Congenital heart malformations associated with dilated cardiomyopathy

Dilated cardiomyopathy: an unusual presentation of aortic coarctation in an infant

Coarctation of the aorta commonly presents in infancy as congestive heart failure, or later in childhood as hypertension or as a heart murmur. However, we experienced a unique infant case of isolated coarctation presenting with acute decompensation of a dilated cardiomyopathy, which recovered completely 8 months postoperatively. Our report highlights the previously unreported presentation of coarctation in infancy as a dilated cardiomyopathy. It also implies that before we label any patient presenting with a dilated cardiomyopathy as an idiopathic cardiomyopathy, we must exclude all possible specific causes of myocardial dysfunction because many such specific cardiomyopathies are curable and very rewarding, just like our patient.

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.