Premature ventricular contraction caries no risk of mortality in the absence of any underlying heart disease. Heart rate turbulence is a phenomenon representing the return to equilibrium of the heart rate after a PVC. These parameters correlate significantly with mortality after myocardial infarction.

• In the absence of ischemic heart disease (CAD) or hypertension (HTN), there is no excess risk of mortality in patients with PVCs.
• On the other hand, PVCs in the presence of structural cardiac abnormalities or hypertension is associated with twice the expected mortality.
• The development of sustained ventricular tachycardia (VT) is most likely among those patients with greater than 12 PVCs/min, couplets, and multifocal PVCs.
• Complex ventricular ectopic activity (VEA) during acute phase of STEMI does not have any prognostic significance.
• Their presence 2 to 3 weeks after acute MI is associated with a 3 fold increase in the risk of sudden death.

1. Healthy patients
   • The most common arrhythmia in patients with and without CAD.
   • Less common in infants and children, more common in the elderly.
   • Usually originate from the RV.
   • In normal patients, they may be either precipitated or suppressed by exercise.
   • No relationship to coffee or smoking has been established.
   • Frequency decreases with sleep.
2. Coronary artery disease
   • Routine ECGs demonstrate PVCs in 10% of patients with CAD.
   • Incidence inreases to 60 to 88% when the monitoring is increased to 12 to 24 hours.
   • The frequency of complex VEA increases with increasing numbers of vessels involved. (40% with one, 53% with two, and 78% with three vessels involved has VEA).
   • Patients with CAD are more prone to develop VEA with exercise (incidence 4 times higher than age matched controls).
   • Reported incidence in acute MI varies, but is near 100%.
   • After the initial 6 hours, the frequency decreases.
   • Persistence of VEA is associated with larger infarct size.
   • In one study, patients with EFs of greater than 50% had no persistent VEA, and patients with EFs of less than 30% had frequent PVCs.
3. Other Organic Heart Diseases:
   • Occur on routine EKG in 1/3rd of patients.
   • 12% of patients with congested cardiomyopathy have PVC on routine tracings.
   • 1.6% of patients with IHSS have PVCs on routine EKG.
4. Drugs:
   • PVCs are the most common arrhythmia in patients with digoxin toxicity.
   • Other drugs that cause PVCs are quinidine, PCA, norpace, phenothiazines and tricyclic antidepressants.
5. Electrolyte Imbalance:
   • Hypokalemia, hypomagnesemia, and hypercalcemia are frequently associated with the appearance of ventricular arrhythmias.^{[1] [2]}

There is insufficient evidence to recommend routine screening for [disease/malignancy].

OR

According to the [guideline name], screening for [disease name] is not recommended.

OR

According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with [condition 1], [condition 2], and [condition 3].

There is insufficient evidence to recommend routine screening for [disease/malignancy].

OR

According to the [guideline name], screening for [disease name] is not recommended.

OR

According to the [guideline name], screening for [disease name] by [test 1] is recommended every [duration] among patients with:

• [Condition 1]
• [Condition 2]
• [Condition 3]