Tachyarrhythmias Flashcards
Tachyarrythmias etiology:
Genetic Structural heart disease Metabolic Toxic Extracardiac
Classification of tachyarrythmias :
🔸supraventricular arrhythmias :
1)atrial tachycardia
2)tachyarrythmias involving atrioventricular junction :
a- atrioventricular nodal re-entrant tachycardia (AVNRT)
b-atrioventricular re entrant tachycardia(AVRT )
3)atrial flutter
4)atrial fibrillation
🔸ventricular arrhythmias :
1)premature ventricular complexe
2)ventricular tachycardia
Supra-ventricular tachycardia:
- rhythm disorder with rate higher than 100/min
- the site is above His bundle
- it associates a narrow QRS complex <120sec
- may have the expression of a wide QRS
Classification of atrial fibrillation:
🔸first diagnosed : not diagnosed before
🔸parixymal: terminates spontaneously or with intervention within 7 days of onset
🔸persistent: continuously sustained beyond 7 days , includes episodes terminated by cardioversion after >7days
🔸long standing persistent: continuous >12 months
🔸permanent: AF that is accepted by the pt and physician , and no futher attempts to restore or maintain sinus rhythm
Mechanisms for the different types of atrial fib:
1) paroxysmal: ectopic foci
2) persistent: single circuit re-entry
3) permanent: multiple circuit re entry
Clinical presentation of atrial fib:
Sympts: asymptomatic , palpitations , dyspnea, dizziness, angina , syncope
Signs :
Irregular cardiac sounds
Pulse deficit
Management of atrial fib:
✅anticouagulant treatment
✅ventricular rate control
✅conversion and maintaining sinus rhythm
***the ABC pathway( a=anticouagulation/avoid stroke , B=better symptom control, c= comorbidities/ CV risk factor )
CHADS2-VASc score =
The risk for stroke
C=congestive heart failure 1️⃣ H=hypertension1️⃣ A=age>75 2️⃣ D= DM1️⃣ S2=prior TIA or stroke2️⃣ V=vascular disease 1️⃣ A= age 65-751️⃣ Sc= sex category (female)1️⃣ If>2 males , females >3
HAS-BLED Score =
Bleeding risk
Hypertension 1️⃣ Abnormal renal/liver function1️⃣or2️⃣ Stroke 1️⃣ Bleeding tendency1️⃣ Labile INR1️⃣ Age (>65)1️⃣ Drugs or alcohol 1️⃣or2️⃣ Max score 9 >3 high risk of bleeding
When cant we adminster DOAC?
Moderate mitral stenosis 
Mechanical valvular prothesis
Target of rate control treatment:
HR<80/min at rest
HR<110/min during effort
Ventricular rate control drugs :
Beta blockers (bisoprolol, metaprolol) Digoxin Clacium channel blockers (diltiazem, verapamil)
Converstion and maintaining sinus rhythm :
🔸electrical cardio version 🔸drug conversion: -Amiodarone Ibutilide , dofetilide Flecainide, dronedarone , sotalol, Propafenone 🔸radiofrequency transcatheter ablation of AF
Atrial Flutter:
-is rarely an arrythmia of a healthy heart , it often complicates structural heart disease
-precipitating factors:
Hypoxemia, hyperthyrodism or alcohol consumption
▪️typical flutter= right atrial macro re entrant circuit with the precipitation of the cavotricuspid isthmus
ECG of atrial Flutter:
🔸F waves with rate of 250-350/min
🔸V1 and the inferior leads
Atrial flutter mechanism:
▪️CC:
-Anticlockwise reentry circuit forms in the R. Atrium
-Left atrial activation occurs via Bachman’s bundle and the coronary sinus os (first occur via os )
-the majority of left atrial conduction and activation occur in a retrograde manner , forming negative flutter waves in inferior leads (
▪️C:
-clockwise reentry circuit forms in the right atrium
-left atrial activation fist occur via BB
-majority of left atrial activation occurs in an anterograde manner , forming positive flutter waves in inferior leads
Atrial flutter management:
Acute treatment:
✅hemodynamic degradation-> electrical cardioversion50-150J
✅hemodynamically stable patient : Amiodarone , ibutilide , dofetilide
Long term treatment:
-thrombolytic risk -> anticoagulant
-HR control: bb, ccb
-rhythm control: radio-frequency ablation of ICT
-elective electrical cardioversion
PSVT: ( paroxymal supraventricular taxhycardia)
Arryhthmia involving atrioventricular junction
Frequent arrhythmia
- clinically: episodes of palpitation with fast rhythm , regular , with sudden onset and end
- outside the crisis , the person has characterstics of healthy person
Types of PSVT:
1) atrioventricular nodal re entrant tachycardia
2) atrioventricular reentrant tachycardia
AVNRT=
-appears frequently in normal women
-clinically: palpitations felt in the neck “cannon waves”
-ECG:
Narrow complex tachycardia (150-200/min)
PR short
Without visible p waves / retrograde p waves
Treatment of AVRT :
Vagal maneuvers :
✅ forced exhalation with closed glove ✅blown into an empty syringe
✅immersion of the face in a cold watter or application of ice to the chest
✅pressing the eyeballs
✅squatting position
Carotid massage
Adenosine
——-
-Giving up consumption of coffee , cola , energy drinks
-Intense symptoms, cardiopathology, risky professions :
Bb, ccb, propafenone , flecainide
- ablation of the slow intranodal pathway and accessory pathways
Premature ventricular complexes :
Ventric. tachyarrhythm
🔸PVC is a large QRS complex that occurs early with origin in the ventricular myocardium
🔸sympts: palpitations , dyspnea, thoracic discomfort
🔸ECG: a large QRS with a morphology of a bundle branch block
****
PVCs originating in the left ventr. Have a RBBB morphology while pVCs originating in the right ventr. Have a LBBB morph.
Treatment of PVCs:
✅pts with no symptoms: no need for treatment
✅ pts with symptoms need treatment:
- first bb treatment + electrolyte supplementation ( k, mg)
- class IC or IIIantiarrhythmic
-radiofrequency ablation-> monomorphic ESV
-AMIODARON- > structural heart disease
Vtach:
Defined as 3 or more consecutive PVCs at a rate grater than 100/min
Vtach classifications:
🔸according to duration:
Non sustained: less than 30 sec
Sustained : longer than 30 sec or hemodynamic instability
Vtach symptoms:
Palpitations Chest pain Dyspnea Syncope Sudden cardiac death
Important questions :
1. QRS regular ? Yes => Vtach/ SVT No =>atrial fibrillation —— 2.QRS large ? Yes=> Vtach No=> SVT —— 3.historic ? Responses to vagal maneuvers? -Age , preexisting pathology
Vtach , unstable hemodynamically;
Electric shock
Treatment of different types of Vtach:
Vtach originated from ischemia : amiodarone +BB
✅Bidirectional Vtach: treatment of digitalis intoxication
✅brugada synd: quinidine
✅torsades de point: magnesium sulfate
✅fascicular tachycardia: verapamil
✅catecholaminergic polymorphic tachycardia: nadolol, propanolol
Implantable cardiac defibrillator (ICD)=
-sustained VT, structural heart disease
-documented myocardial scar and sustained Vt
-
Radiofrequency ablation:
-no structural heart disease -> improvement of sympt.
- structural heart disease :
- when anti arrhythmic medications are not tolerated or recurrent under treatment
-the causes are not reversible
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