Glikson M, Nielsen JC, Kronborg MB, et al; ESC Scientific Document Group. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. Eur Heart J. 2021 Sep 14;42(35):3427-3520. doi: 10.1093/eurheartj/ehab364. Erratum in: Eur Heart J. 2022 May 1;43(17):1651. PMID: 34455430.
Cronin EM, Bogun FM, Maury P, et al; ESC Scientific Document Group. 2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias. Europace. 2019 Aug 1;21(8):1143-1144. doi: 10.1093/europace/euz132. Erratum in: Europace. 2019 Aug 1;21(8):1144. Erratum in: J Arrhythm. 2020 Jan 12;36(1):214. Erratum in: Europace. 2020 Mar 1;22(3):505. PMID: 31075787; PMCID: PMC7967791.
Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2018 Sep 25;138(13):e272-e391. doi: 10.1161/CIR.0000000000000549. Erratum in: Circulation. 2018 Sep 25;138(13):e419-e420. PMID: 29084731.
Bennett M, Parkash R, Nery P, et al. Canadian Cardiovascular Society/Canadian Heart Rhythm Society 2016 Implantable Cardioverter-Defibrillator Guidelines. Can J Cardiol. 2017 Feb;33(2):174-188. doi: 10.1016/j.cjca.2016.09.009. Epub 2016 Oct 6. PMID: 28034580.
Priori SG, Wilde AA, Horie M, et al. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm. 2013 Dec;10(12):1932-63. doi: 10.1016/j.hrthm.2013.05.014. Epub 2013 Aug 30. Review. PubMed PMID: 24011539.
Definition, Etiology, PathogenesisTop
Cardiomyopathies with or without depressed left ventricular (LV) function may be associated with ventricular arrhythmias, most commonly paroxysmal monomorphic ventricular tachycardia (VT). These arrhythmias are more common in the presence of a myocardial scar.
Patients with dilated or hypertrophic cardiomyopathy can present with monomorphic VT or with ventricular fibrillation (VF) usually coming from the LV. In arrhythmogenic right ventricular cardiomyopathy, monomorphic VT is most frequently originating in the right ventricle, thus having a left bundle branch block (LBBB) appearance.
Clinical Features and Natural HistoryTop
Clinical features depend on the VT rate and severity of cardiomyopathy. VT episodes may be recurrent and increase the risk of sudden cardiac death (SCD).
Like in patients after myocardial infarction (MI), the myocardial origin of the monomorphic VT can be inferred by the electrocardiographic (ECG) appearance (right bundle branch block [RBBB]-like vs LBBB-like when coming from the left or right ventricle, respectively) and the axis (superior if QRS is negative in the inferior leads or inferior if positive in the inferior leads).
Bundle branch reentrant VT is a rare type of VT that can occur in patients with cardiomyopathy and abnormal His-Purkinje conduction (wide baseline QRS). It is a circuit that uses both bundle branches. Usually the myocardium is activated by the right bundle, which is why the VT has an LBBB appearance.
Classification of antiarrhythmic drugs: see Table 3.4-1.
Antiarrhythmic agents: see Table 3.4-2.
1. Treatment includes beta-blockers and antiarrhythmics, usually amiodarone or sotalol. Class I antiarrhythmic agents (flecainide, propafenone) are generally contraindicated in these cases. Ablation may reduce the burden of VT, although results are not as good as in ischemic VT ablation. An implantable cardioverter-defibrillator (ICD) is almost always indicated in patients who have had VT or VF episodes and in specific populations as a prophylactic indication (based on LV ejection fraction). Indications for prophylactic ICD implantation in patients with cardiomyopathy to prevent SCD: see Sudden Cardiac Death.
2. In patients with bundle branch reentrant VT, the recommended treatment is catheter ablation. Patients may require permanent pacing after the procedure. Antiarrhythmic therapy is usually ineffective.