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Tachycardia: Difference between revisions
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''Sébastien Krul, MD, Louise Olde Nordkamp, MD''{{DevelopmentPhase}} | ''Sébastien Krul, MD, Louise Olde Nordkamp, MD, Jonas de Jong, MD'' | ||
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=Introduction= | =Introduction= | ||
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[[File:overview.png|thumb|300px|'''Figure 1.''' Classification of tachyarrhythmias.]] | [[File:overview.png|thumb|300px|'''Figure 1.''' Classification of tachyarrhythmias.]] | ||
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 myocardial tissue 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. Supraventricular arrhythmias are relatively common and rarely life-threatening. VT's are rhythm disorders that only involve the ventricles. It can both take place in the myocardial tissue and the conduction system tissue. | ||
=Supra-ventricular tachycardia= | =Supra-ventricular tachycardia= | ||
==Atrial arrhythmias== | ==Atrial arrhythmias== | ||
The following arrhyhmias arise in the atrium. Dependent on the amount of conduction block in the AV-node the ventricles follow the atrial contraction. However, at higher atrial rates the AV-node starts to block conduction from atrium to ventricle. | The following arrhyhmias arise in the atrium. Dependent on the amount of conduction block in the AV-node the ventricles follow the atrial contraction. However, at higher atrial rates the AV-node starts to block conduction from atrium to ventricle.<cite>Blomstrom-Lundqvist</cite> | ||
===Sinus Tachycardia=== | ===Sinus Tachycardia=== | ||
====Pathophysiology:==== | ====Pathophysiology:==== | ||
When the sinus node fires with a frequency between 100-180bpm, the term sinustachycardia is used. The maximum heart rate a person can achieve during exercise can be calculated by subtracting the age in years from 210. Usually it is a physiological reaction to stress (exercise, inflammation, stress). External factors can increase the heart rate like coffee and alcohol or drugs. The term inappropriate sinus tachycardia is | When the sinus node fires with a frequency between 100-180bpm, the term sinustachycardia is used. The maximum heart rate a person can achieve during exercise can be calculated by subtracting the age in years from 210. Usually it is a physiological reaction to stress (exercise, inflammation, stress). External factors can increase the heart rate like coffee and alcohol or drugs. The term inappropriate sinus tachycardia is a persistent increase in resting heart rate or sinus rate unrelated to or an exaggerated response to stress. | ||
====Clinical diagnosis:==== | ====Clinical diagnosis:==== | ||
A sinus tachycardia usually has a gradual start and ending. Diagnosis on the ECG can be made by the morphology of the P-wave. The P-wave has the same morphology during sinus tachycardia as during normal sinus rhythm. | A sinus tachycardia usually has a gradual start and ending. Diagnosis on the ECG can be made by the morphology of the P-wave. The P-wave has the same morphology during sinus tachycardia as during normal sinus rhythm. An inappropriate sinus tachycardia is diagnosed by when the sinus tachycardia is persistent (therefore non-paroxysmal) and no trigger can be identified. | ||
====Management:==== | ====Management:==== | ||
No treatment is indicated, usually the sinustachycardia will pass when the external trigger is removed. If patients have complaints a beta-blocker can be administered. | No treatment is indicated, usually the sinustachycardia will pass when the external trigger is removed. If patients have persistent complaints, the trigger cannot be removed or in case of a inappropriate sinus tachycardia a beta-blocker can be administered. Patients with a contra-indication for beta-blockers can use nondihydropyridine calcium-channel blockers. | ||
===Atrial Tachycardia=== | ===Atrial Tachycardia=== | ||