Conduction properties of the crista terminalis in patients with typical atrial flutter: basis for a line of block in the reentrant circuit

INTRODUCTION: Previous mapping studies in patients with typical atrial flutter have demonstrated the crista terminalis to be a posterior barrier of the reentrant circuit forming a line of block. However, the functional role of the crista terminalis in patients with or without a history of atrial flutter is not well known. The aim of this study was to determine whether the conduction properties of the crista terminalis are different between patients with and those without a history of atrial flutter. METHODS AND RESULTS: The study population consisted of 12 patients with clinically documented atrial flutter (group 1) and 12 patients with paroxysmal supraventricular tachycardia as well as induced atrial flutter (group 2). A 7-French, 20-pole, deflectable Halo catheter was positioned around the tricuspid annulus. A 7-French, 20-pole Crista catheter was placed along the crista terminalis identified by the recording of double potentials with opposite activation sequences during typical atrial flutter. After sinus rhythm was restored, pacing from the low posterior right atrium near the crista terminalis was performed at multiple cycle length to 2:1 atrial capture. No double potentials were recorded along the crista terminalis during sinus rhythm in both groups. In group 1, the longest pacing cycle length that resulted in a line of block with double potentials along the crista terminalis was 638 +/- 119 msec. After infusion of propranolol, it was prolonged to 832 +/- 93 msec without change of the interdeflection intervals of double potentials. In group 2, the longest pacing cycle length that resulted in a line of block with double potentials along the crista terminalis was 214 +/- 23 msec. After infusion of procainamide, it was prolonged to 306 +/- 36 msec with increase of interdeflection interval of double potentials. CONCLUSION: The crista terminalis forms a line of transverse conduction block during typical atrial flutter. Poor transverse conduction property in the crista terminalis may be the requisite substrate for clinical occurrence of typical atrial flutter.     

An investigation into variability in microvascular skin blood flow and the responses to transdermal delivery of acetylcholine at different sites in the forearm and hand

BACKGROUND: Inappropriate sinus tachycardia (IST) is a rare form of supraventricular arrhythmia. It can cause disabling symptoms and may be refractory to medical treatment. In symptomatic drug refractory patients, sinus node excision or total ablation of the sinus node with permanent pacemaker implantation was the only therapeutic option. Recently, radiofrequency (RF) modification of the sinus node has been reported to be an effective treatment for this condition. AIM: To present our experience with sinus node modification using RF energy in the management of IST. METHODS: Between 1989 to 1996 three patients (two females and one male), aged 28-36 years were diagnosed with symptomatic IST. All had failed multiple drugs and hence underwent sinus node modification using RF. In the first two patients, the site of RF application was guided by anatomical landmarks using fluoroscopy to localise the presumed most superior portion of the crista terminalis and also the earliest site of atrial activation. In the third patient, a 20 pole electrode catheter was used to map the crista terminalis and guide the ablation. Success was defined by 20-30% reduction in the heart rate with normal atrial activation sequence after ablation. RESULTS: The three patients described here had IST by clinical, electrocardiographic and electrophysiological criteria and were refractory to multiple antiarrhythmic drugs. The number of RF applications were 11, 15, and three applied at the site of earliest atrial activation for the control of heart rates. Patient 3 had a early recurrence at one month and underwent repeat sinus node modification (five RF applications). All three patients who underwent RF modification of the sinus node had a successful outcome. The procedure was uncomplicated and the patients remain asymptomatic during follow up (20, 12 and three months) with satisfactory control of heart rate, although one patient requires atenolol which was previously ineffective. CONCLUSIONS: RF modification of the sinus node is feasible and effective for IST, and should be the treatment of choice in patients refractory to medical therapy.     

Electrophysiological properties in patients undergoing atrial compartment operation for chronic atrial fibrillation with mitral valve disease

AIMS: Surgical treatment for atrial fibrillation is now feasible in selective cases. The aim of this study was to assess the electrophysiological properties of patients undergoing atrial compartment operation for chronic atrial fibrillation. METHODS AND RESULTS: Electrophysiological studies were performed in 20 mitral valve patients with atrial fibrillation who had been maintained in sinus rhythm for more than 1 year after atrial compartment operation. Intra-cardiac recording and programmed electrical stimulation were performed in various atrial compartments. The parameters studied included sinus node function, atrial conduction and refractoriness, atrioventricular conduction function and inducible arrhythmias if any. Intra-cardiac recordings showed that the rhythm was of sinus origin in all cases, with the earliest atrial activity located in the high right atrium. The mean sinus cycle length was 750 +/- 110 ms, AH time 106 +/- 29 ms, and HV time 53 +/- 7 ms. The sinus node function was normal in 18 patients (90%), and only two patients had prolonged sinus node recovery and sino-atrial conduction. The right atrial appendage compartment was driven by the sinus node in all patients. However, the conduction time from the high right atrium to the right atrial appendage compartment was markedly prolonged in 12 of 15 patients (80%) undergoing the three-compartment operation in which an incision was placed between the high right atrium and right atrial appendage compartments. On the other hand, the electrical activities in the left atrial compartment were much more varied. In 13 of 20 patients (65%), the left atrial compartment was driven by the sinus node; 11 of the 13 patients had a normal or mildly prolonged conduction time (ranged 75 to 146 ms), whereas two patients had a marked delay in conduction (200 ms and 266 ms, respectively). In the remaining seven patients, the left atrial compartments were dissociated from the rest of the heart; five of them had a quiescent left atrium, one a fluttering left atrial rhythm, and one a slow left atrial rhythm. The effective refractory period was longer in the left atrial compartment (242 +/- 47 ms) as compared to that of the high right atrium (224 +/- 26 ms, P < 0.01) and right atrial appendage compartments (219 +/- 25 ms, P < 0.01). Programmed electrical stimulation could not induce atrial fibrillation in any patient, whereas two patients had inducible atrial flutter and three repetitive atrial responses. CONCLUSIONS: (1) Atrial compartment operation does not impair sinus node function in most cases. (2) Elimination of atrial fibrillation while maintaining the electrical connection between different atrial compartments is feasible.     

Direct conversion of atrial flutter to sinus rhythm with low-output, short-duration transesophageal atrial pacing

BACKGROUND AND HYPOTHESIS: Transesophageal atrial pacing (TAP) is useful for terminating paroxysmal non-self terminating atrial flutter (PAF); however, high output pacing of long stimulus duration causes severe symptoms such as chest pain. The objective of this study was to investigate the effect of low-output, short-duration TAP on the conversion of PAF. METHODS: We applied low-output (within 15 mA with a pulse duration of 10 ms), short-duration (within 4 s) TAP in 31 patients (50 +/- 19 years) with PAF. Transesophageal pacing was delivered with 10 pulses of burst pacing at intervals that were 20 ms shorter than those of the flutter wave length. When the conversion was unsuccessful, we delivered 20 pulses of burst pacing. RESULTS: Sixteen patients (52%) were converted directly to sinus rhythm and 12 (38%) to atrial fibrillation. Transesophageal pacing was ineffective in 3 (10%) patients. The duration of atrial flutter, maximum flutter wave amplitude, effective pacing intervals, underlying heart diseases, and cardiac function were not different between patients who had direct conversion to sinus rhythm and those converted to atrial fibrillation. The patients who had direct conversion to sinus rhythm had longer flutter wave cycle lengths than those converted to atrial fibrillation (248 vs. 221 ms, p < 0.005). No patient had complications and complained of any symptoms. CONCLUSION: Low-output, short-duration TAP was useful to convert PAF directly to sinus rhythm without side effects.     

Bone marrow transplantation in the treatment of thalassemia

OBJECTIVE: To investigate the long-term results of the corridor operation in the treatment of symptomatic atrial fibrillation refractory to drug treatment. BACKGROUND: The corridor operation is designed to isolate from the left and right atrium a conduit of atrial tissue connecting the sinus node area with the atrioventricular node region in order to preserve physiological ventricular drive. The excluded atria can fibrillate without affecting the ventricular rhythm. This surgical method offers an alternative treatment when atrial fibrillation becomes refractory to drug treatment. PATIENTS: From 1987 to 1993, 36 patients with drug refractory symptomatic paroxysmal atrial fibrillation underwent surgery. The in hospital rhythm was followed thereafter by continuous rhythm monitoring and with epicardial electrograms. After discharge Holter recording and stress testing were regularly carried out to evaluate the sinus node function and to detect arrhythmias; whereas Doppler echocardiography was used to measure atrial contraction and size. MAIN OUTCOME MEASURES: Maintained absence of atrial fibrillation without drug treatment after operation; preservation of normal chronotropic response in the sinus node. RESULTS: The corridor procedure was successful in 31 (86%) of the 36 patients. After a mean (SD) follow up of 41 (16) months 25 (69%) of the 36 patients were free of arrhythmias without taking drugs (mean (SE) actuarial freedom at four years 72 (9)%)). Paroxysmal atrial fibrillation recurred in three patients; paroxysmal atrial flutter (two patients) and atrial tachycardia (one patient) developed in the corridor in three others. Among the 31 patients in whom the operation was successful sinus node function at rest and during exercise remained undisturbed in 26 and 25 patients respectively (mean (SE) actuarial freedom of sinus node dysfunction at four years (81(7)%)). Pacemakers were needed in five (16%) of the 31 patients for insufficient sinus node rhythm at rest only. Doppler echocardiography showed maintenance of right atrial contribution to right ventricle filling in 26 of the 31 patients after operation in contrast to the left atrium, which never showed such contribution. His bundle ablation was performed and a pacemaker implanted in the five patients in whom the corridor operation was unsuccessful. CONCLUSION: These results substantiate the idea of this surgical procedure. Modification of the technique is, however, needed to achieve a reliable isolation between left atrium and corridor, which would make this experimental surgery widely applicable in the treatment of drug refractory atrial fibrillation.     

Atrial macroreentry involving the myocardium of the coronary sinus: a unique mechanism for atypical flutter

Atrial flutter involving either clockwise or counterclockwise rotation around the tricuspid annulus utilizing the subeustachian isthmus has been well described. However, macroreentrant atrial circuits in atypical atrial flutter in patients who have not undergone previous surgery or without atrial disease are not well defined. We describe a patient without structural heart disease who presented with an atrial macroreentrant rhythm. Entrainment mapping demonstrated a critical isthmus within the coronary sinus. Activation mapping demonstrated double potential throughout the length of the coronary sinus with disparate activation sequences. A circuit involving the myocardium of the coronary sinus, exiting in the lateral left atrium, down the interatrial septum, and reentering into the coronary sinus was identified. Successful ablation of the rhythm was accomplished by a circumferential radiofrequency application within the coronary sinus.     

Transposition of the great arteries and isolated origin of the sinus node artery

We report the cases of 2 newborns who underwent at 7 days of age an arterial switch operation for transposition of the great arteries with a rare coronary anomaly: the left and right coronary arteries originated with a single ostium from sinus 1 and the sinus node artery had an isolated origin from sinus 2. The sinus node artery was reimplanted into the new aorta in both patients. Both babies were discharged in sinus rhythm. Preserving the vascularization of the sinus node may avoid the occurrence of postoperative atrial rhythm disturbances.     

The specificity requirements of bacteriophage T4 lysozyme

The role of the sinoatrial ring bundle (SARB) in internodal conduction was examined by the microelectrode technique in excised rabbit hearts. The spread of the sinus impluse to the surrounding tissues was shown to proceed anteriorly toward the right branch of the crista terminalis significantly faster than toward the other direction. Thus the right SARB and the right branch of the crista terminalis close to the sinus node were the earliest areas excited by the sinus impulse in the areas surrounding the sinus node. It was further shown that the activation sequence does not initiate from the right SARB to the right branch of the crista terminalis via the junction of these two structures. Cutting the SARB did not produce any delay in conduction from the sinus node to the atrioventricular (AV) node. The conduction velocity measured at the endocardial surface by two microelectrodes has proved that conduction in the crista terminalis was significantly faster than in the SARB. The upstroke of the action potential from the crista terminalis was also steeper than that from the SARB. These results suggest that the SARB is not the main route for impulse propagation from the sinus node to the AV node; the fastest internodal conduction therefore takes place with wide wave fronts, along the crista terminalis.     

A non-hypervariable human minisatellite strongly stimulates in vitro intramolecular homologous recombination

BACKGROUND: Late morbidity and mortality after the Fontan operation are largely due to atrial arrhythmias, ventricular failure, and thrombus formation. The extracardiac Fontan procedure avoids extensive atrial manipulation and suture lines, theoretically minimizing the impetus for these events. We examined our experience with the extracardiac Fontan operation with particular attention to thromboembolism and arrhythmias. METHODS AND RESULTS: We retrospectively reviewed the medical and surgical records of all 16 patients who underwent an extracardiac Fontan operation between July 1993 and May 1996. Fifteen patients (94%) were in sinus rhythm before the operation. In the immediate postoperative period, seven (44%) had arrhythmias consisting of accelerated junctional rhythm and ectopic atrial rhythm. No associated hemodynamic compromise and no early deaths occurred. Patients were followed up for 3 to 34 months after the Fontan operation. Arrhythmias were detected in eight patients (50%) on surface electrocardiograms, and seven (44%) showed evidence of sinus node dysfunction on 24-hour Holter monitor studies. Thrombi were found in three patients (19%). All patients were asymptomatic, with no evidence of conduit obstruction by echocardiogram. CONCLUSIONS: The incidence of hemodynamically significant tachyarrhythmias appears to be reduced after the extracardiac Fontan operation. A significant percentage of patients have evidence of sinus node dysfunction, suggesting the presence of other surgical or nonsurgical factors responsible for this finding. Our incidence of thrombotic events is similar to previous reports with other Fontan modifications. It appears to be a reasonable option to maintain these patients on anticoagulation indefinitely.     

Conversion efficacy and safety of intravenous ibutilide compared with intravenous procainamide in patients with atrial flutter or fibrillation

OBJECTIVES: This multicenter study compared the efficacy and safety of ibutilide versus procainamide for conversion of recent-onset atrial flutter or fibrillation. BACKGROUND: Ibutilide fumarate is an intravenous (IV) class III antiarrhythmic agent that has been shown to be significantly more effective than placebo in the pharmacologic conversion of atrial flutter and fibrillation to sinus rhythm. Procainamide is commonly used for conversion of recent-onset atrial fibrillation to normal sinus rhythm. METHODS: One hundred twenty-seven patients (age range 22 to 92 years) with atrial flutter or fibrillation of 3 h to 90 days' (mean 21 days) duration were randomized to receive either two 10-min IV infusions of 1 mg of ibutilide fumarate, separated by a 10-min infusion of 5% dextrose in sterile water, or three successive 10-min IV infusions of 400 mg of procainamide hydrochloride. RESULTS: Of the 127 patients, 120 were evaluated for efficacy: 35 (58.3%) of 60 in the ibutilide group compared with 11 (18.3%) of 60 in the procainamide group had successful termination within 1.5 h of treatment (p < 0.0001). Seven patients were found to have violated the protocol and were not included in the final evaluation. In the patients with atrial flutter, ibutilide had a significantly higher success rate than procainamide (76% [13 of 17] vs. 14% [3 of 22], p=0.001). Similarly, in the atrial fibrillation group, ibutilide had a significantly higher success rate than procainamide (51% [22 of 43] vs. 21% [8 of 38], p=0.005). One patient who received ibutilide, which was found to be a protocol violation, had sustained polymorphic ventricular tachycardia requiring direct current cardioversion. Seven patients who received procainamide became hypotensive. CONCLUSIONS: This study establishes the superior efficacy of ibutilide over procainamide when administered to patients to convert either atrial fibrillation or atrial flutter to sinus rhythm. Hypotension was the major adverse effect seen with procainamide. A low incidence of serious proarrhythmia was seen with the administration of ibutilide occurring at the end of infusion.     

Dissimilar atrial rhythms in a patient with the Wolff-Parkinson-White syndrome

In this report, we present the findings in a patient who had paroxysmal supraventricular tachycardia and atrial flutter associated with the Wolff-Parkinson-White syndrome. During atrial flutter, localized atrial fibrillation was recorded in the coronary sinus (dissimilar atrial rhythms), near the accessory pathway; and during 90 minutes of observation, ventricular activation occurred solely over the normal pathway. We postulate that localized atrial fibrillation repetitively invaded the accessory pathway and rendered it refractory to conduction by flutter impulses.     

Radiofrequency catheter ablation in type I atrial flutter: preliminary experience of 10 cases

Common atrial flutter results from macroreentry in the right atrium. Catheter ablation of slow conduction, between tricuspid annulus and inferior vena cava (TA-IVC) or tricuspid annulus and coronary sinus ostium (TA-CS os) has been reported to terminate and prevent recurrence of this arrhythmia. We reported 10 consecutive patients, 7 men and 3 women, who underwent radiofrequency catheter ablation of common atrial flutter. The mean age was 59.4 +/- 11.2 years (range 42-82 years). During the paroxysmal atrial flutter, all patients had palpitation, 4 had dyspnea on exertion, 3 patients had syncope and 1 patient had presyncope. The mean duration of symptoms was 5.7 +/- 4.9 years (range 0.5-13 years). Two patients had dilated cardiomyopathy, 1 Ebstein's anomaly and 1 chronic obstructive pulmonary disease. Four patients (40%) had history of atrial fibrillation (AF) before ablation. The mean cycle length of atrial rhythm was 257.2 +/- 36.6 ms. Ablation was done by anatomical approach and could terminate arrhythmia in 9 patients (90%), 7 from TA-IVC, 2 from TA-CS os without major complication. The mean number of applications was 20.4 +/- 16.9 and turned atrial flutter to normal sinus rhythm in 13.5 +/- 10.7 seconds. Fluoroscopic and procedure times were 38.4 +/- 31.4 and 157.2 +/- 68.8 minutes, respectively. During the follow-up period of 24.0 +/- 28.7 weeks, 2 patients had recurrent atrial arrhythmia, 1 atrial fibrillation and 1 atrial flutter type I, giving the final success rate of 70 per cent. All patients who had recurrence or failure had a history of paroxysmal AF before ablation. In conclusion, radiofrequency catheter ablation in atrial flutter type I, using anatomical approach, is an effective treatment to terminate and prevent this arrhythmia in short term follow-up. It may be considered as an alternative treatment in patients with atrial flutter who were refractory to antiarrhythmic agents.     

Beta-adrenergic blockade accelerates conversion of postoperative supraventricular tachyarrhythmias

BACKGROUND: Postoperative supraventricular tachyarrhythmia is a common complication of surgery. Because chemical cardioversion is often ineffective, ventricular rate control remains a principal goal of therapy. The authors hypothesized that patients with supraventricular tachyarrhythmia after major noncardiac surgery who receive intravenous beta-adrenergic blockade for ventricular rate control would experience conversion to sinus rhythm at a rate that differs from those receiving intravenous calcium channel blockade. METHODS: The rate of conversion to sinus rhythm at 2 and 12 h after treatment was examined in 64 cases of postoperative supraventricular tachyarrhythmia. After adenosine administration, patients who remained in supraventricular tachyarrhythmia were prospectively randomized to receive either intravenous diltiazem or intravenous esmolol for ventricular rate control (unblinded). Loading and infusion rates were adjusted to achieve equivalent degrees of ventricular rate control. RESULTS: Patients were similar with regard to age and Apache III score. Most patients in both groups had atrial fibrillation (esmolol, 79%; diltiazem, 81%), and none experienced stable conversion with adenosine. Patients randomized to receive esmolol experienced a 59% rate of conversion to sinus rhythm within 2 h of treatment, compared with only 33% for patients randomized to receive diltiazem (intention to treat, P = 0.049; odds ratio, 2.9; 95% confidence interval, 1.046 to 7.8). After 12 h of therapy, the number of patients converting to sinus rhythm increased in both groups (esmolol, 85%; diltiazem, 62%), and the rates of conversion no longer differed significantly. Ventricular rates when supraventricular tachyarrhythmia began and after 2 and 12 h of rate control therapy were similar in the two treatment groups. The in-hospital mortality rate and length of stay in the intensive care unit were not significantly influenced by treatment group. CONCLUSIONS: Among adenosine-resistant patients in the intensive care unit with atrial fibrillation after noncardiac surgery, intravenous esmolol produced a more rapid (2-h) conversion to sinus rhythm than did intravenous diltiazem.     

Coronary sinus pacing initiates counterclockwise atrial flutter while pacing from the low lateral right atrium initiates clockwise atrial flutter. Analysis of episodes of direct initiation of atrial flutter

INTRODUCTION: Rapid atrial pacing in sinus rhythm may directly induce atrial flutter without provoking intervening atrial fibrillation, or initiate atrial flutter indirectly, by a conversion from an episode of transient atrial fibrillation provoked by rapid atrial pacing. The present study was performed to examine whether or not the direct induction of clockwise or counterclockwise atrial flutter was pacing-site (right or left atrium) dependent. METHODS AND RESULTS: We analyzed the mode of direct induction of atrial flutter by rapid atrial pacing. In 46 patients with a history of atrial flutter, rapid atrial pacing with 3 to 20 stimuli (cycle length = 500 - 170 ms) was performed in sinus rhythm to induce atrial flutter from 3 atrial sites, including the high right atrium, the low lateral right atrium, and the proximal coronary sinus, while recording multiple intracardiac electrograms of the atria. Direct induction of atrial flutter by rapid atrial pacing was a rare phenomenon and was documented only 22 times in 15 patients: 3, 11, and 8 times during stimulation, respectively, from the high right atrium, low lateral right atrium, and the proximal coronary sinus. Counterclockwise atrial flutter (12 times) was more frequently induced with stimulation from the proximal coronary sinus than from the low lateral right atrium (8 vs 1, P = .0001); clockwise atrial flutter (10 times) was induced exclusively from the low lateral right atrium (P = .0001 for low lateral right atrium vs proximal coronary sinus, P = .011 for low lateral right atrium vs high right atrium). CONCLUSIONS: Direct induction of either counterclockwise or clockwise atrial flutter was definitively pacing-site dependent; low lateral right atrial pacing induced clockwise, while proximal coronary sinus pacing induced counterclockwise atrial flutter. Anatomic correlation between the flutter circuit and the atrial pacing site may play an important role in the inducibility of counterclockwise or clockwise atrial flutter.     

High-resolution fluorescent imaging does not reveal a distinct atrioventricular nodal anterior input channel (fast pathway) in the rabbit heart during sinus rhythm

INTRODUCTION: We sought to determine the precise pathways of engagement of the AV node during sinus rhythm. METHODS AND RESULTS: Langendorff-perfused rabbit hearts were stained with 20 microM of the voltage-sensitive dye di-4-ANEPPS. Preparations containing the right atrium, sinoatrial (SA) and AV nodes, and interatrial septum were subsequently dissected and mapped in vitro using a 16 X 16 photodiode array with an adjustable resolution of 150 to 750 microns per diode. Motion artifacts were eliminated by using 15 mM 2,3-butanedione monoxime (BDM). Activation time-points were defined as (-dF/dt)max' where F = fluorescence. Isochronal maps of activation were plotted using the triangulation method. In all preparations, spontaneous activation began at the SA node, rapidly spread along the crista terminalis (CrT), entered the AV nodal region via the posterior "slow" pathway, and retrogradely spread to the septal region with a smaller conduction velocity compared to that along the CrT. Collision of anterograde and retrograde wavefronts was frequently observed in the mid-septum. Notably, there was no evidence for the presence of a distinct anterior entrance into the AV node. CONCLUSIONS: Fast pathway conduction during sinus rhythm results from a broad posterior wavefront that envelops the AV node with subsequent retrograde atrial septal activation.     

Thromboembolism in chronic atrial flutter: is the risk underestimated?

OBJECTIVES: We sought to evaluate the risk of thromboembolic events in the presence of chronic atrial flutter and to determine the impact of anticoagulation therapy, if any, on this risk. BACKGROUND: Thromboembolic events are thought to be rare after cardioversion of atrial flutter. METHODS: This study was a retrospective analysis of 110 consecutive patients referred to the electrophysiology laboratory for cardioversion of chronic atrial flutter from 1986 to 1996. Atrial flutter was present for at least 6 months. Of the 110 patients reviewed, 100 had adequate information available regarding the effectiveness of anticoagulation (mean age 64 years, range 27 to 86; 75 men, 25 women; mean left ventricular ejection fraction 42%). RESULTS: Thirteen patients (13%) had a thromboembolic event. Of these, seven were attributable to causes other than atrial flutter. In the remaining six patients (6%), thromboembolic events occurred during a rhythm of atrial flutter or after cardioversion to sinus rhythm. Other causes of thromboembolism were excluded. Effective anticoagulation was associated with a decreased risk of thromboembolism (p = 0.026). CONCLUSIONS: Patients with chronic atrial flutter are at an increased risk of thromboembolic events. Effective anticoagulation may decrease this risk.     

Echocardiographic factors predicting the maintenance of sinus rhythm one year after cardioversion for non-valvular atrial arrhythmias]

Echocardiographic factors predictive of the maintenance of sinus rhythm after successful cardioversion were investigated in 94 patients with non-valvular atrial arrhythmias of recent onset. Seventy-five patients with atrial fibrillation and 19 with atrial flutter admitted for reduction of their arrhythmias underwent transthoracic and transoesophageal echocardiography. After excluding a thrombus in the left atrial appendage or checking that it had disappeared (5 patients), and electrical (n = 74) or pharmacological (n = 20) cardioversion was successfully performed. The maintenance of sinus rhythm (n = 44) or recurrence of arrhythmia (n = 50) were controlled every 3 months for one year. The mean value of the peak positive blood flow in the left atrial appendage was 38 +/- 20 cm/s for the whole group. It was not possible to identify an echocardiographic parameter predictive of maintenance of sinus rhythm at one year either in the whole group or in the subgroups with atrial flutter or atrial fibrillation. In the group in atrial flutter, the mean value of the peak positive blood flow in the left atrial appendage was significantly greater than in the group with atrial fibrillation: 49 +/- 22 cm/s vs 35 +/- 18 cm/s, respectively; p < 0.05. The peak of positive flow in the left atrial appendage was statistically related to indirect parameters of left atrial function and of left ventricular function in the group with atrial fibrillation but only with parameters of left ventricular function in the smaller group with atrial flutter.     

The use of Cordanum in combination with Corinfar-Retard for the treatment of ectopic arrhythmias in the sick sinus syndrome in patients with ischemic heart disease

38 patients with ischemic heart disease (IHD) and sick sinus syndrome (SSS) received combined therapy with nifedipine (Corinfar-Retard) and talinolol (Cordanum). The former drug had a positive chronotropic effect on the heart, the latter's chronotropic effect was slightly negative. All the patients had sinus bradycardia and ectopic arrhythmia which needed therapeutic correction: supraventricular and ventricular extrasystoles, fibrillation paroxysms or/and atrial flutter, paroxysmal supraventricular tachycardia, ventricular tachycardia. Cordanum was given in a dose 50 mg twice a day, Corinfar-Retard 20 mg twice a day for 16 days. 30 patients responded to the treatment. In addition to good subjective response, episodes of extrasystoles, paroxysms, flutter and fibrillation occurred much less frequently. Side effects resulted in the treatment discontinuation in 3 patients.     

An Italian experience of radiofrequency transcatheter ablation in type-I atrial flutter: the results and 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.     

Incidence of normal hearing in acoustic neuroma]

In a 4 1/2 year period fetal, echocardiographic studies were performed on 1600 fetuses. In 55 with arrhythmia, 44 had supraventricular ectopic beats, resolved in all, and none had heart disease. Sustained arrhythmias occurred in 11 fetuses. Atrial flutter was present in 3 all with heart disease (Ebstein disease, right atrial tumour and WPW diagnosed after birth). Another 3 fetuses had supraventricular tachycardia (SVT), all with a normal heart. In the bradycardia group, 2 had complete heart block (CHB) associated with AVSD; 2 sinus bradycardia and one had non conducted atrial ectopic beats. Digoxin was the first choice drug for tachyarrhythmia therapy; association with Verapamil, Flecainide, Quinidine and Procainamide was used in 4 of the 6. One fetus with CHB received Orciprenaline with no results. Atrial flutter resolved or improved; in SVT 2 fetuses converted to sinus rhythm and one died in utero. All fetuses with CHB died in cardiac failure. Mortality was 27% (3 cases) in utero and global 36%. In our experience most fetal arrhythmias (90%) were transitory ectopic beats or non lasting bradycardia in normal heart and did not trigger other kinds of arrhythmias. In sustained arrhythmias, heart failure and heart disease had a negative effect on prognosis.