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Syncope A Diagnostic and Treatment Strategy. Developed by: David G. Benditt, M.D. Richard Sutton, DScMed University of Minnesota Medical Center Royal Brompton Hospital, London, UK. Presentation Overview. Prevalence & Impact Etiology Diagnosis & Evaluation Options
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SyncopeA Diagnostic and Treatment Strategy Developed by: David G. Benditt, M.D. Richard Sutton, DScMed University of Minnesota Medical Center Royal Brompton Hospital, London, UK
Presentation Overview • Prevalence & Impact • Etiology • Diagnosis & Evaluation Options • Specific Conditions • Treatment Options • Insights into more efficient and effective diagnosis and treatment of patients with syncope
The Significance of Syncope The only difference between syncope and sudden death is that in one you wake up.1 1 Engel GL. Psychologic stress, vasodepressor syncope, and sudden death. Ann Intern Med 1978; 89: 403-412.
The Significance of Syncope 1 National Disease and Therapeutic Index on Syncope and Collapse, ICD-9-CM 780.2, IMS America, 1997 2 Blanc J-J, L’her C, Touiza A, et al. Eur Heart J, 2002; 23: 815-820. 3 Day SC, et al, AM J of Med 1982 4 Kapoor W. Evaluation and outcome of patients with syncope. Medicine 1990;69:160-175
Individuals <18 yrs Military Population 17- 46 yrs Individuals 40-59 yrs* Individuals >70 yrs* 15% 20-25% 16-19% 23% Syncope Reported Frequency *during a 10-year period Brignole M, Alboni P, Benditt DG, et al. Eur Heart J, 2001; 22: 1256-1306.
infrequent, unexplained: 38% to 47% 1-4 explained: 53% to 62% The Significance of Syncope • 500,000 new syncope patients each year 5 • 170,000 have recurrent syncope 6 • 70,000 have recurrent, infrequent, unexplained syncope 1-4 1 Kapoor W, Med. 1990;69:160-175. 2 Silverstein M, et al. JAMA. 1982;248:1185-1189. 3 Martin G, et al. Ann Emerg. Med. 1984;12:499-504. 4 Kapoor W, et al. N Eng J Med. 1983;309:197-204. 5 National Disease and Therapeutic Index, IMS America, Syncope and Collapse #780.2; Jan 1997-Dec 1997. 6 Kapoor W, et al. Am J Med. 1987;83:700-708.
The Significance of Syncope • Some causes of syncope are potentially fatal • Cardiac causes of syncope have the highest mortality rates 1 Day SC, et al. Am J of Med 1982;73:15-23. 2 Kapoor W. Medicine 1990;69:160-175. 3 Silverstein M, Sager D, Mulley A. JAMA. 1982;248:1185-1189. 4 Martin G, Adams S, Martin H. Ann Emerg Med. 1984;13:499-504.
Impact of Syncope 73% 1 71% 2 60% 2 Proportion of Patients 37% 2 Anxiety/Depression Alter DailyActivities RestrictedDriving ChangeEmployment 1Linzer, J Clin Epidemiol, 1991. 2Linzer, J Gen Int Med, 1994.
Syncope:ASymptom…Not a Diagnosis • Self-limited loss of consciousness and postural tone • Relatively rapid onset • Variable warning symptoms • Spontaneous complete recovery
Causes of Syncope1 1Kapoor W. In Grubb B, Olshansky B (eds) Syncope: Mechanisms and Management. Armonk NY; Futura Publishing Co, Inc: 1998; 1-13.
Syncope: Etiology Neurally- Mediated Orthostatic Cardiac Arrhythmia Structural Cardio- Pulmonary Non- Cardio- vascular • 1 • Vasovagal • Carotid Sinus • • Situational • Cough • Post- micturition • 2 • Drug • Induced • • ANS • Failure • Primary • Secondary • 3 • Brady • Sick sinus • AV block • • Tachy • VT • SVT • Long QT Syndrome * • 4 • Aortic Stenosis • HOCM • • Pulmonary • Hypertension • 5 • Psychogenic • • Metabolic • e.g. hyper- • ventilation • Neurological 24% 11% 14% 4% 12% Unknown Cause = 34% DG Benditt, UM Cardiac Arrhythmia Center
Causes of Syncope-like States • Migraine* • Acute hypoxemia* • Hyperventilation* • Somatization disorder (psychogenic syncope) • Acute Intoxication (e.g., alcohol) • Seizures • Hypoglycemia • Sleep disorders * may cause ‘true’ syncope
Syncope Diagnostic Objectives • Distinguish ‘True’ Syncope from other ‘Loss of Consciousness’ spells: • Seizures • Psychiatric disturbances • Establish the cause of syncope with sufficient certainty to: • Assess prognosis confidently • Initiate effective preventive treatment
Initial Evaluation(Clinic/Emergency Dept.) • Detailed history • Physical examination • 12-lead ECG • Echocardiogram (as available)
Syncope Basic Diagnostic Steps • Detailed History & Physical • Document details of events • Assess frequency, severity • Obtain careful family history • Heart disease present? • Physical exam • ECG: long QT, WPW, conduction system disease • Echo: LV function, valve status, HOCM • Follow a diagnostic plan...
Conventional Diagnostic Methods/Yield 9 Day S, et al. Am J Med. 1982; 73: 15-23. 10 Stetson P, et al. PACE. 1999; 22 (part II): 782. 5 Kapoor, JAMA, 1992 6 Krahn, Circulation, 1995 7 Krahn, Cardiology Clinics, 1997. 8 Eagle K,, et al. The Yale J Biol and Medicine. 1983; 56: 1-8. 1 Kapoor, et al N Eng J Med, 1983. 2 Kapoor, Am J Med, 1991. 3 Linzer, et al. Ann Int. Med, 1997. 4 Kapoor, Medicine, 1990. * Structural Heart Disease †MRI not studied
SyncopeEvaluation and Differential Diagnosis • Complete Description • From patient and observers • Type of Onset • Duration of Attacks • Posture • Associated Symptoms • Sequelae History – What to Look for
12-Lead ECG • Normal or Abnormal? • Acute MI • Severe Sinus Bradycardia/pause • AV Block • Tachyarrhythmia (SVT, VT) • Preexcitation (WPW), Long QT, Brugada • Short sampling window (approx. 12 sec)
Carotid Sinus Massage • Site: • Carotid arterial pulse just below thyroid cartilage • Method: • Right followed by left, pause between • Massage, NOT occlusion • Duration: 5-10 sec • Posture – supine & erect
Carotid Sinus Massage • Outcome: • 3 sec asystole and/or 50 mmHg fall in systolic blood pressure with reproductionof symptoms = Carotid Sinus Syndrome (CSS) • Contraindications • Carotid bruit, known significant carotid arterial disease, previous CVA, MI last 3 months • Risks • 1 in 5000 massages complicated by TIA
Conventional AECGLow Yield, Poor Symptom / Arrhythmia Concordance* • 8 studies, 2612 patients • 19% pts had symptoms with AECG • Only 4% had arrhythmia with symptoms • 79% pts were without symptoms • 14% had arrhythmia despite absence of symptoms * ACC/AHA Task Force, JACC 1999;912-948
Head-up Tilt Test (HUT) • Unmasks VVS susceptibility • Reproduces symptoms • Patient learns VVS warning symptoms • Physician is better able to give prognostic / treatment advice
Head-Up Tilt Test (HUT) DG Benditt, UM Cardiac Arrhythmia Center
Electroencephalogram • Not a first line of testing • Syncope from Seizures • Abnormal in the interval between two attacks – Epilepsy • Normal – Syncope
Value of Event Recorder in Syncope *Asterisk denotes event marker Linzer M. Am J Cardiol. 1990;66:214-219.
Reveal® Plus Insertable Loop Recorder Patient Activator Reveal® Plus ILR 9790 Programmer
ILR Recordings* 56 yo woman with syncope accompanied with seizures. Infra-Hisian AV Block: Dual chamber pacemaker 65 yo man with syncope accompanied with brief retrograde amnesia. VT and VF: ICD and meds *Medtronic data on file
Unexplained Syncope after history, physical exam, ECG, Holter Low Risk (EF > 35%) ILR Usual care including: External loop recorder Tilt test, EPS and others - + - + External loop recorder Tilt test, EPS, others Diagnosis ILR Randomized Assessmentof Syncope Trial Krahn A, Klein GJ, Skanes Y. Circulation 2001; 104:46-51.
RAST Methods • Prospective randomized trial • 60 patients with unexplained syncope referred for cardiac investigation • Inclusion: • Recurrent unexplained syncope • Referred to the arrhythmia service for cardiac investigation • No clinical diagnosis after history, physical, ECG and at least 24 hours of cardiac monitoring • Exclusion: • LVEF < 35% • Unable to give informed consent • Major morbidity precluding one year of follow-up Krahn A, Klein GJ, Skanes Y. Circulation 2001; 104:46-51.
ILR n=30 Conventional n=30 RAST Results Unexplained Syncope n=60 In Follow-up n=3 Diagnosed n=14 Undiagnosed n=13 Diagnosed n=6 Undiagnosed n=24 Krahn A, Klein GJ, Skanes Y. Circulation 2001; 104:46-51.
RAST Crossover Results Unexplained Syncope n=60 13/30 Undiagnosed after monitoring 6 accepted crossover to conventional 24/30 Undiagnosed after conventional 21 accepted crossover to ILR Diagnosed n=1 Undiagnosed n=5 Diagnosed n=8 Undiagnosed n=5 In follow-up n=8 Krahn A, Klein GJ, Skanes Y. Circulation 2001; 104:46-51.
RAST - Diagnoses number of patients Krahn A, Klein GJ, Skanes Y. Circulation 2001; 104:46-51.
Conventional EP Testing in Syncope • Limited utility in syncope evaluation • Most useful in patients with structural heart disease • Heart disease……..50-80% • No Heart disease…18-50% • Relatively ineffective for assessing bradyarrhythmias Brignole M, Alboni P, Benditt DG, et al. Eur Heart Journal 2001; 22: 1256-1306.
EP Testing in Syncope:Useful Diagnostic Observations • Inducible monomorphic VT • SNRT > 3000 ms or CSRT > 600 ms • Inducible SVT with hypotension • HV interval ≥ 100 ms (especially in absence of inducible VT) • Pacing induced infra-nodal block
ISSUE Study InternationalStudyofSyncopeof UncertainEtiology • Objectives: • Understand the mechanism of syncope in tilt-positive and tilt-negative (isolated) patients • Use the ILR to assess the correlation of rhythms captured during tilt testing and spontaneous recurrent episodes • Inclusion Criteria: • Patients with three or more syncopal episodes in the last 2 years • Groups matched in age, sex, history of syncope, ECG, Echo abnormalities, SHD and arrhythmias Moya A. Circulation. 2001; 104:1261-1267
111 syncope patients 3 episodes in 2 years, first and last episode >6 months apart History, physical exam, ECG, CSM, echo, Holter (24 hr), other tests as appropriate Tilt test followed by implant of Reveal Insertable Loop Recorder Follow-up to recurrent spontaneous episode ISSUE Study Design • Multicenter, prospective Moya A. Circulation. 2001; 104:1261-1267
ISSUE Study Results Moya A. Circulation. 2001; 104:1261-1267
ISSUE Study • Conclusions: • Homogeneous findings from tilt-negative and tilt-positive syncope patients were observed (clinical characteristics and outcomes). Most frequent finding was asystole secondary to progressive sinus bradycardia, suggesting a neuromediated origin • In this study tilt-negative patients had as many arrhythmias (18%) as tilt-positive patients (21%) • In tilt-positive patients the spontaneous episode ECG was more frequently asystolic than what was predicted by tilt test Moya A. Circulation. 2001; 104:1261-1267
ISSUE Study Implications • HUT outcome was not predictive of vasodepressor vs. cardioinhibitory response • Bradycardia is common in spontaneous VVS - independent of HUT outcome • Bradycardia is more prevalent in spontaneous events vs. HUT induced VVS • Clinical Implication: Consider a strategy of postponing treatment until a spontaneous episode can be documented Moya A. Circulation. 2001; 104:1261-1267
Symptom-Rhythm Correlation Auto Activation Point Patient Activation Point
Diagnostic Limitations • Difficult to correlate spontaneous events and laboratory findings • Often must settle for an attributable cause • Unknowns remain 20-30% 1 1Kapoor W. In Grubb B, Olshansky B (eds) Syncope: Mechanisms and Management. Armonk NY; Futura Publishing Co, Inc: 1998; 1-13.
Unexplained Syncope Diagnosis History and Physical Exam Surface ECG ENT Evaluation Endocrine Evaluation • CV Syncope Workup • Holter • ELR or ILR • Tilt Table • Echo • EPS • Neurological Testing • Head CT Scan • Carotid Doppler • MRI • Skull Films • Brain Scan • EEG • Other CV Testing • Angiogram • Exercise Test • SAECG Psychological Evaluation Adapted from: W.Kapoor.An overview of the evaluation and management of syncope. From Grubb B, Olshansky B (eds) Syncope: Mechanisms and Management. Armonk, NY: Futura Publishing Co., Inc.1998.
Tilt Holter/ ELR ILR Tilt ILR Typical Cardiovascular Diagnostic Pathway Syncope History and Physical, ECG KnownSHD NoSHD > 30 days; > 2 Events < 30 days Echo EPS - + Tilt/ILR Treat Adapted from: Linzer M, et al. Annals of Int Med, 1997. 127:76-86. Syncope: Mechanisms and Management. Grubb B, Olshansky B (eds) Futura Publishing 1999 Zimetbaum P, Josephson M. Annals of Int Med, 1999. 130:848-856. Krahn A et al. ACC Current Journal Review,1999. Jan/Feb:80-84.
Neurally-Mediated Reflex Syncope (NMS) • Vasovagal syncope (VVS) • Carotid sinus syndrome (CSS) • Situational syncope • post-micturition • cough • swallow • defecation • blood drawing • etc.
NM Reflex Syncope: Pathophysiology • Multiple triggers • Variable contribution of vasodilatation and bradycardia