and mortality worldwide. Acute coronary syndrome which includes STEMI, NSTEMI and unstable angina commonly diagnosed with the help of 12 lead in ECG in ER with or without elevated biomarkers. Inferior wall myocardial infarction is common cause of ST elevation myocardial infarction with low mortality rate. In this case report, we present a 52 years old male presented to ER with the complain of typical chest pain for more than 2 hours duration. Pain was in center of chest with radiation to back and left arm and associated with excessive sweating. Patient is a known smoker for past 10 years. At presentation Blood pressure was 110/70 mmHg and pulse rate of 55/min. Troponin I level was five times of upper normal limit. Basic investigations including ECG were done at presentation. ECG was showing typical changes of inferior wall myocardial infarction with infarction of right ventricle with hidden unique sign known as dead man sign commonly predict the location of obstruction and course of disease in the setting of acute coronary syndrome.

Subtle Right Ventricular Affection in Patients with Acute Myocardial Infarction, Echocardiographic Assessment

BACKGROUND: The right ventricle (RV) has historically received less attention than its counterpart of the left side of the heart, yet there is a substantial body of evidence showing that RV size and function are perhaps equally important in predicting adverse outcomes in cardiovascular diseases.&#x0D; AIM: The aim of our work was to evaluate incidence and impact of right ventricular (RV) affection in patients with acute left ventricular myocardial infarction subjected to primary percutaneous coronary intervention (1ry PCI).&#x0D; METHODS: The study was conducted on 80 patients who had acute left ventricle ST elevated myocardial infarction (LV STEMI) and subjected to 1ry PCI. The study was done in Cairo University, critical care department. All patients were studied within 2 days after 1ry PCI, RV function was assessed by echocardiography through tricuspid annular plane systolic excursion (TAPSE) and speckle tracking echocardiography. We excluded patients with RV infarction, moderate to severe tricuspid regurgitation, pulmonary hypertension, dilated cardiomyopathy, atrial or ventricular septal defect, and patients who had cardiac dysrhythmias.&#x0D; RESULTS: Out of 80 patients (64 men and 16 women) included in the study, 38 patients (47.5%) had TAPSE &lt;1.7 cm, and 48 patients (60%) had RV longitudinal strain less negative than −19%.There was a statistically significant relationship between RV affection and anterior STEMI, left anterior descending artery as an infarct-related artery, duration of intensive care unit stay, impairment of LV global and regional systolic function, in-hospital complications, and 1-year mortality.&#x0D; CONCLUSION: RV dysfunction is not uncommon in acute LV STEMI when using the definition of TAPSE &lt;17 cm and RV longitudinal strain less negative than −19%.There was a significant relationship between RV dysfunction and poor outcome in patients with acute LV STEMI.

RIGHT VENTRICULAR FAILURE COMPLICATING ACUTE MYOCARDIAL INFARCTION: EARLY SUPPORT IS CRITICAL

Inferior MI often involves the right ventricle (RV) leading to a worse prognosis. We present a case of inferior STEMI complicated by RV infarction and cardiogenic shock despite revascularization, necessitating hemodynamic support with Impella RP. A 63-year-old man presented to the ED with chest

P716 Acute chest pain and new onset severe and asymmetric functional tricuspid regurgitation: What is going on?

Abstract Acute inferior myocardial infarction can be complicated by conduction disorders and/or by extension to the right ventricle (RV). Both situations can resolve with an early percutaneous revascularization. We report a case of a 73-year-old woman, with arterial hypertension, dyslipidemia, and studied by cardiology for atypical chest pain, with several negative ischemia detection tests. She was brought to the Emergency Department due to oppressive chest pain irradiated to the left upper extremity. An electrocardiogram was performed, highlighting a complete atrioventricular block with suprahisian escape and ST segment elevation in inferior leads. Tendency to arterial hypotension and multiple episodes of asymptomatic non-sustained monomorphic ventricular tachycardias as well as self-limiting Torsade de Pointes were registered. The transthoracic echocardiogram (TTE) showed an akinesia circumscribed to the basal segment of the inferior left ventricle wall, a non-dilated RV with akinesia of its anterior wall and a new onset functional and asymmetric severe tricuspid regurgitation (TR) by tethering of the anterior leaflet. It was not possible to estimate the RV-RA gradient by obtaining a dense triangular doppler continuous wave jet contour with early peak. Vena contracta was 7 mm long. An urgent coronary angiography was performed in which the presence of an acute thrombotic occlusion of the proximal segment of the right coronary artery was confirmed. A drug-eluting stent was implanted, with good result. With all this, it was possible to stabilize the patient"s electrical and hemodynamic situation. A TTE was repeated one week after, in which mild to moderate tricuspid regurgitation was observed, coinciding with improvement of the RV systolic function and better mobility of the anterior tricuspid leaflet. Anatomically, the tricuspid valve consists of anterior, septal, and posterior leaflets. Each leaflet is connected via chordae tendineae to the anterior, posterior, and septal papillary muscles of the right ventricle, respectively. The cause of functional TR appears to be tricuspid annular dilatation and tethering of the tricuspid valve leaflets (because of LV failure, pulmonary hypertension, left-to-right shunt, or RV infarction). Primary disorders of the tricuspid valve causing TR are less common. RV myocardial infarction may involve the wall supporting the papillary muscle with resulting tension on the chordae causing TR. The 2D TTE demonstrates incomplete and often asymmetric closure of the tricuspid leaflets with apical displacement of the coaptation point. This phenomenon is similar to that seen with LV myocardial infarction with resulting loss of support of mitral papillary muscle and ischemic mitral regurgitation. We report a case of acute inferior myocardial infarction involving the RV that caused a transient dysfunction of the papillary muscle of the anterior tricuspid leaflet, generating a severe TR that resolved by early revascularization. Abstract P716 Figure. A: severe acute TR. B: few days after

Segmental biventricular analysis of myocardial function using high temporal and spatial resolution tissue phase mapping.

Myocardial dysfunction of the right ventricle (RV) is an important indicator of RV diseases, e.g. RV infarction or pulmonary hypertension. Tissue phase mapping (TPM) has been widely used to determine function of the left ventricle (LV) by analyzing myocardial velocities. The analysis of RV motion is more complicated due to the different geometry and smaller wall thickness. The aim of this work was to adapt and optimize TPM to the demands of the RV. TPM measurements were acquired in 25healthy volunteers using a velocity-encoded phase-contrast sequence and kt-accelerated parallel imaging in combination with optimized navigator strategy and blood saturation. Post processing was extended by a 10-segment RV model and a detailed biventricular analysis of myocardial velocities was performed. High spatio-temporal resolution (1.0×1.0×6mm3, 21.3ms) and the optimized blood saturation enabled good delineation of the RV and its velocities. Global and segmental velocities, as well as time to peak velocities showed significant differences between the LV and RV. Furthermore, complex timing of the RV could be demonstrated by segmental time to peak analysis. High spatio-temporal resolution TPM enables a detailed biventricular analysis of myocardial motion and might provide a reliable tool for description and detection of diseases affecting left and right ventricular function.

Assessment of right ventricular function in patients with first inferior myocardial infarction: strain imaging study

Objective: The aim of the study was to assess strain and strain rate (SR) properties of the right ventricle (RV) in patients with RV myocardial infarction (MI). Background: Quantitative assessment of RV function is still challenging due to its complex anatomy and thin wall structure, and therefore is not incorporated into daily clinical practice. Two-dimensional strain and SR analyses are novel Doppler-independent techniques to obtain these measurements of myocardial movement and deformation. These methods have been frequently used to assess left ventricular function; however, they have yet rarely been used to examine RV function, despite RV function is an important prognostic factor in patients with acute first inferior MI. Patients and methods: A total of 40 patients with acute inferior MI were included in this study; 20 patients had ECG signs of inferior MI without RV infarction (group II) and 20 patients had ECG signs of inferior MI with RV infarction (group III). In all, 20 age-matched and sex-matched healthy volunteers were included as a control group (group I), using two-dimensional speckle tracking measurements of RV free wall longitudinal strain and SR in the apical four-chamber. Results: A statistically highly significant difference was found among the three groups regarding the peak systolic longitudinal strain at apical, mid, and basal segments of RV free wall (P Conclusion: This study demonstrates that RV strain and SR were lower in patients with left ventricular inferior wall MI with RV infarction compared with those without RV infarction.

Right Ventricular Infarction

Right Ventricular Infarction

Échographie et arrêt cardiaque intra- et extrahospitalier : mise au point et perspectives

Cardiac arrest is a frequent emergency for doctors and resuscitation teams. Patients displaying asystole or pulseless electrical activity are non-shockable. They have extremely poor outcomes. The use of sonographers might contribute to a better understanding of cardiac arrest (CA) etiology and facilitate its treatment. A systematic search in databases (NLM-Gateway ®, CNRS-INIST/Pascal ®, Science Direct ®, Ovid ®, and Bibliovie ®) of primary documents and notices allowed us to select clinical trial studies. Editorials, case report and animals studies were excluded from the analysis. The various physiopathological and semiological status revealed by echocardiography are useful to detect the aetiology of cardiac arrest. In the very first minutes following the arrest, a significant increase of right ventricle (RV) volume suggests a pulmonary thromboembolism or a RV infarction. After 4 min of CA, a physiological increase of RV volume is observed, in relation with the pressure balance between high and low arteriovenous pressures. RV and/or left ventricle collapses are straightaway pathological whichever due to pericardic effusion, pneumothorax or schock. A synthesis algorithm dedicated to care of CA, including transthoracic echocardiography for search of curable causes, is proposed. This algorithm fulfills the ILCOR, ERC and AHA recommendations. The echocardiography should be part of ACLS, nevertheless clinical studies are needed to assess its impact on morbimortality.

Reproducibility of Right Ventricular Volumes and Ejection Fraction Using Real-time Three-Dimensional Echocardiography: Comparison With Cardiac MRI

Objectives The nongeometric nature of the right ventricle (RV) makes it difficult to measure. We sought to determine whether real-time three-dimensional echocardiography (RT3DE) is superior to two-dimensional echocardiography (2DE) for the follow-up of RV function by validation vs cardiac MRI. Methods RV volumes and ejection fraction (EF) were studied with 2DE (including area-length [A-L], the modified two-dimensional subtraction [2DS] method, and the Simpson method of discs), RT3DE, and MRI in 50 patients with left ventricular wall motion abnormalities, the results of which suggested possible RV infarction. Test-retest variation was performed by a complete restudy using a separate sonographer within 24 h without the alteration of hemodynamics or therapy. Interobserver and intraobserver variations were noted in a subgroup of 20 patients. Results EF estimations were similar using each technique. The mean (± SD) MRI end-diastolic volume (87 ± 22 mL) was only slightly underestimated by RT3DE (mean difference, −3 ± 10; p < 0.05), with a greater mean difference for 2DE A-L (−29 ± 10; p < 0.05), and the Simpson method of discs (−29 ± 23; p < 0.05), and was greatly overestimated by 2DS (mean difference, 26 ± 23; p < 0.05). Similarly, the mean MRI end-systolic volume (46 ± 17 mL) was only slightly underestimated by RT3DE (−4 ± 7; p < 0.05), compared with 2DE A-L (−16 ± 8; p < 0.05) and the Simpson method of discs (−16 ± 8; p < 0.05), and was overestimated by 2DS (14 ± 13; p < 0.05). RT3DE findings had a higher correlation with each parameter than any 2DE technique. There was also good intraobserver and interobserver correlation between RT3DE by two sonographers. RT3DE had less test-retest variation of RV volumes and EF than any 2DE measure. Conclusions RT3DE is more accurate than two-dimensional approaches and reduces the test-retest variation of RV volumes and EF measurements in follow-up RV assessment. The nongeometric nature of the right ventricle (RV) makes it difficult to measure. We sought to determine whether real-time three-dimensional echocardiography (RT3DE) is superior to two-dimensional echocardiography (2DE) for the follow-up of RV function by validation vs cardiac MRI. RV volumes and ejection fraction (EF) were studied with 2DE (including area-length [A-L], the modified two-dimensional subtraction [2DS] method, and the Simpson method of discs), RT3DE, and MRI in 50 patients with left ventricular wall motion abnormalities, the results of which suggested possible RV infarction. Test-retest variation was performed by a complete restudy using a separate sonographer within 24 h without the alteration of hemodynamics or therapy. Interobserver and intraobserver variations were noted in a subgroup of 20 patients. EF estimations were similar using each technique. The mean (± SD) MRI end-diastolic volume (87 ± 22 mL) was only slightly underestimated by RT3DE (mean difference, −3 ± 10; p < 0.05), with a greater mean difference for 2DE A-L (−29 ± 10; p < 0.05), and the Simpson method of discs (−29 ± 23; p < 0.05), and was greatly overestimated by 2DS (mean difference, 26 ± 23; p < 0.05). Similarly, the mean MRI end-systolic volume (46 ± 17 mL) was only slightly underestimated by RT3DE (−4 ± 7; p < 0.05), compared with 2DE A-L (−16 ± 8; p < 0.05) and the Simpson method of discs (−16 ± 8; p < 0.05), and was overestimated by 2DS (14 ± 13; p < 0.05). RT3DE findings had a higher correlation with each parameter than any 2DE technique. There was also good intraobserver and interobserver correlation between RT3DE by two sonographers. RT3DE had less test-retest variation of RV volumes and EF than any 2DE measure. RT3DE is more accurate than two-dimensional approaches and reduces the test-retest variation of RV volumes and EF measurements in follow-up RV assessment.

Right ventricular infarction causes heterogeneous autonomic denervation of the viable peri-infarct area.

Because efferent autonomic pathways to the right ventricle (RV) differ from the efferent autonomic projections to the left ventricle (LV), we assessed the effects of RV infarction on this innervation. We measured the ventricular effective refractory period (ERP) shortening in response to bilateral ansae subclaviae stimulation and ERP lengthening induced by bilateral vagal stimulation as markers of autonomic innervation before and after RV myocardial infarction (RVMI) produced by coronary ligation (n=28 dogs) or intracoronary latex injection (n=18 dogs) into a marginal branch of the right coronary artery in open-chest anesthetized dogs. In each dog, ERPs measured in viable peri-infarct area at two RV outflow tract (RVOT) sites and two septal and four lateral sites at the RV free wall after RVMI showed reduced or absent ERP shortening during bilateral ansae subclaviae stimulation laterally, septally, and at RVOT sites 3 hours after RVMI. ERP shortening in response to infused norepinephrine was still present. Bilateral vagal stimulation during background norepinephrine infusion (0.10 to 0.25 microg/kg per minute) lengthened the ERP at all test sites before latex injection. After transmural RVMI, vagally induced ERP prolongation was attenuated or lost at lateral, septal, and RVOT test sites. RVMI causes sympathetic and vagal denervation at viable sites at the RVOT, lateral, and, to a lesser extent, septal sides of the viable peri-infarct area. Autonomic denervation in the RVOT might contribute to the development of ventricular tachyarrhythmias after the acute stage of myocardial infarction involving the RV.

Clinical-Echocardiographic Correlation of Myocardial Infarction with Extension to Right Chambers.

In order to determine the transesophageal echocardiographic characteristics in patients with acute myocardial infarction of right ventricle and establish the relationship between these findings, the clinical condition, and their prognostic value, 38 patients consecutively admitted to the Instituto Nacional de Cardiología with a diagnosis of acute left ventricular myocardial infarction with extension to right ventricle and/or atrium were retrospectively studied. Of the left ventricular infarctions, 37 were posteroinferior and one anterior. Significant elevations of CPK and DHL were found in 35. In 30 patients (78%) electrocardiographic evidence of extension of infarction to the right ventricle was found, and in 3, evidence of right atrial infarction. Twenty-one patients presented clinical data compatible with right ventricular infarction. In 19, cardiac rhythm and atrioventricular conduction disturbances were documented. Coronary angiograms practiced on 34 patients demonstrated single-vessel (right coronary) disease in 12, affection of two vessels in 14, and lesions in three or more in 6. Coronary arteries presented no significant lesions in two cases. With TEE, alterations of right ventricular segmental mobility were demonstrated in all patients, and in 6, alterations of right atrial mobility as well. As respects the ventricular wall movement index, 68.5% had total scores (RV + LV) of <5. The other 31.5% had scores >/= 5. In 26%, the right ventricular wall movement index was >/=4. The RVDD/LVDD ratio was 1 or less in 30 patients (78%) and >1 in only 8 (22%). The conclusions from these findings are that: (1) TEE is an excellent diagnostic means of identifying right ventricular and/or atrial infarction; and (2) a relationship exists between the magnitude of right ventricular damage and a wall movement index of 5 or more or an RV/LV diastolic diameter ratio > 1:postinfarction hemodynamic deterioration is significantly greater and the incidence of intrahospitalary complications higher.

A new scintigraphic technique for assessment of right atrial function.

Gated radionuclide imaging with 99mTc-labeled red blood cells was employed to assess changes in right atrial (RA) volume in 17 subjects. Studies were repeated within two hours in five of 12 normal subjects and at two and ten days after infarction in five patients. Time-activity curves were generated for the RA and right ventricle (RV) from variable regions of interest defined by automatic edge detection. The RA time-activity curve exhibited four phases: filling, early emptying, equilibration, and late emptying. Repeated measurements of RA early emptying rates correlated closely in normals (r = 0.93). Early RA emptying and RV filling rates corresponded closely (r = 0.89). In four patients with infarction, the RA emptying rate was slowed on the first study but had normalized by 10 days. In a patient with inferior infarction and suspected RV infarction, the RA emptying rate was depressed and remained so for 10 days. Thus, relative changes in right atrial volume can be assessed reproducibly by a radionuclide technique, which is relatively independent of geometric assumptions. This technique offers great promise as a method to assess atrial function in health and disease.