What is the clinical evidence from this study?

Study design: Cohort. Population: Bronchiolitis (n=100). Intervention: Overnight Holter monitoring. Primary outcome: Incidence and characteristics of arrhythmias.

What question did this study set out to answer?

To investigate the incidence and characteristics of cardiac arrhythmias in infants diagnosed with bronchiolitis.

March 23, 2026Open Access

Significant Cardiac Rhythm Disturbances in Infant Bronchiolitis: A Holter-Based Prospective Analysis

Key Result

Overnight Holter monitoring in infants hospitalized with bronchiolitis revealed significant arrhythmias in 18%, including sinus arrest, bradycardia, and frequent atrial premature complexes.

Key Points

To investigate the incidence and characteristics of cardiac arrhythmias in infants diagnosed with bronchiolitis.
Conducted a prospective cohort study at a single center.
Collected demographic and clinical data via questionnaire.
Performed overnight Holter monitoring for all enrolled infants during hospitalization.
18% of infants demonstrated arrhythmias (n=18), including bradycardia and sinus arrest.
Sinus arrest occurred in 8 infants (lasting 2–13 seconds).
7 infants showed bradycardia (<60 bpm), while 3 infants had frequent atrial premature complexes.

Study Design

Type

Cohort (n=100)

Multicenter

Structured PICO

Population

100 infants under one year of age hospitalized with a clinical diagnosis of bronchiolitis (79% RSV-positive).

Intervention

Overnight Holter monitoring during hospitalization

Outcome

Incidence and characteristics of arrhythmias during bronchiolitis

Infants hospitalized with bronchiolitis frequently experience transient, asymptomatic arrhythmias such as sinus arrest and bradycardia that typically resolve without the need for pacemaker intervention.

Abstract

Bronchiolitis is a major cause of respiratory illness in infants. Few studies have demonstrated arrhythmias during bronchiolitis, including bradycardia and atrioventricular block, some requiring pacemaker implantation. However, the association between bronchiolitis and cardiac arrhythmias remains unclear. To investigate the incidence and characteristics of arrhythmias during bronchiolitis in infants under one year of age. A single center, prospective cohort study was conducted on infants hospitalized with a clinical diagnosis of bronchiolitis. Demographic and clinical data were collected via questionnaire. All infants underwent overnight Holter monitoring during hospitalization. Among 100 enrolled infants (79% RSV-positive), 18 (18%) demonstrated arrhythmias: sinus arrest (2–13 seconds) in 8 infants, bradycardia <60 bpm in 7 infants, and frequent atrial premature complexes (APCs; 3%–18% of beats) in 3 infants. Follow-up Holters in 7 patients (38%) showed resolution of arrhythmias within 1–4 months. No significant demographic or clinical predictors were identified. None of the infants exhibited symptoms (e.g., cyanosis, unresponsiveness) associated with arrhythmia severity. Our study shows that bronchiolitis is associated with significant arrhythmias in infants, particularly sinus arrest, bradycardia and APCs. In our cohort, none of the infants with significant arrhythmia required arrhythmia intervention. Clinicians should be aware of this association and consider delaying decisions regarding pacemaker implantation until after the resolution of bronchiolitis even in cases of infants with severe bradycardia. Future investigations should explore the pathophysiology and prognostic implications of this phenomenon.