Forgotten concepts and drugs in cardiology : Lignocaine for Ventricular tachycardia and fibrillation !
Posted Feb 03 2009 12:09am
Lignocaine , probably has saved more lifes world over than any other cardiac drug .
It was the only choice for ventricular tachycardia till 1990s, both in pre and post thrombolytic era.Every coornary care unit has reverted tens of thousands of unstable VTs with this simple and cheap intravenous drug.the utility value of lignocaine is not limited to ischemic VT alone it is effective in in almost all forms of VT.It was classically administered in two or more boluses followed by an infusion.
What happened to this wonder drug with great performance record ?
The power of statistics , and inappropriate interpretation by the scientific community has left a serious blow to this wonder drug .Now the drug has been made redundant, and mainstream cardiac literature has made everyone feel guilty , if anybody uses this drug for VT .
Why did lignocaine lose the battle ? The reason is three fold
The advent of much fancied Amiodarone
One negative study for antiarrhythmic drugs in post MI period (CAST)
And two so called positive studies for Amiodarone (ALIVE & ARREST) has sounded the death bell for this drug which has resuscitated millions of life !
All , CAST said was routine suppression of asymptomatic ventricular arrhythmias in the post MI period is unwarranted. But you know , how this world interpreted it “Lignocaine has no role in ventricular arrhythmias in post MI setting “ The most funny thing was lignocine was never used in CAST study .
The studies involving one to one comparison of Lignocaine and Amiodarone (ALIVE and ARREST study) was also not interpreted properly.These studied only shock resistant VTs. What about the role of lignocaine where defibrillator was not available ?
Link to ALIVE and ARREST read and make your own conclusion.
Lignocaine is not only a topical anesthetic , it is powerful and gentle myocardial anesthetic when administered in post MI period.
With this property it successfully cardioverts and prevents dangerous ventricular arrhythmias.
Time tested and worthiness proven.
While , we are made to believe the success rate of Amiodarone in VT is far superior than ligncaine .It is a falsehood.
Any experienced cardiologists will recognise , many times even Amiodarone resistant VTs often respond to Lignocaine .
The fact of the matter is , without a good quality one to one study , lignocaine was ditched. One reason for this could be Lignocaine , is a generic drug and has no market value.
Let us take home , the message (scientific or unscientific ! ) Lignocaine still has a great role to play in the management of dangerous ventricular arrhythmias .The only caution is , it should not be used routinely and indiscriminately in all asymptomatic patients with VPDs or nonsustained VT . (Acknowledging CAST conclusion.)