Management of Arrhythmia in the Acute Medical Unit Sudha Mani Associate Specialist in Cardiology Certified Cardiac Device Specialist • Arrhythmia and syncope – Common presentation to A&E and Acute Medical unit • Significant number of admissions and readmissions • Benign or Life threatening condition • May need education and reassurance or referral for interventions A young rugby player admitted with presyncope and breathlessness Polymorphic VT or SVT with LBBB ? A young lady with palpitations and lightheadedness AV nodal reentry or AV reentrant or Atrial Tachycardia? Clinical decisions/Uncertainties • Wide QRS tachycardia - Is it SVT or VT? • IV Adenosine or IV Amiodarone or DC Cardioversion? • Admit or Discharge? Refer to Cardiology? • Is Syncope a simple faint or harbinger of SCD? • AF – Rate control or Rhythm control? Arrhythmias in the Acute Medical Unit • Supraventricular Tachycardia – Regular or Irregular • Sustained or non sustained Ventricular Tachycardia • Syncope or Palpitations with a substrate for Sudden Cardiac Death- Cardiomyopathy or Channelopathy • Rhythms with an Indication for Pacing Interesting? Supraventricular Tachycardia “ Any tachyarrhythmia that requires Atrial or AV nodal tissue or both for its initiation and maintenance” • AV nodal and AV reentrant tachycardia (AVNRT/AVRT) • Atrial tachyarrhythmias Atrial Flutter/Atrial Fibrillation Atrial Tachycardia (focal AT or multifocal AT) Inappropriate Sinus Tachycardia Mechanism - Reentry with differential conduction • AV Nodal Reentrant Tachycardia (AVNRT) - Involves 2 functionally distinct pathways in AV node • AV Reentrant Tachycardia (AVRT) - Involves AV node and an accessory pathway • Atrial Flutter- Macro-reentrant tachycardia involving the cavo- tricuspid isthmus with counterclockwise or clockwise activation Mechanism of AV Nodal Reentrant Tachycardia Slow Fast AVNRT Antidromic AVRT Broad QRS Tachycardia Orthodromic AVRT Narrow QRS Tachycardia Atrial Flutter reentrant circuit in RA SVT- Clinical presentation • Palpitations, lightheadedness or syncope, fatigue, SOB • Polyuria - Higher Atrial Natriuretic Peptide levels • AVRT – in younger patients, no underlying heart disease – higher SVT rate • AVNRT – Middle aged or older, female patients – Pounding sensation in neck – Cannon A waves, Frog sign ECG Diagnosis of SVT • AVNRT-P waves within the terminal portion of QRS, pseudo S in inferior leads and pseudo R prime in V1 • AVRT- P waves in the early part of the ST segment • Irregular narrow QRS tachycardia A flutter, AF or Multifocal Atrial tachycardia • Inappropriate Sinus Tachycardia -Normal P waves preceding every QRS complex Typical AVNRT (Slow-Fast) Orthodromic AVRT-Regular Narrow QRS tachycardia Antidromic AVRT -Regular Broad QRS Tachycardia AVNRT/AVRT Principles of Medical therapy • Induce a block in one of the the pathways preventing reentry • Valsalva Manoeuvre -Bearing down against a closed glottis for 10-30 seconds • Diving reflex-Ice cold wet towel to face • Carotid sinus Massage - 5 to 10 seconds • Overall success rate - 27% in AV node dependent SVT Pharmacological treatment of AVNRT/AVRT • Adenosine short acting, half life 1-2 minutes Rapid bolus 6mg, 12 mg or 18 mg, successful in 80 -96% SE - SOB, flushing, chest discomfort • Terminates most reentrant and some triggered arrhythmia • Diagnose and unmask Atrial Flutter and Atrial Tachycardia Pharmacological treatment of AVNRT/AVRT • IV Verapamil 5-10 mg or IV Metoprolol 2.5-5 mg • May be used in suspected Antidromic AVRT, immediate access to defibrillation as AVRT may convert to AF • AF with pre-excitation - Immediate DC Cardioversion • Cardioversion if haemodynamic instability • SVT in pregnancy - Vagal manoeuvre, Adenosine, Verapamil or Metoprolol. AVNRT and AVRT -Long term management • Risk of recurrence after a single episode not well defined • Betablockers, Verapamil or Diltiazem effective in preventing recurrence in AVNRT and AVRT • Flecainide or Propafenone - AVRT or AF with pre- excitation • Ablation therapy offers a potential of definitive cure, first line therapy in AVRT and AF with WPW Atrial flutter and Atrial fibrillation • Flutter- Macro reentrant Atrial arrhythmia • Regular flutter rate and constant morphology • May co-exist with AF, management and stroke risk similar • AF risk Factors- HT, DM, Obesity, Elderly, CAD, HF and CKD. • Management AF/A flutter with haemodynamic instability- DCCV Stable AF- Rate control or Rhythm Control (<48 hr) Counterclockwise Atrial flutter 2:1 Block Atrial fibrillation AF Management - Rate control • If onset uncertain or > 48 hrs - Rate control and anticoagulation before rhythm control • IV or oral Metoprolol, Verapamil or Diltiazem • Preferred over digoxin as rapid onset and effectiveness at high sympathetic tone • Digoxin or Bisoprolol in heart failure or IV Amiodarone 150-300 mg over 30-60 mins • AF in Pregnancy- Betablockers and Digoxin safe for rate control Rhythm control in AF • Pharmacological cardioversion successful in 50% of recent onset AF • Flecainide 200 to 300 mg or Propafenone 450 to 600 mg • “Pill in the Pocket” after safety confirmed in hospital setting • DC Cardioversion more effective and quicker, but needs sedation and fasting, and more resource intensive • Amiodarone- Ischaemic heart disease or LVSD • Rhythm control strategy preferred option in • younger patients, highly symptomatic patients • first presentation with lone AF • AF with congestive heart failure Stable AF – Discharge once HR<110, or revert to SR AF with heart failure or poor rate control – Admission and referral to Cardiologist Ventricular arrhythmia • Arrhythmias in the setting of ACS/MI/LVSD • Inherited primary arrhythmia syndrome Channelopathies - LQTS, Brugada ,CPVT Cardiomyopathy - ARVC, HCM, DCM • Idiopathic Ventricular Tachycardia - RV outflow VT, Fascicular VT Ventricular Arrhythmias associated with CAD/HF • Betablockers , Betablockers and Betablockers • IV Metoprolol 5-10 mg or oral Metoprolol 50 mg • Correction of Hypokalemia and Hypomagnesemia • IV Amiodarone 150 -300 mg if frequent VT/VF • DCCV if haemodynamically unstable VT • IV Lignocaine if unresponsive to Betablockers and Amiodarone in ischaemic VT Idiopathic Right Ventricular Outflow Tract VT • Monomorphic VT, usually from RVOT or TV annulus • Usually seen in patients without any structural heart disease • May also occur in ARVC • ECG - LBBB morphology, Inferior axis • May be precipitated by catecholamine excess • May respond to adenosine /Betablockers 24 year old footballer collapsed on field RVOT tachycardia- LBBB with inferior axis A 16 year old with palpitations and breathlessness whilst swimming Left Ventricular Fascicular VT RBBB with Left Axis deviation Idiopathic fascicular VT • 10-15% of all idiopathic VT, reentrant tachycardia • Young patients 15-40 yrs, male predominance • May occur at rest, or exercise • ECG-Monomorphic VT, RBBB with LAD or RAD,QRS narrower than other VT(100-140 ms) • Verapamil Sensitive, unresponsive to Adenosine Catheter Ablation is used early in Idiopathic monomorphic VT arising from the RV or LV Inherited Channelopathy and Cardiomyopathy Undiagnosed cardiomyopathy is a common cause of sudden cardiac arrest (SCA) in otherwise healthy young adults; Arrhythmogenic Right Ventricular Cardiomyopathy • Autosomal dominant trait, Replacement of Cardiac myocytes by adipose tissue • Palpitations, syncope, VT and SCD, 2nd to 4th decade • Ventricular arrhythmia originates in RV, frequent VPC and NSVT common, LBBB morphology • ICD for secondary prevention (aborted SCD,VT) • ICD for Primary Prevention (unexplained syncope) ECG Arrhythmogenic right ventricular cardiomyopathy T inversion in V1 to V5, Epsilon waves Syncope in a young athlete Hypertrophic cardiomyopathy • Common genetically inherited disease ( 1 in 500) • Risk of sudden cardiac death <1% • Usually treated with beta blockers • Risk factors for sudden cardiac death • Previous sustained VT (>30 seconds) or cardiac arrest • Family history of sudden cardiac death • Severe LVH (>30mm) • Previous unexplained syncope Primary Inherited Arrhythmia Syndromes LQTS and Brugada Long QT syndrome (LQTS) • QTC > 480 msec or 460 msec if h/o syncope • Annual rate of SCD 0.3 -0.9%, higher if h/o syncope • Mutations in genes coding for potassium/sodium or calcium ion channels (KCNQ1, KCNH2 and SCN5A) Brugada syndrome • Autosomal dominant trait SCN5A mutation • Clinical manifestations more frequent in adults and men • 2mm ST elevation in right precordial leads Long QT Syndrome Brugada syndrome LQTS management Betablockers in all patients, avoid QT prolonging drugs, electrolyte abnormalities ICD therapy in LQTS • Documented spontaneous sustained VT/VF • VT or syncope in patients on betablockers ICD therapy in Brugada syndrome • Survivors of cardiac arrest • Documented spontaneous sustained VT • Spontaneous Type I ECG pattern with h/o syncope Atrial flutter with slow ventricular rate or CHB To Pace or not to Pace? Trifascicular Block with syncope To Pace or not to Pace? A 17 year old presents to A&E with a h/o palpitations while playing football. On arrival, he is stable and his BP is 130/85 • A regular broad complex tachycardia, 190 bpm , QRSd of 150 msec • LBBB morphology, normal axis, no visible P waves • DD - – AV nodal reentrant tachycardia with LBBB – AV reentrant tachycardia with antegrade conduction over an accessory pathway-Antidromic AVRT – Ventricular Tachycardia Factors favouring VT • Broad QRS (>160msec) Northwest axis • Absence of typical LBBB or RBBB pattern • Positive or negative concordance in precordial leads •