Second degree AV block surgery
Second degree AV block Microchapters |
Diagnosis |
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Treatment |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohammed Salih, M.D., Cafer Zorkun, M.D., Ph.D. [2]; Raviteja Guddeti, M.B.B.S. [3]
Overview
If no reversible causes are present, definitive treatment of Mobitz type II second degree AV block involves permanent pacemaker placement in most patients. Dual-chamber pacing to maintain AV synchrony is preferred (rather than single chamber right ventricular pacing) in most patients due to the favorable hemodynamic benefits of AV synchrony. Unlike asymptomatic patients with Mobitz type I second degree AV block who do not require any specific therapy, patients with Mobitz type II second degree AV block have a high likelihood of progressing to symptomatic Mobitz type II second degree AV block or complete heart block and should be considered candidates for pacemaker insertion on initial presentation.
Patients with Mobitz type II second degree AV block who are hemodynamically stable do not require urgent therapy with atropine or temporary cardiac pacing. However, Mobitz type II second degree AV block is by nature unstable and frequently progresses to third degree (complete) AV block, so patients should be continuously monitored with transcutaneous pacing pads in place in the event of clinical deterioration. While stable patients are being monitored, reversible causes of Mobitz type II second degree AV block such as myocardial ischemia, increased vagal tone, hypothyroidism, hyperkalemia, and drugs that depress conduction, should be excluded in patients prior to implantation of a permanent pacemaker.
Surgery
Management of bradycardia attributable to atrioventricular block
AV block | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Mobitz type1 block | Mobitz type2 block, evidence of infranodal block | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Symtoms | Permanent pacing (class1) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Permanent pacing (class1) | Neuromascular disease associated with progressive conduction disorder | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Permanent pacing (class1) | Observation | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Permanent pacing (class3), Harm | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Risk of ventricular arrhythmia, heart failure symptoms(LVEF<35%) | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Medical therapy | Infrequent pacing? Other comorbidities? | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Single chamber ventricular pacing (class1) | Permanent atrial fibrillation | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Single chamber ventricular pacing | Dual chamber ventricular pacing | ||||||||||||||||||||||||||||||||||||||||||||||||||||
LVEF>50% | |||||||||||||||||||||||||||||||||||||||||||||||||||||
Yes | NO, Predicted pacing>40% | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Right ventricular pacing (class2a) | Pacing for maintaining physiologic function of left ventricle (class2a) | ||||||||||||||||||||||||||||||||||||||||||||||||||||
His bundle pacing (class2b) | |||||||||||||||||||||||||||||||||||||||||||||||||||||
The above algorithm adopted from 2018 AHA/ACC/HRS Guideline[1] |
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Recommendations for management of bradycardia associated atrioventricular block |
(Class III (Harm), Level of Evidence C): |
❑ Permanent pacing is not recommended in patients with first degree atrioventricular block or mobitz type 1 second degree atrioventricular block (wenchebach), or 2:1 atrioventricular block when the level of block is in atrioventricular node or symptoms are not related to atrioventricular block |
Notes
- Common factors associated with implantation of permanent pacemaker include:
- Symptoms related to atrioventricular bradycardia
- Infranodal atrioventricular block that may progress to complete AV block with unstable ventricular scape rhythm
- Side effects of right ventricular pacing
- Permanent pacing may not be effective when the symptoms of dizziness, presyncope, syncope are not related to atrioventricular block in patients with second-degree Mobitz type I (Wenckebach) or 2:1 atrioventricular block.
- When atrioventricular block is above or at the nodal level progression to higher degree atrioventricular block is unlikely.
- First- and second-degree Mobitz type I (Wenckebach) atrioventricular blocks or 2:1 atrioventricular block are benign if the level of block is at the atrioventricular node.[2]
- In the presence of second-degree Mobitz type I (Wenckebach) infranodal atrioventricular block, implantation of pacemaker is considered even in the absence of symptoms.
- For finding the level of the atrioventricular node block whether nodal or intranodal in the narrow QRS complex, EPS is necessary.
- Ambulatory electrocardiographic monitoring or a treadmill exercise test may be useful to determine the correlation of symptoms and atrioventricular block.
- Improvement in atrioventricular conduction with exercise suggests that the site of block is at the atrioventricular node, but worsening atrioventricular conduction suggests infranodal block.
- There is no benefit of implantation of permanent pacacemaker in patients with long-standing asymptomatic persistent or permanent AF with a low heart rate and appropriate chronotropic response.
Mobitz I
Indications for implantation of a pacemaker include[3][4][5]:
- Symptomatic bradycardia
- Heart failure
- Asystole for more than 3 sec
- Pseudopacemaker syndrome: Rarely second degree type I AV block can present with symptoms similar to pacemaker syndrome. In such cases placement of a pacemaker is warranted.
Dual chamber DDD pacing mode is usually employed in patients with Mobitz I and symptomatic bradycardia. This mode maintains the normal physiologic synchrony between the atria and the ventricles unlike the single chamber VVI mode.
Mobitz II
- Type II Mobitz (symptomatic or asymptomatic) is by itself an indication for insertion of a pacemaker. Other indications include[6][7]:
- Myotonic dystrophy
- Kearns-Sayre syndrome
- Erb's dystrophy
- Peroneal muscular atrophy. These neuromuscular disorders have a high potential for unpredictable rapid progression to complete heart block.
- Implantation of permanent pacemakers in both asymptomatic and symptomatic patients is usually done. Asymptomatic Mobitz II are prone to be converted to symptomatic or third degree heart block. Thus, they should be considered for a pacemaker even if asymptomatic.
- A dual chamber DDD pacemaker is preferred over a single chambered VVI pacemakers as it maintains physiologic AV synchrony.
- A dual-chamber artificial pacemaker is a type of device that typically listens for a pulse from the SA node and sends a pulse to the AV node at an appropriate interval, essentially completing the connection between the two nodes. Pacemakers in this role are usually programmed to enforce a minimum heart rate and to record instances of atrial flutter and atrial fibrillation.
References
- ↑ Kusumoto, Fred M.; Schoenfeld, Mark H.; Barrett, Coletta; Edgerton, James R.; Ellenbogen, Kenneth A.; Gold, Michael R.; Goldschlager, Nora F.; Hamilton, Robert M.; Joglar, José A.; Kim, Robert J.; Lee, Richard; Marine, Joseph E.; McLeod, Christopher J.; Oken, Keith R.; Patton, Kristen K.; Pellegrini, Cara N.; Selzman, Kimberly A.; Thompson, Annemarie; Varosy, Paul D. (2019). "2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society". Circulation. 140 (8). doi:10.1161/CIR.0000000000000628. ISSN 0009-7322.
- ↑ Barold SS, Ilercil A, Leonelli F, Herweg B (November 2006). "First-degree atrioventricular block. Clinical manifestations, indications for pacing, pacemaker management & consequences during cardiac resynchronization". J Interv Card Electrophysiol. 17 (2): 139–52. doi:10.1007/s10840-006-9065-x. PMID 17334913.
- ↑ Shigematsu-Locatelli M, Kawano T, Nishigaki A, Yamanaka D, Aoyama B, Tateiwa H, Kitaoka N, Yokoyama M (2017). "General anesthesia in a patient with asymptomatic second-degree two-to-one atrioventricular block". JA Clin Rep. 3 (1): 27. doi:10.1186/s40981-017-0099-0. PMC 5804611. PMID 29457071.
- ↑ Dhingra RC, Palileo E, Strasberg B, Swiryn S, Bauernfeind RA, Wyndham CR, Rosen KM (December 1981). "Significance of the HV interval in 517 patients with chronic bifascicular block". Circulation. 64 (6): 1265–71. doi:10.1161/01.cir.64.6.1265. PMID 7296798.
- ↑ Brignole M, Auricchio A, Baron-Esquivias G, Bordachar P, Boriani G, Breithardt OA, Cleland J, Deharo JC, Delgado V, Elliott PM, Gorenek B, Israel CW, Leclercq C, Linde C, Mont L, Padeletti L, Sutton R, Vardas PE, Zamorano JL, Achenbach S, Baumgartner H, Bax JJ, Bueno H, Dean V, Deaton C, Erol C, Fagard R, Ferrari R, Hasdai D, Hoes AW, Kirchhof P, Knuuti J, Kolh P, Lancellotti P, Linhart A, Nihoyannopoulos P, Piepoli MF, Ponikowski P, Sirnes PA, Tamargo JL, Tendera M, Torbicki A, Wijns W, Windecker S, Kirchhof P, Blomstrom-Lundqvist C, Badano LP, Aliyev F, Bänsch D, Baumgartner H, Bsata W, Buser P, Charron P, Daubert JC, Dobreanu D, Faerestrand S, Hasdai D, Hoes AW, Le Heuzey JY, Mavrakis H, McDonagh T, Merino JL, Nawar MM, Nielsen JC, Pieske B, Poposka L, Ruschitzka F, Tendera M, Van Gelder IC, Wilson CM (August 2013). "2013 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy: the Task Force on cardiac pacing and resynchronization therapy of the European Society of Cardiology (ESC). Developed in collaboration with the European Heart Rhythm Association (EHRA)". Eur. Heart J. 34 (29): 2281–329. doi:10.1093/eurheartj/eht150. PMID 23801822.
- ↑ Kusumoto FM, Schoenfeld MH, Barrett C, Edgerton JR, Ellenbogen KA, Gold MR, Goldschlager NF, Hamilton RM, Joglar JA, Kim RJ, Lee R, Marine JE, McLeod CJ, Oken KR, Patton KK, Pellegrini CN, Selzman KA, Thompson A, Varosy PD (August 2019). "2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society". J. Am. Coll. Cardiol. 74 (7): e51–e156. doi:10.1016/j.jacc.2018.10.044. PMID 30412709.
- ↑ Strasberg B, Amat-Y-Leon F, Dhingra RC, Palileo E, Swiryn S, Bauernfeind R, Wyndham C, Rosen KM (May 1981). "Natural history of chronic second-degree atrioventricular nodal block". Circulation. 63 (5): 1043–9. doi:10.1161/01.cir.63.5.1043. PMID 7471363.