2 min read - Tachyarrhythmias

A 32 years old previously healthy male patient admitted with a history of palpitations for 1 hour duration. He had experienced a similar episode a few months back which lasted only for few minutes.

What are your concerns?

• First priority is to make sure that the patient is stable.
• Who is unstable?
• Hypotensive patient (Systolic BP < 90mmHg)
• Coronary ischemia (Ischemic chest pain)
• Cardiac failure (Patient has SOB)
• Patient with brain hypoperfusion (reduced conscious level)

IF ANY OF ABOVE ARE PRESENT IRRESPECTIVE OF THE TYPE OF ARRHYTHMIA YOU WILL HAVE TO PERFORM DC CARDIOVERSION (SHOCK)

ECG

• Analysing tachyarrhythmias is a long topic, which might bore you.
• Let's learn a few short cuts to diagnose common arrhythmias.

• Look at the QRS

• Is it narrow or broad?

• Narrow complex tachycardias we usually encounter are
• SVT (Read and understand the proper nomenclature. SVT is a wrong term!)
• Atrial fibrillation/ flutter
• In most patients both are managed the same way.
• READ ABOUT THE OTHER NARROW COMPLEX TACHYCARDIAS.

• Broad complex tachycardias UNLESS PROVEN OTHERWISE ARE VENTRICULAR TACHYCARDIAS
• However some 'supra' ventricular tachycardias can mimic ventricular tachycardias
• Eg: SVT with a bundle branch block.

• Is it regular or irregular

• Regular narrow complex tachycardia = SVT
• Irregular narrow complex tachycardia = Atrial Fibrillation/ flutter

• Regular broad complex tachycardia = VT
• Irregular broad complex tachycardia = Ventricular Fibrillation

• However, as you start to learn more and more about ECGs you will realize that this is oversimplified and there are so many other arrhythmias in each category.
• REMEMBER, THIS IS ONLY A SURVIVAL GUIDE!

Diagnosis??

Diagnosis??

Diagnosis??

Diagnosis??

Now you've made a diagnosis what have you got to do?

• I repeat, irrespective of the type of arrhythmia if the patient is unstable - SHOCK 
• If the patient is stable

• SVT
• Perform vagal manouvers
• Medications
• Drug of choice is adenosine
• Contraindication is ASTHMA
• Give IV 6mg bolus (FAST) followed by a 10-20ml saline flush.
• patient will respond in a few seconds
• If it fails, you may try about two boluses of 12mg.
• However in the case of a SVT, even if the patient is unstable you may try adenosine as it's response is very very fast!

See the response to adenosine!

• ATRIAL FIBRILLATION
• This is kind of complicated!
• We shall discuss it on a separate day.

• VENTRICULAR TACHYCARDIA
• Most patients will require SHOCK
• If the patient is stable you may try medications
• Amiadarone
• 150mg over 10 minutes
• Followed by 1mg/min infusion
• Lidocaine
• 1-1.5mg/kg bolus
• you may repeat up to a total cumulative dose of 3mg/kg every 5-10 minutes

• VENTRICULAR FIBRILLATION
• Homework
• What medications can you give for a patient who is hemodynamically stable with a VF??

Few facts about SHOCK

• Don't EVER shock yourself or your colleagues while attempting to shock the patient!

• Sedate the patient!
• Widely used medication is midazolam given as a bolus of 1-2.5mg

• Most of the defibrillators available are Biphasic

• Press the SYNC button for
• SVT
• VT
• AF
• NEVER FOR VF

• Energy level
• SVT 50-100 
• AF 120-200
• VT 100
• VF - well, I guess you know what to give.

Vagal manouvers

• Avoid carotid massage in older patients
• You might give them a stroke!

• Modified valsalva manouver 
• Read and check on youtube!

• Diving reflex

What if there is no response?

• Consider following 
• Metabolic causes such as
• Electrolyte abnormalities
• Thyrotoxicosis
• Acidosis
• Hypo/Hyperglycemia
• Hypo/hyperthermia
• Toxins
• MI/ Pulmonary embolism

Isn't it too much for a day? Let's take a break.