Low dose quinidine test in patients with Brugada syndrome

Low dose quinidine test in patients with Brugada syndrome

S266 heart disease: 20% (CAD 69%). 123 pts (28%) with Sync/Presync were admitted, representing 0.51% of all ER. The average length of stay was 7.4⫾9.8...

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S266 heart disease: 20% (CAD 69%). 123 pts (28%) with Sync/Presync were admitted, representing 0.51% of all ER. The average length of stay was 7.4⫾9.8 days. The average estimated cost in admitted pts was CAN$ 4570.33⫾4700 (HHSC). Diagnosis at the ER visit, discharge and RESASTER diagnosis are summarized in the table:

Conclusions: Application of a retrospective algorithmic diagnostic approach applied during ER assessment of pts with sync/presync increased diagnostic yield (15% to 77%), with vasovagal syncope accounting for more than half of the diagnosis. Simple clinical markers obtained from history and physical examination may reduce unnecessary testing, costs and hospital admissions in pts presenting with syncope to the ER. P5-37 TILT TESTING - IS IT NECESSARY IN ALL PATIENTS WITH NEURALLY MEDIATED SYNCOPE? Piotr Kulakowski, MD, Dorota Piotrowska and Agnieszka Konofalska. Grochowski Hospital, Warsaw, Poland. Tilt testing is a well-established diagnostic tool in neurally mediated syncope (NMS). However, it is time consuming, requires special equipment and its value in predicting effective therapy is questionable. Symptomatology of NMS is often very typical and in some patients history alone may be sufficient to diagnose NMS which may obviate the need for TT. The aim of the study was to assess which symptoms associated with syncope can predict TT results. The study group consisted of 202 unselected patients (69 males, mean age 43⫾20 years) who underwent TT (700, 45 min, no pharmacological provocation) due to suspected NMS. A detailed history, including 34 variables concerning symptoms, and clinical parameters were evaluated (multivariate stepwise logistic regression, ROC curves). Results: TT was positive in 71 (34 %) patients. Of 6 variables which were significantly more frequently encountered in patients with positive TT, two - prolonged standing before syncope and sweating associated with syncope, independently predicted TT results. Sensitivity, specificity and accuracy values of the point scores based on symptoms in the whole study group, in a subgroup with a history of ⬎ 4 syncopal episodes, and in patients with ⬎ 2 syncopal spells during 1 month before TT are presented in Table Conclusions: In patients with recurrent syncope, certain details from medical history can predict TT results. Thus, TT may be omitted in these patients.

P5-38 PREDICTORS OF RESIDUAL RISK EVENT IN PATIENTS WITH ISOLATED SYNCOPE OR PRESYNCOPE AND A NEGATIVE ELECTROPHYSIOLOGIC STUDY Antoine Da Costa, MD, PhD, Jean Luc Gulian, MD, Ce´cile Rome´yer-Bouchard, MD, Michel Messier, PhD, Je´roˆme The´venin, MD, Bernard Samuel, RN, Abdel Kihel, MD and Karl Isaaz, MD. University Jean Monnet of Saint-Etienne, St. Etienne, France. Background: Patients with syncope (S) or near S of unknown etiology represent a great challenge to cardiologists. Objective: This study targets predictors of cardiac rhythmic events in pts with a reported episode of S or near S presenting with negative diagnostics and electrophysiologic study (EPS). A significant cardiac rhythmic event

Heart Rhythm, Vol 2, No 5, May Supplement 2005 was defined as a combined end-point of symptomatic (1) AV block; (2) conduction abnormalities requiring pacemaker therapy; (3) sustained ventricular arrhythmia; and (4) sudden death. Methods: All pts undergoing EPS after a first episode of S or pre-S between 01.97 and 12.01 were included. The population consisted of 329 pts (42.6% women), mean age of 70⫾15 years. Results: Of the 329 pts who underwent EPS, 305 (92.7%) had follow-up data. Characteristics of pts were as following: history of myocardial infarction (MI) (12%), history of atrial fibrillation (10%), structural heart disease (17.4%), LVEF (61⫾11%) and ECG abnormalities (37%). These anomalies included right (RBBB) or left (LBBB) bundle branch blocks, left anterior or posterior fascicular block (LAFB or LPFB), bifascicular block (RBBB ⫹ LAFB) and traces of MI. The mean follow-up was 31⫾20 months with 5% of pts recording arrhythmic events (15/305): AV block in 7 pts, sinus dysfunction in 4, sudden death in 3 and ventricular tachycardia in 1. Univariate analysis reveals structural heart disease, ECG abnormalities and LVEF associated with the risk of significant cardiac rhythmic events. Multivariate analysis using a Cox model found that the only independent predictor was an ECG abnormality. The long-term risk of event in the subset with ECG abnormalities is of 10.6% (12/113). If unexplained S recurrence was included in the end-point, ECG abnormality and LVEF were both determinants with a 13.3% (15/113) risk of a arrhythmic events in the subset of pts presenting with ECG abnormalities and Cox model found ECG abnormality as the only independent predictor. Conclusions: This study demonstrated that an ECG abnormality is the only predictive variable associated with a significant arrhythmic event in pts with a lone episode of S or near S and a negative EPS.

P5-39 LOW DOSE QUINIDINE TEST IN PATIENTS WITH BRUGADA SYNDROME Atsuyuki Watanabe, MD, Kengo Fukushima Kusano, MD, Hiroshi Morita, MD, Kimikazu Banba, MD, Nobuhiro Nishii, MD, Satoshi Nagase, MD, Kazufumi Nakamura, MD, Hironori Saitoh, MD and Tohru Ohe, MD. Okayama Graduate School of Medcine and Dentistry, Japan. Background: Brugada syndrome is characterized by ST segment elevation in right precordial leads. Some reports indicate that the mechanism of ST segment elevation is explained by the difference in the expression of the transient outward current (Ito) between end- and epi-cardium. Several reports suggest that quinidine administration normalizes ST segment elevation by reducing Ito current and prevent spontaneous ventricular fibrillation (VF) in Brugada syndrome. Therefore we examine the effect of low dose quinidine on electrocardiographic changes in patients with Brugada syndrome. Methods and Results: Twenty-eight patients of BS were examined (4 symptomaic patients and 24 asymptomatic patients). The degree of ST segment elevation in the right precordial leads and late potentials (LP) were evaluated before and after administration of low dose quinidine (200mg). We divided into 2 groups{responder: attenuation of ST segment elevation (⌬ST⬍-0.2mV) and non-responder}. Four patients of 28 patients (14%) were responder. Three of 4 responder patients were symptomatic patients. Quinidine concentration was not different between 2 groups. All indices of LP after quinidine were not different between 2 groups. During mean follow up periods of 10 months, 3 patients, who were all responder, had documented several clinical VF attacks. In one patient, quinidine was administered for the prevention of electrical storm and VF was completely suppressed. In one symptomatic patient who was non-responder, VF attack was not documented during three years. Conclusion: These data indicate that the mechanism of ST elevation may be different between symptomatic and asymptomatic patients with Brugada syndrome. Low dose quinidine test may be useful to predict clinical VF attack with BS.