Right ventricular function in adult atrial septal defect. Preoperative and postoperative assessment and clinical implications

Incomplete RV Remodeling After Transcatheter ASD Closure in Pediatric Age

Published data showing the intermediate effect of transcatheter device closure of atrial septal defect (ASD) in the pediatric age-group are scarce. The objective of the study was to assess the effects of transcatheter ASD closure on right and left ventricular functions by tissue Doppler imaging (TDI). The study included 37 consecutive patients diagnosed as ASD secundum by transthoracic echocardiography and TEE and referred for transcatheter closure at Cairo University Specialized Pediatric Hospital, Egypt, from October 2010 to July 2013. Thirty-seven age- and sex-matched controls were selected. TDI was obtained using the pulsed Doppler mode, interrogating the right cardiac border (the tricuspid annulus) and lateral mitral annulus, and myocardial performance index (MPI) was calculated at 1-, 3-, 6- and 12-month post-device closure. Transcatheter closure of ASD and echocardiographic examinations were successfully performed in all patients. There were no significant differences between two groups as regards the age, gender, weight or BSA. TDI showed that patients with ASD had significantly prolonged isovolumetric contraction, relaxation time and MPI compared with control group. Decreased tissue Doppler velocities of RV and LV began at one-month post-closure compared with the controls. Improvement in RVMPI and LVMPI began at 1-month post-closure, but they are still prolonged till 1 year. Reverse remodeling of right and left ventricles began 1 month after transcatheter ASD closure, but did not completely normalize even after 1 year of follow-up by tissue Doppler imaging.

Role of right ventricular wall motion abnormalities in risk stratification and prognosis of patients referred for stress echocardiography

OBJECTIVES

The purpose of this study was to evaluate the prognostic value of assessing right ventricular (RV) wall motion abnormalities during stress echocardiography (SE).

BACKGROUND

The results of SE are usually interpreted based on wall motion abnormalities of the left ventricle (LV). There is increasing recognition of the prognostic importance of RV. However, RV is still a "forgotten" chamber during routine SE.

METHODS

We evaluated 2,703 patients referred for SE. The LV was evaluated on a 16-segment model 5-point scale and the RV was evaluated on a 3-segment model 5-point scale for wall motion abnormalities. An abnormal RV or LV was defined as one with new (ischemic) or fixed (infarction) wall motion abnormalities. Follow-up (2.7 +/- 1.0 years) for confirmed myocardial infarction and cardiac death (n = 122) were obtained.

RESULTS

An abnormal RV was seen in 112 patients (4%). In the presence of an abnormal LV, patients with abnormal RV had a worse prognosis than those with normal RV. Abnormal RV was a significant predictor of events (adjusted hazard ratio 2.69, 95% confidence interval 1.22 to 5.92; p = 0.014) independent of LV ischemia and ejection fraction. A forward conditional Cox model showed that peak RV wall motion score index provided incremental prognostic value over rest and conventional SE variables (global chi-square increased from 141.4 to 161.8 to 197.0; p < 0.0001 and p = 0.006, respectively).

CONCLUSIONS

In patients referred for SE, RV wall motion analysis provides prognostic value independent of LV ischemia and ejection fraction and provides incremental value over rest and conventional SE variables. Right ventricular wall motion analysis should be routinely performed in patients referred for SE for effective risk stratification.

The determinants of right ventricular function in patients with atrial septal defect

OBJECTIVE

The purpose of this study was to ascertain the determinants of right ventricular (RV) systolic and diastolic functions in patients with atrial septal defect.

METHODS

Thirty-three patients with atrial septal defect having left to right shunt were enrolled in this study. RV function parameters were assessed echocardiographically. RV systolic function was assessed using tricuspid tissue Doppler S velocity (St). With regard to RV diastolic function parameters, E/A ratio, deceleration time (DT), E/Et ratio (Et = tissue Doppler E velocity), RV isovolumetric relaxation time (RVIVRT) were assessed. RV myocardial performance index (MPI) was calculated as an index of both systolic and diastolic function. Pulmonary artery stiffness (PAS) was also calculated. After echocardiography, right and left heart catheterization was performed. Mean pulmonary artery pressure (MPAP), mean right atrial pressure (MRAP), systemic flow (Qs), pulmonary flow (Qp), systemic vascular resistance (SVR), and pulmonary vascular resistance (PVR) were obtained using the data of invasive measurements.

RESULTS

In multivariate analysis, MPAP was found to be the parameter closest related to RVIVRT (r = 0.73, p < 0.001) and E/Et (r = 0.66, p < 0.001), while PAS was found to be the parameter closest related to MPI (r = 0.53, p = 0.002). In addition, St velocity was found the only parameter related to PVR (r = -0.39) in univariate analysis. There was no relationship between QP/QS and any of the RV function parameters.

CONCLUSION

The pulmonary vascular bed appears to be the predictor of the RV functions in patients with atrial left to right shunts, and the amount of the shunt seems to have no direct adverse influence on the RV functions.

Anesthetic management of the adult patient with congenital heart disease

As the number of CHD repairs in adults continues to increase, these operations will be performed in a wider variety of institutions and systems. Unfortunately, not all of these centers will have an optimal environment for correcting CHD in adults. This type of surgery is best accomplished in a facility specifically designed for treating adults with CHD. Optimal care of these patients is provided by cardiologists who are trained and experienced in pediatric and adult cardiology, by surgeons who are trained and experienced in treating CHD, and by anesthesiologists who are experienced in caring for adults with CHD. Whatever the setting, cardiac anesthesiologists involved in these cases must be thoroughly aware of the anesthetic implications for the unique pathophysiology of each patient, and they must not rely on their "usual" expectations of either true pediatric CHD or acquired adult heart disease.

[Surgical closure of atrial septal defect before or after the age of 25 years. Comparison with the natural history of unoperated patients]

INTRODUCTION

Surgical closure of an atrial septal defect (ASD) before the age of 25 years has been demonstrated to reduce complications during adulthood. However, the outcome for patients operated after the age of 25 is still debated.

METHODS

In a retrospective study we examined the outcome of early and late surgical repair of ASD in adults, as compared with the natural evolution of unoperated patients. The study population was 280 patients (mean age 40 18 years) with non-restrictive ASD: 102 patients (group 1) underwent surgery before the age of 25 years, 90 patients (group 2) underwent surgery after the age of 25 years, and 88 unoperated patients were older than 25 years at the time of study (group 3). The variables analyzed were left ventricular systolic function, left atrial dimensions, systolic pulmonary pressure, right ventricular dimensions, the degree of mitral and tricuspid regurgitation, and the prevalence of late atrial fibrillation.

RESULTS

Left ventricular systolic function and the degree of mitral regurgitation were not statistically different between groups. Compared with the patients in group 2, the patients in group 1 had a significantly lower systolic pulmonary arterial pressure (p < 0.001) and less dilated right ventricle (p < 0.001) and left atrium (p < 0.001). The degree of tricuspid regurgitation (p < 0.001) and prevalence of atrial fibrillation (p < 0.001) were significantly higher in the patients of group 2. Compared with group 3, the patients in group 2 had a significantly lower systolic pulmonary arterial pressure (p < 0.001) and less dilated right ventricle (p < 0.001). However, the left atrial dimensions, degree of tricuspid regurgitation, and prevalence of atrial fibrillation did not differ in a statistically significant way between the two groups.

CONCLUSIONS

Surgical repair of an atrial septal defect in patients over 25 years of age does not fully prevent hemodynamic deterioration and the development of atrial arrhythmias. Therefore it seems that the surgical closure of ASD before adulthood should be strongly recommended.

Predisposing conditions for atrial fibrillation in atrial septal defect with and without operative closure

The aims of this study were to determine the prevalence and predisposing conditions for atrial fibrillation (AF) in adults with atrial septal defect (ASD) and to evaluate the influence of age at surgical repair. The study population consisted of 286 adults with ASD (mean age 39.5 +/- 19 years). All patients had >or = 1 follow-up visit and a Doppler echocardiographic study. One hundred ninety-two of the patients underwent surgical closure 1 to 34 years before the study. Analyzed variables were entered into univariate (Mann-Whitney U) and multivariate (stepwise logistic regression) models to assess independent predictors for AF. The prevalence of AF was similar in surgically treated patients (15.6%) and in the nonsurgical group (13.8%) (p = 0.69). Multivariate analysis showed that current age (RR 1.9 per each decade of age, 95% confidence interval [CI] 1.3 to 2.7, p = 0.001), mitral regurgitation (RR 3.0 per each degree of regurgitation, 95% CI 1.6 to 5.8, p = 0.001), left atrial enlargement (RR 2.8 per each 10 mm increase in size, 95% CI 1.5 to 5.2, p = 0.001), and tricuspid regurgitation (RR 1.9 per each degree of regurgitation, 95% CI 1.0 to 3.7, p = 0.04) were independent predictors of AF; however, gender, anatomic type, defect size, Qp:Qs, pulmonary artery pressure, right ventricular dimension, left ventricular shortening fraction, and prior surgical repair were not related to late AF development. In the surgical group, age >25 years at the time of surgery was the only predictor for AF independent of age at the time of the study (p = 0.02).

Right ventricular form and function after percutaneous atrial septal defect device closure

OBJECTIVES

We sought to assess the right heart's response to percutaneous device closure of moderate sized atrial septal defects (ASDs) in adults over a one-year follow-up period.

BACKGROUND

Percutaneous ASD device closure is a safe and effective means of reducing or eliminating interatrial shunting. The response of the adult's right heart to device closure is incompletely understood.

METHODS

Forty consecutive patients had 40 device implantations (32 with the CardioSeal implant and 8 with the Amplatzer device). The patients were assessed with echocardiography, chest radiography and electrocardiography before the procedure and at 1, 6 and 12 months.

RESULTS

The mean ASD size was 13+/-4 mm, and the device size ranged from 33 to 40 mm for CardioSeal and 12 to 36 mm for Amplatzer. At one month, heart size (49% vs. 46%), four-chamber right ventricular (RV) size (45 vs. 41 mm), paradoxical septal motion (60% vs. 5%), QRS duration (125 vs. 119 ms), PR interval (181 vs. 155 ms) and echocardiographically determined pulmonary artery systolic pressure decreased significantly and was maintained at 12-month follow-up. At six months, right atrial length decreased from 50 to 47 mm. At one year, 29% of patients had persistent RV enlargement.

CONCLUSIONS

Right heart morphology undergoes rapid improvement within one month of defect closure, with associated mechanoelectrical benefit. A small number of patients had persistent RV enlargement or pulmonary hypertension, or both, at one year. Our data support the application of transcatheter methods in achieving excellent hemodynamic and anatomic outcomes.

Normal myocardial function in severe right ventricular volume overload hypertrophy

Severe left ventricular volume overloading causes myocardial and cellular contractile dysfunction. Whether this is also true for severe right ventricular volume overloading was unknown. We therefore created severe tricuspid regurgitation percutaneously in seven dogs and then observed them for 3.5-4.0 yr. All five surviving operated dogs had severe tricuspid regurgitation and right heart failure, including massive ascites, but they did not have left heart failure. Right ventricular cardiocytes were isolated from these and from normal dogs, and sarcomere mechanics were assessed via laser diffraction. Right ventricular cardiocytes from the tricuspid regurgitation dogs were 20% longer than control cells, but neither the extent (0.171 +/- 0.005 microm) nor the velocity (2.92 +/- 0.12 microm/s) of sarcomere shortening differed from controls (0.179 +/- 0.005 microm and 3.09 +/- 0.11 microm/s, respectively). Thus, despite massive tricuspid regurgitation causing overt right heart failure, intrinsic right ventricular contractile function was normal. This finding for the severely volume-overloaded right ventricle stands in distinct contrast to our finding for the left ventricle severely volume overloaded by mitral regurgitation, wherein intrinsic contractile function is depressed.

Effect of surgical repair of secundum-type atrial septal defect on right atrial, right ventricular, and left ventricular volumes in adults

Surgical repair of atrial septal defect in adults reduces right ventricular and right atrial diameters and volumes, and improves left ventricular filling.

Atrial arrhythmia after surgical closure of atrial septal defects in adults

BACKGROUND

Atrial flutter and atrial fibrillation are causes of morbidity in adults with an atrial septal defect. In this study, we attempted to identify risk factors for atrial flutter and fibrillation both before and after the surgical closure of an atrial septal defect.

METHODS

We searched for preoperative and postoperative atrial flutter or fibrillation in 213 adult patients (82 men and 131 women) who underwent surgical closure of atrial septal defects because of symptoms, a substantial left-to-right shunt (ratio of pulmonary to systemic blood flow, >1.5:1), or both at Toronto Hospital between 1986 and 1997.

RESULTS

Forty patients (19 percent) had sustained atrial flutter or fibrillation before surgery. As compared with the patients who did not have atrial flutter or fibrillation before surgery, those who did were older (59+/-11 vs. 37+/-13 years, P<0.001) and had higher mean pulmonary arterial pressures (25.0+/-9.7 vs. 19.7+/-8.2 mm Hg, P=0.001). There were no perioperative deaths. After a mean follow-up period of 3.8+/-2.5 years, 24 of the 40 patients (60 percent) continued to have atrial flutter or fibrillation. The mean age of these patients was greater than that of the 16 who converted to sinus rhythm (P=0.02). New-onset atrial flutter or atrial fibrillation was more likely to have developed at follow-up in patients who were older than 40 years at the time of surgery than in those who were 40 or younger (5 of 67 vs. 0 of 106, P=0.008). Late events (those occurring more than one month after surgery) included stroke in six patients (all but one with atrial flutter or fibrillation, one of whom died) and death from noncardiac causes in two patients. Multivariate analysis showed that older age (>40 years) at the time of surgery (P=0.001), the presence of preoperative atrial flutter or fibrillation (P<0.001), and the presence of postoperative atrial flutter or fibrillation or junctional rhythm (P=0.02) were predictive of late postoperative atrial flutter or fibrillation.

CONCLUSIONS

The risk of atrial flutter or atrial fibrillation in adults with atrial septal defects is related to the age at the time of surgical repair and the pulmonary arterial pressure. To reduce the morbidity associated with atrial flutter and fibrillation, the timely closure of atrial septal defects is warranted.

Plain film diagnosis of common cardiac anomalies in the adult

Congenital cardiac lesions in the adult have characteristic roentgen patterns that should be recognized by the radiologist. In other instances, abnormalities in the aorta or the position of the organs can indicate the likelihood of associated cardiac anomalies. An increasing number of congenital cardiac patients are surviving into adult life because of successful treatment. Some of the complications of these repairs can be recognized on routine chest films.

Role of right ventricular and pulmonary functional abnormalities in limiting exercise capacity in adults with congenital heart disease

This study evaluates right ventricular (RV) and pulmonary function during exercise in adults with congenital heart disease (CHD). Thirty-one patients with CHD involving the right side of the heart underwent symptom-limited bicycle exercise testing with simultaneous expired gas analysis and measurement of RV ejection fraction (EF). Twenty-one age-matched normal controls underwent the identical exercise protocol. Maximal oxygen consumption was lower in the CHD than in normal controls (19.5 +/- 6.4 vs 30.5 +/- 0.8 ml/kg/min, p = 0.0001 patients vs controls). Both heart rate (156 +/- 25 vs 171 +/- 13 beats/min, p = 0.01) and oxygen pulse (9.3 +/- 3.7 vs 12.3 +/- 3.7 ml/beat, p = 0.01), an indirect measure of stroke volume, were found to be lower in the CHD group at peak exercise. Pulmonary dysfunction was evidenced in the CHD group by decreased forced expiratory volume, forced vital capacity and maximum voluntary ventilation, and by a higher ventilation/expired carbon dioxide ratio at peak exercise (37.2 +/- 6.9 vs 33.0 +/- 5.4, p = 0.02), suggesting an increase in dead space ventilation. Maximal oxygen consumption was lower in patients whose RVEF decreased with exercise (17.6 +/- 5.4 vs 22.8 +/- 6.4 ml/kg/min, p = 0.03 "decrease RVEF" group vs "increase RVEF" group). Maximal oxygen consumption correlated with the change in RVEF only in the group whose RVEF decreased with exercise (r = 0.5, p = 0.03). In the group that had increased RVEF with exercise, maximal oxygen consumption correlated with forced expiratory volume (r = 0.7, p = 0.02). Thus, adults with CHD have a reduced functional capacity compared with normal controls. This phenomenon appears to be associated with both RV and pulmonary abnormalities.

The adult patient with congenital heart disease

In adults with congenital heart disease who are confronted with noncardiac surgery, perioperative risks can be reduced, often appreciably, when problems inherent to this patient population are anticipated. The first necessity is to clarify the diagnosis and to be certain that appropriate information is obtained from a cardiologist with adequate knowledge of congenital heart disease in adults. Physiology and anatomy can vary significantly among patients who superficially carry identical diagnoses. Elective noncardiac surgery should be preceded by clinical assessment including review of clinical and laboratory data and securing the results of necessary diagnostic studies. Preoperative assessment should be performed far enough in advance of the anticipated date of surgery to allow critical assessment of the data and potential discussions with colleagues. Appropriate cardiovascular laboratory studies to be obtained or reviewed include electrocardiograms, chest radiographs, echocardiograms, and cardiac catheterization data, which may include specialized intracardiac electrophysiologic testing. Congenital heart disease in adults is a new and evolving area of special interest and expertise in cardiovascular medicine. Multidisciplinary centers for the care of these patients are being developed. The 22nd Bethesda Conference recommended that these centers include among their consultants anesthesiologists with special expertise in managing patients with congenital heart disease. These anesthesiologists can have the option of serving either as the attending anesthesiologists when patients require noncardiac surgery or as consultants and resource individuals to other anesthesiologists.

The forgotten chamber: the importance of the right ventricle

Historically, the right heart was viewed as less important than the left heart in the maintenance of normal overall hemodynamic performance. However, there is now considerable evidence that emphasizes the significance of intact right ventricular (RV) function. The RV's anatomy and physiology are reviewed in order to provide insight into how changes in volume can be accommodated within a low-pressure environment and how this contributes to hemodynamic stability. The interdependent relationship between the right and left ventricles is also explored. The contribution of RV performance to overall hemodynamics is best exemplified when the RV becomes diseased. RV infarction, atrial septal defect, and cor pulmonale are used as examples to illustrate the dramatic sequelae associated with RV dysfunction, as well as to identify the RV's specific adaptive mechanisms.

Long-term follow-up (9 to 20 years) after surgical closure of atrial septal defect at a young age

To assess the long-term cardiac status after surgical closure of an atrial septal defect (ASD) at a young age, 104 of 135 children who consecutively underwent surgery (aged 0 to 14 years) at 1 institution between 1968 and 1980 participated in a follow-up study and underwent a complete cardiologic examination. Mean follow-up was 14.5 +/- 2.8 years. Most patients (87%) believed their health to be good or very good. At physical examination, all patients were in good health. Ninety-three patients (89%) were in sinus rhythm. Echocardiography showed that right ventricular dilatation was present in 27 patients (26%), 2 of whom had a residual ASD. Bicycle ergometry revealed that 88 patients (88%) had a normal exercise capacity. Both supraventricular and ventricular arrhythmias were observed in 67% of patients by 24-hour ambulatory electrocardiography, but only 3 (3%) had received antiarrhythmic medication, and 4 (4%) had needed a pacemaker. In the group of patients with right ventricular dilatation, the exercise capacity and prevalence of arrhythmias did not differ significantly from those in the group with a normal sized right ventricule. The outcome in patients with a secundum-type ASD was not different from that of those with a sinus venosus-type ASD. The finding of anatomic, functional or electrophysiologic abnormalities was not associated with a longer duration of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Ostium secundum atrial septal defect in the elderly

Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies in adults. Life expectancy is shortened, and almost 90% of patients die by the age of 60 years. The progression of this congenital disease to congestive heart failure has been related to several factors such as the onset of pulmonary hypertension, arrhythmias, bronchopulmonary infections, or the development of other cardiovascular disease. We describe three cases of very old patients with significant ASDs and late development of symptoms. Given the higher risks and poorer long-term results of surgical closure of the defect in advanced age, the indications for such an intervention in elderly patients should be carefully evaluated.

Exercise after surgical repair of congenital cardiac lesions

Congenital heart defects arise in approximately 1% of all live births, independent of ethnic and geographical considerations. With the development of new surgical procedures and current technologies a large number of these heart lesions can be surgically corrected in infancy. In the majority of cases patients evaluated some 10 to 20 years after surgery are asymptomatic and can lead a normal life. Despite their satisfactory clinical outcome patients may, nevertheless, show an abnormal pattern of physiological responses when submitted to dynamic exercise. This paper reviews the scientific literature concerning the exercise capabilities and the cardiorespiratory adjustments to exercise in patients surgically corrected for 4 of the most common congenital heart lesions: isolated atrial septal defect, isolated ventricular septal defects, pulmonary stenosis and tetralogy of Fallot. The maximal exercise tolerance of postoperative congenital heart defect patients may usually be related to: (a) the age of the patients at the time of surgery; (b) the severity of the lesions remaining after surgery; and (c) the age of the patients at the time of investigation. Although normal maximal exercise capabilities may be found in a good number of patients operated for either of the 4 lesions considered, this does not imply normal exercise haemodynamics. A general observation made in these 4 groups of patients is that of a subnormal exercise cardiac output which may or may not be fully compensated by an increase in peripheral oxygen extraction. The limitation in exercising cardiac output may, in turn, be attributed to either a subnormal stroke volume or a limitation in the chronotropic response to exercise or a combination of both factors. Residual pulmonary stenosis, increased pulmonary vascular resistance, increased myocardial stiffness are all factors that may contribute to the cardiac output limitation. A thorough explanation of underlying causes for the abnormal haemodynamic response to exercise, however, still remains to be provided.

Radionuclide measurement of right ventricular function in atrial septal defect, ventricular septal defect and complete transposition of the great arteries

Right ventricular (RV) function was assessed in 80 patients with congenital heart disease by first-pass and gated equilibrium radionuclide angiography. In 30 patients with a ventricular septal defect (VSD) the mean RV ejection fraction (+/- standard deviation) was 64 +/- 7%. In 30 patients with a secundum atrial septal defect it was 61 +/- 9% and in 20 patients with surgically corrected complete transposition of the great arteries it was 49 +/- 13%. These values are in close agreement with values established with cineangiography for similar groups of patients. The mean ejection fraction in the group with transposition of the great arteries was significantly less than in the group with VSD (p less than 0.001). Phase analysis of the equilibrium studies showed that there was delayed RV contraction in many patients in the absence of conduction abnormalities. This delay was significantly greater in patients with atrial septal defect than in those with VSD (p less than 0.05). There was a strong correlation between size of left-to-right shunt and phase delay in patients with VSD (r = -0.72). Thus, first-pass gated radionuclide angiography provides a valid measurement of RV ejection fraction, and delayed RV contraction on phase analysis may be a sensitive index of early RV dysfunction.

Some immediate hemodynamic consequences of closure of atrial septal defects of the secundum type

The circumclusion method for surgical closure of atrial septal defects (ASDs) of the secundum type makes it possible, during surgery, to close and reopen the defect as desired. In each of 23 patients the following statistically significant pressure and flow changes were found when the ASD was closed: increasing mean pressures in the ascending aorta (from 74 to 87 mm Hg), left atrium (from 10 to 18 mm Hg), and right pulmonary artery (from 20 to 24 mm Hg); increasing mean flows in the ascending aorta (from 84 to 111 ml/min/kg); decreasing mean pressures in the right atrium (from 9.0 to 7.7 mm Hg); and decreasing mean flows in the right pulmonary artery (from 78 to 46 ml/min/kg). Surprisingly, no correlation between shunt size determined before and during surgery was found. However, in the calculation of the intraoperative shunt, several factors might have contributed to an erroneous result. In 17 patients a right heart catheterization was performed in the third to thirteenth postoperative month and the following statistically significant changes from the intraoperative results with closed ASD were found: The intraoperative mean pressure in the left atrium (18 mm Hg) decreased to 7.3 mm Hg after surgery (pulmonary wedge pressure), the pulmonary arterial pressure decreased from 23 to 13 mm Hg, and the right atrial pressure from 8.2 to 1.6 mm Hg.

Right ventricular function: methodologic and clinical considerations in noninvasive scintigraphic assessment

Right ventricular function plays an important role in many cardiac disorders. Changes in left ventricular function, right ventricular afterload and preload, cardiac medications and ischemia may affect right ventricular function. Radionuclide ventriculography permits quantitative assessment of regional and global function of the right ventricle. This assessment can be made at rest, during exercise or after pharmacologic interventions. The overlap between right ventricle and right atrium is a major limitation for gated scintigraphic techniques. The use of imaging with newer short-lived radionuclides may permit more accurate and reproducible assessment of right ventricular function by means of the first pass method. Further work in areas related to improvement of techniques and the impact of right ventricular function on prognosis is needed.

The diagnosis and early complications of right ventricular infarction

Studies of pathology have shown that involvement of the right ventricle (RV) in acute myocardial infarction (AMI) is relatively common. Our experience in the noninvasive diagnosis of RVAMI and its early prognosis is presented. Sixty patients with AMI were prospectively studied: 40 patients with inferior AMI and 20 patients with anterior AMI. The evaluation was made by: (1) CLINICAL FINDINGS: hypotension, congestive heart failure, sinus bradycardia less than 40/min, dysrhythmia, and conduction disturbances; (2) ECG record including precordial lead (V4R); (3) Radioisotope heart scintigraphy: 99mTc-PYP infarct scintigraphy and multigated acquisition MUGA blood pool scanning. Of the 40 patients diagnosed as having inferior AMI, 20 cases (50%) were found to be associated with RVAMI. All of them were diagnosed by positive radionuclide studies, and 17 (85%) also demonstrated a ST segment elevation of 0.1 mV, and pathological Q waves in the V4R lead. The ejection fraction (EF) of RV was found to be significantly decreased in patients with RVAMI compared with the other group (mean, 27% versus 57%). Among the 20 patients with RVAMI, 16 (80%) showed various complications during the hospitalization period, versus 9 patients (45%) from the group with inferior AMI. The most common complication in RVAMI patients was conduction disturbances (7 of 20 versus 2 of 20 patients). The clinical and prognostic importance of the early diagnosis of RVAMI is stressed.

Determination of right ventricular ejection fraction utilising a radionuclide washout technique

A radionuclide washout technique (WO), for calculation of the right ventricular ejection fraction (RVEF) which is independent of the exact position of the right ventricular region of interest was evaluated and results compared with first pass (FP) and equilibrium gated blood pool (GBP) values. Regression analysis between RVEF values of 24 patients obtained from FP and WO yielded a correlation coefficient (r) of 0.89, while a slightly poorer correlation coefficient was obtained when FP and GBP were compared (r = 0.79) and between WO and GBP (r = 0.71). No significant difference between RVEF values calculated from the three techniques was found (P less than 0.05) on inter- and intraobserver level. The radionuclide washout technique yields an accurate determination of RVEF without the necessity of outlining the RV accurately.

Radionuclide ventriculography to evaluate myocardial function

Developments over the past decade have allowed one to visualize the right and left ventricles using radionuclide techniques and to study the influence of a wide range of physiologic, pharmacologic and surgical interventions on global and regional ventricular function thereby providing important diagnostic insight and improved therapeutic capabilities. These tests are relatively non-invasive, they can be performed serially, they may be performed in patients that are seriously ill, and they have no recognized risk other than low level radiation exposure. With continued improvement in noninvasive imaging and processing and in the sophistication of associated computer systems, one may expect significant and wide ranging additional contributions in the assessment of myocardial function using radionuclide ventriculographic techniques.

Ventricular performance in adults after operation for congenital heart disease

Symptomatic ventricular dysfunction in adults who have had reparative operations for the more common congenital heart defects is uncommon. However, both invasive and noninvasive laboratory assessments of ventricular function have revealed abnormalities in some subsets of patients after repair of atrial septal defect, ventricular septal defect, aortic or pulmonary stenosis, tetralogy of Fallot, transposition of the great arteries and tricuspid atresia. Possible causative factors of late ventricular dysfunction after repair include the duration and severity of volume or pressure overload; the duration and severity of cyanosis; intermittent episodes of imbalance between myocardial oxygen supply and demand; residuae, sequelae and complications of treatment; and acquired disease. Further long-term follow-up studies are needed to assess the effect of current methods of therapy as well as timing of operative intervention on ventricular function in adults.