Synopsis of Management on Ventricular arrhythmias Rouge/1613 Soni_TB_4x3/VT_20… · ICD therapy,...
Transcript of Synopsis of Management on Ventricular arrhythmias Rouge/1613 Soni_TB_4x3/VT_20… · ICD therapy,...
(Torsades de pointes)“Twists of points”
Comment: The QRS changes from negative to positive polarity and appears to twist around the isoelectric line.
Ventricular arrhythmias
• Asymptomatic ventricular arrhythmias in the absence of identifiable heart disease predicted a small increase in risk (Ann Intern Med 1992;117:990–6) , while another study suggested no increased risk.(J Intern Med 1999;246:363–72)
• PVCs and runs of NSVT in subjects with structural heart disease contribute to an increased mortality risk.
• Suppression of PVCs – Severe and disabling symptoms.
• Beta blocker – Antiarrhythmic
• Refractory cases: Radiofrequency catheter ablation.
Ventricular arrhythmias
• SCD is leading cause of death in USA. estimates in the range of 300,000 to 350,000 SCDs annually.
• At least 50% of all SCDs due to CHD occur as a first clinical event or among subgroups of patients thought to be at relatively low risk for SCD.
• The rhythm most often recorded at the time of sudden cardiac arrest is ventricular tachyarrhythmia (VF>>VT).
Automated external defibrillator
• Approximately 80% of cardiac arrests occur out-of hospital.
• AED saves lives when external defibrillation can be rendered within minutes of onset of VF.
• Its use by both traditional and nontraditional first responders appears to be safe and effective.
• Federal, state and community efforts have been effective in placing AEDs in schools, sporting events, high-density residential sites and airports as well as on airplanes and in police and fire department vehicles.
EVALUATION OF PATIENTS WITH DOCUMENTEDOR SUSPECTED VENTRICULAR ARRHYTHMIAS
• Resting Electrocardiogram
• Exercise Testing
• Ambulatory Electrocardiography
• Left Ventricular Function and Imaging –Echocardiogram, Cardiac CT/MRI, Myocardial perfusion SPECT, Coronary angiogram
• Electrophysiological Testing
• EP testing for the evaluation of VT was introduced in 1972 by Wellens et al.
Ventricular arrhythmias
• Beta blocker
• Antiarrhythmic till 1980 (Class I III)
• ICD (First ICD placed in feb 1980)
• Ischemia
• Electrolytes (K and Mg)
• Drugs
• Ablation
• Surgery
Therapies For Ventricular Arrhythmia
• Beta blockers are effective in suppressing ventricular ectopic beats and arrhythmias as well as in reducing SCD in a spectrum of cardiac disorders in patients with and without HF.
• With the exception of beta blockers, the currently available antiarrhythmic drugs have not been shown in randomized clinical trials to be effective in the primary management of patients with life-threatening ventricular arrhythmias or in the prevention of SCD.
Special Considerations WhereAntiarrhythmic Drugs May Be Indicated
• Patients With Ventricular Tachyarrhythmias Who Do Not Meet Criteria for an Implantable Cardioverter-Defibrillator
• Patients With ICD Who Have Recurrent Ventricular Tachycardia/Ventricular Fibrillation With Frequent Appropriate ICD Firing.
• Patients With ICD Who Have Paroxysmal or Chronic Atrial Fibrillation With Rapid Rates and Inappropriate ICD Firing.
Conclusions:Among survivors of ventricular fibrillationor sustained ventricular tachycardia causingsevere symptoms, the implantable cardioverter–defibrillator is superior to antiarrhythmic drugs forincreasing overall survival.
(N Engl J Med 1997;337:1576-83.)
Conclusions::In patients with a prior myocardial infarctionwho are at high risk for ventricular tachyarrhythmia,prophylactic therapy with an implanted defibrillatorleads to improved survival as comparedwith conventional medical therapy.
(N Engl J Med 1996;335:1933-40.)
ConclusionsIn patients with a prior myocardial infarctionand advanced left ventricular dysfunction,prophylactic implantation of a defibrillator improvessurvival and should be considered as a recommendedtherapy.
(N Engl J Med 2002;346:877-83.)
Conclusions::In patients with NYHA class II or III CHF and LVEF of 35 percent or less, amiodarone has no favorable effect on survival, whereas single-lead, shock-only ICD therapy reduces overall mortality by 23 percent.
NEJM 352;3 January 20, 2005
Implantable Cardioverter Defibrillator
ICD therapy, compared with conventional or traditional antiarrhythmicdrug therapy, has been associated with mortality reductionsfrom 23% to 55% depending on the risk group participatingin the trial, with the improvement in survival due almostexclusively to a reduction in SCD.
ACC/AHA/ESC 2006
Catheter Ablation Therapy
• Used for more than 25 years.
• Success rate; Normal heart > 90%, Structural heart disease 50-75%
• Initially used in the treatment of patients with multiple ICD shocks for VT (VT storm), it is now used more frequently and earlier in the management of VT.
• Excellent choice for patients when medications are not effective, tolerated, or preferred.
Mapping of VT
Surgical therapy
• EP mapping and surgical resection of an arrhythmogenic focus.
• Left cervicothoracic sympathetic ganglionectomy in LQTS
• Large myocardial aneurysms secondary to MI are associated with hemodynamic compromise and are frequently accompanied by major ventricular arrhythmias.
• In selected patient aneurysm resection can improve cardiac function and may reduce or eliminate the accompanying ventricular arrhythmia.