Related Experiment Video

Updated: May 24, 2026

Intratracheal Instillation of Stem Cells in Term Neonatal Rats
04:27

Intratracheal Instillation of Stem Cells in Term Neonatal Rats

Published on: May 4, 2020

Prolonged sinoatrial block in an infant with respiratory syncytial viral bronchiolitis

Wajed Haddad1, Melissa Agoudemous, Sangita Basnet

  • 1Department of Pediatrics, Southern Illinois University School of Medicine, P.O. Box-19676, Springfield, IL 62794-9676, USA.

Pediatric Cardiology
|March 8, 2012
PubMed

Insights

Respiratory syncytial virus (RSV) infection can cause prolonged sinoatrial block in infants. This case report details the longest recorded sinoatrial block event, highlighting a potential link between RSV and cardiac arrhythmias in children.

Area of Science:

  • Pediatrics
  • Infectious Diseases
  • Cardiology

Background:

  • Complete heart block associated with Respiratory Syncytial Virus (RSV) infections in pediatric intensive care units has been previously documented.
  • Sinoatrial (SA) block is a less common cardiac arrhythmia that can occur in infants.

Observation:

  • This case report details an infant experiencing a prolonged sinoatrial block lasting over 4 seconds during an RSV infection.
  • This represents the longest duration of SA block associated with RSV reported in medical literature.
  • Shorter episodes of SA block occurred within 24 hours, with no other identifiable cause for bradycardia found after extensive investigation.

Findings:

  • The infant recovered from the prolonged SA block and remained asymptomatic after discharge.
  • Subsequent 48-hour Holter monitoring showed normal cardiac rhythm.
  • The study suggests a potential causal link between RSV infection and prolonged SA block in healthy infants.

Implications:

  • Respiratory Syncytial Virus infections should be considered as a potential cause of significant sinoatrial block in infants.
  • This finding may prompt closer cardiac monitoring in infants diagnosed with RSV, particularly those presenting with bradycardia.
  • Further research is warranted to understand the mechanisms and long-term cardiac implications of RSV-induced SA block.

Related Concept Videos

Dysrhythmias IV: Characteristics of Bradyarrhythmias01:18

Dysrhythmias IV: Characteristics of Bradyarrhythmias

Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...
Pulmonary Cycle: Exhalation01:17

Pulmonary Cycle: Exhalation

In terms of human respiration, the act of expelling air, known as exhalation (or expiration), operates on the principle of pressure gradients. During expiration, the pressure within the lungs exceeds that of the surrounding atmosphere. Under normal conditions, quiet breathing involves passive exhalation and is free of muscular contractions. This is because the exhalation process is driven by the natural elastic recoil of the lungs and chest wall, both of which have an inherent tendency to...
Acute Respiratory Failure-II01:21

Acute Respiratory Failure-II

Type I Respiratory Failure, or hypoxemic respiratory failure, occurs when the partial pressure of oxygen (PaO2) in arterial blood falls below 60 mmHg while breathing room air without a corresponding increase in arterial carbon dioxide levels (PaCO2). This condition highlights a significant impairment in the lungs' capacity to oxygenate the blood.
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Acute Respiratory Failure-V01:29

Acute Respiratory Failure-V

The treatment for acute respiratory failure varies based on factors like the underlying cause, overall health, and severity. A collaborative healthcare team is essential for early detection, often through arterial blood gas analysis. Identifying the cause is the primary goal, with treatment strategies adjusted for ventilation/perfusion (V/Q) mismatch, shunting, or diffusion impairment.
Ensure that patients are monitored continuously for their response to therapy, including changes in...
Depolarizing Blockers: Pharmocokinetics01:19

Depolarizing Blockers: Pharmocokinetics

Depolarizing blockers are administered through intravenous injection. Succinylcholine is the most common choice of depolarizing blockers in emergency clinical practices. Although they have a rapid onset, they readily diffuse away from the motor end plate into the extracellular fluid. They are metabolized by enzymes such as liver butyrylcholinesterase and plasma pseudocholinesterases. This produces a short duration of action, typically 5-10 minutes long, unlike nondepolarizing blockers, which...
Atelectasis II: Pathophysiology01:10

Atelectasis II: Pathophysiology

Atelectasis develops when alveoli lose their air and collapse inward. Because lung tissue is naturally elastic, these air sacs shrink rather than remaining open. Collapsed alveoli are no longer ventilated, reducing their role in gas exchange. Blood flow may continue in these regions, creating a ventilation–perfusion mismatch. Clinical findings include decreased breath sounds, dullness to percussion, reduced chest expansion, and decreased tactile fremitus as sound transmission through collapsed...