Cardiogenic Syncope
Cardiovascular syncope is a brief loss of consciousness (from a few seconds to a few minutes), that is characterized by rapid onset and spontaneous recovery.
Transient loss of consciousness is a dramatic symptom, which has many possible mechanisms and hence different therapeutic, psychosocial, and prognostic implications. It is a common cause both for emergency room visits and for hospitalisation.
Tentative strategy for evaluation of the cardiovascular mechanism of syncope in a patient without palpitations or history of familial (genetic) disease predisposing to loss of consciousness, and episodes less frequent than weekly. A surface ECG is considered a mandatory part of the initial evaluation, as well as hospitalisation and ECG monitoring, if the patient arrives at the emergency department because of a recent episode. Echocardiography for evaluation of cardiac structure and function is a useful early investigation.
| Surface ECG abnormal, but not immediately diagnostic |
| A Cardiovascular disorders: |
| Q waves suggesting myocardial infarction, or other signs of ischaemic heart disease |
| Negative T waves in V1–3 with/without epsilon waves, suggestive of arrhythmogenic right ventricular dysplasia (cardiomyopathy) |
| High amplitudes with/without ST segment depression and negative T waves in left sided precordial leads, suggestive of left ventricular hypertrophy |
| B Primary electrophysiologic abnormalities: |
| Prolonged QT interval |
| Right bundle branch block pattern with ST elevation in V1–3, suggestive of the Brugada syndrome |
| Bifascicular block* or undetermined intraventricular conduction abnormalities (QRS ≥ 0.12 s) |
| Mobitz type I second degree atrioventricular block |
| Sinus bradycardia (< 50 beats/min) or sinus pauses |
| Invasive electrophysiological testing or therapeutic actions without further delay |
| Surface ECG normal |
| A In a young person with normal physical examination, first episode: |
| Head-up tilt testing |
| If there are recurrent episodes, also: |
| Evaluation of the presence of SHD with echocardiography and stress testing |
| Holter monitoring 48 hours |
| Implantable loop recorder |
| B In a middle aged person: |
| Evaluation of the presence of SHD: |
| SHD yes: Invasive electrophysiologic study |
| Head-up tilt testing |
| Implantable loop recorder |
| SHD no: Head-up tilt testing |
| Implantable loop recorder |
| (Invasive electrophysiologic study) |
| C. In an older person: |
| Carotid sinus massage |
| Evaluation of the presence of SHD |
| Head-up tilt testing |
| Invasive electrophysiologic study |
| Implantable loop recorder |
