Clin. Cardiol. 15,4344(1992)
Electrophydology, Padng, and Antrythmla This section edited by A. John Camm, M.D., ER.C.I?, EA.C.C.
Which Ventricular Tachycardia Is Dangerous? SINAN GURSOY, M.D., RAMON BRUGADA, M.D., JOSEP BRUGADA, M.D.,
PEDRO BRUGADA, M.D., ERIKANDRIES, M.D
Cardiovascular Center, OLV Hospital, Aalst, Belgium
Summary: The treatment of ventricular arrhythmias remains a major challenge in cardiology. Several very helpful pieces of information can be obtained from the clinical history. The left ventricular function and the hemodynamic effects of a ventricular tachycardia are the two main factors affecting survival. Therefore, if a patient with sustained ventricular tachycardia presents with syncope or cardiac arrest, or if his functional class for dyspnea is IIIIV (NYHA classification), he is a candidate for an implantable defibrillator while otherwise medical therapy is advised.
of the most difficult problems to tackle in clinical cardiology. Treatment modalities presently available remain sparse and mostly palliative. A major misconception that still exists is that ventricular arrhythmias per se are not a disease entity themselves but a manifestation of an underlying one. However, with the presently available epidemiologic data, the patient with ventricular arrhythmias can be offered optimal care based on simple but solid clinical grounds.
Analysis of the Available Therapeutic Modalities Key words: ventricular tachycardia, implantable defibrillator, antiarrhythmic, cardiac arrest, syncope
Introduction Our understanding of facts in rhythmology has expanded in a quite exponential manner in the last two decades and the abundance of available data, a phenomenon seen in most fields in medicine, has made things very difficult if not impossible to follow, even for the subspecialist. Despite all these changes, ventricular arrhythmias remain one
Address for reprints: Pedro Brugada, M.D. Cardiovascular Center OLV Hospital 9300 Aalst Belgium Received: October 9, 1991 Accepted: November 1, 1991
There are very effective drugs for treating ventricular arrhythmias at the disposition of the clinician. The CAST study, although it did not achieve its set goals, has clearly shown that even simple medical therapy carries a significant mortality and morbidity.' Within the context of medical therapy, serial drug testing is an ineffective, costly, and inefficient way of approaching the problemq2The other therapeutic alternatives include the implantable defibrillators, ablation techniques (chemical or catheter), and The defibrillators, although extremely effective in treating recurrences, only offer palliation and the perioperative mortality and morbidity is not negligible. Antiarrhythmic surgery, even in the most experienced hands, carries an even higher risk which is prohibitive in most patients. Finally, ablation techniques are still at a very experimental stage and can be used only in a very selected small group of patients. Therefore, before choosing one of these options the risk-benefit ratio has to be weighed very carefully in each patient.
Risk Stratificationof the Patient with Ventricular Arrhythmias As no benign treatment is available and as treatment has not been shown to affect overall survival (which is usually good), the patient with nonsustained ventricular arrhyth-
Clin. Cardiol. Vol. 15, January 1992
44
mias should not be treated. In patients with sustained ventricular arrhythmias there are subgroups of patients that are at a specially high risk; patients with syncopal ventricular tachycardia or cardiac arrest occurring with exercise have a risk of 35%, patients with syncopal ventricular tachycardia or cardiac arrest and a compromised left ventricular function have a risk of 25% and those with a history of multiple myocardial infarctions have a risk of 20%.5. But if all the subsets are analyzed, two factors have emerged as affecting survival: first, the nature of the presenting arrhythmia, in other words, the presence of hernodynamic collapse; and second, the overall left ventricular function of the patient^.^. Patients having either of these two risk factors, regardless of the other variables involved, have a risk of sudden death of more than 10%.These two pieces of information can be obtained easily from the clinical history? Syncope or cardiac arrest due to the arrhythmia will point to hernodynamic collapse, while the presence of a functional class for dyspnea greater than two will underline the severity of the left ventricular dysfunction. As the overall risk involved in the implantation of a defibrillator is far below lo%, we find it justified in this high-risk subset to proceed with the implantation of such a device. The remaining patients have a good prognosis with medical therapy alone and no further intervention is required unless there is a recurrence of the ventricular tachycardia. In that case the patient needs to be re-evaluated (Fig. 1).
*
Syncope/Cardiac Arrest or NYHk3
ICD
Medical Rx
Ablation (chemical or catheter)
FIG.1 Decision tree for the selection of therapy in patients with sustained ventricular tachycardia or fibrillation. A patient who presents with sudden cardiac death or syncope during the arrhythmic event or has a NYHA functional class for dyspnea greater than two is assigned to the ICD branch. The patient is otherwise treated with medical therapy until a recurrence is observed. ICD =implantable cardioverter defibrillator, NYHA = New York Heart Association functional class for dyspnea, Rx= therapy.
Impact of a Simplified Approach on Overall Care If patients with sustained ventricular arrhythmias are examined as a whole group, only 23% of these patients fall in the high-risk group and therefore are assigned to the implantable defibrillator arm of the decision tree. The remaining patients can be managed medically with such drugs as amiodarone, sotalol, or propafenone. The number of patients who require surgery or ablation still amounts to fewer than 15%. It should be remembered that our approach might be even more aggressive in the near future as progress is made in all areas. Transplantation is becoming a more widely used alternative, ablation techniques are becoming more refined and effective, and with the advent of new technology, transvenous sophisticated defibrillators with antitachycardia functions are becoming available which may have a lower rate of morbidity. Although care for patients with ventricular tachycardia is becoming more and more complex, the decision to treat can be reached with relative ease based on information available to all clinicians and the appropriate patient be referred, if necessary, to a tertiary care facility.
References 1. Task Force of the Working Group on Arrhythmias of the European Society of Cardiology: CAST and beyond. Implications of the cardiac arrhythmia suppression trial. Circulation 8 1, 1123-1127 (1990) 2. Bmgada P, Wellens HJJ: Cardiac Arrhythmias: Where to Go from Here? Futura Publishing Co., Inc., Mount Kisco, NY (1987) 3. Winkle RA, Mead RH, Ruder MA, Gaudian VA, Smith NA, Buch WS, Schmidt P,Shipman T:Long term outcome with the automatic implantable cardioverter-defibrillator. J Am Coll Cardiol 13, 1353 (1989) 4. Bmgada P, de Swart H, Smeets J, Wellens HJJ: Transcoronary chemical ablation of ventricular tachycardia. Circulation 79, 475-482 (1989) 5. Bmgada P, Talajic M, Smeets J, Mulleneers R, Wellens HJJ: Risk stratification of patients with ventricular tachycardia or fibrillationafter myocardial infarction. The value of the clinical history. Eur Heart J 10,747-752 (1989) 6. Rodriguez LM, Waleffe A, Brugada P, Dehareng A, Lezaun R, Sternick AB, Kulbertus HE: Exercise induced sustained symptomatic ventricular tachycardia: Incidence, clinical angiographic and electrophysiologic characteristics.Eur Heart J 11,
225-232 (1989)
7. Swerdlow CD, Winkle RA, Mason Jw: Determinants of survival in patients with ventricular tachymhythmias. N Engl J Med 308, 1436-1442 (1983) 8. Bigger JT Jr, Fleiss JL, Kleiger R, Miller JP, Rolintzky LM, and the Multicenter Post-Infarction Research Group: The relationships among ventricular arrhythmias, left ventricular dysfunction and mortality in the two years after myocardial infarction. Circulation 69,2508 (1984)
Electrophydology, Padng, and Antrythmla This section edited by A. John Camm, M.D., ER.C.I?, EA.C.C.
Which Ventricular Tachycardia Is Dangerous? SINAN GURSOY, M.D., RAMON BRUGADA, M.D., JOSEP BRUGADA, M.D.,
PEDRO BRUGADA, M.D., ERIKANDRIES, M.D
Cardiovascular Center, OLV Hospital, Aalst, Belgium
Summary: The treatment of ventricular arrhythmias remains a major challenge in cardiology. Several very helpful pieces of information can be obtained from the clinical history. The left ventricular function and the hemodynamic effects of a ventricular tachycardia are the two main factors affecting survival. Therefore, if a patient with sustained ventricular tachycardia presents with syncope or cardiac arrest, or if his functional class for dyspnea is IIIIV (NYHA classification), he is a candidate for an implantable defibrillator while otherwise medical therapy is advised.
of the most difficult problems to tackle in clinical cardiology. Treatment modalities presently available remain sparse and mostly palliative. A major misconception that still exists is that ventricular arrhythmias per se are not a disease entity themselves but a manifestation of an underlying one. However, with the presently available epidemiologic data, the patient with ventricular arrhythmias can be offered optimal care based on simple but solid clinical grounds.
Analysis of the Available Therapeutic Modalities Key words: ventricular tachycardia, implantable defibrillator, antiarrhythmic, cardiac arrest, syncope
Introduction Our understanding of facts in rhythmology has expanded in a quite exponential manner in the last two decades and the abundance of available data, a phenomenon seen in most fields in medicine, has made things very difficult if not impossible to follow, even for the subspecialist. Despite all these changes, ventricular arrhythmias remain one
Address for reprints: Pedro Brugada, M.D. Cardiovascular Center OLV Hospital 9300 Aalst Belgium Received: October 9, 1991 Accepted: November 1, 1991
There are very effective drugs for treating ventricular arrhythmias at the disposition of the clinician. The CAST study, although it did not achieve its set goals, has clearly shown that even simple medical therapy carries a significant mortality and morbidity.' Within the context of medical therapy, serial drug testing is an ineffective, costly, and inefficient way of approaching the problemq2The other therapeutic alternatives include the implantable defibrillators, ablation techniques (chemical or catheter), and The defibrillators, although extremely effective in treating recurrences, only offer palliation and the perioperative mortality and morbidity is not negligible. Antiarrhythmic surgery, even in the most experienced hands, carries an even higher risk which is prohibitive in most patients. Finally, ablation techniques are still at a very experimental stage and can be used only in a very selected small group of patients. Therefore, before choosing one of these options the risk-benefit ratio has to be weighed very carefully in each patient.
Risk Stratificationof the Patient with Ventricular Arrhythmias As no benign treatment is available and as treatment has not been shown to affect overall survival (which is usually good), the patient with nonsustained ventricular arrhyth-
Clin. Cardiol. Vol. 15, January 1992
44
mias should not be treated. In patients with sustained ventricular arrhythmias there are subgroups of patients that are at a specially high risk; patients with syncopal ventricular tachycardia or cardiac arrest occurring with exercise have a risk of 35%, patients with syncopal ventricular tachycardia or cardiac arrest and a compromised left ventricular function have a risk of 25% and those with a history of multiple myocardial infarctions have a risk of 20%.5. But if all the subsets are analyzed, two factors have emerged as affecting survival: first, the nature of the presenting arrhythmia, in other words, the presence of hernodynamic collapse; and second, the overall left ventricular function of the patient^.^. Patients having either of these two risk factors, regardless of the other variables involved, have a risk of sudden death of more than 10%.These two pieces of information can be obtained easily from the clinical history? Syncope or cardiac arrest due to the arrhythmia will point to hernodynamic collapse, while the presence of a functional class for dyspnea greater than two will underline the severity of the left ventricular dysfunction. As the overall risk involved in the implantation of a defibrillator is far below lo%, we find it justified in this high-risk subset to proceed with the implantation of such a device. The remaining patients have a good prognosis with medical therapy alone and no further intervention is required unless there is a recurrence of the ventricular tachycardia. In that case the patient needs to be re-evaluated (Fig. 1).
*
Syncope/Cardiac Arrest or NYHk3
ICD
Medical Rx
Ablation (chemical or catheter)
FIG.1 Decision tree for the selection of therapy in patients with sustained ventricular tachycardia or fibrillation. A patient who presents with sudden cardiac death or syncope during the arrhythmic event or has a NYHA functional class for dyspnea greater than two is assigned to the ICD branch. The patient is otherwise treated with medical therapy until a recurrence is observed. ICD =implantable cardioverter defibrillator, NYHA = New York Heart Association functional class for dyspnea, Rx= therapy.
Impact of a Simplified Approach on Overall Care If patients with sustained ventricular arrhythmias are examined as a whole group, only 23% of these patients fall in the high-risk group and therefore are assigned to the implantable defibrillator arm of the decision tree. The remaining patients can be managed medically with such drugs as amiodarone, sotalol, or propafenone. The number of patients who require surgery or ablation still amounts to fewer than 15%. It should be remembered that our approach might be even more aggressive in the near future as progress is made in all areas. Transplantation is becoming a more widely used alternative, ablation techniques are becoming more refined and effective, and with the advent of new technology, transvenous sophisticated defibrillators with antitachycardia functions are becoming available which may have a lower rate of morbidity. Although care for patients with ventricular tachycardia is becoming more and more complex, the decision to treat can be reached with relative ease based on information available to all clinicians and the appropriate patient be referred, if necessary, to a tertiary care facility.
References 1. Task Force of the Working Group on Arrhythmias of the European Society of Cardiology: CAST and beyond. Implications of the cardiac arrhythmia suppression trial. Circulation 8 1, 1123-1127 (1990) 2. Bmgada P, Wellens HJJ: Cardiac Arrhythmias: Where to Go from Here? Futura Publishing Co., Inc., Mount Kisco, NY (1987) 3. Winkle RA, Mead RH, Ruder MA, Gaudian VA, Smith NA, Buch WS, Schmidt P,Shipman T:Long term outcome with the automatic implantable cardioverter-defibrillator. J Am Coll Cardiol 13, 1353 (1989) 4. Bmgada P, de Swart H, Smeets J, Wellens HJJ: Transcoronary chemical ablation of ventricular tachycardia. Circulation 79, 475-482 (1989) 5. Bmgada P, Talajic M, Smeets J, Mulleneers R, Wellens HJJ: Risk stratification of patients with ventricular tachycardia or fibrillationafter myocardial infarction. The value of the clinical history. Eur Heart J 10,747-752 (1989) 6. Rodriguez LM, Waleffe A, Brugada P, Dehareng A, Lezaun R, Sternick AB, Kulbertus HE: Exercise induced sustained symptomatic ventricular tachycardia: Incidence, clinical angiographic and electrophysiologic characteristics.Eur Heart J 11,
225-232 (1989)
7. Swerdlow CD, Winkle RA, Mason Jw: Determinants of survival in patients with ventricular tachymhythmias. N Engl J Med 308, 1436-1442 (1983) 8. Bigger JT Jr, Fleiss JL, Kleiger R, Miller JP, Rolintzky LM, and the Multicenter Post-Infarction Research Group: The relationships among ventricular arrhythmias, left ventricular dysfunction and mortality in the two years after myocardial infarction. Circulation 69,2508 (1984)
