Fatal cardiac arrhythmias in patients with heart failure: Risk stratification, treatment and prevention Dr Reginald Liew MA, MB BS (Hons), PhD, FRCP, FACC, FESC, FAsCC Director/ Senior Consultant Cardiologist The Harley Street Heart and Cancer Centre Mount Elizabeth Novena Specialist Centre, Singapore Outline of presentation • • • • • Incidence and epidemiology Risk stratification for SCD Role of ICDs for 1ry and 2ry prevention Catheter ablation and drug treatment Other considerations Outline of presentation • • • • • Incidence and epidemiology Risk stratification for SCD Role of ICDs for 1ry and 2ry prevention Catheter ablation and drug treatment Other considerations Incidence of Sudden Cardiac Death SCD in post MI patients • Atherosclerotic coronary artery disease remain the most important underlying substrate for accountable sudden cardiac death • Survivors of myocardial infarction especially with left ventricular dysfunction, is the high risk population being focused on and where most of the data has been available Events leading to SCD in post MI patients Liew R; Heart 2010 Outline of presentation • • • • • Incidence and epidemiology Risk stratification for SCD Role of ICDs for 1ry and 2ry prevention Catheter ablation and drug treatment Other considerations Which parameters will help identifying patients who require ICD? • • • • • • • • NYHA functional class Non-sustained VT QT dispersion and variability Cardiac autonomic modulation (HRV, BRS, HRT) Signal –averaged ECG Microvolt T wave alternans EP testing LVEF Signal averaged ECG •Late potential represents low amplitude high frequency electrical activity at the terminal portion of QRS Thought to be due to slow conduction and delayed myocardial activation, a marker of ischemic substrate •The prognostic value of SAECG had been reported In MUSTT trial, patients with abnormal SAECG has higher rate of arrhythmic and total mortality (36% vs 13% yr incidence) but the sensitiviy and specificity was inadequate to guide ICD therapy Liew R; Heart 2010 WEARABLE CARDIOVERTER DEFIBRILLATOR Conclusions • Various methods for risk stratification of fatal arrhythmias in pts with heart failure - LVEF remains most widely used and featured in guidelines • ICDs can lower risk of SCD- timing is important • Medical therapy not effective to reduce SCD but can be useful to reduce ICD shocks • Catheter ablation of VT/ VF indicated for recurrent ventricular arrhythmias or ICD shocks; should be done in experienced EP centres • Newer options to consider- subcutaneous ICD, wearable cardioverter defibrillator (short term measure) Gleneagles Hospital, #02-38/41, Annexe Block 6A Napier Road, Singapore T +65 6472 3703 Email: reginald.liew@harleystreet.sg www.harleystreet.sg Mount Elizabeth Novena Specialist Centre #07-41, 38 Irrawaddy Road, Singapore T +65 6694 0050 Which parameters will help identifying patients who require ICD? • NYHA functional class and presence of nonsustained VT not provide incremental value in risk assessment over other parameters such as LVEF • In MADIT II and some small epidemiological studies, QT measurements had been shown to be associated with malignant ventricular arrhythmias However the sensitivitiy was too low to be clinically useful Which parameters will help identifying patients who require ICD? • Patients with depressed baroreflex sensitivity(BRS)