The intriguing problem of atrial fibrillation in competitive athletes.

Atrial fibrillation (AF) is the most frequent cause of prolonged palpitations in young competitive athletes, even including those performing elite sport activity. This arrhythmia may occasionally affect impair athletes' ability to compete thus leading to non-eligibility at prequalification screening. Competitive sport has a significant impact on the autonomous nervous system. In fact, long-term regular intense physical training determines an increase in vagal tone leading to resting bradycardia. During physical activity, particularly in the setting of competition, a marked release of catecholamines occurs as a result of both the intense physical effort and emotional stress. Both of these adaptive phenomena may precipitate AF. Furthermore, in several athletes with AF an association with sick sinus syndrome has been found, even though the pathophysiological basis of this finding is not clear. This picture is further complicated by the increasingly intake of illicit substances, whose arrhythmogenic effect has been shown both at the ventricular and atrial levels. Moreover, the use of recreational drugs, such as amphetamines, ecstasy, alcohol, cannabinoids, cocaine and so called new drugs in clubs has dramatically increased, with several cases of drug-induced arrhythmic events. These effects are often exacerbated by the combined use of different drugs, especially in situations such as sports competitions, in which the adrenergic system is already hyperactivated. No data have been published on the efficacy of antiarrhythmic therapy in athletes with AF, but it has been reported that athletes are more predisposed to the development of pro-arrhythmic effects induced by antiarrhythmic drugs when compared to general population. Most recently, radiofrequency catheter ablation involving electrical disconnection of the pulmonary veins in athletes with AF limiting their normal training activity and participation in sports competitions has proven highly effective to restore stable sinus rhythm and enable subsequent re-eligibility.

Long-term follow-up of patients with inducible supraventricular tachycardia treated with flecainide or propafenone: therapy guided by transesophageal electropharmacologic testing.

We report our experience with flecainide and propafenone therapy for inducible supraventricular tachycardias and paroxysmal supraventricular tachycardias due to atrioventricular (AV) nodal reentry or the Wolff-Parkinson-White syndrome. We performed an electropharmacologic test (ET) that consisted of first inducing a clinical arrhythmia by transesophageal atrial pacing (TAP) protocol. This was followed by intravenous drug administration and TAP reevaluation, either after acute intravenous administration or in oral steady-state. We used ET with flecainide and/or propafenone to study 2 groups of patients at least 3 years before the long-term clinical observation period. The first group was comprised of 58 patients with reciprocating tachycardias--due to AV node reentry in 17 (29.3%) and anomalous pathway in 41 (70.7%). Twelve (29.3%) of the latter had reciprocating tachycardias, 15 (36.6%) had atrial fibrillation, and 14 (34.2%) had both arrhythmias. During ET, flecainide was administered to 42 patients, and the ET was considered positive in 28 (66.7%). Propafenone was administered to 32 patients, with positive results in 15 (46.9%). In 15 patients, both flecainide and propafenone were tested, 8 receiving flecainide after a negative ET with propafenone, and 7 receiving propafenone after a negative ET with flecainide. In the first group, the ET was positive in 7 (87.5%), and in the second group, it was positive in 3 (42.9%). In a follow-up of 40.1 +/- 11 months, 38 (65.5%) patients had positive outcomes, 5 (8.6%) had to stop receiving the drugs because of side effects, 3 (5.2%) stopped because of inefficacy, and 12 (20.7%) dropped out.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter ablation of Wolff-Parkinson-White syndrome associated with congenital absence of inferior vena cava.

In the present report we describe a patient (a 36-year-old woman with 15 year history of supraventricular tachyarrhythmias) with congenital absence of inferior vena cava (IVC) revealed during radiofrequency (RF) catheter ablation procedure for right postero-septal Wolff-Parkinson-White syndrome (WPW). For the absence of IVC, the ablation procedure was more difficult, because we had to perform the ablation with the catheters (the ablator catheter and the coronary sinus catheter) introduced both through the superior vena cava. The application of RF energy (35 Watt for 60 seconds) at successful site abolished accessory pathway conduction. The following day was performed the venous angiography, showing the absence of the IVC and a venous return via paravertebral venous plexus to the azygous vein and superior vena cava into the right atrium. Computer tomography confirmed the absence of the IVC with azygous continuation. The drainage via the azygous system modified the radiological image on chest roentgenogram of the right mediastinal silhouette. During cardiogenesis fusion of the IVC and organisation of the heart occur between the 33rd to 40th embryonic days. It is therefore possible that some unknown teratogenic mechanism at this critical period might have caused, in the patient, both the developmental arrest of IVC and failure of regression of atrio-ventricular anatomical and electrical continuity in the right postero-septal region.

Clinical evaluation of new antiarrhythmic agents: experiences with propafenone.

The authors propose a general design for the clinical evaluation of new antiarrhythmic agents with special reference to their experience with propafenone, a new Class 1 agent. The drug was studied in 61 patients affected by PSRT, VEBs or RVT often unresponsive to other drugs. Both acute i.v. sensitivity tests and evaluation of chronic oral treatment were carried out. The results indicate that propafenone is a highly effective drug and that its oral activity may be predicted in individual patients by an acute i.v. administration. The most frequent adverse reaction was a widening of QRS complex. However the drug had to be withdrawn due to impaired intraventricular conduction in one patient only. More frequently (four cases) its withdrawal was due to adverse extracardiac reactions.

Improved late potential analysis in frequency domain.

This work presents a technique to improve the identification of late potentials (LP) in patients affected by greater arrhythmogenic right ventricular disease (GARVD). Several authors have documented the correlation between GARVD and LP by means of time domain analysis. Moreover, the high incidence of bundle branch block in patients affected by GARVD suggests LP analysis in the frequency domain be performed. The method of spectral mapping of the ECG with Fourier transform was adopted. This consists in dividing the ST segment into 25 subsegments and estimating their frequency components by means of the fast Fourier transform. Recently, it was documented that this technique suffers from poor reproducibility of results. Low reproducibility is the consequence of an improper localization of the analysed QRS segments. An algorithm to increase the QRS end point identification reproducibility is proposed. An optimal QRS filter was adopted as well as a technique based on the Hilbert transform. This technique allowed the reliability of the normality factor estimates to be improved. The computed normality factors on the XYZ leads and on the vector magnitude were used to classify patients and healthy subjects; 28 patients affected by greater arrhythmogenic right ventricular disease and 35 healthy subjects were analysed in the study. High sensitivity was obtained with respect to GARVD and clinical sustained ventricular tachycardia by means of a cluster analysis technique. By applying the technique proposed in this paper the identification of LP in GARVD was increased from 47% to 88%, when clinical sustained ventricular tachycardia was documented, whereas in patients affected by GARVD but not prone to sustained ventricular tachycardia LP identification increases from 18% to 64%.

[Venous infusion of nerapamil in the treatment of refractory angina pectoris and arrhythmia due to associated electric instability]. / Il verapamil per infusione venosa nel trattamento dell'angor refrattario e delle aritmie da instabilità elettrica associate

The therapeutic effect of Verapamil in 45 patients with angina that had failed to respond to other drugs is described. Angina was distinguished in terms of its clinical and ECG features. Verapamil was administered i.v., usually in infusions of 10-250 mg/day over periods of hours or days; alternatively, direct injections of 2,5-5 mg were employed. The effect on arterial pressure is particularly stressed. In the great majority of cases, there was a marked improvement in the symptomatology and in arrhythmic changes arising during angina. The importance of the therapeutic effects of the drug is examined and its possible mechanisms of action are discussed.

[Anti-arrhythmic therapy with verapamil by intravenous infusion]. / Terapia antiaritmica con il verapamil per infusione endovenosa

Rapid and slow venous infusion of various doses of Verapamil in a mixed series of 185 cases of arrhythmia since 1968 is reported. Results and electrophysiological and ECG changes observed for each type of arrhythmia examined are considered separately: atrial fibrillation-flutter, supraventricular paroxystic tachycardia (atrial and/or junctional), and hyperkinetic ventricular arrhythmia. An association of i.v. Verapamil and a quinidine salt per os is suggested as an alternative to cardioversion in cases of recent atrial fibrillation-flutter. Results obtained in the treatment of arrhythmia due to electrical instability following angina and of angina following arrhythmia are also described. A study of His potentials as the premiss for using Verapamil in subjects with stimulus conductivity changes, including W.P.W. syndrome, is also reported. I.v. Verapamil was used in association with atrial and/or ventricular electrostimulation, and/or with electrical counter-shock in cases of arrhythmia (mostly supraventricular) that were especially refractory. Attention is drawn to the use of Verapamil in the control of arrhythmia after electrical cardioversion.

[Multicenter study of the effectiveness and tolerance of clotiazepam in cardiology]. / Studio policentrico sull'efficacia e tollerabilità del clotiazepam in cardiologia.

In a phase IV study with clotiazepam 9 cardiologists were involved to treat 86 patients (52 female, 32 male, mean age 51 years) effected by cardiovascular diseases and anxiety. The dosage was 5-10 mg TID, and the treatment lasted for 3 weeks. Variations of the dosage were requested in 21% of patients and generally at the 2nd week of treatment. The safety of clotiazepam was good: only in the 14% of patients side-effects were observed (especially drowsiness 9.3% and asthenia 2.3%). Clotiazepam was judged to be effective in 75% of patients. The Hamilton psychiatric rating scale for anxiety showed a progressive decrease both of the total score and of the scores of every item; the cardiovascular symptoms particularly improved at both the controls.

[Transesophageal electric atrial stimulation as an electro- pharmacological method of treatment of supraventricular tachycardia]. / Chrespishchevodnaia élektrostimuliatsiia predserdii kak élektro- farmakologicheskii metod lecheniia supraventrikuliarnykh takhikardii.

From 1985 to 1988 the authors performed 299 procedures of transesophageal atrial pacing in 162 patients with hyperkinetic supraventricular arrhythmias. The pacing abolition of atrial flutter had been mainly applied with an invasive technique. The employment of transesophageal atrial pacing received its large development, but simplified this, the probability of abolishing supraventricular tachycardia becoming lower.

[Stable ventricular tachycardia in arrhythmogenic dysplasia of the right ventricle in sportsmen]. / Stabil'naia zheludochkovaia takhikardiia pri aritmogennoi displazii pravogo zheludochka u sportsmenov.

Right ventricular arrhythmogenic dysplasia (RVAD) is a typical asymptomatic arrhythmogenic cardiopathy in athletes, which is occasionally concurrent with normal ventricular function and life-threatening arrhythmias. A total of 32 athletes (28 males and 4 females, mean age, 23 years, mean follow-up, 6.7 years) were examined for severe cardiac arrhythmias with left bundle branch block. The conclusive diagnosis of RVAD was established from clinical, echocardio-, and angiographic evidence. The protocol of the examination involved Holter monitoring, loading tests, electrophysiological study, two-dimensional echocardiography, cardiac angiography of the right and left ventricles, coronary angiography. The most severe arrhythmias were observed in athletes whose mean age was 23.4 years, 20 patients had sustained ventricular tachycardia (it occurred only in 19 who were indulging in sports), 6 presented with transient ventricular tachycardia, and 1 had ventricular fibrillation. They all had been considered fit for sports. The disease proceeded severely in 16 of 32 athletes (in 13 of 16 while indulging in sports), the conditions close to syncope were seen in 9 patients (8 had sustained ventricular tachycardias and 1 had transient ventricular tachycardias), syncopes were observed in 5 patients (sustained ventricular tachycardias).