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3 minutes crash course on ventricular ectopic beats (VPDs)

Posted Jul 09 2009 4:45pm

Ventricular ectopic beats are the most common cardiac electrical abnormality for which cardiologist’s consultation is sought.VPDs are one of most benign observations in ECG and  and almost every  heart experiences it. In 24 hour holter recordings it was reported up to 25% of healthy  individuals .

In spite of this ,  the fear of  noting a VPD in a given tracing of ECG is genuine both for the patient and his physician.This is because  VPDs  can be  a forerunner of dangerous ventricular arrhythmias.

  • VPDs are often graded according to the count and morphology and frequency.(Lown’s ,Bigger’s grading)
  • VPDs that occur in single are less fearsome.( It may not be so . . .)
  • VPDs in couplets and  triplets raise considerable anxiety.( Again it need not be . . .)
  • A series of VPD lasting for 30 seconds is called non sustained ventricular tachycardia(NSVT)
  • If it exceeds 30second it called sustained VT.
  • VT may remain as VT in many.
  • VT may degenerate into VF  ventricular fibrillation in minority( ie cardiac arrest)

The importance of VPDs do not lie  in the number ,  morphology or frequency  but most importantly  in  the underlying etiology. If it occurs in a structurally normal heart it is largely benign.

New onset VPDs should be investigated thoroughly. The commonest symptom is palpitation.

vpd ectopic

Friendly VPD s : Some of  situations where VPDs are  commonly observed and has little significance are.

  • Exercise induced VPDs
  • Pregnancy induced VPDs  (PIH /Peripartum DCM are  rare possibilities)
  • Thyroid associated VPDs
  • Alcohol /Smoke related

What are the VPDs that could be clinically  important ?

VPDs with chest pain(Ischemic etiology )

VPDs in patients with dyspnea.(CHF , COPD)

Drug induced VPDs(Digoxin etc)

Renal failure associated VPDs

VPDs due to hypoxia/Hypokalemia

In patients with pre existing heart disease.(Congenital, valvular, myocardial disease)

What prevents a non sustained VT from becoming sustained ?

No one really knows the answer.Most of the NSVT self terminates.A healthy heart some how gets the capacity to self terminate the arrhythmia.The normal  LV  fails to sustain the abnormal electrical circuit . A diseased heart may not be able to do so . Further if there is electrolyte abnormality (low potassium), or lack of oxygen it may maintain a VT.

What are the most dangerous forms of VPDs ?

  • VPDs that occur during  acute coronary syndrome.
  • VPDs associated with cardiomyopathy( Ischemic , nonischmic,)
  • Some forms of primary electrical disorders of heart( Brugada syndrome, ARVD , CMVT etc)

How do you investigate patients with VPDs?

General medical work up in all.

Echocardiogram is usually necessary in most.

Holter monitoring in occasionally.

Coroanry angiogram rarely

Electrophysiological study in high risk category

How do you manage  patients with VPDs?

  1. Generally do not require any specific drugs in vast majority of individuals .
  2. Reassurance is the key
  3. Ask them to avoid potential triggers like smoke, alcohol, coffee, tea and related bevarages.
  4. If palpitation is troublesome beta blockers( Propronolol, Atenolol, metoprolol can be used.)
  5. Anxiolytic may also be given.

* If the patient has  systemic disorder like hyperthyroidsm , anemia  or underlying heart disease he has to get the specific treatment.

Caution:It has become fashionable for the physicians  to use powerful antiarrhythmic drugs like amiodarone (Cordarone) liberally in patients with asymptomatic VPDs with structurally normal hearts.this practice must be absolutely avoided as amiodarone is one of most toxic  cardiac drugs known  with great pro arrhythmic activity.

When to refer a patient with VPD to a electrophysiologist ?

Physicians   can  treat   most of these patients. But the following will require EP consultations

  • Patients with syncope
  • Patient who have LV dysfunction(Low ejection fraction EF%)
  • Has had an episode of ventricular tachycardia
  • Cardiac arrest

What will the Electrophysiologist  do ?

These patients will be evaluated for inducibility of VT/VF and if the LV function is poor (EF<30%  MADIT 2 criteria ) many would receive implantable cardivertor defibrillator(ICD) or life long anti arrhythmic  drugs.

Some times radiofrequency (RF ablation)  waves are used to ablate the focus of VT.This is possible only if it occurs close to endocardium as  intracardiac catheters do not have access to epicardial  focus. Among  ICD and RF ablation later could be preferred whenever feasible as it eliminates the arrhythmia , while  the former only tackles it only after it occurs .( Hence ICDs  , even though a technological marvel can not be labelled as curative ! )

Final message

VPDs are the   most common cardiac arrhythmia .Most of them are benign. Few of them require extensive investigation.

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