From the Guidelines
PVCs should be diagnosed and evaluated using a combination of electrocardiogram (ECG), Holter monitoring, exercise stress testing, and echocardiography, with further testing such as cardiac MRI considered in cases with high frequency or complexity of PVCs, as recommended by the most recent guidelines 1. The diagnostic approach to PVCs involves several key steps, including:
- Electrocardiogram (ECG) to identify the characteristic pattern of a wide QRS complex without a preceding P wave, followed by a compensatory pause
- Holter monitoring or event recorders to capture PVCs over 24-48 hours or longer periods in patients with intermittent symptoms
- Exercise stress testing to reveal exercise-induced PVCs
- Echocardiography to evaluate underlying structural heart disease that might be causing the PVCs
- Laboratory tests to check for electrolyte abnormalities (particularly potassium and magnesium) and thyroid function, as these can trigger PVCs The frequency and complexity of PVCs can help guide the extent of evaluation, with athletes with >2000 PVCs per 24 hours requiring annual cardiological evaluation and consideration of further testing such as contrast-enhanced cardiac MRI 1. In cases where PVCs are frequent or complex, additional evaluation may include contrast-enhanced cardiac MRI and more invasive electrophysiology study, as recommended by recent guidelines 1. The diagnostic approach should be tailored to the patient's symptoms, with asymptomatic patients with infrequent PVCs often requiring minimal testing, while those with frequent PVCs, symptoms like palpitations, dizziness, or syncope, or known heart disease needing more comprehensive evaluation 1.
From the FDA Drug Label
In post-myocardial infarction patients with asymptomatic PVCs and non-sustained ventricular tachycardia, flecainide therapy was found to be associated with a 5.1% rate of death and non-fatal cardiac arrest, compared with a 2.3% rate in a matched placebo group. New or exacerbated ventricular arrhythmias which occurred in 7% of 1330 patients with PVCs, non-sustained or sustained VT Ventricular proarrhythmic effects range from an increase in frequency of PVCs to the development of more severe ventricular tachycardia, e.g., tachycardia that is more sustained or more resistant to conversion to sinus rhythm, with potentially fatal consequences.
Flecainide can cause new or worsened ventricular arrhythmias, including an increase in frequency of PVCs. The incidence of new or exacerbated ventricular arrhythmias, including PVCs, was 7% in patients with PVCs, non-sustained or sustained VT 2 2.
- Key points:
- Flecainide can increase the frequency of PVCs.
- The incidence of new or exacerbated ventricular arrhythmias, including PVCs, was 7% in patients with PVCs, non-sustained or sustained VT.
- Flecainide therapy was associated with a 5.1% rate of death and non-fatal cardiac arrest in post-myocardial infarction patients with asymptomatic PVCs and non-sustained ventricular tachycardia.
From the Research
PVC Diagnoses
- Premature ventricular complexes (PVCs) are extremely common, found in the majority of individuals undergoing long-term ambulatory monitoring 3.
- The history, physical examination, and 12-lead ECG are each critical to the diagnosis and evaluation of a PVC 3.
- An echocardiogram is indicated in the presence of symptoms or particularly frequent PVCs, and cardiac magnetic resonance imaging is helpful when the evaluation suggests the presence of associated structural heart disease 3.
- Ambulatory monitoring is required to assess PVC frequency 3.
Diagnostic Testing
- Novel electrocardiographic criteria can be used for localizing premature ventricular complexes (PVCs) originating from the base of the left ventricle (LV) 4.
- The ECG criteria had a sensitivity and specificity of 91% and 84%, respectively, for localizing PVCs originating from the base of the LV 4.
Predictors of Positive Response to Treatment
- Patients who responded to beta-blockers had significantly higher ratio of patients who had positive correlation between hourly heart rate and corresponding hourly PVC number (fast HR-PVC status) compared with non-responders 5.
- Binary logistic regression analysis revealed PVC QRS width and fast HR-PVC status as the independent predictors of positive response to beta-blockers for treatment of PVC 5.