Nocturnal enuresis can be a presentation of congenital long QT syndrome, which may cause life-threatening nocturnal arrhythmias, a condition that is rarely considered when evaluating these patients due to lack of awareness, suggests a recent article from Israel reported in the journal Heart Rhythm.¹

Chorin et al describe the case of a 23-year-old apparently healthy woman who died suddenly during sleep. She had had two isolated episodes of nocturnal enuresis in a gap of 2 years and no other symptoms. The second incident of nocturnal enuresis occurred at 20 years of age. Medication history and alcohol and substance use history were negative. Both times, she had been treated empirically with antibiotics for unconfirmed UTI. A positive history of two sudden deaths in the family was elicited later on. ECG of the mother was suggestive of congenital long QT syndrome type 2. Genetic testing confirmed the diagnosis after detection of a pathogenic mutation in KCNH2 (potassium Voltage-Gated Channel Subfamily H Member 2) gene, which is associated with LQTS2.

Researchers conducted an online survey of physicians about their selection of diagnostic methods apropos of this particular case. A total of 346 physicians inclusive of 102 pediatricians, 73 family physicians, 57 internal medicine specialists, 35 residents in internal medicine, 37 interns and 42 advanced medical students) responded to the surgery. The array of diagnostic modalities suggested in the survey were complete blood count, urinalysis/urine culture, basic metabolic profile, A1c, OGTT, imaging (USG, CT), EEG, ECG, uroflometry or referral to urologist/nephrologist/psychiatrist.

More than 75% opted for urinalysis and more than half favored urine culture. Other selected diagnostic methods were CBC, basic metabolic profile, A1c, kidney USG, CBC and referral to urologist. Notably, only four (1%) physicians suggested an ECG as part of the diagnostic work up for this patient and 19% said they would do an EEG for nocturnal epileptic seizures.

Individuals with congenital LQTS are at high risk of arrhythmias that are potentially fatal. It is a major cause of sudden cardiac death in the young, who are otherwise healthy. However, with timely diagnosis and management, the prognosis is good. If a patient has been diagnosed with LQTS, then the family should also be screened.²

According to the authors, the most probable cause of sudden death in this young female patient was congenital long QT syndrome. They propose that the two episodes of nocturnal enuresis were due to “self-terminating ventricular tachyarrhythmias, leading to cerebral hypoperfusion and resulting in urine incontinence”. In this patient, nocturnal enuresis episodes occurred in a gap of two years, in contrast to bedwetting occurring more than once every week in children. This, they suggest, should have “raised the suspicion of underlying arrhythmias”. 

The 2010 NICE clinical guidelines on “Bedwetting in under 19s” do not mention arrhythmias as a cause to be considered in the evaluation of the patient with enuresis. Neither do textbooks, note the authors.

Physicians, in particular the primary care physicians, should be aware of the association of congenital long QT syndrome with nocturnal enuresis. Cardiac arrhythmias should be considered in the differential diagnosis of enuresis, which typically includes urinary tract infections, anatomic malformations, emotional disturbances, epilepsy etc. An ECG should be a part of the diagnostic protocol in the young patients who present with “sporadic nocturnal enuresis”. This case also underscores the significance of family history.

The authors very aptly write, “It is time for a paradigm shift in the minimal diagnostic evaluation of enuresis.”

References

1. Chorin E, et al. Bedwetting from the heart: Time for a paradigm shift in the minimal diagnostic evaluation of enuresis. Heart Rhythm. 2022 Apr 6. DOI:https://doi.org/10.1016/j.hrthm.2022.01.031
2. Crotti L, et al. Congenital long QT syndrome. Orphanet J Rare Dis. 2008 Jul 7;3:18.