Non Sustained V Tachycardia:::
●A variety of definitions of nonsustained ventricular tachycardia (NSVT) have been published, but the most commonly used definition is three or more consecutive ventricular beats, a heart rate of >120 beats per minute, and a duration of arrhythmia of less than 30 seconds.
●Patients with NSVT are usually asymptomatic, although some patients may notice symptoms associated with episodes of NSVT. The type and intensity of symptoms, which may include palpitations, chest pain, shortness of breath, syncope, or presyncope, will vary depending upon the rate and duration of the NSVT along with the presence or absence of significant comorbid conditions.
●Few physical examination findings in patients with NSVT are unique and specific. By definition, patients will have a pulse exceeding 100 beats per minute during the episode. In addition, if the physical examination coincides with an episode of NSVT, this can reveal evidence of atrioventricular (AV) dissociation, including marked fluctuations in blood pressure, variability in the occurrence and intensity of heart sounds (especially S1), and cannon A waves.
●All patients with suspected NSVT should have a 12-lead electrocardiogram (ECG), although NSVT is frequently identified on continuous telemetric monitoring, in which case only one or two leads may be available for review.
●Once nonsustained ventricular tachycardia (NSVT) has been identified, reversible causes of arrhythmia should be sought, including electrolyte imbalances, myocardial ischemia, hypoxia, adverse drug effects, anemia, hypotension, and heart failure. For patients who have only a single asymptomatic episode of NSVT, often no further investigation is required. However, for patients with multiple episodes or for those with symptoms felt to be related to NSVT, a thorough diagnostic evaluation to exclude structural heart disease is warranted, including cardiac imaging and ambulatory ECG monitoring for most patients and invasive electrophysiology studies (EPS) only on rare occasions.
●Treatment of patients with NSVT is as follows:
•Patients with NSVT and no identified symptoms do not require any specific therapy directed toward the NSVT. However, some patients with NSVT who are found to have a cardiomyopathy with significantly reduced left ventricular systolic function may be evaluated for implantable cardioverter defibrillator (ICD) placement for primary prevention of sudden cardiac death related to sustained ventricular tachyarrhythmias.
•For the initial treatment of patients with symptomatic NSVT, we suggest beta blockers rather than calcium channel blockers or antiarrhythmic medications (Grade 2C).
•For patients with NSVT who remain symptomatic in spite of beta blockers, or who are unable to tolerate beta blockers due to side effects, we suggest adding a nondihydropyridine calcium channel blocker (ie, verapamil or diltiazem) rather than an antiarrhythmic medication
•For some patients who have frequent, highly symptomatic NSVT not adequately suppressed by beta blockers or calcium channel blockers, the addition of antiarrhythmic medications (table 1) may be helpful. We suggest amiodarone as the initial choice, rather than other antiarrhythmic drugs, based on its efficacy (Grade 2C).
•In patients who have very frequent, symptomatic monomorphic NSVT not controlled by medications or who are unable or unwilling to take medications, catheter ablation can be effective for reducing or eliminating NSVT and associated symptoms
●A variety of definitions of nonsustained ventricular tachycardia (NSVT) have been published, but the most commonly used definition is three or more consecutive ventricular beats, a heart rate of >120 beats per minute, and a duration of arrhythmia of less than 30 seconds.
●Patients with NSVT are usually asymptomatic, although some patients may notice symptoms associated with episodes of NSVT. The type and intensity of symptoms, which may include palpitations, chest pain, shortness of breath, syncope, or presyncope, will vary depending upon the rate and duration of the NSVT along with the presence or absence of significant comorbid conditions.
●Few physical examination findings in patients with NSVT are unique and specific. By definition, patients will have a pulse exceeding 100 beats per minute during the episode. In addition, if the physical examination coincides with an episode of NSVT, this can reveal evidence of atrioventricular (AV) dissociation, including marked fluctuations in blood pressure, variability in the occurrence and intensity of heart sounds (especially S1), and cannon A waves.
●All patients with suspected NSVT should have a 12-lead electrocardiogram (ECG), although NSVT is frequently identified on continuous telemetric monitoring, in which case only one or two leads may be available for review.
●Once nonsustained ventricular tachycardia (NSVT) has been identified, reversible causes of arrhythmia should be sought, including electrolyte imbalances, myocardial ischemia, hypoxia, adverse drug effects, anemia, hypotension, and heart failure. For patients who have only a single asymptomatic episode of NSVT, often no further investigation is required. However, for patients with multiple episodes or for those with symptoms felt to be related to NSVT, a thorough diagnostic evaluation to exclude structural heart disease is warranted, including cardiac imaging and ambulatory ECG monitoring for most patients and invasive electrophysiology studies (EPS) only on rare occasions.
●Treatment of patients with NSVT is as follows:
•Patients with NSVT and no identified symptoms do not require any specific therapy directed toward the NSVT. However, some patients with NSVT who are found to have a cardiomyopathy with significantly reduced left ventricular systolic function may be evaluated for implantable cardioverter defibrillator (ICD) placement for primary prevention of sudden cardiac death related to sustained ventricular tachyarrhythmias.
•For the initial treatment of patients with symptomatic NSVT, we suggest beta blockers rather than calcium channel blockers or antiarrhythmic medications (Grade 2C).
•For patients with NSVT who remain symptomatic in spite of beta blockers, or who are unable to tolerate beta blockers due to side effects, we suggest adding a nondihydropyridine calcium channel blocker (ie, verapamil or diltiazem) rather than an antiarrhythmic medication
•For some patients who have frequent, highly symptomatic NSVT not adequately suppressed by beta blockers or calcium channel blockers, the addition of antiarrhythmic medications (table 1) may be helpful. We suggest amiodarone as the initial choice, rather than other antiarrhythmic drugs, based on its efficacy (Grade 2C).
•In patients who have very frequent, symptomatic monomorphic NSVT not controlled by medications or who are unable or unwilling to take medications, catheter ablation can be effective for reducing or eliminating NSVT and associated symptoms
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