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Circulation. 2018;138:e272–e391. DOI: 10.1161/CIR.0000000000000549 September 25, 2018 e285 CLINICAL STATEMENTS AND GUIDELINES

symptoms, particularly in patients with known or discovered structural or electrical heart disease should prompt focused investigation for possible association with VA (Table 6). The elucidation of precipitating factors, such as exertional or emotional stress, concurrent medications or illness, and alleviating factors is important. The presence of a family history of SCD, ischemic heart disease, valvular heart disease, nonischemic cardiomyopathy (NICM), or HF raises concern for the presence of one of these disorders associated with VA. Obtaining a complete medication history is important. Various antiarrhythmic and other medications can cause QT prolongation and torsades de pointes (www.crediblemeds.org)S4.1-8; some medications can also induce Brugada type I electrocardiographic pattern and VF (www.brugadadrugs.org).S4.1-9,S4.1-10 Patients with bigeminy and trigeminy can present with effective bradycardia, an apical-radial pulse deficit and relative hypertension with a wide pulse pressure. Effective bradycardia from PVCs can result in inaccurate estimation of the heart rate. Although premature beats on auscultation of the heart can be detected, the physical examination is focused largely on finding evidence of structural heart disease. Carotid bruits or diminished peripheral pulses may be indicators of atherosclerotic disease associated with ischemic heart disease. Jugular venous distention, rales, gallops, and peripheral edema provide evidence of HF. Auscultation may reveal cardiac murmurs consistent with valvular heart disease, such as aortic stenosis or mitral regurgitation, and may be associated with HF and VA. A midsystolic click may indicate mitral valve prolapse that can be associated with VA.S4.1-11–S4.1-13 Many VA are asymptomatic and detected only on an ECG or telemetry. Such cases highlight the need to search for evidence of underlying heart disease.

Recommendation-Specific Supportive Text

1.	Rapid, sustained VT may result in syncope secondary to marked reduction in cardiac output,

Table 6.  Important Considerations in the Evaluation of Patients With Known or Suspected VA

Component Assessment and Findings Relevant

for VA and/or SCD Risk

History 1. Symptoms/events related to arrhythmia: Palpitations, lightheadedness, syncope, dyspnea, chest pain, cardiac arrest

2. Symptoms related to underlying heart disease: Dyspnea at rest or on exertion, orthopnea, paroxysmal nocturnal dyspnea, chest pain, edema

3 Precipitating factors: Exercise, emotional stress

4. Known heart disease: Coronary, valvular (eg, mitral valve prolapse), congenital heart disease, other 5. Risk factors for heart disease: Hypertension, diabetes mellitus, hyperlipidemia, and smoking

6 Medications

Antiarrhythmic medications Other medications with potential for QT

prolongation and torsades de pointes Medications with potential to provoke or

aggravate VA Stimulants including cocaine and amphetamines Supplements including anabolic steroids Medication-medication interaction that could cause

QT prolongation and torsades de pointes

7 Past medical history

Thyroid disease Acute kidney injury, chronic kidney disease, or

electrolyte abnormalities Stroke or embolic events Lung disease Epilepsy (arrhythmic syncope can be misdiagnosed

as epilepsy) Alcohol or illicit drug use Use of over-the-counter medications that could

cause QT prolongation and torsades de pointes Unexplained motor vehicle crashes

Family History 1. SCD, SCA, or unexplained drowning in a first-degree relative

2. SIDS or repetitive spontaneous pregnancy losses given their potential association with cardiac channelopathies

3 Heart disease

IHD Cardiomyopathy: Hypertrophic, dilated, ARVC Congenital heart disease Cardiac channelopathies: Long QT, Brugada, Short

QT, CPVT Arrhythmias Conduction disorders, pacemakers/ICDs

4 Neuromuscular disease associated with cardiomyopathies

Muscular dystrophy

5 Epilepsy

(Continued ) Examination 1. Heart rate and regularity, blood pressure

2 Jugular venous pressure

3 Murmurs

4 Pulses and bruits

5 Edema

6 Sternotomy scars

ARVC indicates arrhythmogenic right ventricular cardiomyopathy; CPVT, catecholaminergic polymorphic ventricular tachycardia; IHD, ischemic heart disease; SCA, sudden cardiac arrest; SCD, sudden cardiac death; SIDS, sudden infant death syndrome; and VA, ventricular arrhythmia.

Table 6.  Continued

Component Assessment and Findings Relevant

for VA and/or SCD Risk

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