Contrast echocardiography for pulmonary arteriovenous malformations screening: does any bubble matter?

AIMS: To evaluate diagnostic accuracy of contrast echocardiography (CE) as compared with CT, for the screening of pulmonary arteriovenous malformations (PAVMs) in hereditary haemorrhagic telangiectasia (HHT); to evaluate the clinical significance of semi-quantitative analysis of a shunt on CE. METHODS AND RESULTS: A blinded prospective study was conducted in 190 consecutive subjects at risk of HHT who underwent screening for PAVMs, including clinical evaluation, pulse oximetry, standard and CE, and chest multirow CT without contrast medium. A semi-quantitative analysis of the shunt size was performed according to the contrast echo opacification of the left-sided chambers: Grade 0, no bubbles; 1, occasional filling with <20 bubbles; 2, moderate filling; 3, complete opacification. The first 100 patients were compared with 100 controls. A total of 119 (63%) patients had positive CE (32.2% Grade 1, 13.1% Grade 2, 11% Grade 3, 6.3% with patent foramen ovale). The overall diagnostic performance of CE was sensitivity 1.00, specificity 0.49, positive predictive value (PPV) 0.32, negative predictive value (NPV) 1.00. The PPV for the different grades was 0.00 for Grade 1, 0.56 for Grade 2, 1.00 for Grade 3; the NPV of Grade 0 was 1.00. A significant correlation was found between the CE grading and the number of PAVM, and complications (P < 0.0001). CONCLUSION: CE is an extremely sensitive procedure for the detection of PAVMs with substantial clinical impact.

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.

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.

[An Italian experience of radiofrequency transcatheter ablation in type-I atrial flutter: the results and follow-up]. / Un'esperienza italiana sull'ablazione transcatetere con radiofrequenza nel flutter atriale tipo I: risultati e follow-up.

BACKGROUND: Type I atrial flutter (AF) is a supraventricular tachycardia that is notoriously disabling and resistant to antiarrhythmic drugs. The introduction of an effective non-pharmacologic technique, such as radiofrequency catheter ablation (RF), opened new therapeutic prospects for the management of this arrhythmia. The aim of our study was to evaluate the long-term efficacy of atrial flutter RF using a successful procedure marker of bi-directional conduction block in the isthmus. METHODS: In the last consecutive 50 patients (pts) who underwent RF procedure for AF at our Center (46 pts during spontaneous or induced AF and 4 in sinus rhythm) after the successful interruption of AF we performed the usual reinduction attempts and well atrial pacing from 2 sites in the right atrium (in 18 pts before and after RF and in 32 only after RF). The sites of pacing were site 1: low lateral right atrium (LRA); site 2: proximal coronary sinus (PCS). The 50 pts consisted of 13 females, 37 males with a mean age of 62.5 +/- 9.7 years (35-83). The end-point for the procedure was: 1) abrupt interruption of AF; 2) inability to reinduce AF; 3) recognition of atrial activation sequence during pacing in LRA and in PCS compatible with conduction block in the isthmus. RESULTS: The RF was successful in terminating AF in all pts after 11 +/- 7 applications of energy. After ablation, sustained AF was no longer inducible by atrial pacing. After RF, during pacing in sinus rhythm from LRA, the lower septum and PCS presented a delayed activation after the His region. Similarly, during pacing from PCS after ablation, the atrial activation sequence was modified: the low lateral right atrium was now activated by a single front after the high lateral atrium. No acute complications were noted in any pts during or after procedure. AF recurred in 9 pts. Four pts now present chronic atrial fibrillation. The mean follow-up period is 14.8 +/- 8 months. All the patients were discharged without antiarrhythmic therapy. CONCLUSIONS: The mechanism of successful ablation is the bi-directional conduction block in the isthmus with the evidence of the changes in the right atrial activation sequence during atrial pacing in sinus rhythm in LRA and in PCS before and after RF.

Cardiac arrest and sudden death in competitive athletes with arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a predisposing factor for sport-related cardiac arrest (CA), sudden cardiac death (SD), and life-threatening ventricular tachyarrhythmias (VT). The aim of this study was the assessment of athletes with ARVD, particularly the CA survivors. From 1974 to January 1996, 1642 competitive athletes (aver. 25.5 yr.), 136 of whom were top level athletes (TLA), were studied for important arrhythmic manifestations. All athletes underwent an individualised study protocol including a series of non invasive and invasive diagnostic techniques. One hundred and one athletes (90 males, 11 females, aver. 25.9 yr.) were diagnosed as being affected by ARVD on the basis of the WHO/ISFC criteria. The same percentage (about 6%) of ARVD is present in both the general arrhythmic athletes population and in the subgroup of TLA. Prevalence of ARVD among athletes with CA or SD is high (respectively 23% and 25%), confirming the observation that ARVD is one of the major causes of SD in Italian athletes. All CA were athletic activity related, indicating the potentiality of exercise as a cause of electrical destabilisation in subjects with ARVD. In athletes with documented ARVD intense sport activity has to be proscribed. In athletes at risk of CA or SD an aggressive treatment, ICD implantation and RF catheter ablation must be taken into consideration.

Catheter ablation in competitive athletes: indication.

Some supraventricular tachyarrhythmias (SVT), particularly if paroxysmal and/or related to Wolff-Parkinson-White syndrome (WPW), may in some cases endanger an athlete's professional career due to hemodynamic consequences during athletic activity, which in some instances may be life-threatening. One must also take into account that in Italy the law makes antiarrhythmic drug treatment (AAD) incompatible with sport eligibility. For these reasons, the utilization of radiofrequency ablation (RFA) in athletes has different indications as opposed to the normal population, since the primary goal is "the eligibility of the athlete." In our study, we discuss the criteria for indication of RFA in athletes with SVT on the basis of the data obtained from our population of athletes, studied over a 20-year period, from 1974 to the 31st of December 1993. These athletes were evaluated for arrhythmic events, utilizing a standardized cardioarrhythmological protocol: 1,325 athletes (1,125 men, 200 women, mean age 20.7 years). One subgroup included 380 athletes with WPW (28.7%), 22 athletes with aborted sudden death (1.6%), 6 of whom had WPW, 13 athletes with sudden death (0.98%), and 2 of whom had WPW. Another subgroup was formed by 116 top level elite professional athletes (TLA) (mean age 22.9 years), of which 10 of 116 (8.6%) had WPW and 12 of 116 (10.3%) had paroxysmal SVT. The most important indications for RFA in athletes are represented by: WPW asymptomatic at risk, symptomatic during athletic activity, and/or requiring AAD treatment: paroxysmal junctional reentrant tachycardia: when this condition is disabling and related to exercise and therefore compromising an athlete's performance and sports career. Paroxysmal junctional reentrant tachycardia is easily reproduced via transesophageal atrial pacing (TAP) during exercise (bicycle ergometer), common in athletes but normally the recurrences are concentrated only during the period in which the athlete is engaged in sport. Rare indications for RFA are focal or reentry, permanent SVT, and particularly junctional reentrant tachycardia. For each individual athlete, we have to consider the possible side-effects of RFA, the possible recurrences with psychobiological traumatic consequences, the effective recovery period, and the natural history of the tachyarrhythmias, which frequently disappear after interruption of the sports career.

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)

[Sotalol in the Wolff-Parkinson-White syndrome: an electrophysiological and clinical study]. / Il sotalolo nella sindrome di Wolff-Parkinson-White: studio elettrofisiologico e clinico.

Distinctly different from the other beta-blocking agents, sotalol prolongs action potential duration in myocardial and Purkinje fibers, and increases atrial as well as ventricular effective refractory periods. Similarly, antegrade and retrograde accessory pathway refractory periods are increased by sotalol. The electrophysiologic and clinical effects of sotalol were studied in 40 patients (31 male and 9 female, mean age 32 +/- 14 years) with Wolff-Parkinson-White Syndrome (WPW). All patients had disabling episodes of supraventricular tachyarrhythmias (ST). Of the 40 patients, 15 (37%) had spontaneous recurrence of paroxysmal supraventricular reciprocating tachycardia (PSRT), 14 (35%) of atrial fibrillation (AF) and 11 (28%) of both PSRT and AF. All of the patients were non responders to serial transesophageal electropharmacological tests using I C class drugs. Sotalol 252 +/- 73 mg daily was administered, and, in steady-state, a new transesophageal study (TS) was performed to observe the re-induction of PSRT and/or AF. 34 patients (85%) were responders to TS (noninducibility of ST, or nonsustained ST or AF inducibility with an increase of 30% in the minimum R-R interval between pre-excitated beats during AF) and the results were confirmed during a follow-up of 17 +/- 9 months. In the non-responder group (5 patients), a I C class drug was associated with sotalol. One patient, who was a "non responder" to sotalol, sotalol + I C class drug, and to amiodarone, underwent surgical therapy. In the 26 patients (65%) who had episodes of PSRT (37%) or episodes of PSRT and AF (28%), it was impossible to reinduce PSRT in 85% of the cases. AF was induced at baseline in all of the studied patients, but after sotalol administration in 15 patients, it was impossible to reinduce AF. The rate of induced AF decreased from 208 +/- 39 beats/min to 156 +/- 36 beats/min (p < 0.001). The mean shortest R-R interval between pre-excitated beats increased from 214 +/- 35 (baseline) to 293 +/- 97 msec (sotalol steady state) (p < 0.001). No side effects were observed. A significant prolongation (p < 0.001) of the QTc interval was observed in all the patients after sotalol administration (from 0.39 +/- 0.2 to 0.42 +/- 0.02 sec.). On the basis of our results, we may conclude that sotalol has a potent effect on the antegrade refractoriness of the anomalous pathway and, in WPW syndrome at risk, is also effective in patients who don't respond to I C class drugs.

Electropharmacological testing by transoesophageal atrial pacing in inducible supraventricular tachyarrhythmias. A good approach for selection of long-term anti-arrhythmic therapy.

Sixty-eight patients with disabling episodes of inducible supraventricular tachyarrhythmia were tested electropharmacologically by transoesophageal atrial pacing. Using this technique we induced clinical arrhythmia in 67 (98.5%); 26 (38.8%) had a reciprocating tachycardia due to AV node reentry and 41 (61.2%) a by-pass tract. In the latter we induced a reciprocating tachycardia in 12 (29.3%), atrial fibrillation in 25 (36.5%) and both in 14 (34.2%). We then performed an anti-arrhythmic drug test and a transoesophageal reevaluation either after acute intravenous drug administration or during oral steady state. Altogether we tested 111 drugs or a combination of drugs before the results were considered positive; all patients tolerated the procedure well and were discharged with the drug or combination of drugs judged effective. At follow-up of 16.6 +/- 8.5 months, 42 patients (62.7%) were symptom-free, 17 (25.3%) had minor and non-disabling relapses, six (9%) stopped the drug because of inefficacy (1-1.5%) or side effects (5-7.5%); two (3%) dropped out. We conclude that electropharmacological testing with transoesophageal pacing constitutes a very good approach for inducible supraventricular tachyarrhythmias: it permits selection of optimal long-term anti-arrhythmic treatment and is well tolerated, only slightly invasive and without adverse effects.

[Role of antitachycardia pacemakers in the treatment of supraventricular hyperkinetic arrhythmias]. / Ruolo dei pacemaker antitachicardici nel trattamento delle aritmie ipercinetiche sopraventricolari.

The use of an antitachycardia pacemaker in the treatment of hyperkinetic supraventricular arrhythmias is founded on a reliable electrophysiological ground and on an high technology. Nevertheless the clinical impact of this approach is not considerable since the 5% to 7% of the potential candidates are in effect treated with an antitachycardia device. The success of new therapeutical procedures (i.e. catheter ablation) together with the shifting of the clinical, technical and commercial interest towards the electrical treatment of the malignant ventricular tachyarrhythmias are the main causes of the minor role that now the antitachycardia pacemakers play in the management of the patients with hyperkinetic supraventricular arrhythmias.

[Electropharmacological test with class-I C drugs in paroxysmal supraventricular re-entrant tachycardia: is a negative result with a drug predictive of the ineffectiveness of other drugs of the same class?]. / Test elettrofarmacologici con farmaci della classe I C nella tachicardia parossistica sopraventricolare reciprocante: il risultato negativo di un farmaco è predittivo di inefficacia per altri farmaci della stessa classe?

UNLABELLED: Propafenone and flecainide, both I C class drugs, are first choice in the treatment of paroxysmal supraventricular reciprocating tachycardia. The aim of this study was to check whether a negative or paradoxical electropharmacological test with one of the two drugs was predictive of an equally negative or paradoxical test with the other drug. Thirty patients with disabling paroxysmal supraventricular reciprocating tachycardia, 16 M, 14 F, mean age 30.6 +/- 16 years, were studied with serial electropharmacological tests using esophageal approach. The reentry circuit was sustained by an anomalous pathway in 25 patients (83.5%) whereas it was idionodal in the other 5 (16.5%). Propafenone was tested in 13 patients (43.5%, group A) after flecainide had resulted negative or paradoxical in the first test. In 17 patients (56.5%, group B) flecainide was tested after propafenone had resulted negative or paradoxical. The second drug tested was also ineffective in 14 of the 30 patients (group A + group B) while it had positive results in 16 patients. Specifically, propafenone was positive in 6 of the 13 patients (group A) in whom flecainide had been negative, and flecainide was positive in 10 of the 17 patients (group B) with acute negative or paradoxical propafenone test. These "acute" results were confirmed in steady-state with esophageal study and in the follow-up (21.9 +/- 9.3 months). CONCLUSIONS: 53.5% of the patients who are "non responders" to the electropharmacological test with one of the two drugs (propafenone or flecainide) may be "responders" to the other drug. Thus the ineffectiveness of one of the two drugs is not predictive of ineffectiveness of the other.

[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).

Electropharmacological test with pentisomide (CM 7857) in patients with sustained ventricular tachycardia.

Pentisomide (CM 7857) is a new class I antiarrhythmic drug whose effect on sustained ventricular tachycardia has only been slightly investigated to date. The aim of this paper is to examine the pentisomide action on selected patients with ventricular tachycardia inducible during intracavitary electrophysiological study. Thus, 12 patients (9 M, 3 F, mean age: 45.2 years, range: 24-78), all but two with detectable heart disease, underwent electropharmacological tests with pentisomide after they had resulted "non responders" (8 patients) or had had a proarrhythmic worsening effect (3 patients) to electropharmacological tests with amiodarone or flecainide or propafenone or mexiletine. After the inducibility and the reproducibility of ventricular tachycardia has been assessed in the basal state, all patients underwent several attempts to reinduce ventricular tachycardia, during the i.v. infusion of pentisomide 1.5 mg/kg/5 min followed by continuous infusion of 1 mg/kg/h, at the same time drug plasma level was assessed. Ventricular tachycardia inducibility was still inducible after pentisomide, but with a longer cycle length (446 +/- 88 versus 337 +/- 82 msec) than in the basal state (p less than 0.0025). No patients had proarrhythmic worsening effects. The pentisomide plasma level (available in 5 patients) ranged from 3.4 to 22.3 (mean 8.9 micrograms/ml). Four patients underwent chronic oral treatment (in 1 pt in association with amiodarone) with a good clinical outcome (mean follow-up 6.25 months, range 1-12). We stress the absence of proarrhythmic worsening effects and the powerful effect of the drug on ventricular tachycardia cycle length.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmia patterns in athletes with arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a typical 'silent' arrhythmogenic cardiomyopathy in athletes, with the possibility of normal ventricular performance and life-threatening arrhythmias. We studied 32 athletes (28 M, 4 F), mean age 23 years, follow-up 6.7 years, all previously declared fit for sports activity. They were studied for significant ventricular arrhythmias with LBBB with a final diagnosis of ARVD based on accepted clinical, echocardiographic and angiographic criteria. The study protocol included Holter monitoring (HM), stress test (ST), electrophysiological endocavitary study (EES), 2D echocardiography, RV and LV cardioangiography and coronarography. The most serious arrhythmia appeared at a mean age of 23.4 years, 20 had clinical sustained ventricular tachycardia (VT) (19/20, 95% during sports activity), six non-sustained VT and one ventricular fibrillation (VF). Severe symptoms occurred in 16/32 athletes (50%) during sports activity in 13/16 (81%): presyncope in nine (non-sustained VT in one, sustained VT in eight); syncope in five (sustained VT); aborted sudden death (SD) in one, SD (follow-up) in one. The reproducibility (HM, ST, EES) of clinically severe arrhythmic manifestations which occurred during sports activity was not high. In fact, during sport many factors are at work which may activate several arrhythmogenic mechanisms not easily reproducible in the laboratory. We conclude that a cardioarrhythmological study is mandatory in suspected right ventricular arrhythmias, including morphological study of the RV, to avoid arrhythmic risk during athletic activity.