Relation of symptoms to contractility and defect size in infants with ventricular septal defect

Congenital heart disease in Nigerian children: a multicenter echocardiographic study

BACKGROUND

Congenital heart disease (CHD) is among the leading causes of morbidity and mortality in childhood. We report on the spectrum of echocardiographically diagnosed CHD from three different centers across Nigeria.

METHODS

Over a period of 42 months, children who were referred for echocardiographic evaluation in the centers located in three large metropolitan cities were consecutively recruited if they were confirmed to have identifiable CHD. Data were collected on age, gender, and types of CHD and analyzed using SPSS 16 (Chicago, Illinois,).

RESULTS

A total of 605 children were recruited, their mean age was 2.1 ± 3.5 (range 0-17) years, and 296 (48.9%) were males. Nearly half (42.5%) had echocardiographic diagnosis of their CHD within the first year of life. Only 17% of the diagnoses were made in the neonatal age group. Acyanotic CHDs were more common than the cyanotic heart diseases (82.8% vs 17.2%). The most common CHD was ventricular septal defect (VSD; 46.6%) followed by patent ductus arteriosus (12.1%), atrial septal defect (8.7%), atrioventricular septal defect (8.2%), and tetralogy of Fallot (7.8%). More than half of the VSDs were perimembranous (55.1%) followed by outlet VSD (23.8%), muscular (10.7%), and inlet VSD (9.6%). Only 42 (6.9%) of the entire study population had definitive intervention.

CONCLUSION

The VSD is the most prevalent CHD in Nigerian children. There is increasing awareness, availability, and use of diagnostic facilities as mirrored in the age distribution of the children. However, access to definitive surgery is poor and draws attention to the urgent need for affordable surgical facilities in the country.

Longitudinal Strain and Strain Rate in Patients With Hemodynamically Significant Ventricular Septal Defects

Background:

Patients with significant overcirculation from large ventricular septal defects (VSDs) may have altered contractility compared to normal patients.

Methods:

Patients were enrolled prospectively. Patients were excluded if they were acutely ill or over age five. Left ventricular longitudinal strain and strain rate were measured in patients with VSDs referred for surgical correction and control participants with structurally normal hearts.

Results:

There was no difference in the average longitudinal strain or strain rate of six segments in the left ventricle. The mean for both the groups was 19.9% ( P = .95). Strain rate was 1.5 s−1 in the patients with a VSD and 1.42 s−1 in the control group ( P = .30). The left ventricular end diastolic dimension was significantly larger in the group with ventricular defects (z score 1.38 vs −0.37) than the control group ( P = .000).

Conclusions:

The left ventricle end-diastolic dimension in patients with ventricular defects was significantly larger, but there was no difference in longitudinal strain or strain rate.

Underlying congenital heart disease in Nigerian children with pneumonia

BACKGROUND

Pneumonia is a common cause of childhood morbidity and mortality globally. Some congenital heart disease (CHD) may predispose their sufferer to bronchopneumonia.

OBJECTIVE

To evaluate the contribution of CHD to pneumonia in children seen in a tertiary hospital.

METHODS

Over a year, consecutive children diagnosed radiologically with pneumonia were evaluated echocardiographically for CHD. Certain characteristics in children with pneumonia and CHD were compared to those without CHD.

RESULTS

There were 121 children with pneumonia of which 61(50.40%) were males and their mean age was 10.2 ± 10.93 months. The prevalence of CHD was 14(11.57%), the commonest CHD was ventricular septal defect (VSD) in 7(50.00%). Most of the CHD with septal defect had moderate to large defects. Children with CHD were 3 and 256 times more likely to have heart failure and murmur respectively compared to those without CHD, p = 0.084 and <0.0001. Children with CHD stayed longer in the hospital 11.50 ± 7.03 days than those without CHD 7.38 ± 5.34 days, p = 0.012.

CONCLUSION

The children with CHD were more likely to have heart failure and murmur compared to those without CHD. Prevalence of CHD in children with pneumonia in this study is high, evaluation of children with pneumonia for CHD is therefore recommended.

[Ventricular septal defects: anatomic, clinical, therapeutic and prognostic aspects. 44 cases]

OBJECTIVES

The aim of this study is to analyze epidemiologic, anatomic, clinical and prognostic aspects of ventricular septal defect (VSD) in the pediatric population in Morocco.

METHODS

This retrospective descriptive study included 44 consecutive patients admitted to the cardiology B department of Rabat University Hospital Center from January 2000 through March 2003. The inclusion criteria were: VSD, isolated or associated with other left-right shunt defects, diagnosed by transthoracic echocardiography, and hospitalized in the service.

RESULTS

VSD accounted for 10.6% of the congenital cardiac diseases hospitalized in our department. Patients' mean age was 2.25 +/- 2.6 years; the consanguinity rate was 29%. The primary clinical symptoms were dominated by failure to gain weight (84%), exertional dyspnea (82%), and repeated bronchitis (72%). Early complications were infundibular stenosis (4 cases), aortic regurgitation (3 cases), and infectious endocarditis (1 case). Nine children had other abnormalities, including 6 with trisomy 21. Echocardiography showed that membranous defects were by far the most common type (88%). All patients received symptomatic medical treatment. Only 31.7% (n=14) had surgery: 11.3% (n=5) to close the hole (corrective) and 20.4% (n=9) for pulmonary artery (palliative) banding. After two years of follow-up, those with surgical correction were all doing well.

CONCLUSION

Surgically closing the VSD is the best way to avoid irreversible pulmonary arterial hypertension; banding should be only a temporary measure while awaiting corrective surgery.

Patent Ductus Arteriosus: An Uncommon Cause of Tracheobronchial Compression in Infants

Tracheobronchial compression is an important cause of respiratory distress in children, requiring precise diagnosis and early surgical management. Common causes of the compression are either intrinsic or extrinsic, the latter being usually due to vascular rings. We report a 10 weeks old boy in whom a dilated pulmonary artery due a large patent ductus arteriosus was the cause for extrinsic compression.

Regional functional depression immediately after ventricular septal defect closure

Left ventricular ejection is depressed immediately after repair of ventricular septal defect (VSD). Postrepair functional depression seen after VSD closure could result from a reduction in preload. However, other mechanisms could be at work. Functional depression could also be caused by closure of a low-impedance path for left ventricular ejection, the introduction of a stiff akinetic patch, or the operation itself. We reasoned that functional depression mediated by changes in preload or afterload should symmetrically affect end-diastole and end-systole, whereas depression resulting from changes in septal mechanics should be localized. We, therefore, performed segmental wall-motion analysis on intraoperative echocardiograms from patients undergoing VSD and atrial septal defect repair. After VSD closure, there was an asymmetric change in left ventricular end-systolic segment length and a decrease in fractional segment shortening localized to the septal and lateral walls, whereas patients with atrial septal defect had a symmetric increase in fractional shortening. These results suggest that acute functional depression after VSD repair is a result of localized impairment of septal function.

Effects of therapeutic beta blockade on myocardial function and cardiac remodelling in congenital cardiac disease

BACKGROUND

Cardiac remodelling is now recognised as an important aspect of cardiovascular disease progression and is, therefore, emerging as a therapeutic target in cardiac failure due to different etiologies. Little is known about the influence of different therapies for cardiac failure on the remodelling seen in infants with congenital cardiac disease.

METHODS

During follow-up of a prospective and randomized trial, we investigated therapeutic effects on neurohormonal activation, ventricular function, and myocardial gene expression. We compared the data from 8 infants with severe congestive heart failure due to left-to-right shunts, who received digoxin and diuretics alone, to 9 infants who received additional treatment with propranolol.

RESULTS

In these infants, beta-adrenergic blockade significantly reduced highly elevated levels of renin, from 284 +/- 319 microU/ml compared to 1061 +/- 769 microU/ml. Systolic ventricular function was normal in both groups, but diastolic ventricular function was improved in those receiving propranolol, indicated by significantly lower left atrial pressures, lower end-diastolic pressures, and less pronounced ventricular hypertrophy, the latter estimated by lower ratios of myocardial wall to ventricular cavity areas on average of 42%. Further hemodynamic parameters showed no significant differences between the groups, except for the lower heart rate in infants treated with propranolol. In those treated with digoxin and diuretics, there was a significant downregulation of beta2-receptor and angiotensin-2 receptor genes, and up-regulation of endothelin A receptor and connective tissue growth factor genes, that were partially prevented by additional treatment with propranolol.

CONCLUSIONS

Beta-blockade is a new therapeutic approach for congestive heart failure in infants with congenital cardiac disease, producing with significant benefits on neurohormonal activation, diastolic ventricular function, and cardiac remodelling.

Propranolol treatment of congestive heart failure in infants with congenital heart disease: The CHF-PRO-INFANT Trial. Congestive heart failure in infants treated with propanol

AIM

Infants with congenital heart disease and left-to-right shunts may develop significant clinical symptoms of congestive heart failure in spite of therapy with digoxin and diuretics. We investigated the effects of beta-blockade in infants with severe heart failure.

METHODS AND RESULTS

We performed a prospective, randomized, open monocenter trial in infants treated with digoxin and diuretics (n=10) in comparison to 10 infants receiving additional beta-blocker therapy. After 17 days on average beta-blocker treated infants (propranolol:1,6 mg/kg/day) improved significantly with respect to Ross heart failure score (3.3+/-2.3 vs. 8.3+/-1.9, P=0.002), lower renin levels (338+/-236 vs. 704+/-490 microU/l, P=0.008) and lower mean heart rates in Holter ECG (118+/-10 vs. 142+/-11 beats/min, P<0.001). While digoxin and diuretic treated infants had unchanged mean heart rate (149+/-8 vs. 148+/-10 beats/min), less decrease of symptoms (Ross Score: 8.5+/-1.7 vs. 6.8+/-2.3, P=0.02) but a significant increase of renin levels (139+/-102 vs. 938+/-607 microU/l, P=0.001).

CONCLUSION

Additional propranolol treatment but not digoxin and diuretics alone can effectively reduce clinical symptoms of heart failure in infants with congenital heart disease, who suffer from increased neurohormonal activation.

Effectiveness of low dose captopril versus propranolol therapy in infants with severe congestive failure due to left-to-right shunts

To evaluate the therapeutical effects of the angiotensin converting enzyme inhibitor Captopril to the beta-blocker Propranolol in infants with congestive failure due to pulmonary overcirculation, we retrospectively analysed clinical, neurohormonal and hemodynamic data in 22 infants, 11 of whom were treated with Captopril (Group 1), 11 with Propranolol (Group 2). Age, weight, number of palliative operations, plasma renin activities and pulmonary to systemic flow ratios (3.5 vs. 3.5) were not significantly different prior to Captopril or Propranolol therapy. If treatment with digoxin and diuretics did not succeed, the infants were additionally treated with Captopril (1 mg/kg) for a mean of 7.4 months, or with 1.9 mg/kg Propranolol for 9.2 months.

RESULTS

1 mg/kg Captopril did not effectively suppress angiotensin converting enzyme in the steady state at trough level (92+/-52 vs. 87+/-50 nmol/min/ml). In the Propranolol group, the clinical heart failure score (2.6+/-1.5 vs. 7. 4+/-2.5) and plasma renin activities (14+/-10 vs. 101+/-70 ng/ml/h) were significantly lower, compared to the Captopril group. Length of hospital stay (23+/-9 vs. 52+/-24 days) was lower and weight gain (126+/-38 vs. 86+/-84 g/week) was higher within 3 months after starting Propranolol therapy. Significantly lower left atrial pressures (6.2+/-2.2 vs. 13.4+/-9.2 mmHg) and lower endiastolic ventricular pressures (7.6+/-2.5 vs. 12.6+/-4.0 mmHg) during pre-operative cardiac catheterization indicated a better diastolic ventricular function under chronic Propranolol treatment.

CONCLUSION

Although high dose Captopril was not evaluated in this study, when compared to patients on low Captopril dosages, infants who received Propranolol treatment showed improvement in heart failure scores, shorter lengths of hospital stay, lower plasma renin activities and better diastolic ventricular functions.

Reduction of carotid arterial blood flow in ventricular septal defect associated with severe congestive heart failure

After diagnosing abnormality of cardiac and carotid-cerebral circulation in an infant with isolated ventricular septal defect (VSD) associated with severe congestive heart failure, the authors measured the carotid arterial blood flow volume (CABF). At 3 months, the patient was not thriving and had dyspnea because of severe congestive heart failure. The authors measured the VSD size/body surface area (BSA) ratio relative to the predicted value of the left ventricular end-diastolic dimension (%LVEDd), left-to-right shunt ratio (Qp/Qs), and the small stroke volume (SV)/BSA using echocardiography and cardiac catheterization. The mean, maximum, and minimum CABF (mean CABF, maxCABF, and minCABF) among R-R intervals on electrocardiogram were measured by Doppler flowmetry in this patient and 5 healthy age-matched control children. The patient had a large VSD size/BSA ratio (37.9 mm/m2), %LVEDd (164%), and Qp/Qs (3.8), and a small SV/BSA ratio (18 mL/m2). The mean CABF, maxCABF, and minCABF were significantly lower than those of control children (VSD patient vs. controls; 2.7 +/- 0.4 vs. 4.5 +/- 0.6, 6.1 +/- 0.9 vs. 12.0 +/- 2.1, 1.2 +/- 0.2 vs. 1.7 +/- 0.4 mL/sec (mean +/- S.D.)), respectively (p < 0.01). The authors' results showed abnormal cardiac and carotid-cerebral circulation in an infant with large VSD associated with severe congestive heart failure.

Assessment of global left ventricular function in normal children and in children with dilated cardiomyopathy

A Doppler index combining systolic and diastolic time intervals (Tei index) has been reported to be useful for assessing global left ventricular (LV) function and predicting clinical outcome in adult patients with LV dysfunction. However, normal values in children and age-related changes in the index have not yet been clarified. The aim of this study was to prospectively determine normal values of the Tei index and the effect of aging on the index in children and to assess the global cardiac function in patients with dilated cardiomyopathy with this index. The subjects included 161 consecutive normal children aged 30 days to 18 years and 5 patients with dilated cardiomyopathy. The Tei index was defined as the sum of the isovolumetric contraction time and the isovolumetric relaxation time divided by the ejection time and was measured from conventional LV outflow and inflow Doppler velocity profiles. The Tei index correlated significantly with the logarithm of age (r = 0.51, P <. 001). The index decreased with aging until 3 years and then did not change after age 3 years. The Tei index in children under age 3 years (0.40 +/- 0.09, n = 80) was significantly higher than that in children ranging in age from 3 to 18 years old (0.33 +/- 0.02, n = 81). The index in patients with dilated cardiomyopathy (0.78 +/- 0. 28) was markedly increased compared with that in normal subjects. Age-related changes in the Tei index may reflect maturational or developmental alterations in the LV properties in infants. The data in this study give basic information for further quantitative assessment of global cardiac function in children with congenital or acquired heart disease.

Effect of ligation of patent ductus arteriosus on left ventricular performance and its determinants in premature neonates

OBJECTIVES

The purpose of this study was to determine in preterm newborn infants the effects of ductal ligation on ventricular performance and its determinants: preload, afterload and contractility.

BACKGROUND

Neonatal ventricular performance is highly sensitive to afterload. Therefore, the increase in systemic vascular resistance associated with ligation of a patent ductus arteriosus might worsen ventricular performance in the preterm infant.

METHODS

All 14 premature infants undergoing patent ductus arteriosus ligation in a 1-year period at our institution underwent echocardiography at three times: before, immediately after and 24 h after ligation. Indexes studied included ventricular performance (fractional area change), preload (left ventricular end-diastolic dimension), afterload (end-systolic wall stress) and contractility (the difference between the measured and predicted velocity of circumferential fiber shortening). Blood pressure was measured; systemic resistance was calculated. These data were compared with those of 14 preterm infants without patent ductus arteriosus.

RESULTS

The infants with patent ductus arteriosus had higher values for ventricular performance (mean +/- SD fractional area change 60 +/- 9% vs. 52 +/- 11%, p < 0.05) and lower values for wall stress (22 +/- 6 vs. 44 +/- 17 g/cm2, p < 0.05) before ligation than did the control group. At 24 h after ligation, ventricular performance was not significantly changed (fractional area change 60 +/- 9% to 57 +/- 12%). There were significant increases in blood pressure and systemic vascular resistance but no changes in wall stress or contractility.

CONCLUSIONS

Ventricular performance is higher in premature infants with than in those without patent ductus arteriosus because afterload is lower in the former group. Although ductal ligation increases blood pressure and systemic resistance, wall stress and ventricular performance are maintained. Our results suggest that the premature newborn maintains ventricular performance during stress, at least in part, by manipulating afterload.

Noninvasive assessment of myocardial contractility, preload, and afterload in healthy newborn infants

Assessment of ventricular contractility in the newborn infant using standard echocardiographic indexes can result in error due to the unique physiologic state that exists in the neonatal period. It has been suggested from animal and human studies that maturational alterations in contractility occur with birth and continue throughout infancy. To further investigate these developmental changes, 41 newborn infants aged 3 to 10 days and 37 children aged 3 to 18 years were evaluated with 2-dimensional and M-mode echocardiography. The rate-corrected velocity of circumferential fiber shortening (VCFc)-end-systolic wall stress (ESWS) relation was used as a load-independent estimate of contractility. Preload, afterload, and ventricular mass were also measured. Despite similar shortening fractions, the infant group had significantly higher mean VCFc and lower ESWS than the older age group (1.28 vs 1.08 circ/s and 30.2 vs 37.3 gm/m2, respectively). An inverse linear relation between VCFc and ESWS was found in both age groups. The y-intercept was higher in the infant group (p < 0.01), and the slope of the mean regression line was steeper than in the older children (p < 0.01). Ventricular mass in relation to body surface area increased with age. We conclude that (1) newborn infants have a higher basal contractile state that cannot be accounted for by lower afterload, (2) myocardial performance is more sensitive to afterload in the immature heart, and (3) shortening fraction may underestimate ventricular function in the newborn.

Persistent hyperdynamic cardiovascular state at rest and during exercise in children after successful repair of coarctation of the aorta

OBJECTIVES

The purposes of this study were to evaluate left ventricular performance and contractility at rest and during exercise to determine mechanisms and correlates for alterations in performance and blood pressure in pediatric patients after successful repair of coarctation of the aorta.

BACKGROUND

Blood pressure and left ventricular function are elevated in children despite successful repair. The mechanisms for these changes are not understood.

METHODS

Thirty asymptomatic pediatric patients with successful coarctation repair (mean age [+/- SD] 12.5 +/- 4 years) underwent echocardiographic determination of left ventricular mass, performance (shortening fraction), preload (indexed diastolic dimension), afterload (end-systolic wall stress), contractility (velocity of circumferential fiber shortening/wall stress relation) and Doppler gradient at rest and during exercise. Data were compared with those of 24 control subjects (mean age 21.0 +- 4 years). Because of the age discrepancy between groups, age-dependent echocardiographic data were indexed by body surface area.

RESULTS

The mean age at operation was 5 +/- 4 years, and the average follow-up period was 7.5 +/- 3 years. The average blood pressure gradient between upper and lower limbs was 4 mm Hg. Left ventricular mass was higher in the postoperative group than in the control group (1.58 vs. 1.31 g/ht2.7, p = 0.04), as were values at rest for performance (44% vs. 31%, p = 0.0001), preload (3.9 vs. 3.7 cm/body surface area0.5), indexes systolic blood pressure (1.05 vs. 0.91, p = 0.0001) and contractility (0.23 vs. -0.05 circumferences/s, p= 0.001). Afterload was lower at rest (36 vs. 52 g/cm2, p = 0.0004). These differences between groups persisted during and after exercise. Contractility underwent an exaggerated increase after exercise in the postoperative group.

CONCLUSIONS

Left ventricular performance in children after coarctation repair is higher at rest and during exercise than in control subjects as a result of higher preload and contractility and lower afterload. These changes may be due to associated hypertrophy. Persistent postoperative hypertension may be due to a hyperdynamic, hypercontractile state caused by residual gradients manifested only during exertion.

Relation of left ventricular mass, preload, afterload and contractility in pediatric patients with essential hypertension

OBJECTIVES

The aim of this study was to determine if left ventricular preload, afterload or contractility is a correlate of left ventricular mass index in hypertensive pediatric patients.

BACKGROUND

It is believed that decreased contractility and increased preload are associated with left ventricular hypertrophy in adult hypertensive patients.

METHODS

Ninety pediatric hypertensive patients underwent echocardiography to assess left ventricular mass, preload (diastolic dimension and volume) and afterload (end-systolic wall stress, vascular resistance and blood pressure). Contractility was assessed by 1) the end-systolic stress/volume ratio, and 2) the difference between measured and predicted velocity of circumferential fiber shortening. Univariate and multivariate analyses were performed.

RESULTS

Univariate analysis showed significant correlations between left ventricular mass and 1) body mass (r = 0.33, p < 0.001), 2) black race (r = 0.37, p < 0.0003), 3) diastolic dimension (r = 0.26, p < 0.01), 4) diastolic volume (r = 0.20, p < 0.05), and 5) stress/volume ratio (r = -0.53, p < 0.0001) but not the difference between measured and predicted velocity of circumferential fiber shortening. A multivariate model included body mass, age at diagnosis, diastolic dimension, wall stress and vascular resistance but not the difference between measured and predicted velocity of circumferential fiber shortening.

CONCLUSIONS

Contractility is not significantly related to left ventricular mass. The positive correlation between mass and stress/volume may be due to the dependence of the latter variable on loading conditions. We speculate that both elevated preload and systemic vascular resistance may have a role in the development of hypertrophy in hypertensive pediatric patients.

Left ventricular mechanics in the preterm infant and their effect on the measurement of cardiac performance

The effects of the transition from fetal to postnatal circulation on left ventricular geometry, wall motion, and echocardiographic measurements of function in the human preterm infant are largely unknown. To determine whether abnormalities in left ventricular geometry are present in the normal preterm infant after birth and, if so, for how long, and to examine possible contributing factors and their effect on the measurement of cardiac performance, we obtained serial echocardiograms of 14 healthy preterm infants (gestational age, 33 +/- 2 weeks; birth weight, 1940 +/- 470 gm) at 9.5 +/- 3.5 days of age (time 1) and again at 51 +/- 16 days (time 2). Left ventricular shape and wall motion were measured and estimates of wall stress and mass were made. Performance was assessed by standard M-mode shortening fraction and by transverse two-dimensional area shortening. At time 1 septal flattening caused distortion of left ventricular shape. As the patients grew older, septal flattening resolved and the left ventricle tended to assume a circular cross-sectional shape. Wall-motion analysis demonstrated poor motion of the midseptum and anterior free wall at time 1, which improved at time 2 (p = 0.06). Left ventricular mass increased from 24 +/- 5 to 41 +/- 7 gm/m2 (p = 0.0001) and wall stress decreased from 49 +/- 21 to 38 +/- 13 gm/cm2 (p = 0.005) between time 1 and time 2. Shortening fraction was lower at time 1 than at time 2 (18% +/- 7% vs 28% +/- 8%; p = 0.001; normal limit = 28% to 45%); however, there was no significant difference in area shortening between time 1 and time 2 (49% +/- 10% vs 53% +/- 8%; normal limit = 45% to 65%). We conclude that the preterm newborn infant has distorted left ventricular shape and abnormal wall motion, which alter measurements of shortening fraction and persist for the first weeks of life. Area shortening may be necessary to assess left ventricular performance during the first weeks of life in the premature infant.

Effect of digoxin on contractility and symptoms in infants with a large ventricular septal defect

The effect of digoxin on contractility and symptoms in infants with a large ventricular septal defect (VSD) is controversial. Nineteen infants with symptoms of congestive heart failure due to a VSD were studied with load-independent indexes during 4 study periods: (1) before any medication; (2) while on chronic diuretics; (3) while on both diuretics and digoxin; and (4) while on diuretics alone, to determine if digoxin: (a) increases "contractility" when added to diuretic therapy; and (b) improves symptoms. Symptoms, signs (heart and respiratory rates, and weight gain), shortening fraction, preload (left ventricular end-diastolic dimension), afterload (left ventricular end-systolic wall stress) and contractility were measured at each period. The difference between the measured and predicted velocities of circumferential fiber shortening for the measured left ventricular end-systolic wall stress served as an index of contractility. Eighteen infants also underwent catheterization. Mean pulmonary-to-systemic blood flow ratio was 3:1. When digoxin was added to diuretics, contractility index was significantly greater than in control subjects (0.13 +/- 0.15 vs 0.0 +/- 0.12 circ/s, p = 0.04). When patients were again on diuretics alone (after discontinuation of digoxin), contractility index was no longer different. Symptoms and signs were not significantly improved by either diuretics or digoxin. It is concluded that in infants with a large left-to-right VSD shunt and receiving digoxin and diuretics, contractility index was significantly greater than in control subjects. However, neither diuretics alone nor in combination with digoxin improved symptoms significantly.