Clinical course of idiopathic dilated cardiomyopathy in children

QT dispersion predicts ventricular arrhythmia in pediatric cardiomyopathy patients referred for heart transplantation

BACKGROUND

QT dispersion has been used in stratifying risk for sudden death in adults with dilated cardiomyopathy, but its role in the pediatric population has not been delineated.

METHODS

We reviewed electrocardiograms in pediatric patients with dilated cardiomyopathy referred for heart transplantation, to evaluate the role of QT dispersion in predicting malignant arrhythmias in these patients. Three groups were defined: Group I (n = 13) had dilated cardiomyopathy and malignant ventricular arrhythmias, Group II (n = 13) had dilated cardiomyopathy with no ventricular arrhythmias and Group III (n = 30) consisted of normals. QT dispersion was defined as the duration of the shortest QT subtracted from that of the longest. In addition, the standard deviation of the QT intervals was calculated for each ECG, using 12 leads.

RESULTS

QT dispersion was significantly prolonged in Group I (97 +/- 33 msec) compared to Group II (74 +/- 19 msec) and Group III (42 +/- 17 msec). QT standard deviation was also prolonged in Group I (30 +/- 11 msec) vs Group II (22 +/- 5 msec) and Group III (13 +/- 4 msec). Using a threshold value of 90 msec for QT dispersion or 25 msec for QT standard deviation, a sensitivity of 78% and a specificity of 70% was obtained for identifying patients who would subsequently develop ventricular arrhythmias.

CONCLUSIONS

In pediatric heart transplant candidates with dilated cardiomyopathy, QT dispersion and QT standard deviation identify patients at higher risk for the development of malignant ventricular arrhythmia. This simple test can be helpful in the evaluation and management of these patients awaiting transplantation.

Superselective Intra-Arterial Thrombolysis for Acute Cardioembolic Stroke in a Child with Idiopathic Dilated Cardiomyopathy

We describe a case of cardioembolic dominant hemisphere internal carotid artery occlusion in a child with idiopathic dilated cardiomyopathy. The patient was subjected to superselective local intra-arterial thrombolysis using recombinant tissue plasminogen activator (Alteplase; Actilyse®). In presence of good collateral flow local intra-arterial thrombolysis prevented a major dominant hemisphere ischaemic stroke, although post-interventional computed tomographic scans disclosed haemorrhagic conversion in the left corpus striatum. Forty eight months after ischaemic stroke and thrombolysis the patient is ambulatory with a moderate neurologic deficit.

Pediatric myocardial disease

Cardiomyopathies are diseases of the heart muscles. This article reviews the causes, clinical presentation, diagnosis, management, and long-term outcomes of dilated and hypertrophic cardiomyopathy.

Improved prognosis of heart failure due to idiopathic dilated cardiomyopathy in children

We analyzed the outcome of 18 children with idiopathic dilated cardiomyopathy (IDC). There was a striking female preponderance (M:F = 1:3.5) and 15 (83%) presented below the age of 2 years. Follow up for a mean duration of 3.5 years revealed complete recovery in seven (43%) and an additional three (19%) became asymptomatic. Three (19%) died and another three (19%) continued to be symptomatic but in controlled heart failure. Two were lost to follow up. Among those who improved, the majority (75%) did so in 1.5 years. Three of five patients who received periodic dobutamine infusion showed improvement in quality of life. The survivals of 94% at 1 year and 87% at 3 years are significantly better than those previously reported. This is the first such study of IDC in children from the Arab peninsula.

Idiopathic dilated cardiomyopathy in children: prognostic indicators and outcome

OBJECTIVE

To determine the outcome of Finnish children and adolescents with idiopathic dilated cardiomyopathy (IDCM) and factors that might be useful as prognostic indicators.

METHODOLOGY

The clinical profile and course of 62 Finnish children and adolescents (median age, 13 months; range, 1 day to 20 years) with IDCM in 1980 to 1991 were evaluated to detect factors that might predict outcome. Factors studied included age, gender, family history, previous viral illness, and symptoms and signs at presentation. Furthermore, data on serial electrocardiographic, echocardiographic, and chest x-ray examinations, histologic findings, and treatments were analyzed.

RESULTS

During a mean (+/-SD) follow-up of 3.9 +/- 4.5 years (range, 1 day to 25 years), 10 patients (16%) recovered, 17 (27%) had residual disease, 4 (6.4%) underwent heart transplantation, and 31 (50%) died. Infants (<1 year of age) and adolescent (>/=15 years of age) male patients with progressing symptoms of left ventricular failure after initiation of medical therapy tended to have the poorest outcome. However, in multivariate analysis, only histologic evidence of endocardial fibroelastosis, clinical signs of right ventricular failure at presentation, and the need for anticoagulative therapy during follow-up, the last an expression of a severely impaired left ventricular systolic function, appeared to be significant predictors of long-term outcome.

CONCLUSIONS

Our study confirms that the outcome of children with IDCM still remains poor. However, a group of patients, mainly infants, make a full recovery. Adolescent male patients as well as infants suffering from endocardial fibroelastosis with persisting symptoms of congestive heart failure after initiation of medical therapy tend to have the poorest outcome. These patients need a careful follow-up at short time intervals and, in the case of lacking response to medical treatment with resulting growth failure and/or poor quality of life, should be offered urgent heart transplantation.

Selection and treatment of candidates for heart transplantation. A statement for health professionals from the Committee on Heart Failure and Cardiac Transplantation of the Council on Clinical Cardiology, American Heart Association

Improved outcome of heart failure in response to medical therapy, coupled with a critical shortage of donor organs, makes it imperative to restrict heart transplantation to patients who are most disabled by heart failure and who are likely to derive the maximum benefit from transplantation. Hemodynamic and functional indexes of prognosis are helpful in identifying these patients. Stratification of ambulatory heart failure patients by objective criteria, such as peak exercise oxygen consumption, has improved ability to select appropriate adult patients for heart transplantation. Such patients will have a poor prognosis despite optimal medical therapy. When determining the impact of individual comorbid conditions on a patient's candidacy for heart transplantation, the detrimental effects of each condition on posttransplantation outcome should be weighed. Evaluation of patients with severe heart failure should be done by a multidisciplinary team that is expert in management of heart failure, performance of cardiac surgery in patients with low left ventricular ejection fraction, and transplantation. Potential heart transplant candidates should be reevaluated on a regular basis to assess continued need for transplantation. Long-term management of heart failure should include continuity of care by an experienced physician, optimal dosing in conventional therapy, and periodic reevaluation of left ventricular function and exercise capacity. The outcome of high-risk conventional cardiovascular surgery should be weighed against that of transplantation in patients with ischemic and valvular heart disease. Establishment of regional specialized heart failure centers may improve access to optimal medical therapy and new promising medical and surgical treatments for these patients as well as stimulate investigative efforts to accelerate progress in this critical area.

Cardiac dysrhythmias in children with idiopathic dilated or hypertrophic cardiomyopathy

To assess the incidence and prognostic significance of cardiac dysrhythmias in children with idiopathic dilated or hypertrophic cardiomyopathy, the clinical course of 59 patients was retrospectively reviewed over a period of 27 years. Dilated cardiomyopathy (DCM) was diagnosed in 28 patients and hypertrophic cardiomyopathy (HCM) in 31 patients. The mean age at the time of diagnosis was 2.8 +/- 0.7 years in DCM patients and 6.7 +/- 0.8 years in HCM patients. Mean follow-up time after diagnosis of cardiomyopathy was 4.1 +/- 1.0 years in DCM patients and 6.6 +/- 0.8 years in HCM patients. Clinically significant cardiac dysrhythmias were found in 17 of 59 patients (29%): 7 of 28 patients (25%) with DCM and 10 of 31 patients (32%) with HCM. The initial diagnosis of a cardiac dysrhythmia was made by standard electrocardiography in 12 of 17 patients (71%) and by 24-hour Holter monitoring in 5 of 17 patients (29%). Ventricular dysrhythmias were present in 5 of 7 patients with dilated cardiomyopathy and in 5 of 10 patients with hypertrophic cardiomyopathy. During the followup time, death occurred in 18 of 59 patients (31%): 8 of 59 patients (14%) died from congestive heart failure and 10 of 59 patients (17%) died suddenly. Among the sudden deaths were 4 of 28 patients (14%) with dilated cardiomyopathy and 6 of 31 patients (19%) with hypertrophic cardiomyopathy. Cardiac dysrhythmias had been documented in 6 of the 10 patients dying suddenly (3 of 4 patients with DCM and 3 of 6 patients with HCM).(ABSTRACT TRUNCATED AT 250 WORDS)

Dilated cardiomyopathy in children: determinants of outcome

OBJECTIVE

To determine the outcome of dilated cardiomyopathy presenting in childhood and the features that might be useful for prognostic stratification.

SETTING

Supraregional paediatric cardiology unit.

DESIGN

Retrospective analysis.

BACKGROUND

The natural history of dilated cardiomyopathy in children is not well characterised. Previous studies have shown a variable relation between age at presentation and outcome, and sudden death has been infrequent.

METHODS

Retrospective study of 63 consecutive patients with idiopathic dilated cardiomyopathy presenting between 1979 and 1992. Survival curves were constructed by the Kaplan-Meier method.

RESULTS

Age at diagnosis ranged from 1 day to 15 years (median 12 months) and follow up ranged from 1 day to 13 years (median 19 months). Actuarial survival from presentation was 79% at one year (95% confidence interval (95% CI) 66%-88%) and 61% (44%-74%) at five years. Univariate analysis showed that mural thrombus, left ventricular end diastolic pressure > 20 mm Hg, and age at presentation > 2 years were predictors of adverse outcome, but on multivariate analysis only age at presentation was significant. Left ventricular echocardiographic indices either did not improve or deteriorated in 36 children (17 of whom died, four suddenly, and three were transplanted), partially improved in 16 (three of whom died, all suddenly), and returned to normal in 11 (all of whom have survived).

CONCLUSIONS

Older age at presentation and lack of improvement in systolic function are associated with an adverse outcome, and early transplantation should be considered in these patients. There is a persistent risk of late sudden death in those children in whom echocardiographic dimensions remain abnormal.

Prognostic value of echocardiography in children with idiopathic dilated cardiomyopathy

Mortality of pediatric patients with idiopathic dilated cardiomyopathy (IDC) is highest during the first 1 to 2 years the child is first seen. The echocardiograms of 72 infants and children with IDC were reviewed to determine whether left ventricular shortening fraction (LVSF), end-diastolic dimension, and wall mass were helpful in predicting outcome. Patients who were alive at last follow-up (group 1) were compared to those who died or required heart transplant (group 2). None of the indexes obtained at first examination were predictive of survival. Shortening fraction had improved significantly at follow-up 1 to 6 months after first examination in group 1 (15.1 +/- 0.9 to 24.4 +/- 1.8, p < 0.001) but remained unchanged in group 2 (14.1 +/- 1.5 to 15.3 +/- 3.2). No significant trends were noted in left ventricular end-diastolic dimension or wall mass. The 1- and 5-year actuarial survival for all patients was 75% and 60%, respectively. Persistent depression of LVSF < 15% was associated with a significantly lower survival rate (1-year 46%; 5-year 29%) compared to patients in whom follow-up LVSF was > 15% (1-year 97%; 5-year 90%; p < 0.05). It is concluded that the follow-up LVSF obtained at least 1 month after first examination is helpful in identifying pediatric patients who would benefit from early cardiac transplantation.

Dilated cardiomyopathy in children: clinical course and prognosis

The clinical profile of 19 patients with dilated cardiomyopathy ages 2-18 years (mean 13.4 +/- 4 years) was reviewed to detect any factors that might be predictive for their survival. Follow-up range from 5 to 105 months (mean 39 +/- 33 months). Routine treatment consisted of digitalis and diuretics: 14 patients received antiarrhythmics, 6 received vasodilators, and 12 were managed with immunosuppression. There were 12 survivors and 7 nonsurvivors: The 1-year mortality was 21.2% and the 2-year mortality 35.8%. All deaths were within first 2 years. Of the 12 patients who survived 2 years, a significant improvement was noticed in 9. In 3 patients tachycardia-induced cardiomyopathy was diagnosed, and abolition of supraventricular tachycardia was followed by improvement and regression of cardiomegaly. Endomyocardial biopsy was performed in 16 patients. Four with a histologic diagnosis of active myocarditis survived, and in 3 of them a considerable improvement was noticed. Of the 12 patients with nonspecific histologic findings, 6 died (p < 0.05). There were no significant differences between survivors and nonsurvivors for any of the following parameters: incidence of severe heart failure (NYHA class III-IV) and severe ventricular arrhythmias (Lown class III-V), relative heart volume, echocardiographic left ventricular diastolic diameter and shortening fraction, and the hemodynamic parameters of cardiac index, left ventricular ejection fraction, left ventricular end-diastolic pressure, and left ventricular end-diastolic volume index.

Prolonged QT interval in hypertrophic and dilated cardiomyopathy in children

When the QT interval is prolonged in a patient with structural heart disease, there is a question of whether the QT interval prolongation is the result of coexistent long QT interval syndrome or ventricular hypertrophy. The purpose of this study was to assess whether QT interval prolongation can be attributed to ventricular hypertrophy/dilation alone. Electrocardiograms (ECGs) of 25 children in each of six echocardiographically proven groups (right ventricular hypertrophy, left ventricular hypertrophy, biventricular hypertrophy, hypertrophic cardiomyopathy, dilated cardiomyopathy, and normals) were analyzed. All patients had QRS interval durations < 100 msec, and patients with ventriculotomies were excluded. No patients in the normal group had a QTc interval > or = 0.45 sec. Eight (32%) of 25 patients with dilated cardiomyopathy had a QTc interval > or = 0.45 sec (p = 0.007 vs normal), 6 (24%) of 25 patients with hypertrophic cardiomyopathy had a QTc interval > or = 0.45 sec (p = 0.03 vs normal), and 2 of 25 patients each with right ventricular hypertrophy, left ventricular hypertrophy, and biventricular hypertrophy had a QTc interval > or = 0.45 sec (p = NS vs normal). There was no relation of the QTc interval to age, QRS duration, T-wave axis, or heart rate in any group. In the dilated cardiomyopathy group, there was no relationship of QTc interval to age, shortening fraction, or left ventricular end diastolic dimension. In conclusion, (1) a significant number of patients (24% to 32%) with dilated or hypertrophic cardiomyopathy may have a long QTc interval on the surface ECG, and (2) ventricular hypertrophy/dilation may be additional rare causes of acquired prolongation of the QT interval.