Incessant ventricular tachycardia due to multiple cardiac rhabdomyomas in an infant with Tuberous Sclerosis

Evaluation of cardiac arrhythmias by electrocardiographic markers in pediatric patients who have tuberous sclerosis without cardiac rhabdomyoma

BACKGROUND

Tuberous sclerosis (TS) is an autosomal dominant and hereditary disorder. Cardiac rhabdomyoma and arrhythmias are the most deleterious risk factors linked to TS. Although arrhythmias in pediatric patients with TS who have cardiac rhabdomyoma have been frequently reported, arrhythmia in patients who have TS without rhabdomyoma is rarely reported in the literature. The study aimed to assess the susceptibility of pediatric patients who have TS without cardiac rhabdomyoma to cardiac arrhythmia using electrocardiographic (ECG) markers.

METHODS

This prospective study included 10 patients who had TS without cardiac rhabdomyoma. The control group was made up of 30 healthy children of the same age and sex as the patient group. P wave, P wave dispersion, QT dispersion, QTc dispersion, TP-e interval, and TP-e interval dispersion were calculated on 12-lead surface ECGs for each patient in both groups and compared.

RESULTS

P wave, P wave dispersion, QT dispersion, and QTc dispersion were found to be significantly higher in the patient group (P<0.001). Furthermore, patients had a greater Tp-e interval and Tp-e interval dispersion than healthy children (P<0.001).

CONCLUSION

Pediatric patients with TS without cardiac rhabdomyoma might be prone to atrial and ventricular arrhythmias according to their prolonged ECG markers. Our findings suggest that patients with TS without cardiac rhabdomyoma need close monitoring for atrial and ventricular arrhythmias.

Perinatal unusual rhabdomyoma location - case report and systematic reviews of the literature

Objective: To report a case of prenatal diagnosis of cardiac rhabdomyoma (CR) and neonatal surgical treatment as well as undertaking a systematic review of the literature to determine most frequent localization of CR, common signs and symptoms, associated pathologies, incidence of surgery, and prognoses for CR.Methods: We conducted systematic review of the literature on CR that were diagnosed and treated in the perinatal period, searching for English language articles in the PubMed/Medline database that were published within the past 20 years, using the following search terms: "cardiac rhabdomyoma"; "neonates"; "newborn"; "surgery".Results: Eighty-two studies were selected, but only 46 studies met the inclusion criteria. After birth, the majority of newborns were asymptomatic; however, murmurs and arrhythmia were also the two most prevalent signs of CR. The most prevalent location was the ventricles, corresponding to 40.3% of all cases, with 53% of these having a rhabdomyoma in the left ventricle. The incidence of multiple tumors was 56%, and in those cases the location of tumors was also most common in the ventricles. Tuberous sclerosis was the most commonly associated pathology, being present in 72% of cases of CR. Surgical treatment occurred in 27% of cases, and 3% of cases required surgery and prostaglandin. Regarding the perinatal outcome, 6% of cases resulted in fetal or neonatal death.Conclusion: CR are benign tumors which tend to spontaneously regress during early childhood but may have unfavorable outcomes in the presence of obstructive lesions and arrhythmias. Surgery is generally necessary in symptomatic patients.

Accelerated Cardiac Rhabdomyoma Regression with Everolimus in Infants with Tuberous Sclerosis Complex

Tuberous sclerosis complex is associated with benign tumors such as cardiac rhabdomyomas (RHM) caused by the disinhibition of the mammalian target of rapamycin (mTOR) protein. Recent reports on everolimus, an mTOR inhibitor, have shown size reduction of RHM. We compared cases recently treated with everolimus to historic controls whose first echocardiography was within first month of life. The largest dimension of the largest RHM was reported as a percentage compared to the earliest echocardiography study. Treatment of the four cases was started at a median age of 6.5 days (range 2-20) with an initial enteral dose of 0.1 mg daily, aiming at a therapeutic serum trough level of 5-15 ng/mL. Median duration of everolimus treatment was 73 days (range 34-138). Compared to 10 historic controls, everolimus-treated patients had 11.8 times faster RHM size regression rate (slope -0.0285 vs. -0.0024; p < 0.001). The average time to 50% size reduction was 1.13 ± 0.33 month (range 0.66-1.4 months) with everolimus versus 72.9 ± 53.03 months in controls (p = 0.026). Following treatment with everolimus, one case was operated for congenital heart disease, without requirement of RHM resection, two others had the massive left ventricle RHM shrink to non-consequential size. The latter had a disappearance of RHM, but everolimus therapy was maintained to prevent the regrowth of a significant cerebral tumor. Everolimus is efficacious for size reduction of RHM during the neonatal period. With limited safety data, this approach should be used with caution in selective cases.