Sinus BradycardiaCardiac impulses arise in the sinus node at a rate lessthan 60/min.Etiology:A- Physiologic: Athletes, sleep, and carotid sinuscompression.B- Pharmacologic: Digitalis, propranolol, verapamiland diltiazem.C- Pathologic: Convalescence from infections,hypothyroidism, obstructive jaundice, rapid rise ofthe intracranial tension, hypothermia and myocardialinfarction (particularly inferior wall infarction)
SUPRAVENTRICULARTACHYARRHYTHMIASSVTs may be separated into three groups based onduration: brief paroxysms, persistent, and chronic(permanent).Arrhythmias that are paroxysmal in onset and offset(e.g. paroxysmal SVT due to AV nodal reentry orWPW syndrome, paroxysmal atrial fibrillation,paroxysmal atrial flutter) tend to be recurrent and ofshort duration
Supraventricular tachyarrhythmiasinclude:atrial tachycardia,atrial flutter,atrial fibrillationand AV tachycardias.
Management of PSVT Due to AV Nodal ReentryThe acute attack: Vagal maneuvers serve as the firstline of therapy. Simple procedures to terminateparoxysmal SVT- Carotid sinus massage: If effective the rhythm isabruptly stopped; occasionally only moderateslowing occurs- Cold water splash on face.- Performance of Valsalvas maneuver (ofteneffective).
Management of PSVT Due to AV Nodal ReentryIntravenous adenosine, Ca channel blockers(verapamil), digoxin or B-blockers are the choicesfor managing the acute episodes.Adenosine, 6 mg given intravenously, followedby one or two 6-mg boluses if necessary, iseffective and safe for acute treatment.A 5-mg bolus of verapamil (isoptin) , followed byone or two additional 5-mg boluses 10 min apartif the initial dose does not convert thearrhythmia
short PR interval, less than 3 small squares (120 ms)slurred upstroke to the QRS indicating pre-excitation (delta wave)broad QRSsecondary ST and T wave changesLocalising the accessory pathwayAn accessory pathway, bundle of Kent, exists between atria and ventricles and causesearly depolarisation of the ventricle. The location of the pathway may be deduced as follows:-LOCATION V1 V2 QRS axisleft posteroseptal (type A) +ve +ve leftright lateral (type B) -ve -ve leftleft lateral (type C) +ve +ve inferior (90 degrees)right posteroseptal -ve -ve leftanteroseptal -ve -ve normalWolf-Parkinson-White syndrome
PSVT Due to Accessory Pathways (The Wolff-Parkinson-WhiteSyndrome)
atrial fibrillation:Duration- Paroxysmal Minutes/hours- Short-lasting Seconds --<1 hour- Long-lasting >1 hour; -- < 48 hours- Persistent Two days -- weeks- Permanent (Chronic) Months / years
A 53 year old man with Ischaemic Heart Disease.
A woman with loud first heart sound and mid-diastolicmurmur.
Treatment of Atrial FibrillationPharmacologic Management of Patients with RecurrentPersistent or Permanent AF:- Recurrent Persistent AF:A) Minimal or no symptoms: Anticoagulation and ratecontrol as needed.B) Disabling symptoms in AF:1- Anticoagulation and rate control2- Antiarrhythmic drug therapy3- Electrical cardioversion as needed, continueanticoagulation as needed and therapy to maintain sinusrhythm- Permanent AF: Anticoagulation and rate control asneeded.
Drugs for Pharmacologic Cardioversion of AF (Rhythmcontrol)Drug Route of Admin. And DosageAmiodarone Oral: 1.2 to 1.8 g /day then 200 to 400 mg /d maintenance.IV: 1.2 g /d IV continuous or in divided doses, then 200 to 400mg /d maintenanceDofetilide Oral: Creatinine clearance > 60 ml/min: 500 mcg BIDFlecainide Oral 200 to 300 mgIV: 1.5 to 3 mg /kg over 10 to 20 minPropafenone Oral: 450 to 600 mgIV: 1.5 to 2 mg per kg over 10 to 20 min
Orally Administered Pharmacological Agents for HeartRate Control in Patients with AFDrug Maintenance doseDigoxin 0.125 to 0.375 mg dailyMetoprolol* 25 to 100 BIDPropranolol 80 to 360 mg daily in divided dosesVerapamil 120 to 360 mg daily in divided dosesDiltiazem 120 to 360 mg daily in divided doses
Anticoagulation of Patients with AtrialFibrillation: IndicationsRheumatic mitral valve disease with recurrent orchronic atrial fibrillation.Dilated cardiomyopathy with recurrent persistent orchronic atrial fibrillation.Prosthetic valves.Prior to (>3 weeks) elective cardioversion ofpersistent or chronic atrial fibrillation, and also for 3weeks after cardioversion (because of atrialstunning).Coronary heart disease or hypertensive heart diseasewith recurrent persistent or chronic atrial fibrillation
Treatment of Cardiac Arrhythmias with CatheterAblative TechniquesRadiofrequency ablation destroys tissue bycontrolled heat production. Catheter ablation isused to treat patients with four majortachyarrhythmias:atrial flutter/fibrillation, AV nodal reentry,accessory pathways and ventricular tachycardia.