Mobitz Type I and First Degree AV Block: When to Permanently Pace?

Purpose: A case report of a patient who presented with an acute onset, fluctuating atrioventricular (AV) block and was diagnosed with Lyme carditis is presented. Summary: A 55-year-old man with progressively worsening generalized malaise, flu-like symptoms, dyspnea on exertion, and near syncope was admitted with bradycardia (heart rate was between 20 and 30 beats per minute upon admission). He endorsed having several tick bites after which he developed erythema migrans on his arm and abdomen. An electrocardiogram (ECG) revealed a second-degree AV block, fluctuating between Mobitz type I and Mobitz type II heart block, with a P-R interval of 300 ms. A presumptive diagnosis of Lyme carditis was made based on a confirmed history of tick exposure, presence of erythema migrans, and AV block. The patient was started on ceftriaxone. On day 3 of hospitalization, patient’s heart rate was between 50 and 60 beats per minute. A diagnosis of Lyme disease was confirmed based on serologic testing. A repeat ECG revealed a first-degree AV block with a P-R interval of 300 ms. On day 5 of hospitalization, a peripherally inserted central catheter line was placed and the patient was discharged to his home on a 28-day course of ceftriaxone. Patient’s heart rate was 65 beats per minute on discharge day. Conclusion: Considering Lyme carditis as a differential diagnosis in patients with an AV block of an unknown etiology can result in a timely diagnosis and treatment of Lyme carditis.

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AV Block Second Degree Mobitz Type I

10.32388/q310ml ◽

2020 ◽

Author(s):

Keyword(s):

Type I ◽

Av Block ◽

Mobitz Type ◽

Second Degree

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Bradyarrhythmias

10.1093/med/9780199568741.003.0119 ◽

2018 ◽

Author(s):

Kim Rajappan

Keyword(s):

Heart Rate ◽

Sick Sinus Syndrome ◽

Sinus Bradycardia ◽

Sinus Node ◽

Ventricular Rate ◽

Type I ◽

Av Block ◽

Node Disease ◽

Wenckebach Phenomenon ◽

Mobitz Type

A bradyarrhythmia is defined as a rhythm disturbance that results in a heart rate of less than 60 bpm. It is important to note that many healthy people have a resting heart rate that is less than 60 bpm, most commonly due to sinus bradycardia (i.e. a rhythm arising from the sinus node but with a ventricular rate less than 60 bpm). Other forms of bradyarrhythmia are sinus node disease, sick sinus syndrome, first-degree atrioventricular (AV) block, second-degree AV block (which can be characterized as Möbitz type I (Wenckebach phenomenon) or Möbitz type II), and third-degree AV block (also known as complete heart block). This chapter discusses the bradyarrhythmias, focusing on their etiology, symptoms, demographics, diagnosis, prognosis, and treatment.

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Implantable loop recorder follow-up

European Heart Journal ◽

10.1093/eurheartj/ehab724.0318 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

J Pena Mellado ◽

R Macias ◽

L Tercedor ◽

M Alvarez Lopez

Keyword(s):

Head Trauma ◽

Type I ◽

Av Block ◽

Implantable Loop Recorder ◽

Ecg Monitoring ◽

Loop Recorder ◽

Tertiary Center ◽

Unexplained Syncope ◽

Baseline Characteristics

Abstract Introduction Long ambulatory ECG monitoring can be a useful component in the evaluation of the patient with unexplained syncope or syncope with suspected arrhythmic origin, as well as a sensitive tool for detecting asymptomatic spontaneous cardiac arrhythmias or conduction abnormalities in predisposed patients. Purpose To determine the diagnostic cost-effectiveness of the implantable loop recorder (ILR) in the origin of unexplained syncope in our center. Methods A retrospective observational study was carried out in a tertiary center, those patients with an ILR between August 2014 and March 2021 were included. Baseline characteristics of the population and their previous ECG, arrythmias detected during follow-up and pacemaker implant rate were evaluated. Results One hundred twenty-seven patients with a ILR were included (age 67 years, 49.6% males). Most often cause of ILR was unexplained syncope (90.6%) followed by monitoring after TAVI implant (3.9%). Normal LVEF (>50%) was present in 85.6%,and 75.6% had NYHA I functional class. 118 patients (92.9%) presented sinus rhythm at implant time, and 8 (6.3%) presented AF. 12.6% presented first degree atrioventricular (AV) block, 2 patients (1.6%) had presented previously Mobitz Type I AV block and one patient 2:1 block. Left bundle branch block (LBBB) was present in 13.4%,RBBB in 3.1%,LAFB in 9.4%, RBBB+LAFB in 11% and RBBB+LPFB in 2.4%. Median time of follow-up was 21 months. 3rd degree AV block was the most frequent arrhythmia detected (12.1%), followed by >3s pause (8%) and previously unknown AF (2.4%).The patients with syncope who suffered head trauma (33%) presented a higher rate of pacemaker (PCM) implant compared to those without head trauma: 31.6% vs 14.7%. In total,19.8% PCM rate implant during follow-up. No complications ILR related. Conclusion In conclusion, long home ECG monitoring with ILR is a powerful and helpful tool to find out or rule out potentially dangerous arrhythmias as cause of syncope, with no complications in our experience. FUNDunding Acknowledgement Type of funding sources: None. Baseline characteristics Arrhythmias detected during follow-up

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Vagally Induced Second Degree A-V Block Mobitz Type I, and the Hyporeactive SA Node

CHEST Journal ◽

10.1378/chest.62.2.152 ◽

1972 ◽

Vol 62 (2) ◽

pp. 152-155 ◽

Cited By ~ 20

Author(s):

Miguel Gambetta ◽

Pablo Denes ◽

Roderick W. Childers

Keyword(s):

Type I ◽

Sa Node ◽

Mobitz Type ◽

Second Degree

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Atrioventricular conduction abnormalities and atrioventricular blocks: ECG patterns and diagnosis

10.1093/med/9780198784906.003.0453 ◽

2018 ◽

Author(s):

S. Serge Barold

Keyword(s):

P Wave ◽

Conduction Time ◽

Type I ◽

Type Ii ◽

Av Block ◽

Ventricular Extrasystoles ◽

Av Conduction ◽

Pr Interval ◽

Before And After ◽

Second Degree

The diagnosis of first-degree and third-degree atrioventricular (AV) block is straightforward but that of second-degree AV block is more involved. Type I block and type II second-degree AV block are electrocardiographic patterns that refer to the behaviour of the PR intervals (in sinus rhythm) in sequences (with at least two consecutive conducted PR intervals) where a single P wave fails to conduct to the ventricles. Type I second-degree AV block describes visible, differing, and generally decremental AV conduction. Type II second-degree AV block describes what appears to be an all-or-none conduction without visible changes in the AV conduction time before and after the blocked impulse. The diagnosis of type II block requires a stable sinus rate, an important criterion because a vagal surge (generally benign) can cause simultaneous sinus slowing and AV nodal block, which can resemble type II block. The diagnosis of type II block cannot be established if the first post-block P wave is followed by a shortened PR interval or by an undiscernible P wave. A narrow QRS type I block is almost always AV nodal, whereas a type I block with bundle branch block barring acute myocardial infarction is infranodal in 60–70% of cases. All correctly defined type II blocks are infranodal. A 2:1 AV block cannot be classified in terms of type I or type II block, but it can be AV nodal or infranodal. Concealed His bundle or ventricular extrasystoles may mimic both type I or type II block (pseudo-AV block), or both

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