adult tachycardia

ADULT TACHYCARDIA : ADULT TACHYCARDIA : AN OVERVIEWAN OVERVIEW

Faez BaherinEmergency Physician

ED Hospital Melaka

OUTLINE

• Definition and introduction• Approach to tachycardia1. Pulseless algorithm2. Stable tachycardia3. Unstable tachycardia• Cardioversion• Take-home message

Introduction

• A heart rate of more than 100 beats per minute (BPM) in adults is called TACHYCARDIA

• Tachyarrhythmia is part of tachycardia – it deviates from normal heart rhythm

• Definition varies

Introduction

• Tachycardia can be classified in several ways, based on the appearance of – Heart rate – QRS complex – wide or narrow complexes– Regularity – regular vs irregular

Approach to tachycardia

• The first question that should be asked when initiating the ACLS tachycardia algorithm is:

“Is the patient stable or unstable?” • The answer to this question will determine

which path of the tachycardia algorithm is executed.

Approach to tachycardia

• When encountering patients with tachycardia, efforts should be made to determine whether the tachycardia is the primary cause of the presenting symptoms or secondary to an underlying condition

Approach to tachycardia

A patient with tachycardia, check if patient :

1.Pulseless or with pulse2.stable or unstable

THEN treat the patient based on the patient's condition and rhythm.

Approach to tachycardia : Pulseless algorithm

• If the patient does not have a pulse, follow the ACLS Pulseless Arrest Algorithm.

Stable Tachycardia

Approach to tachycardia : Stable Tachycardia

• For a diagnosis of stable tachycardia, the patient meets the following criteria:– The patient's heart rate is greater than 100 bpm.– The patient does not have any serious signs or

symptoms as a result of the increased heart rate.– Symptoms / signs : altered mental status, ongoing

chest pain, hypotension, other signs of shock.

Approach to tachycardia : Stable Tachycardia

• Many experts suggest that when HR is < 150 bpm, it is unlikely that symptoms of instability are caused primarily by the tachycardia unless there is impaired ventricular function

Approach to tachycardia : Stable Tachycardia

• Does the patient have a pulse? • Yes, the patient has a pulse.

Complete the following:– ABC– Give oxygen and monitor oxygen saturation– Get an ECG– Identify rhythm– Check blood pressure– Identify and treat reversible causes

Approach to tachycardia : Stable Tachycardia

• Yes, the patient is stable. – IV access– Analyze ECG

Approach to tachycardia : Narrow regular tachycardia

• Is the QRS complex wide or narrow?If the patient's QRS is narrow and rhythm is regular.

↓1)Try vagal maneuvers + modified Valsalva2)Give adenosine 6 mg rapid IV push3)If patient does not convert, give adenosine 12 mg rapid IV push.

Alternative of adenosine ?

Approach to tachycardia : Narrow regular tachycardia

• If the patient's rhythm convert, it was probably reentry supraventricular tachycardia. At this point, watch for a recurrence.

• If the tachycardia resumes, treat with longer-acting AV nodal blocking agents, such Ca channel blocker(verapamil or diltiazem) or beta-blockers.

Approach to tachycardia : Narrow irregular tachycardia

• If the rhythm pattern is irregular narrow-complex tachycardia, it is probably atrial fibrillation, possible atrial flutter, or multi-focal atrial tachycardia.

↓Control patient's rate with diltiazem or beta-blockers. Use beta-blockers with caution for patients with pulmonary disease or CCF.

Approach to tachycardia : Stable Atrial fibrillation

1. Less than 48 hours -Amiodarone-CCB-B-Blocker

2. Persistent or permanent AF-CCB -B-Blocker-Digoxin

Approach to tachycardia : Wide regular/ irregular tachycardia• If the patient has wide QRS complex– Obtain 12 lead ECG to evaluate rhythm– Determine if the rhythm is regular or irregular• A regular wide-complex tachycardia is likely to be VT or

SVT with abberancy• An irregular wide-complex tachycardia may be AF with

abberancy, pre-excited AF or polymorphic VT/torsade de pointes

– Consider the need to obtain expert consultation

Approach to tachycardia : Wide regular/ irregular tachycardia• If the etiology of the rhythm cannot be

determined, the rate is regular, and the QRS is wide and monomorphic, IV adenosine is relatively safe – both prognostic and therapeutic

• Adenosine should not be given for unstable or for irregular or polymorphic wide complex tachycardia as it may cause degeneration of the arrhythmia to VF

Approach to tachycardia : Wide regular/ irregular tachycardia• If the wide-complex tachycardia proves to be

SVT with aberrancy, adenosine will transiently slowed or converted to SR

• If due to VT there will be no effect on rhythm• In stable VT : Amiodarone, procainamide,

sotalol

Unstable Tachycardia

Approach to tachycardia : Unstable Tachycardia

• Two keys to managing patients with unstable tachycardia– quickly recognizing that the patient has significant

symptoms and is unstable– recognize that the patient's signs and symptoms

are caused by the tachycardia.

Approach to tachycardia : Unstable Tachycardia

• Assess pt• Look for altered mental status, ongoing chest

pain, hypotension, or other signs of shock.• If the patient is unstable and has a wide-

complex tachycardia, assume the rhythm is VT until proven otherwise.

Approach to tachycardia : Unstable Tachycardia

• Perform immediate synchronized cardioversion.– IV access– Give sedation if the patient is conscious.– Do not delay cardioversion.– Consider expert consultation

Cardioversion

• Function : deliver a stimulus to stun the heart in hoping that the rhythm will start back from the SA

• Synchronized cardioversion is shock delivery that is timed (synchronized) with the QRS

Cardioversion

• This synchronization avoids shock delivery during the relative refractory period of the cardiac cycle when a shock could produce VF

Cardioversion

• Synchronized cardioversion is recommended to treat (1) unstable SVT(2) unstable atrial fibrillation(3) unstable atrial flutter(4) unstable monomorphic (regular) VT.

Cardioversion

• The recommended initial biphasic energy dose for cardioversion of atrial fibrillation is 120 to 200 J

• If the initial shock fails, increase the dose in a stepwise fashion

• Cardioversion with monophasic waveforms should begin at 200 J and increase in stepwise fashion if not successful

Cardioversion

• Cardioversion of atrial flutter and other SVTs generally requires less energy, an initial energy of 50 J to 100 J is often sufficient.

• Arrhythmias with a polymorphic QRS appearance (such as torsades de pointes) will usually not permit synchronization. Thus, if a patient has polymorphic VT, treat the rhythm as VF and deliver high-energy unsynchronized shocks

Cardioversion

Possible Underlying Reversible Causes

H’s• Hypovolemia• Hypoxia• Hydrogen ion

(acidosis)• Hyperkalemia/

hypokalemia/ metabolic disorders

• Hypothermia/ hyperthermia

T’s• Toxins/tablets

(drug overdose)• Tamponade, cardiac• Tension

pneumothorax• Thrombosis,

coronary• Thrombosis,

pulmonary

Take-home message

• Learn the AHA tachycardia algorithm by heart• Pulseless vs with pulse• Stable vs unstable• Narrow vs wide complex• Regular vs irregular• Underlying reversible cause• Early referrals, interdepartmental management