Primary diagnosis of atrioventricular pseudo‐block in a neonate with definitive diagnosis of long QT syndrome: diagnostic considerations and therapeutic approaches
Dublin Core
Title
Primary diagnosis of atrioventricular pseudo‐block in a neonate with definitive diagnosis of long QT syndrome: diagnostic considerations and therapeutic approaches
Subject
Atrioventricular block, Arrhythmias, Case report, Long QT syndrome, Sudden cardiac death
Description
Abstract
Introduction Long QT syndrome (LQTS) is a potentially lethal medical condition that might never be diagnosed
and cause sudden cardiac death. It is mainly caused by mutation in electrolyte transporter genes. Due to the sig-
nificant difference in the treatment approach of heart block and other rhythm disorders that mimic this condition,
it is necessary to discriminate these conditions. The occurrence of pseudo-block in electrocardiography features
but without disturbance in the function of the conduction system can mask the definite diagnosis of the real underly-
ing disorder, and this issue leads to the selection of an unfavorable treatment protocol and sometimes the sudden
death of the patient.
Case presentation We described an infant who showed evidence of atrioventricular (AV) block in initial electrocar-
diography (ECG) on his first day, but in further evaluations, the final diagnosis of LQTS was raised. The patient recov-
ered after performing the treatment protocol, which included Mexiletine and beta-blockers. After the genetic test
of the parents and the patient, it was determined that a defective allele of the gene had caused the condition.
Conclusion Our report shows the importance of timely differentiation between heart block and LQTS in neonates
and choosing the correct treatment approach to faster patient recovery and prevent sudden death.
Clinical key message Primary diagnosis of LQTS in neonates might not be a straightforward process due to resem-
bling AV pseudo-block and can cause misleading diagnosis and treatment. Long QT syndrome has several nonspecific
presentations. They might be asymptomatic until adulthood and be diagnosed after sudden cardiac death. Preventive
measures such as timely initiation of medications, ICD or PPM implantation, and continuous observation by caregivers
are the mainstay of survival and quality of life improvement.
Keywords Atrioventricular block, Arrhythmias, Case report, Long QT syndrome, Sudden cardiac death
Introduction Long QT syndrome (LQTS) is a potentially lethal medical condition that might never be diagnosed
and cause sudden cardiac death. It is mainly caused by mutation in electrolyte transporter genes. Due to the sig-
nificant difference in the treatment approach of heart block and other rhythm disorders that mimic this condition,
it is necessary to discriminate these conditions. The occurrence of pseudo-block in electrocardiography features
but without disturbance in the function of the conduction system can mask the definite diagnosis of the real underly-
ing disorder, and this issue leads to the selection of an unfavorable treatment protocol and sometimes the sudden
death of the patient.
Case presentation We described an infant who showed evidence of atrioventricular (AV) block in initial electrocar-
diography (ECG) on his first day, but in further evaluations, the final diagnosis of LQTS was raised. The patient recov-
ered after performing the treatment protocol, which included Mexiletine and beta-blockers. After the genetic test
of the parents and the patient, it was determined that a defective allele of the gene had caused the condition.
Conclusion Our report shows the importance of timely differentiation between heart block and LQTS in neonates
and choosing the correct treatment approach to faster patient recovery and prevent sudden death.
Clinical key message Primary diagnosis of LQTS in neonates might not be a straightforward process due to resem-
bling AV pseudo-block and can cause misleading diagnosis and treatment. Long QT syndrome has several nonspecific
presentations. They might be asymptomatic until adulthood and be diagnosed after sudden cardiac death. Preventive
measures such as timely initiation of medications, ICD or PPM implantation, and continuous observation by caregivers
are the mainstay of survival and quality of life improvement.
Keywords Atrioventricular block, Arrhythmias, Case report, Long QT syndrome, Sudden cardiac death
Creator
Mohammadrafie Khorgami1
, Fatemeh Naderi2* and Samira Kalayinia3
, Fatemeh Naderi2* and Samira Kalayinia3
Source
https://doi.org/10.1186/s12245-025-00827-1
Date
2025
Contributor
Peri Irawan
Format
pdf
Language
english
Type
text
Files
Collection
Citation
Mohammadrafie Khorgami1
, Fatemeh Naderi2* and Samira Kalayinia3, “Primary diagnosis of atrioventricular pseudo‐block in a neonate with definitive diagnosis of long QT syndrome: diagnostic considerations and therapeutic approaches,” Repository Horizon University Indonesia, accessed April 11, 2026, https://repository.horizon.ac.id/items/show/12657.