Mobitz type 1
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Understanding Mobitz Type 1 Atrioventricular Block
Introduction to Mobitz Type 1 Atrioventricular Block
Mobitz Type 1, also known as Wenckebach block, is a type of second-degree atrioventricular (AV) block characterized by progressive prolongation of the PR interval until a beat is dropped. This condition can manifest in various clinical scenarios and patient demographics, ranging from benign to potentially serious outcomes.
Mobitz Type 1 in Children and Adolescents
Initial Presentation in Multisystem Inflammatory Syndrome in Children (MIS-C)
Mobitz Type 1 can be an initial presentation of Multisystem Inflammatory Syndrome in Children (MIS-C), a severe condition associated with COVID-19. This highlights the importance of considering cardiac conduction abnormalities in pediatric patients presenting with systemic inflammatory symptoms 1.
Prognosis and Progression in Young Patients
In children and adolescents, Mobitz Type 1 is often considered benign, especially in the absence of overt heart disease or drug intoxication. However, long-term follow-up studies indicate that it can progress to more severe forms of heart block, including complete heart block, suggesting that it may represent significant underlying cardiac conduction system disease 4. This progression underscores the need for careful monitoring in young patients diagnosed with Mobitz Type 1.
Mobitz Type 1 in Adults
Discrepancies in Pacing Guidelines
There is a notable discrepancy between North American and European guidelines regarding the management of Mobitz Type 1 in adults. North American guidelines generally classify it as a Class 3 indication for permanent pacing unless electrophysiological studies indicate a block below the His bundle. In contrast, European guidelines recommend pacing as a Class 2A indication, particularly in older patients 2. This difference is partly due to evidence suggesting that older patients with Mobitz Type 1 have similar mortality rates to those with Mobitz Type 2 and may benefit from pacing 2.
Prognosis and Need for Pacing
Mobitz Type 1 is not always benign in adults, particularly those aged 45 and older. Studies have shown that unpaced patients have reduced survival rates compared to the general population, and those who receive pacemakers tend to fare better 8. This suggests that pacemaker implantation should be considered even in the absence of symptomatic bradycardia or organic heart disease, especially in older adults 8.
Case Reports and Special Considerations
Tejocote Root Toxicity
A compelling case report highlights the potential cardiovascular repercussions of Tejocote root consumption, an over-the-counter laxative. A patient presented with Mobitz Type 1 heart block and detectable Digoxin levels, which resolved after treatment with atropine. This case emphasizes the importance of clinical awareness regarding herbal supplement usage and its potential to cause significant cardiac issues 3.
Anorexia Nervosa
Anorexia nervosa (AN) can lead to various cardiac complications, including Mobitz Type 1. A case report of a 12-year-old girl with AN presented with symptomatic Mobitz Type 1, suggesting that this condition can be an acquired conduction abnormality related to the severe metabolic and structural changes associated with AN 7.
Conclusion
Mobitz Type 1 AV block presents a complex clinical picture that varies significantly across different patient populations. While often benign in younger individuals, it can progress to more severe forms of heart block and may require careful monitoring and intervention. In adults, particularly those over 45, the condition is associated with reduced survival rates, and pacemaker implantation should be considered. Awareness of potential external factors, such as herbal supplements and underlying conditions like anorexia nervosa, is crucial for timely diagnosis and management.
Sources and full results
Most relevant research papers on this topic
Mobitz Type I as the Initial Presentation of Multisystem Inflammatory Syndrome in Children
Mobitz Type I is the initial presentation of multisystem inflammatory syndrome in children, with a high prevalence in the first year of life.
Mobitz type 1 second degree atrioventricular block: the value of permanent pacing in the older patient
European guidelines recommend permanent pacing for Mobitz type 1 atrioventricular block, while North American guidelines classify it as a Class 3 indication, despite evidence from the Devon Heart study showing improved survival in older patients with the condition.
Rigorous JournalTejocote Root's Role in Symptomatic Mobitz Type 1 Heart Block: A Compelling Case Report
Tejocote root consumption can cause Mobitz Type 1 heart block, highlighting the need for increased clinical awareness and heightened clinical awareness in areas where herbal supplement usage is prevalent.
Case ReportWenckebach atrioventricular block (Mobitz type I) in children and adolescents.
Wenckebach atrioventricular block is more common than previously recognized in children and adolescents, often representing significant cardiac conduction system disease with a guarded prognosis.
Case ReportMobitz type I atrioventricular block in the ventricular specialized conduction system.
Electrophysiologic studies are recommended for patients with Mobitz type I atrioventricular block and bundle branch block to rule out potential conduction system abnormalities.
Case ReportWoldemar Mobitz and His 1924 classification of second-degree atrioventricular block.
Mobitz's classification of second-degree atrioventricular block into two types, Mobitz type I (Wenckebach) and Mobitz type II (Hay), differentiates between reversible type I and complete type II, with implications for treatment and prevention.
Second-degree atrioventricular block (Mobitz Type I) in an adolescent with anorexia nervosa: intrinsic or acquired conduction abnormality.
Second-degree atrioventricular block (Mobitz Type I) is a potential complication of anorexia nervosa and an intrinsic conduction system disease in adolescents.
Case Report
Some Examples of Wenckebach Periodicity in Cardiac Tissues, with an Appraisal of Mechanisms
Wenckebach periodicity in cardiac tissues occurs when atrioventricular nodal conductivity temporarily restitution leads to a new cycle of P-R intervals, resulting in Mobitz type 1 AV block.
Mobitz type I 2nd degree atrioventricular (Wenckebach) block and cardiovascular death using 978,901 12 lead ECGs recordings
Wenckebach type I 2nd degree atrioventricular block is associated with a higher risk of cardiovascular death compared to patients with normal ECGs.
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