Ventricular arrhythmias
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor: Cafer Zorkun, M.D., Ph.D. [2] Vishnu Vardhan Serla M.B.B.S. [3] Nehal Eid, M.D.[4]
Overview
Ventricular arrhythmias (VAs) are abnormal cardiac rhythms originating from the ventricles, encompassing a spectrum from benign premature ventricular complexes (PVCs) to life-threatening ventricular tachycardia (VT) and ventricular fibrillation (VF). VAs are the most common cause of sudden cardiac death (SCD), which accounts for approximately 50% of all cardiovascular deaths in the United States.[1] The 2017 AHA/ACC/HRS guideline and the 2022 ESC guideline provide the primary frameworks for the evaluation, risk stratification, and management of patients with VAs and for the prevention of SCD.[2]
Historical Perspective
The recognition of ventricular arrhythmias dates to the early days of electrocardiography. The development of the implantable cardioverter-defibrillator (ICD) by Michel Mirowski in the 1980s revolutionized the management of life-threatening VAs. Landmark trials including MADIT, MADIT-II, SCD-HeFT, and AVID established the role of ICDs in both primary and secondary prevention of SCD. The CAST trial in 1989 demonstrated that suppression of PVCs with class IC antiarrhythmic drugs (flecainide, encainide) paradoxically increased mortality in post-myocardial infarction patients, fundamentally changing the approach to pharmacologic management of VAs.
Classification
Ventricular arrhythmias are classified by morphology, duration, and clinical context:[3]
| Type | Definition |
|---|---|
| Premature ventricular complex (PVC) | A premature depolarization originating from the ventricles |
| Nonsustained VT (NSVT) | ≥3 consecutive ventricular beats at a rate >100 bpm lasting 30 seconds and not requiring termination due to hemodynamic compromise |
| Sustained VT | VT lasting ≥30 seconds or requiring termination due to hemodynamic compromise in 30 seconds |
| Monomorphic VT | Sustained VT with a stable single QRS morphology |
| Polymorphic VT | Sustained VT with a changing or multiform QRS morphology at cycle length between 600 and 180 ms |
| Torsades de pointes | Polymorphic VT associated with a prolonged QT or QTc, characterized by twisting of the QRS peaks around the isoelectric line |
| Bundle-branch re-entrant tachycardia | VT due to re-entry involving the His-Purkinje system, usually with LBBB morphology; typically occurs in the setting of cardiomyopathy |
| Bidirectional VT | VT with beat-to-beat alternation in the QRS frontal plane axis; often associated with digitalis toxicity or catecholaminergic polymorphic ventricular tachycardia ↗ |
| Ventricular flutter | Regular ventricular arrhythmia at approximately 300 bpm with monomorphic appearance and no isoelectric interval between successive QRS complexes |
| Ventricular fibrillation | Rapid (usually >300 bpm), grossly irregular ventricular rhythm with marked variability in QRS cycle length, morphology, and amplitude |
| Electrical storm | ≥3 episodes of sustained VT, VF, or appropriate ICD shocks within 24 hours |
Pathophysiology
The mechanisms underlying ventricular arrhythmias include:
Re-entry: The most common mechanism in structural heart disease. Scar tissue from prior myocardial infarction or fibrosis creates zones of slow conduction bordered by areas of functional or anatomic block, forming a re-entrant circuit. The border zone between viable and fibrotic tissue is the typical substrate for monomorphic VT in ischemic cardiomyopathy.[4]
Triggered activity: Caused by afterdepolarizations. Delayed afterdepolarizations (DADs) are the mechanism of outflow tract VT and digitalis-induced arrhythmias. Early afterdepolarizations (EADs) underlie torsades de pointes in the setting of QT prolongation.
Abnormal automaticity: Enhanced automaticity in ventricular tissue, particularly in ischemic or injured myocardium, or in Purkinje fibers.
Channelopathies: Genetic mutations affecting cardiac ion channels (e.g., long QT syndrome, Brugada syndrome ↗, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome) create spatial electrical heterogeneity that predisposes to VF.
Causes
Structural Heart Disease:
Coronary artery disease: The most common cause of VT and VF, accounting for 76–82% of clinically documented cases
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Congenital heart disease (e.g., tetralogy of Fallot ↗)
Valvular heart disease (e.g., aortic stenosis, mitral valve prolapse)
Left ventricular noncompaction
Inherited Channelopathies (Structurally Normal Heart):
Long QT syndrome (LQTS)
Catecholaminergic polymorphic ventricular tachycardia (CPVT)
Short QT syndrome (SQTS)
Idiopathic VF
Idiopathic VT (Structurally Normal Heart):[5]
Outflow tract VT: Right ventricular outflow tract (RVOT) or left ventricular outflow tract (LVOT), including aortic sinus of Valsalva origin
Idiopathic left ventricular tachycardia: Left posterior fascicular (verapamil-sensitive), left anterior fascicular, or high septal fascicular VTach.
Papillary muscle VT
Mitral or tricuspid annular VT
Reversible / Secondary Causes:
Electrolyte abnormalities (hypokalemia, hypomagnesemia, hypocalcemia)
Myocardial ischemia or acute myocardial infarction Drug-induced (QT-prolonging medications, digitalis toxicity, sympathomimetics, class IC antiarrhythmics in structural heart disease)
Thyroid disorders
Cocaine or other stimulant use
Differentiating Ventricular Arrhythmias from Other Diseases
The differential diagnosis of a wide QRS complex tachycardia includes:
| Diagnosis | Key Distinguishing Features |
|---|---|
| Ventricular tachycardia | AV dissociation, capture/fusion beats, concordance in precordial leads, QRS >140 ms (RBBB) or >160 ms (LBBB), northwest axis |
| Supraventricular tachycardia with aberrant conduction | Typical RBBB or LBBB morphology, preceding P waves, prior ECG showing bundle branch block |
| Supraventricular tachycardia with pre-excitation (Wolff-Parkinson-White syndrome) | History of pre-excitation on baseline ECG, irregular rate (pre-excited atrial fibrillation) |
| Pacemaker-mediated tachycardia | Pacing spikes visible, device interrogation confirms diagnosis |
| Artifact | Baseline rhythm visible between artifact deflections, patient clinically stable |
The Brugada algorithm is a widely used stepwise approach for differentiating VT from SVT with aberrancy, with reported sensitivity and specificity exceeding 95%.
Epidemiology and Demographics
SCD accounts for approximately 230,000 to 350,000 deaths per year in the United States. The estimated total annual burden of out-of-hospital cardiac arrest is approximately 356,500, with an additional 209,000 in-hospital cardiac arrests occurring annually.
Age: Risk of SCD in the general population beginning at age 35 is estimated at approximately 1 per 1,000 per year. In children, adolescents, and young adults, the annual risk is approximately 1 per 100,000.
Sex: SCD is more common in men than in women across all age groups.
Underlying substrate: Ischemic heart disease remains the most common substrate associated with SCD, although its relative contribution appears to be decreasing, with various forms of cardiomyopathy increasing.
PVCs: Found on longer-term monitoring in approximately 50% of all people with or without heart disease. Frequent PVCs (≥1 PVC on a 12-lead ECG or >30 PVCs per hour) are associated with increased cardiovascular risk and mortality.
Risk Factors
Reduced left ventricular ejection fraction (LVEF)
Prior myocardial infarction
Family history of SCD
Inherited cardiomyopathy or channelopathy
Electrolyte abnormalities
QT-prolonging medications
Stimulant drug use
Natural History, Complications, and Prognosis
The prognosis of ventricular arrhythmias depends on the underlying substrate:
PVCs in structurally normal hearts: Generally benign prognosis. Very frequent PVCs (>10,000–20,000 per day) may cause PVC-induced cardiomyopathy, which is potentially reversible with PVC suppression. NSVT: In the absence of structural heart disease, prognosis is generally favorable. In patients with ischemic or nonischemic cardiomyopathy, NSVT is associated with increased risk of SCD.[6] Sustained VT/VF: Associated with high mortality without treatment. Electrical storm is associated with increased mortality. Out-of-hospital cardiac arrest: Overall survival rate is estimated at approximately 10%. Survival is better when the initial rhythm is shockable (VF or pulseless VT) compared with pulseless electrical activity or asystole. Idiopathic VT: Outflow tract VT and fascicular VT in structurally normal hearts carry an excellent prognosis.
Management
Patients Without Heart Disease
In the absence of heart disease, PVCs are associated with little or no increased risk of developing a dangerous arrhythmia. In this situation, the risk-to-benefit ratio of antiarrhythmic drug therapy does not support routine treatment.[7] It is important to review medications, determine if stimulants are being used, and correct electrolyte abnormalities. If no underlying cause is found, the optimal approach is patient reassurance. Patients should be made aware of the potential dangers of antiarrhythmic drug therapy as determined in the Cardiac Arrhythmia Suppression Trials (CAST and CAST II).[8] [9]
CAST showed that the risk of dying increased, rather than decreased, with successful long-term suppression of premature ventricular complexes after myocardial infarction in older patients. At best, CAST II showed no impact on long-term survival from drug treatment that successfully suppressed premature ventricular complexes. If patients with multiple premature ventricular complexes have severe, disabling symptoms, beta blockers are the safest initial choice.Referral to a cardiologist is indicated if beta-blocker therapy is not effective. In this situation, the next agents to be tried would be class I antiarrhythmic drugs, such as flecainide (Tambocor) and amiodarone (Cordarone), although radiofrequency ablation of an ectopic focus may also be an appropriate treatment.
Patients with Structural Heart Disease
The occurrence of premature ventricular complexes in patients with structural heart disease has been shown to significantly increase the risk of subsequent morbidity and mortality. Coronary heart disease, cardiomyopathy, and congestive heart failure are the major cardiac diseases associated with unfavorable outcomes in patients with premature ventricular complexes.
Ventricular Tachycardia
Ventricular tachycardia refers to a rhythm originating from a ventricular ectopic focus at a rate >100 bpm. The electrocardiogram shows a wide complex tachycardia with no associated P waves.
In patients with bundle branch block,Wolff-Parkinson-White syndrome, or aberrant conduction, supraventricular tachycardia can resemble ventricular tachycardia. Because of the morbidity and mortality associated with untreated ventricular tachycardia, any wide-complex tachycardia should be assumed to be ventricular tachycardia until proved otherwise. Physicians should keep in mind that patients with ventricular tachycardia can have minimal symptoms.
Management of Ventricular Tachycardia
The mortality rate within two years is reported to be higher than 30% in patients with non sustained ventricular tachycardia on Holter monitoring and impaired left ventricular function.[10] Two large multicenter trials [11] [12] showed a clear advantage for automatic cardioverter defibrillator implantation over drug therapy in patients who had a malignant ventricular arrhythmia or who had been resuscitated from sudden cardiac death. The selection of high-risk patients for defibrillator implantation should be based on left ventricular function and the findings of electrophysiologic studies.
Implantable defibrillators appear to be most beneficial in patients with a low ejection fraction who are noted to have frequent premature ventricular complexes, non sustained ventricular tachycardia on Holter monitoring, and a history of syncope or nearsyncope. It is critical to rule out coronary heart disease and to optimize the treatment of congestive heart failure in these patients. When ventricular tachycardia is diagnosed in relatively asymptomatic patients, medical treatment should be attempted. New recommendations from the American Heart Association [13] emphasize the initial use of 300 mg of iv. administered amiodarone, followed by repeated 150 mg iv. doses every 8-10 minutes, in patients with pulseless VT.
Patients with stable ventricular tachycardia should be given 150 mg of amiodarone intravenously over 10 minutes, followed by an infusion at 1 mg/minute for 6 hours and then at 0.5 mg/minute until the VT converts to sinus rhythm or another less dangerous rhythm. The alternative treatment is intravenously administered lidocaine (Xylocaine), given first in a 100 mg bolus (or 1 mg/kg) and then in an infusion at 1-4 mg/minute.
In hemodynamically unstable patients, electrical cardioversion should be attempted in accordance with the recently revised advanced cardiac life support (ACLS) protocols.
Automatic implantable cardioverter defibrillators (ICD) are considered the most effective treatment for patients with life-threatening VT or VF. According to expert recommendations, implantation of an automatic cardioverter defibrillator should be considered in these situations[14]:
1. Cardiac arrest resulting from ventricular fibrillation or tachycardia not caused by a transient or reversible cause
2. Spontaneous, sustained ventricular tachycardia
3. Syncope of undetermined origin and sustained VT or ventricular fibrillation (VF) induced during electrophysiologic studies
4. Non sustained VT with coronary artery disease and LV dysfunction if VT or VF is induced during electrophysiologic studies.
Diagnostic Evaluation (2017 AHA/ACC/HRS)
12-Lead ECG and Exercise Testing (2017 AHA/ACC/HRS)
| Class I |
| 1. In patients with sustained, hemodynamically stable, wide complex tachycardia, a 12-lead ECG during tachycardia should be obtained. (Level of Evidence: B-NR) |
| 2. In patients with VA symptoms associated with exertion, suspected ischemic heart disease, or [[[catecholaminergic polymorphic ventricular tachycardia](https://www.openevidence.com/rare-disease/catecholaminergic-polymorphic-ventricular-tachycardia)]], exercise treadmill testing is useful to assess for exercise-induced VA. (Level of Evidence: B-NR) |
| 3. In patients with suspected or documented VA, a 12-lead ECG should be obtained in sinus rhythm to look for evidence of heart disease. (Level of Evidence: B-NR) |
Note: The 2017 AHA/ACC/HRS guideline states that data on the use of microvolt T-wave alternans (TWA) and the signal-averaged ECG (SAECG) are inconclusive, and as such these tests are not routinely used in clinical practice; the one exception is the potential use of SAECG in patients with arrhythmogenic right ventricular cardiomyopathy.
Ambulatory Electrocardiography (2017 AHA/ACC/HRS)
| Class I |
| 1. Ambulatory electrocardiographic monitoring is useful to evaluate whether symptoms, including palpitations, presyncope, or syncope, are caused by VA. (Level of Evidence: B-NR) |
A 24-hour continuous Holter monitor recording is appropriate when symptoms occur at least once a day or when quantitation of PVCs/NSVT is desired to assess possible VA-related depressed ventricular function. For sporadic symptoms, event or "looping" monitors are more appropriate because they can be activated over extended periods of time and increase diagnostic yield. Adhesive patch electrocardiographic monitors can record for weeks and allow for continuous short-term 1-lead monitoring and patient activation for symptoms. Importantly, when the suspicion of VA in a patient is high, outpatient ambulatory monitoring is inappropriate as prompt diagnosis and prevention of VA are warranted.
Implanted Cardiac Monitors (2017 AHA/ACC/HRS)
| Class IIa |
| 1. In patients with sporadic symptoms (including syncope) suspected to be related to VA, implanted cardiac monitors can be useful. (Level of Evidence: B-R) |
Implanted cardiac monitors provide continuous rhythm monitoring and stored recordings of electrograms based on patient activation or preset parameters, allowing a prolonged monitoring period of a few years. They are generally reserved for patients in whom other ambulatory monitoring is nonrevealing due to the infrequency of events. A 25% added yield in diagnosis has been described after an unrevealing external ambulatory monitor.
Noninvasive Cardiac Imaging (2017 AHA/ACC/HRS)
| Class I |
| 1. In patients with known or suspected VA that may be associated with underlying structural heart disease or a risk of SCA, echocardiography is recommended for evaluation of cardiac structure and function. (Level of Evidence: B-NR) |
| Class IIa |
| 1. In patients presenting with VA who are suspected of having structural heart disease, cardiac magnetic resonance imaging (MRI) or computed tomography (CT) can be useful to detect and characterize underlying structural heart disease. (Level of Evidence: C-EO) |
Cardiac magnetic resonance imaging allows for evaluation of structural heart disease and assessment of LV and RV function including quantification of LVEF, LV mass and volume, valvular structure and coronary anatomy. Cardiac MRI can be useful in the evaluation for myocardial scar and infiltrative processes evident as late gadolinium enhancement and is particularly useful in arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy.
The 2022 ESC guideline places greater emphasis on CMR as part of the diagnostic evaluation, including in hypertrophic cardiomyopathy, in inconclusive cases, and in patients with suspected PVC-induced cardiomyopathy to rule out underlying structural heart disease.[17]
Electrophysiological Study (2017 AHA/ACC/HRS)
| Class IIa |
| 1. In patients with ischemic cardiomyopathy, NICM, or adult congenital heart disease who have syncope or other VA symptoms and who do not meet indications for a primary prevention ICD, an electrophysiological study can be useful for assessing the risk of sustained VT. (Level of Evidence: B-R) |
| Class III: No Benefit |
| 1. In patients who meet criteria for ICD implantation, an electrophysiological study for the sole reason of inducing VA is not indicated for risk stratification. (Level of Evidence: B-R) |
| 2. An electrophysiological study is not recommended for risk stratification for VA in the setting of long QT syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, or early repolarization syndromes. (Level of Evidence: B-NR) |
With the advent of the ICD and its proven benefit in the primary and secondary prevention of SCD, there are fewer indications for programmed stimulation to provoke VA. Patients with heart failure and LVEF ≤35% generally will have an indication for an ICD and specific induction of VT/VF before implantation is not necessary. Patients with LVEF 35% and unexplained syncope or near-syncope may benefit from an electrophysiological study to determine if VT/VF is the cause of symptoms and to guide further therapy.
Management of Special Patient Populations:
2017 AHA/ACC/HRS and 2023 HRS Guidelines for Ventricular Arrhythmias in Pregnancy[18]
| Class I |
| 1. In mothers with long QT syndrome, a beta blocker should be continued during pregnancy and throughout the postpartum period including in women who are breastfeeding. (Level of Evidence: B-NR) |
| 2. In the pregnant patient with sustained VA, electrical cardioversion is safe and effective and should be used with standard electrode configuration. (Level of Evidence: C-EO) |
| Class IIa |
| 1. In pregnant patients needing an ICD or VT ablation, it is reasonable to undergo these procedures during pregnancy, preferably after the first trimester. (Level of Evidence: B-NR) |
The risk of SCA or SCD is significantly higher during the 9 months after delivery, most notably among women with LQT2. A large retrospective analysis from the long QT syndrome registry demonstrated an odds ratio of 40.8 for syncope, SCA, or SCD among women with long QT syndrome in the 9 months postpartum; treatment with beta blockers during pregnancy was independently associated with decreased risk.
The 2023 HRS Expert Consensus Statement on the Management of Arrhythmias During Pregnancy provides more detailed and expanded recommendations for ventricular arrhythmias in pregnancy:[19]
| Class I |
| 1. In pregnant patients with sustained VT and hemodynamic compromise, direct current cardioversion is recommended, with energy dosing as in the nonpregnant patient. (Level of Evidence: C-LD) |
| 2. In pregnant patients with idiopathic VT and hemodynamic stability, intravenous beta blocker or adenosine for outflow tract VT and intravenous verapamil for fascicular VT are recommended as first-line options. (Level of Evidence: C-LD) |
| 3. In pregnant patients with hemodynamically stable VT, when pharmacological therapy is deemed necessary, intravenous procainamide is recommended for acute therapy. (Level of Evidence: C-LD) |
| 4. In pregnant patients with sustained VT refractory or with contraindications to beta blockers and/or other antiarrhythmic drugs, synchronized cardioversion is recommended, with energy dosing as in the nonpregnant patient. (Level of Evidence: C-LD) |
| 5. In pregnant patients who meet indications for ICD placement due to sustained ventricular arrhythmias or due to high risk for sudden cardiac death, device implantation is recommended with attention to and techniques for eliminating or minimizing radiation exposure to as low as reasonably achievable. (Level of Evidence: C-LD) |
| 6. In pregnant patients with ICDs prior to pregnancy, it is recommended to continue routine ICD care according to the underlying cardiac substrate. (Level of Evidence: C-LD) |
| 7. In women who are considering pregnancy and would otherwise meet indications for ICD, pacemaker, or cardiac resynchronization therapy device placement, these procedures should be performed prior to pregnancy and according to the underlying cardiac substrate. (Level of Evidence: C-LD) |
| 8. In pregnant patients with chronic or recurrent VT, beta blockers, alone or in combination with other antiarrhythmic drugs, are recommended for arrhythmia suppression due to their overall safety profile in pregnancy. (Level of Evidence: C-LD) |
| 9. In pregnant patients with recurrent VT refractory or with contraindications to beta blockers who require additional antiarrhythmic drug therapy, treatment with flecainide, sotalol, or mexiletine is recommended with the choice of drug based on the underlying cardiac substrate. (Level of Evidence: C-LD) |
| Class IIa |
| 1. In pregnant patients with recurrent symptomatic or hemodynamically unstable VT in whom pharmacological therapy is either ineffective or contraindicated, catheter ablation is reasonable with an experienced operator and with attention to and techniques for eliminating or minimizing radiation exposure to as low as reasonably achievable. (Level of Evidence: C-LD) |
| 2. In pregnant patients with recurrent VT associated with hemodynamic impairment or ICD shocks, amiodarone is reasonable for arrhythmia suppression if alternative therapies, including ablation, are contraindicated or ineffective. (Level of Evidence: C-LD) |
| Class IIb |
| 1. In pregnant patients who meet indications for sudden death prevention due to high-risk features or VT that may be of a reversible etiology, such as peripartum cardiomyopathy, a wearable cardioverter defibrillator may be reasonable. (Level of Evidence: C-LD) |
2017 AHA/ACC/HRS Guideline for Older Patients With Comorbidities
The 2017 AHA/ACC/HRS guideline provides the following recommendation for older patients (defined as ≥75 years) with comorbidities:
| Class IIa |
| 1. For older patients and those with significant comorbidities, who meet indications for a primary prevention ICD, an ICD is reasonable if meaningful survival of greater than 1 year is expected. (Level of Evidence: B-NR) (Systematic Review) |
The guideline notes that neither age nor comorbidities alone should be exclusions for an ICD. However, older adults are prone to higher complication rates, shorter life expectancies (and thus, fewer years during which they could derive benefit from an ICD), and varying preferences. For these reasons, a particularly nuanced and patient-centered approach is important in treating these patients.
Shared Decision-Making (2017 AHA/ACC/HRS)
| Class I |
| 1. In patients with VA or at increased risk for SCD, clinicians should adopt a shared decision-making approach in which treatment decisions are based not only on the best available evidence but also on the patients' health goals, preferences, and values. (Level of Evidence: B-NR) |
| 2. Patients considering implantation of a new ICD or replacement of an existing ICD for a low battery should be informed of their individual risk of SCD and nonsudden death from heart failure or noncardiac conditions and the effectiveness, safety, and potential complications of the ICD in light of their health goals, preferences, and values. (Level of Evidence: B-NR) |
The guideline emphasizes that ICD replacement is an important point in time where patients and clinicians should discuss whether replacing an ICD is still consistent with the patients' goals. What made sense at 70 years of age may not make sense at 80 years of age. The possibility of deactivation of an existing ICD should be discussed with patients who have terminal illnesses.
Updated Recommendations: 2021 PACES Expert Consensus Statement for Pediatric Patients
The 2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients (developed in collaboration with HRS, ACC, AHA, and AEPC) provides updated recommendations for ICD therapy in pediatric patients (defined as ≤21 years of age):Shah MJ, Silka MJ, Avari Silva JN, Balaji S, Beach CM, Benjamin MN, Berul CI, Cannon B, Cecchin F, Cohen MI, Dalal AS, Dechert BE, Foster A, Gebauer R, Gonzalez Corcia MC, Kannankeril PJ, Karpawich PP, Kim JJ, Krishna MR, Kubuš P, LaPage MJ, Mah DY, Malloy-Walton L, Miyazaki A, Motonaga KS, Niu MC, Olen M, Paul T, Rosenthal E, Saarel EV, Silvetti MS, Stephenson EA, Tan RB, Triedman J, Von Bergen NH, Wackel PL (2021). "2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients". Heart Rhythm. 18 (11): 1888–1924. doi:10.1016/j.hrthm.2021.07.038. PMID 34794667 Check |pmid= value (help).
General Recommendations for ICD Therapy in Pediatric Patients (2021 PACES)
| Class I |
| 1. ICD implantation is indicated for survivors of SCA due to VT/VF if completely reversible causes have been excluded and an ICD is considered to be more beneficial than alternative treatments that may significantly reduce the risk of SCA. (Level of Evidence: B-NR) |
| Class IIb |
| 1. ICD implantation may be considered for patients with sustained VT that cannot be adequately controlled with medication and/or catheter ablation. (Level of Evidence: C-EO) |
| 2. ICD therapy may be considered for primary prevention of SCD in patients with genetic cardiovascular diseases and risk factors for SCA or pathogenic mutations and family history of recurrent SCA. (Level of Evidence: C-EO) |
| Class III: Harm |
| 1. ICD therapy is not indicated for patients with incessant ventricular tachyarrhythmias due to risk of ICD storm. (Level of Evidence: C-EO) |
| 2. ICD therapy is not indicated for patients with ventricular arrhythmias that are adequately treated with medication and/or catheter ablation. (Level of Evidence: C-LD) |
| 3. ICD therapy is not indicated for patients who have an expected survival <1 year, even if they meet ICD implantation criteria specified in the above recommendations. (Level of Evidence: C-EO) |
| 4. Endocardial leads should be avoided in patients with intracardiac shunts except in select cases, when there should be an individualized consideration of the risk/benefit ratio. In these exceptional cases anticoagulation is mandatory, but thromboembolism remains a risk. (Level of Evidence: B-NR) |
The 2021 PACES statement emphasizes that ICD implantation should be a shared decision between the patient, family, and physician considering specific pediatric characteristics including age, size of the patient, need for an epicardial device, religious/cultural beliefs, and patient quality of life. This includes the physical as well as the psychological impact of an ICD on the patient's well-being. A pediatric cardiologist should be involved in the decision to implant an ICD in pediatric patients, and the procedure should be performed by a cardiologist or cardiothoracic surgeon with special training and/or experience in CIED implantation in the pediatric age group.
ICD Indications for Nonischemic Dilated Cardiomyopathy in Pediatric Patients (2021 PACES)
| Class I |
| 1. ICD implantation is indicated in patients with NIDCM who either survive SCA or experience sustained VT not due to completely reversible causes. (Level of Evidence: B-NR) |
| Class IIb |
| 1. ICD implantation may be considered in patients with NIDCM and syncope or an LVEF ≤35%, despite optimal medical therapy. (Level of Evidence: C-LD) |
| Class III: Harm |
| 1. ICD implantation is NOT recommended in patients with medication-refractory advanced heart failure who are not cardiac transplantation or left ventricular assist device candidates. (Level of Evidence: C-EO) |
The 2021 PACES statement notes that the annual incidence of SCD in pediatric patients with NIDCM is only 1%–5%, which is significantly less than in adult patients. In contrast to some studies of adult patients with NIDCM and LVEF ≤35%, there is no clear evidence that ICDs implanted for primary prevention improve survival for pediatric patients with NIDCM. The Sudden Death in Childhood Cardiomyopathy study showed that the cumulative incidence of SCD at 15 years was 5% for idiopathic dilated cardiomyopathy compared to 23% for left ventricular noncompaction.
ICD Indications for Arrhythmogenic Cardiomyopathies in Pediatric Patients (2021 PACES)
| Class I |
| 1. ICD implantation is indicated in patients with arrhythmogenic cardiomyopathy (ACM) who have been resuscitated from SCA or sustained VT that is not hemodynamically tolerated. (Level of Evidence: B-NR) |
| Class IIa |
| 1. ICD implantation is reasonable in patients with ACM with hemodynamically tolerated sustained VT, syncope presumed due to ventricular arrhythmia, or an LVEF ≤35%. (Level of Evidence: B-NR) |
| Class IIb |
| 1. ICD implantation may be considered in patients with inherited ACM associated with increased risk of SCD based on an assessment of additional risk factors. (Level of Evidence: C-LD) |
SCD occurs in 2%–15% of young patients with ACM. The 2021 PACES statement notes that arrhythmogenic cardiomyopathy encompasses a spectrum of primary myocardial disorders including genetic disorders such as arrhythmogenic right/left ventricular cardiomyopathy, lamin A/C mutations, filamin-C, phospholamban, and cardiac amyloidosis. These entities are infrequent before puberty and often overlap with other cardiomyopathies.
2006 ACC/AHA/ESC Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death (DO NOT EDIT) [20]
Diagnostic EvaluationElectrocardiographic Techniques and Measurements (DO NOT EDIT)[20]
Resting Electrocardiogram (DO NOT EDIT)[20]
Ambulatory Electrocardiography Recommendations (DO NOT EDIT)[20]
Exercise Testing Recommendations (DO NOT EDIT)[20]
Left Ventricular Function and Imaging (DO NOT EDIT)[20]
Electrophysiological Testing (DO NOT EDIT)[20]
Management of Special Patient PopulationsManagement of Ventricular Arrhythmias in Pregnancy (DO NOT EDIT)[20]
Management of Ventricular Arrhythmias in Elderly Patients (DO NOT EDIT)[20]
Management of Ventricular Arrhythmias in Pediatric Patients (DO NOT EDIT)[20]
Resources1. Zipes DP, Camm AJ, Borggrefe M, et al., ACC/AHA/ESC 2006 Guidelines 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 and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death)Circulation 2006;114;e385-e484 2. Kesh Hebbar A, Hueston WJ, Management of Common Arrhythmias: Part II.Ventricular Arrhythmias and Arrhythmias in Special Populations Am Fam Physician 2002;65:2491-6. References
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