Tachycardia: Difference between revisions

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Differentiation between supraventricular tachycardias (SVT) and ventricular tachycardias (VT) can be challenging, especially in acute emergency settings. SVT's are rhythm disturbances in the atria or AV-nodal ring or rhythm disorders in which these structures are involved. VT's are rhythm disorders that only involve the ventricles. It can both take place in the myocardium and the conduction system tissue.
Differentiation between supraventricular tachycardias (SVT) and ventricular tachycardias (VT) can be challenging, especially in acute emergency settings. SVT's are rhythm disturbances in the atria or AV-nodal ring or rhythm disorders in which these structures are involved. VT's are rhythm disorders that only involve the ventricles. It can both take place in the myocardium and the conduction system tissue.


 
===Definitions:===
'''
'''Tachycardia:''' heartrate above 100 bpm
Definitions:'''
Tachycardia: heartrate above 100 bpm


'''Small complex tachycardia:''' QRS duration < 120 ms.
'''Small complex tachycardia:''' QRS duration < 120 ms.
A small complex tachycardia is most likely to be a SVT. However, also a septal VT or His-tachycardia can appear as a small complex tachycardia. (Figure 1, small complex tachy algorithm)
A small complex tachycardia is most likely to be a SVT. However, also a septal VT or His-tachycardia can appear as a small complex tachycardia.  


'''Broad complex tachycardia:''' QRS duration > 120 ms.
'''Broad complex tachycardia:''' QRS duration > 120 ms.
A broad complex tachycardia can be due to a SVT with aberration, pre-exited tachycardia (eg antidrome re-entry tachycardia) or VT. (Figure 2, broad complex tachy algorithm)
A broad complex tachycardia can be due to a SVT with aberration, pre-exited tachycardia (eg antidrome re-entry tachycardia) or VT.  
 
===Differentiation:===
(Figure 1, small complex tachy algorithm)
(Figure 2, broad complex tachy algorithm)
 
===Treatment:===
 
'''Haemodynamical instability (high heartrate, low blood pressure):''' electrical cardioversion
 
'''Haemodynamical stability in a regular small complex tachycardia:'''
- Carotid massage (after palpation and ausculatation of carotid arteries for exclusion of carotid occlusion/stenosis)
- Vasalva manoevre
- Adenosine bolus (if patient is not asthmatic or having COPD)
- Verapamil (if patient is not having systolic heart failure)
- Beta-blocker (if patient is not having systolic heart failure)
 
'''Haemodynamical stability in a regular monomorphic broadcomplex tachycardia (systolic blood pressure >100 mmHg:'''
- Procaïnamide
- Amiodaron

Revision as of 22:50, 12 May 2011

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Introduction

Tachycardia's are arranged as follows;

Supra-ventricular tachycardia

Atrial arrhythmias

Sinus Tachycardia

Atrial Tachycardia

Atrial Flutter

Atrial Fibrillation

Pathophysiology

Patient characteristics

History

Physical Examination

Investigations

Differential diagnosis

Treatment and Follow up

Prognosis

AV node arrhythmias

AV junctional tachycardia

AVNRT

AVRT

Ventricular tachycardia

Ventricular tachycardia

Ventricular flutter

Ventricular fibrillation

Torsade de Pointes

Differentiation between SVT and VT

Differentiation between supraventricular tachycardias (SVT) and ventricular tachycardias (VT) can be challenging, especially in acute emergency settings. SVT's are rhythm disturbances in the atria or AV-nodal ring or rhythm disorders in which these structures are involved. VT's are rhythm disorders that only involve the ventricles. It can both take place in the myocardium and the conduction system tissue.

Definitions:

Tachycardia: heartrate above 100 bpm

Small complex tachycardia: QRS duration < 120 ms. A small complex tachycardia is most likely to be a SVT. However, also a septal VT or His-tachycardia can appear as a small complex tachycardia.

Broad complex tachycardia: QRS duration > 120 ms. A broad complex tachycardia can be due to a SVT with aberration, pre-exited tachycardia (eg antidrome re-entry tachycardia) or VT.

Differentiation:

(Figure 1, small complex tachy algorithm) (Figure 2, broad complex tachy algorithm)

Treatment:

Haemodynamical instability (high heartrate, low blood pressure): electrical cardioversion

Haemodynamical stability in a regular small complex tachycardia: - Carotid massage (after palpation and ausculatation of carotid arteries for exclusion of carotid occlusion/stenosis) - Vasalva manoevre - Adenosine bolus (if patient is not asthmatic or having COPD) - Verapamil (if patient is not having systolic heart failure) - Beta-blocker (if patient is not having systolic heart failure)

Haemodynamical stability in a regular monomorphic broadcomplex tachycardia (systolic blood pressure >100 mmHg: - Procaïnamide - Amiodaron