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. PMID: 34455430.
Stiles MK, Wilde AAM, Abrams DJ, et al. 2020 APHRS/HRS expert consensus statement on the investigation of decedents with sudden unexplained death and patients with sudden cardiac arrest, and of their families. Heart Rhythm. 2021 Jan;18(1):e1-e50. doi: 10.1016/j.hrthm.2020.10.010. Epub 2020 Oct 19. PMID: 33091602; PMCID: PMC8194370.
Kusumoto FM, Schoenfeld MH, Barrett C, et al. 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. Heart Rhythm. 2019 Sep;16(9):e128-e226. doi: 10.1016/j.hrthm.2018.10.037. Epub 2018 Nov 6. PMID: 30412778.
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: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2018 Oct;15(10):e190-e252. doi: 10.1016/j.hrthm.2017.10.035. Epub 2017 Oct 30. Erratum in: Heart Rhythm. 2018 Sep 26;: PMID: 29097320.
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 and EtiologyTop
Sudden cardiac death (SCD) is defined as death due to cardiac causes preceded by a sudden loss of consciousness in a patient in whom a change in clinical status heralding cardiac arrest was observed ≤1 hour prior to SCD.
Causes: SCD is usually triggered by malignant ventricular arrhythmias that may be caused by ischemic heart disease (IHD), any type of cardiomyopathy, congenital heart disease, or genetic channelopathy (eg, long QT, Brugada pattern). IHD is the most common cause (in 80% of patients). Severe left ventricular dysfunction significantly increases the risk of SCD.
1. Prevention of ischemia in IHD patients.
2. Prevention of specific triggers according to the disorders listed above (eg, QT-prolonging drugs in patients with long QT syndrome).
3. Placement of an implantable cardioverter-defibrillator (ICD) for prevention of SCD is recommended in high-risk patients with life expectancy >1 year and good functional status, in jurisdictions where the device is available. High-risk patients include:
1) Patients ≥40 days after myocardial infarction (MI) with a left ventricular ejection fraction (LVEF) ≤35%.
2) Patients with dilated nonischemic cardiomyopathy with an LVEF ≤35% and New York Heart Association (NYHA) class II or III heart failure (see Table 3.8-1).
ICD implantation in survivors of SCD unless a reversible cause (eg, acute phase of MI, drug-related QT prolongation, bradycardia-induced polymorphic ventricular tachycardia) or noncardiac cause is documented.
For the investigation of SCD of unclear cause, a detailed personal and family history is essential, with attention to sentinel symptoms during life such as syncope or seizures, witness accounts, premorbid investigations, and inspection of any cardiac rhythm monitoring around the time of death.
For victims of SCD or survivors of cardiac arrest with a known or suspected form of cardiomyopathy (other than IHD), genetic testing of the proband focused on likely candidate genes, along with clinical evaluation of family members, aids in identifying family members with or at risk of the same condition.