Document 6576790
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Document 6576790
Cardiac arrest and resuscitation / Wolff-Parkinson-White syndrome | P 2 0 4 2 Concentrations of serum lnterteukin-8 after successful cardiopulmonary resuscitation in humans with cardiac arrest P2044 379 Who survives non-shocked out of hospital cardiopulmonary arrest Arretttype Intubated % Suntval to dtecharge(%) Crew witnessed (n-303) Bystander (n-3192) Unwitnessed <n-543) Ye» No Yes Mo Yes No 17 63 43 57 44 56 1Z0 55.6* 7.4 14.9* 1.7 4.3 "p < 0 001 intubatod versus non-lntubated Murrjvariate regression analysis showed that both the number of shocks delivered and intubation were adverse predictors of the outcome of resuscitation, although there was no statistical Interaction between the two. Patients who arrested before the arrival of the ambulance and/or required multiple D.C. shocks were more likely to be Intubated. The poor outcome in arrest requiring paramedic skills Is likely to reflect the length and difficulty of the resuscitation attempt However, only a randomised prospective trial could confirm its value or otherwise in pre-hospltal resuscitation. It has been observed that electrocardlographic preexcrtatlon changes over time. However, few papers describe the natural course of Wolff-ParkinsonWhite (WPW) syndrome occurring on the routine etectrogram (ECG) in young people. Methods: To evaluate the natural course of WPW syndrome In young people, We examined the record of annual medical examination and the annually recorded routine ECG in 13459 (12898 male and 561 female) consecutive healthy college students while they are enrolled in Nagasaki Institute of Applied Science between 1965 and 1995. Results: 32 subjects were found to have preexcftation at enrollment, for a prevalence ol 2.4 per 1000. An additional 2 subjects were found to have a delta wave during follow up. Total 34 study subjects (0.25%) (33 male, 1 female) were found to have WPW syndrome In the 4-year follow up. The mean age at entry was 18.4 years (range, 18 to 21 years). 8 subjects (24%) had palpitations. Of these, 3 subjects had clinical evidence of paroxysmal supraventricular tachycardia. However, these subjects did not need to be treated for symptoms of their arrhythmias. 5 of 34 study subjects (15%) had intermittent WPW syndrome: 4 of 5 wtth Intermittent preexcftation at enrollment 3 of 32 study subjects (9%) whofirstdemonstrated preexdtatJon did not have a delta wave by the end of follow up. All subjects remained alive during study. The location of accessory pathways determined by surface ECG was left lateral 15, left posterior 4, posteroseptal 5, right free wall 9, anteroseptal 1. In conclusion, 4-year follow up of college students with WPW syndrome revealed that delta wave has disappeared, WPW syndrome did not confer excess mortality, even in the subject who developed symptomatic arrhythmias and there were many left sided accessory pathways. Downloaded from by guest on October 28, 2014 AJ. Mortey-Davies, J. Sirel, S.M. Cobbe. Dept. of Medical Cardiology, K.G. Shyu, H. Chang, C.C. Un, C.S. Un, P.L Kuan, C.R. Hung. Departments Glasgow Royal Infirmary, Glasgow, UK of Internal Medicine, Emergency Medicine and Surgery, ShtnKong Wu Ho-Su Cardiopulmonary arrest Is the leading cause of death in the UK. Patients preMemorial Hospital, Taipei, Taiwan senting in rhythms other than ventricular tachyarrhythmias i.e. non-shocked arrests (NSA). have a dismal outlook but there is limited data on their contribulnterteukin-8 (IL-8) is produced by various types ol human cells. It was the tion to total survival. mediator of reperfusion injury in animal models. In humans, the elect of cardiac arrest (CA) and successful CPR on serum IL-8 levels is not known. In Methods: From 1988 all out of hospital cardtopulmonary resuscitation (CPR) attempts in Scotland have been registered on the Heartstart Scotland 2000 order to measure serum IL-8 after CPR and compare changes of IL-8 levels database. NSA were defined as ambulance calls requiring either bystander or with hemodynamic variables after CPR, we conducted a prospective study in crew CPR where no shockable rhythm wasrecordedby the deflbrillator. Results patients with normothermlc, non-traumatic CA. are presented In the Utsteln Style. Response time is defined as emergency caB Methods: 39 patients (pts) with out-of-hospltal CA undergoing CPR were to arrival at the scene. enrolled. Venous blood samples were taken after CPR and at 1, and 2 hours after restoration of spontaneous circulation (ROSC) in order to measure serum Results: 9161 arrests had complete outcome data, 4906 were shocked and IL-8 by EUSA method. Heart rate and blood pressure were measured at the 4255 non-shocked. Survival was significantly greater in shocked arrests (13% Vs 1%, p < 0.001 CW Square). There were 44 NSA survivors, accounting same time when blood samples were taken. for over 6% of all survivors In this data series. 4 arrests were excluded from Results: In 19 pts, ROSC was achieved; In the remaining 20 pts successful analysis as the victims were fully conscious on crew arrival and they may not CPR was not possible. Mean serum IL-8 levels after CPR were significantly represent "true" cardiopulmonary arrest. higher in resuscitated pts than In nonresuscitated pts (228 ± 85 vs 5.9 ± 2.2 pg/ml, p < 0.01). The IL-8 levels in nonresuscitated pts were not significantly Non-shocked Witness dlf erent from those of normal healthy control. At 1 and 2 hours after ROSC, the Unwitnessed Bystander C/ew mean serum IL-8 levels were 282 ± 8 2 and 416 ±143 pg/ml, respectively. Mean values of systolic Wood pressure Immediately after, 1 and 2 hours after ROSC 1534 Total 2387 279 CPR pre ambulance CPF1+ CPRCPR+ C P f l were 117 ± 9, 130 ± 11, and 136 ± 13 mmHg, respectively. No significant 525 1009 992 279 1395 correlations were found between hemodynamic values and serum IL-8 levels. 67% 42% CPR% 33% 58% The levels of IL-8 were not significantly different between those pts who could 37 Admitted to ward 25 55 78 30 be discharged from the hospital and those pts who could not Admitted % 3.8% 5.7% 4.8% 5.5% 11% In conclusion, successful Initial CPR was associated with increased serum 1 Discharged alive 6 17 10 10 IL-8 concentrations in pts with CA. The serum IL-8 levels remained at high 0.6% 1.2% 0.2% Otscharged% 1.0% 36% values at 2 hours after ROSC. There were no significant differences in age, response time, or frequency of pre-ambulance CPR between survivors and non-survivors of NSA (MannWhitney p > 0.1). More NSA survivors had witnessed arrests. Arrest cause: 16 Out of hospital cardiac arrest and advanced life were cardiac, 12respiratory,6 secondary to drug overdose, 2 to trauma and support skills: the Heartstart Scotland project one each to pulmonary embolus, cerebrovascular accident and "cot death". J.N. Adams, S.M. Cobbe, J. Sirel, A.K. Marsden'. Department Medical The cause was unknown in 5 cases. 1 Cardiology, Royal Infirmary; Scottish Ambulance Service, Glasgow, UK Conclusion: Patients with out of hospital cardiopulmonary arrest presenting in non-shockable rhythms represent a heterogeneous group. Despite the low Increasing numbers of paramedic ambulance personnel are trained In advanced survival rate they constitute a significant proportion of all survivors. life support techniques including endotracheal intubation. However the value of these skills used in the management of pre-hospftal arrest has never been confirmed in a randomised clinical trial and it has been suggested that the use of full paramedic skills results in a poorer outcome than defibrillation alone. We reviewed data from all pre-hospital cardiac arrest between 1991 WOLFF-PARKINSON-WHITE SYNDROME and 1994. In 3872 (45.5%) case paramedic skills were used and of these 217 (5.6%) survived to discharge compared with a survival rale of 7.9% when these P2045 Follow up study of 4 years In college students with skills were not utilised. Data on the 4038 patients who received one or more Wolff-Parklnson-Whhe syndrome D.C. shocks were reviewed separately; patients were categorised according to whether the arrest occurred after arrival of the ambulance (crew witnessed), M. Hayano', S. Ozaki 2 , C. Ueyama', T. Hlrata', R. Sakamoto1, N. Komiya', or before arrival (bystander witnessed or unwitnessed). The outcome in these M. Nonaka'.S. Nakao1, K. Tsukahara1, K. Yano1. The 3rd Department of patients Is indicated In the table below. Internal Medicine, School ot Medicine, Nagasaki University;2 Health Center, Nagasaki Institute of Applied Science, Nagasaki, Japan 380 Wolff-Parkinson-White syndrome P 2 0 4 6 Ventricular fibrillation In Wolff-Parklnson-Whlte syndrome: lesson from a population non-pharmacologically treated J A Salerno, R. Do Ponti, C. Storti, M. Zarcflni, A. Ferrari, M. VTgano1. Dlv. of CarrOol.;1 Dtv. of CarxSosurg., IRCCS Pol. S. Matteo, Univ. of Pavia, Italy P2047 Incidence of documented atrial fibrillation after successful catheter ablation of the Wolff-Parklnson-Whlte syndrome Hjortur Oddsson', Nils Edvardsson, Hakan Walfridsson. 1 DMston of Cardiology, Orebro; Sahlgrens' University Hospital, Gdteborg, Sweden Background: Radiofrequency catheter ablation (RF) is an effective treatment of reentrant tachycardias but It is less -well known to what extent recurrence of atrial fibrillation (AF) is prevented by successful RF. Material: 183 consecutive patients (pts) with Woll-ParWnson-Wrifte syndrome (WPW) underwent successful RF. Mean age 37.2 ± 16.5 year (range 10-79 year). 141 pts had overt WPW w h i l e ^ e f t s had concealed WPW. 53 of 183 pts (29%) had AF prior to RF, 7 eeneealee'-ane' 46 overt WPW. Evaluation of recurrent arrhythmias was done using a questionnafre, hospital records and individual contacts. The follow-up period was 21.8 ± 11.5 months. Results: The 53 pts who had AF before RF were characterised by higher age (45 ± 15.2 vs 33 ± 15.9 p = 0.0001), increased atrial vulnerability (42 vs 18% p - 0.001) (induced AF during Incremental atrial pacing or single or double extrastimuD), male gender (75 vs 52% p - 0.004), and preexcitation (87 vs 73% p - 0.05), while no correlation was found between the location of the accessory pathways, structural heart disease or the duration of symptoms. AF occurred In 11 ef 183 pts after successful RF (6%). All eleven pts had AF prior to RF. The following factors predicted recurrence of AF; previous AF (100 vs 24% p - 0.0001), higher age (56 ± 11.8 vs 36 ± 16.1 year p - 0.0004), longer duration of symptoms (24 ± 16.3 vs 15 ± 12.7 year p - 0.03), and Increased atrial vulnerability (82 vs 22% p = 0.0001). Conclusions: The reduction in incidence of AF after successful RF indicates that the accessory pathway often Is Involved In the occurrence of AF but is not the only etiotogfcal factor. Previous AF, high age and atrial vulnerability appears to predict reoccurrence of atrial fforillation after successful RF. R. Hatala', W. Supper, W. Kaltenbrunner, F. Freihoff, K. Stelnbach. L-Boltzmarm Arrhythmia Research InsL, Withelminenhospital, Vienna, Austria:1 Cardiovascular Dis. InsL, Bratislava, Slovakia Though atrial fibrBlation (A-FIb) is common In patients (pts) with WPW syndrome, relatively BttJe Is known about its recurrence (REC) following a successful (8ucc) raofofrequency catheter ablation (RFCA) of accessory pathway (AP). Therefore, It was the aim of this study to determine the value of post-RFCA follow-up (F-U) etectrophystotogic study (EPS) in predicting spontaneous A-Fft> REC after succ RFCA. Induced A-Ftt) was considered clinically relevant only if: 1. it was indudbte under basal condrttons (no teoproterenol) 2. it persisted for > 1 hour ("sustained" A-Fto) and required acute antiarrhythmic medication. For this purpose, 152 WPW pts free of structural heart disease undergoing succ RFCA of AP were prospectjvety evaluated. All pts underwent a F-U EPS (basal conditions and isoproterenol infusion) 32 ± 14 days post succ RFCA. The atrial stimulation protocol comprised programmed stimulation on 2 basic drives with up to 2 extrastimuli and rapid pacing with decremental cycle lengths until 1:1 AV nodal conduction was tost All pts were clinically followed for a mean period of 16 ± 9 months. Results: A-Fib was clinically documented prior to RFCA in 46/152 pts (30%). During F-U EPS, sustained A-FIb was induced in 8 pts: 7 had A-Rb documented prior to RFCA, 1 pt had not Thus, A-Flb was Inducible on F-U EPS In 7/46 pts with pre-RFCA A-Fib occurrence and In 1/106 pts without It (p < 0.001). Succ RFCA of AP has eliminated In long term the REC of A-Rb In 38/46 pts (83%). A-Flb spontaneously recurred post-succ RFCA In 8 pts, 5 of them had A-Flb inducWe during F-U EPS. The specificity and sensitivity of A-Fto induced during F-U EPS for the later spontaneous A-Fib REC is 98% and 63%, respectively. CondusJons: Pts with sustained A-Rb inducible during F-U EPS post-RFCA are prone to spontaneous clinically relevant A-Fib REC during subsequent F-U. Thus, F-U EPS helps to identify pts who are at risk of A-Rb REC despite successful RFCA of AP. P2049 Comparative Inducibility and subsequent duration of atrial fibrillation In asymptomatic Wofff-Parklnson-Whrte syndrome patients and In normal subjects D.-D. lonescu, A. Antonovtci, M. Enache, E. Danalla. Cardiology Department, Central Military Hospital, Bucharest, Romania Stressful activities may induee atrial fibrillation (AF) In Wolff-Parklnson-Whlte (WPW) Individuals who had no-previous symptoms. To address the issue we studied the comparative indudbiDty and subsequent duration of AF in 23 asymptomatic otherwise healthy youngsters with overt WPW syndrome aged 19-22 taken as patients (P) and in 10 normals (N) of the same age. The ATlrtdDCtionTJfotocol conststed In high-frequency (toea/min.) pacing of the right atrium (RA) in 6 successive attempts of 1, 5, 10, 20, 30 and 60 sec duration until either AF Induction or completion of protocol. The serial number of the successful attempt was considered as an inverse index of Inducibility (I,). AF was induced In all P (I) = 1 In 3, li - 2 In 8, \ - 3 In 7,1, - 4 In 2, I | - 5 l n 1 a n d l | = 6in2)butin only 7 N (li - 3 in 1, \ - 4 in 1, l| - 5 In 3 and l| in 2) the rest of 3 N being computed with l| = 7 as nonindudble. Statistical analysis of I) (Mann-WNtney-Wilcoxon test) revealed significant differences between P and N (p - 0.00027). AF duration (AFD) determined on a filtered bieolar RA electrograrn was less than 5 sec in 2 N, 5-60 sec in 4 N and 3 P, 1-5 mln in 1 N and 5 P and more than 5 min In 15 P. For measurement of the shortest preexcited RR interval (SRR-PX) in 8 P we performed more inducing attempts until an AF lasting more than 5 min was obtained (not counted as AFD). In 3 P AFD was more than 30 mln (47 min, 1 h 22 min, and 5 h) and in 1 P cardioversfon had to be performed after 10 min because of high ventricular rate and hypotension. The AFD was also significantly dif erent between P and N (Mann-Whitney-Wilcoxon test; p = 0.00053). In P, the SRR-PX correlated well with I, (r - 0.82, p < 0.0001) but not with AFD (r - 0.3433, p = 0.1176). Conclusion: In asymptomatic WPW P with no other pathologic finding AF is much more easily indudble and lasts longer than In healthy subjects of the same age. The presence of accessory pathways and the shortness of their artegrade refractory period appear to be risk factors for AF. Downloaded from by guest on October 28, 2014 Ventricular fibrillation (VF) in pts with Wotfl-Parkinson-White syndrome (WPW) can be a rare but potentially fatal event; in a selected population referred for non pharmacological treatment its incidence may be not irrelevant The aim of this study Is to report the characteristics of WPW pts who had previously experienced documented VF. Among the 715 WPW pts referred tor surgical ablation (185 pts) or racflofrequency catheter ablation (530 pts), 21 pts (15M, 6F; age 30 ± 12 yrs, range 18-57) with manifest accessory pathway experienced at least 1 episode of VF; pts with associated heart disease were excluded. In 9/21 pts (43%), VF was present at hospital admission, in another 9/21 pts (43%) atrial ftorillatlon (AF) degenerated Into VF during in-hospital Intravenous administration of antiarrhythmic drugs; in the remalng 3/21 pts (14%) the degeneration into VF was observed only during AF Induced at electrophyslologlcal study (EPS). Seven/21 pts (33%) had history of palpitation, another 6/21 pts (29%) of non documented syncopal episodes; the remaining 8/21 pts (38%) were completely asymptomatic. At EPS, the shortest R-R interval during induced AF was 180 ± 21 ms with 90-100% of preexcftated beats. The accessory pathway localization was as follows: free wall In 10/21 (48%) pts (left-sided in 9 and right-sided In 1), septal in 1/21 (4%) pts, postero-medal In 10/21 (48%) pts (left-sided In 5 and right-sided In 5). The accessory pathway was Interrupted by surgical cryoablation in the first 9 pts and by RFCA In the last 12. In conclusion: in a selected population of WPW pts, the occurrence of VF accounts for 3% and Is unrelated to organic heart disease. A considerable group of pts was asymptomatic before the potentially fatal episode of VF. Intravenous administration of antiarrhythmic drugs during preexcited AF, although of common practice in Italian emergency rooms, might possajly contribute to degeneration into VF. In this population, the prevalence of postero-medial accessory pathway location seems to be higher than in the general population of WPW pts. P2048 Inducibillty of atrial fibrillation during follow-up electrophysiotoojc study predicts Its spontaneous recurrence after successful catheter ablation of accessory pathways Wolff-Parkinson- White syndrome I Heart rate variability P2050 Value of several electrocardiographs algorithms to localize the ventricular Insertion of accessory pathways In Wotff-Parkinson-White syndrome J. Farre, J.A. Cabrera, J.M. Rubto, F. Navauo, L Sanziard, I. Lopez-Bravo, E. Aguado, R. Buj, P.P. Perez, M. Zamora. Arrhythmia Unit, Fundaddn Jimtnez Diaz, Madrid, Spain Several ECG algorithms (ALG) have been proposed to localize the accessory pathway (AP) in WPW patients (Pts). In 50 consecutive WPW Pts undergoing a successful radlofrequency catheter ablation (RFCA) of a single AP we have compared the reported positive predictive value (PPVREP) of 4 ECG-ALG with our own application of them In these Pts (PPV OURS)- We have developed a new ECG-ALG and have blindly subjected to its diagnostic ability the 12-lead ECG of 97 consecutive WPW Pts that had undergone a successful RFCA of a single AP. Fluorographic views in RAO and LAO projections of the successful RFCA sites were available for review. ECG-ALG are shown by the names of the institutions. As shown In the table, our ECG-ALG Is superior, in our hands, to the other 4. The sensitivity (SEN) and PPV of our ALG relative to AP location is: arrteroseptal (AS) 100% & 100%, right anterolateral (RAL) 100% & 100%, right posteroseptal (RPS) 100% & 56%, left lateral (LL) 100% & 100%, midseptaJ (MS) 79% a 100%, left posteroseptal (LPS) 88% & 100% coronary sinus posteroseptal (CSPS) 80% & 67%, right posterior (RP) 86% & 100%, left posterior (LP) 92% & 100%. Sites ECG-ALG St George's Aalst CaBfornla Univ. Oklahoma Our own 9 8 7 10 S PPVREP 86% 90% 95% 89% _ PPVOURS 36% 50% 38% 40% 98% AVLQor-(rS)LL* V1+- III+AS III±RAL IIIV2RSorRs notch III/V1 MS Q 4 notch II CSPS smooth Q III RPS V2 rS, ll+/± RAL, I I - RP V1 RSor Ra Q in III LPS V1 R QlnllILP "lack ol Q In III suggests atypical LL, 'marked pre-exdtatlon with V1 - . AS Conclusions: Reproduclblllty of ECG-ALG to localize the AP In WPW is poor. Dif erences in the interpretation of the fluoroscoptc anatomy may explain discrepancies. Each laboratory should validate an ECG-ALG according to their own anatomic abstractions from the fluoroscopic views of catheters. HEART RATE VARIABILITY P2051 Linear Indices of heart rate variability In male patients with mild heart failure due to coronary artery disease: comparison of patients with and without prior myocardlal Infarction T. Ristimae, M. Thetlol, R. Teesalu. Department ol Cardiology, University ol Tartu, Tartu, Estonia Heart rate variability (HRV) has become an Important tool for indirect assessment of autonomic dysbalance as well as prognosis in various cardiac diseases. In patients with congestive heart failure secondary to coronary artery disease (CAD), diminished values of HRV have been shown previously. However, no data concerning possible impact of different manifestations of CAD on HRV indices In subjects with heart failure are currently available. Subjects: 39 non-diabetic, age-matched male patients In NYHA functional class M l (mean age 57.1 ± 8.7 yr.) were studied. 28 patients had documented history of acute myocardial infarction (AMI) > 1 year ago (group I). In the remaining 11 patients without prior AMI the ischaemlc etiology was evidenced by coronary arteriography (group II). Patients with unstable angina and/or arterial hypertension were not enrolled. All patients were in sinus rhythm. Two groups were similar in respect to aspirin and nitrates administration during the study. No other medication was used. There were no differences between groups with regard to carcflothoracic ratio (0.47 ± 0.06 In group I vs 0.46 ± 0.04 in group II) and left ventricular ejection fraction, evaluated by M-mode echocardiography (47.0 ± 13.0 In group I v s 4 4 . 8 ± 11.9 ml In group II). Methods: 24-hour ECG monitoring was performed using 3-channel recorder with modified V 2 , V s and III leads (SpaceLabs Medical FT 2000A™/FT 3000™), Three time domain indices were considered: 1)SDANN (standard deviation of all mean 5-minute normal sinus intervals over 24 hours) 2)pNN50 (percent of difference between adjacent normal R-R intervals that are > 50 msec), 3) r-MSSD (square root of the mean of the sum of the squares of differences between adjacent normal R-R intervals). The following frequency domain measures of HRV were evaluated: LF- with frequency range of 0.025-0.1 Hz; MF-0.1-0.2 Hz; HF- 0.2-0.3 Hz (represents parasympathetic nervous activity), and LF/HF ratio (as index of sympathetic nervous activity). Results: No statistically significant dilerences (p < 0.05) between groups were found, although group I demonstrated lower values of all HRV Indices. Group I SO ANN (msec) pNN50(%) r-MSSD (msec) Total power (msec2) LFfiraec2) MFfraec 2 ) HFfmsec2) LF/HF 118.8 ±27.5 3.6 ± 3 ^ 24.1 ± 8 8 1935.2 ± 1076.6 752.9 ±502.5 130.6 ±107.6 75.3 ±74.7 13.4±76 Group II 123.0 ±35.1 4.2 ±3.2 26.6 ±10.3 2524.1 ±1488.2 996.3 ±657.9 163.0 ±147.1 76.9 ±50.0 18.1 ±13.3 Conclusion: We found that autonomic Input to heart in CHF-patients, as assessed by linear Indices of HRV, is similar for clinically stable patients with and without previous AMI. However, further studies are needed to evaluate other methods of HRV as well as possWe relauonshlps between different characteristics of neurohormonal modulation In this population. P2052 Ability of heart rate variability in predicting arrhythmic recurrences In patients with paroxysmal atrlal fibrillation without structural heart disease G.L Botto, W. Bonlni, T. Broffonl, G. Ferrari. Department ol Cardiology, S. Anna Hospital, Como, Italy The ability of heart rate variability (HRV) to predict paroxysmal atrial fibrillation (PAF) recurrences was evaluated in 70 patients (pts) (41 male), mean age 53 ± 13 years, without structural heart disease. Each pts underwent 24-hour Hotter, while In sinus rhythm, 4 weeks after a PAF episode. None of them was taking dgltalis or antiarrhythmk: drugs during the follow-up. HRV parameters were calculated in the time domain (TD) over 24 hours and In the frequency domain (FD) as total (TP 0.017-0.50 Hz), low (LF 0.05-0.15 Hz) and high (HF 0.15-0.35 Hz) frequency components, using FFT analysis (Del Mar-Avionics 563). Five-minute epochs in a 30-mlnute period between 8 AM and 2 PM with the pts in baseline condition, were analyzed. A mean follow-up of 357 ± 95 days was performed for identifying pts without (GrA 51 pts) and with (Gr.B, 19 pts) PAF recurrence, In order to define the risk prerJctor value of the considered parameters. TD Mean FIR (msec) Gr. A 805 ± 9 1 Gr.B 8 0 3 ± 7 0 pval NS FD TPfmsec2) SDANN (msec) SDNN (rmec) SO (msec) 125 ± 3 7 123±38 NS 138±35 134 ± 3 8 NS LFfrmec2) HFfmsec2) LFnorm-U r-MSSD (msec) pNN50 (%) 57.5 ±19.1 32-7 ±19.7 11.5± 13.6 54 1 ± 12.9 35.2 ±12.3 12.8 ±10.9 NS NS NS HFnorrrMJ LF/HF ratio Gr. A 4040 ±5968 1510±2111 606±2756 025 ±0.12 0.15 ±0.11 2.47 ± £23 Gr B 2334 ±2207 460 ± 3 1 8 962 ±1089 0.16 ±0.09 0.29 ±0.16 0.70 ± 0.48 < 0.001 < 0 001 0.0O5 0.024 NS pval NS In the discrimination of the 2 groups a LF/HF ratio < 1.2 (p < 0.001) showed 89% sensitivity, 80% specificity, 63% positive and 95% negative predictive value. Frequency domain measures of HRV could be useful in the evaluation of pts with PAF to predict recurrence after a single arrhythmic episode and could allow to Identify a subgroup of pts at low risk of arrhythmic recurrence. A simpato-vagal Imbalance, with Increase in the HF components, could play a role in causing arrhythmic recurrences in pts with PAF without heart disease. 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