Rhythm-symptom correlation in patients on continuous monitoring after catheter ablation of atrial fibrillation.

INTRODUCTION: Correlation between symptoms and atrial fibrillation (AF) episodes after catheter ablation may have clinical relevance, especially for anticoagulation usage. The aim of our project was to analyze the relationship between symptoms and AF recurrences in unselected patients following AF catheter ablation during long-term follow-up. METHODS AND RESULTS: One hundred and forty-three consecutive patients (mean age 59 ± 9 years, 85% male) were implanted with a continuous cardiac monitor (RevealXT, Medtronic Inc., Minneapolis, MN, USA) following first pulmonary vein ablation procedure. Device data were downloaded every 3 months and correlated to patients' symptom diary. AF was paroxysmal in 55% and persistent in 45%. At a mean follow-up of 14 ± 6 months, 98/143 (69%) patients had at least one AF recurrence. Among these, 53 (54%) reported AF-related symptoms while 45 (46%) were totally asymptomatic. Conversely, 13 (29%) out of 45 patients without AF recurrences reported symptoms. Globally, a significant reduction of symptoms (from 82% at baseline to 44% at last follow-up; P < 0.0001) was observed. SF-12 questionnaire showed a significant improvement of physical and mental functioning (respectively 44.5 ± 8.5 vs 51.0 ± 6.7, and 45.7 ± 9.3 vs 49.2 ± 6.1, P < 0.05 baseline vs last follow-up). At the 12-month follow-up, 80% and 77% of patients were on AAD and anticoagulant drugs, respectively. There were not differences in AAD usage in symptomatic and asymptomatic patients. CONCLUSIONS: Continuous ECG monitoring is a valuable tool for long-term follow-up after AF catheter ablation facilitating reliable assessment of symptomatic and asymptomatic AF episodes. This may have clinical implications with regards to anticoagulation therapy in high-risk patients.

Radiation-induced heart disease.

The recent improvement in radiation techniques and the associated significant prolongation of survival have resulted in a widespread utilization of mediastinal irradiation in patients with various neoplasms. However, a large number of experimental and clinical studies have clearly demonstrated that high-dose therapeutic mediastinal irradiation can produce delayed, severe cardiovascular disease. This review presents the data from the Literature regarding the pathogenesis, pathology, prevalence and clinical manifestation of the radiation-related heart disease.

Overdrive atrial stimulation during transesophageal electrophysiological study: usefulness of post-pacing VA interval analysis in differentiating supraventricular tachycardias with 1:1 atrio-ventricular relationship.

We evaluated the feasibility and usefulness of overdrive atrial pacing to identify the relationship between atrial and ventricular activation in supraventricular tachycardias with a stable 1:1 atrio-ventricular (AV) conduction ratio during a transesophageal electrophysiological investigation. Overdrive atrial stimulation was performed in 42 consecutive patients (11 males and 31 females; mean age 49 +/- 17 years) during AV junctional reentrant tachycardia, orthodromic AV reentrant tachycardia and ectopic atrial tachycardia (22, 13 and seven subjects, respectively). Trains of 12 stimuli at a constant rate were introduced starting at a cycle length 10 ms shorter than the tachycardia cycle length; stimulation was repeated with a 10-ms decrement in pacing cycle length at each step until tachycardia terminated and/or second-degree AV block occurred. The difference between the VA interval duration at baseline and in the first post-pacing tachycardia beat was measured at each step and provided identification of the AV relationship. At least one post-pacing VA interval was evaluable in 90% of the cases and measured 2 +/- 4 and 1 +/- 3 ms in AV junctional and AV reentrant tachycardia groups, respectively, and 83 +/- 42 ms in the ectopic atrial tachycardia group (P < 0.0000001 ectopic atrial tachycardia group vs. others). When three or more post-pacing VA intervals were obtained during the same tachycardia, a curve was constructed by plotting their values against the corresponding pacing cycle lengths. A curve could be constructed in 36% of the cases and was flat in all patients with AV junctional and AV reentry, while it was completely irregular in the ectopic atrial tachycardia group (P < 0.003). The analysis of post-pacing VA interval behaviour in response to overdrive atrial stimulation provides a rapid and reliable differentiation between supraventricular tachycardias with 1:1 AV conduction ratio during a transesophageal electrophysiological study.

Transesophageal versus intracardiac atrial stimulation in assessing anterograde conduction properties of the accessory pathway in Wolff-Parkinson-White syndrome.

Electrophysiologic intracardiac and noninvasive transesophageal testing, used to evaluate parameters of anterograde conduction across the accessory pathway, the refractory period and shortest atrial cycle length with 1:1 conduction over the pathway, were compared to assess the reliability of the noninvasive technique in identifying patients with Wolff-Parkinson-White syndrome, at risk of rapid ventricular response during atrial fibrillation when this arrhythmia is not inducible. Sixteen patients with Wolff-Parkinson-White syndrome were submitted both to invasive and transesophageal atrial stimulation. We evaluated both the functional and effective refractory periods of the accessory pathway, using the same drive cycle length, and the shortest cycle length with 1:1 atrioventricular conduction over the accessory pathway. There were no differences between the parameters obtained by intracardiac atrial stimulation and by transesophageal atrial stimulation. The two approaches correlated well: mean functional refractory periods of the accessory pathway were 285 +/- 42 msec and 289 +/- 32 msec, respectively (NS, r = 0.88); mean effective refractory periods of the accessory pathway were 267 +/- 41 msec and 271 +/- 32 msec, respectively (NS, r = 0.89); mean shortest cycle lengths with 1:1 conduction over the accessory pathway were 255 +/- 48 msec and 255 +/- 44 msec, respectively (NS, r = 0.94). These data demonstrate the reliability of transesophageal atrial stimulation in estimating the parameters for anterograde conduction across an accessory pathway. These results, and the already documented ability of transesophageal atrial stimulation to induce atrial fibrillation, suggest this noninvasive technique should be taken as a first approach in screening patients with Wolff-Parkinson-White syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiologic evaluation of intravenous L-propionylcarnitine in man.

L-propionylcarnitine, a short-chain acylcarnitine, has been shown in experimental studies to induce, during acidic and hypoxic conditions, some electrophysiological changes such as an increase of duration of the action potential and of the effective refractory period. In this study, the acute electrophysiological effects of intravenous L-propionylcarnitine (30 mg/kg in 3 min) were studied in 12 subjects with estimated normal function of the sinus node and normal parameters for atrioventricular conduction. Statistically significant changes were observed 2 min after infusion. The sinus cycle length shortened (866 +/- 138 vs 818 +/- 124 msec, P less than 0.05) while refractory periods of the atrioventricular node increased (effective by 30-50 msec in four cases; functional from 425 +/- 52 to 436 +/- 55 msec, P less than 0.05). Sinuatrial conduction time, atrial refractory periods, infranodal conduction, bundle branch, His-Purkinje system and ventricular refractoriness were unchanged. Systolic and diastolic blood pressure were also unchanged. Because of the limited effects on electrophysiological parameters, L-propionylcarnitine should be used as a metabolic drug even in patients with mild disturbances of conduction.

Usefulness of transesophageal atrial pacing in hyperkalemia-induced impulse formation and conduction disturbances.

This report describes the usefulness of transesophageal atrial pacing in the treatment of five patients with hyperkalemia-induced bradycardias. Three patients had marked sinus bradycardia while the other two had a regular rhythm with QRS of left bundle branch block morphology, with no P waves visible on the surface electrocardiogram. Four patients were in chronic hemodialysis three times a week, and one had severe post-traumatic hemorrhage. In three patients, hyperkalemia had been precipitated by food intoxication. In one case the cause was unknown while, in the last case, hyperkalemia was due to rapid infusion of stored blood and solutions containing high concentrations of potassium. Transesophageal atrial pacing was performed in all cases utilizing a bipolar catheter introduced into the esophagus and a constant current generator delivering square wave pulses of 10 msec duration and 19-28 mA intensity. Atrial capture, followed by impulse conduction to the ventricles, was constant in all cases, being performed for between 15 and 35 minutes until a normal sinus rhythm was restored. The procedure was well tolerated. The advantages of this procedure as opposed to invasive ventricular pacing are discussed.

The nature and evolution of ventricular arrhythmias in acute myocardial infarction.

The natural evolution of ventricular arrhythmias complicating a first episode of acute myocardial infarction has been studied in a group of 56 consecutive patients, who were admitted to the Coronary Care Unit within three hours of the onset of symptoms, and in whom drug administration (digitalis, antiarrhythmics, diuretics and heparin) was limited. Ventricular arrhythmias have been evaluated by means of Holter monitoring performed during the first 24 hours, the second 24 hours, the eighth day, the 18th day and two years after discharge when antiarrhythmic drugs has been discontinued for at least five half-lives. The overall incidence and prevalence of ventricular arrhythmias showed a steady and statistically significant reduction from the first to the eighth day, and a not statistically significant increase from the eighth to the 18th day. The latter increase was still present at the two-year follow-up. The one-by-one behaviour analysis of discharged patients delineated three different patterns: patients who presented a steady reduction in ventricular arrhythmias from the first to the 18th day (44%); patients who showed an almost constant incidence of ventricular arrhythmias during all phases of acute myocardial infarction (24%); and patients who presented both a decrease and an increase in their ventricular arrhythmias (31%). The follow-up at two years showed that the majority of patients, especially those discharged in a high Lown class, had the same arrhythmias as at their follow-up on the 18th day. Correlation of ventricular arrhythmias with the extent of the infarcted area demonstrated that only the peak and mean values of lactic dehydrogenase correlated with the severity of ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical use of transoesophageal atrial stimulation in terminating ventricular tachycardia.

This study was performed to evaluate whether transoesophageal atrial pacing could also stop ventricular tachycardias with low rates and no haemodynamic impairment. Prior to resorting to ventricular endocardial pacing, seven male patients, aged between 15 and 73 years, were treated by transoesophageal atrial pacing for 10 spontaneous episodes of sustained ventricular tachycardia at rates between 105 and 160 beats per minute, without haemodynamic impairment. When atrial pacing did not allow ventricular capture, atropine sulphate was administered. Transoesophageal atrial pacing led to ventricular capture in seven episodes, which made overdriving possible, and blocked six episodes of ventricular tachycardia. In no case did transoesophageal atrial pacing lead to an acceleration of ventricular tachycardia or to degeneration into ventricular fibrillation. Transoesophageal atrial pacing can block low-rate sustained ventricular tachycardias (less than or equal to 150 beats per minute). For low-rate sustained ventricular tachycardias without haemodynamic impairment, transoesophageal atrial pacing can thus be used as the method of choice thanks to its good ratio of risk to efficiency.

Radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia: selective approach to the slow pathway via the superior vena cava.

Selective radiofrequency catheter ablation of the slow atrioventricular nodal pathway is currently considered the first-line therapy for patients suffering from recurrent symptomatic atrioventricular nodal reentry tachycardia. In most cases slow pathway conduction may be selectively eliminated or modified by the application of radiofrequency current at the posterior portion of Koch's triangle. The ablation site is usually targeted by careful mapping of this area performed using an ablation catheter advanced via the inferior vena cava approach. In this report we describe 2 cases in which the conventional approach to the target site was either impossible owing to the presence of an atresic inferior vena cava (case 1), or contraindicated in view of a history of common femoral vein thrombosis, subsequently extended up to the inferior vena cava (case 2). In both patients a superior vena cava approach was utilized and the slow pathway was successfully ablated. In case of arrhythmias necessitating slow pathway mapping and ablation, such an approach may be considered as a feasible and safe alternative whenever, owing to the presence of anomalies and/or diseases of the inferior vena cava, the conventional approach cannot be employed.

[Cardiac rhythm disturbances in hypertensive cardiopathy]. / Le alterazioni del ritmo cardiaco nella cardiopatia ipertensiva.

Patients with hypertensive heart disease are at a significantly increased risk for cardiovascular morbidity and mortality. Ultrastructural and gross anatomical cardiac changes, combined with hemodynamic and neurovegetative balance fluctuations, are frequently responsible for cardiac arrhythmias of atrial and/or ventricular origin. The prevalence, the pathophysiologic mechanism and the prognostic significance of cardiac rhythm disturbances occurring in hypertensive heart disease are discussed in this review.

Management of keloids and hypertrophic scars.

Keloids and hypertrophic scars may complicate elective foot surgery. Differentiation between these two entities is important before treatment is contemplated. The authors review current theories on the etiology of these lesions and outline various treatment options.

Unusual resetting patterns in response to single atrial extrastimuli during AV junctional reentrant tachycardia.

INTRODUCTION: Two unusual resetting patterns were observed in two patients with slow-fast AV junctional reentrant tachycardia (AVJRT) submitted to an electrophysiologic study. METHODS AND RESULTS: After AVJRT induction, resetting was evaluated by introducing single extrastimuli at progressively shorter coupling intervals from the high right atrium (HRA) and the proximal coronary sinus (CS). An alteration in the return cycle length duration allowed demonstration of resetting. In the first patient, during and AVJRT with a large excitable gap, properly timed extrastimuli delivered both from the HRA and CS simultaneously reset the tachycardia and advanced the H electrogram of the preceding tachycardia beat. In the second patient, both HRA and CS stimulation apparently failed to reset AVJRT (return cycle length unchanged), but, at critical coupling intervals, the cycle length duration of the tachycardia beat following the return cycle was consistently shortened. CONCLUSION: During slow-fast AVJRT, single atrial stimulation from sites remote to the reentrant circuit may result in unusual resetting patterns. Further studies are required to evidence the full spectrum of resetting in AVJRT.

["Double nodal pathway" as a common electrogenic pathway at the base of first and second degree paroxysmal atrioventricular node and nodal reentrant tachycardia]. / La "doppia via nodale" come comune substrato elettrogenetico alla base di blocchi atrioventricolari parossistici di primo e secondo grado e della tachicardia da rientro nodale.

The combined occurrence of conduction disturbances and reentry in subjects with a dual atrioventricular nodal pathway is extremely rare and poorly documented, only by means of short electrocardiographic strips. This case report deals with a young woman with frequent episodes of paroxysmal first- and second-degree type I atrioventricular block due to a dual atrioventricular nodal pathway at Holter monitoring, and atrioventricular nodal reentrant tachycardia inducible at transesophageal electrophysiologic study. This case confirms that some paroxysmal first- and second-degree atrioventricular block and the atrioventricular nodal reentrant tachycardia may share the same electrogenetic substrate represented by a dual atrioventricular nodal pathway. This finding may be of clinical significance because of its potential therapeutical implications. Further studies are needed in order to explain the rarity of this association.

Intra-atrial and atrioventricular nodal reentrant tachycardia in the same subject diagnosed at transesophageal electrophysiologic study.

The case report deals with a young woman with frequent episodes of paroxysmal narrow QRS tachycardia of uncertain etiology at Holter monitoring in whom a transesophageal electrophysiologic study was carried out in order to identify the electrogenetic mechanism of the presenting arrhythmia. During the electrophysiologic study, 2 different types of supraventricular tachycardia were induced and diagnosed as intra-atrial and atrioventricular nodal reentrant tachycardia. This association represents a rare finding and can provide a possible explanation to the intriguing electrocardiographic pattern observed at Holter monitoring. Therefore, transesophageal electrophysiologic study proved to be a valuable method for evaluating subjects with complex supraventricular tachycardias.

[Method for the characterization of peripheral lymphocytes in humans and their significance]. / Metodica per la caratterizzazione dei linfociti periferici nell'uomo e loro significato.

The Authors describe a technique for the identification of the lymphocytic subpopulations of peripheral human blood. It is pointed out the importance of using iron powder, AET, 20 hours incubation. The percentages of cells forming E rosets in patients suffering of acute lymphatic leukaemias and in normal subjects is valued.

[Intraserosal proximal hemideferentectomy versus classical proximal hemivasectomy in the rat. Anatomo-functional aspects and proposal for a new terminology]. / La emideferentectomia prossimale intrasierosa versus la emivasectomia prossimale classica nel ratto. Aspetti anatomo-funzionali e proposta di una nuova terminologia.

According to new trends and terms in microsurgery, the intra-serous proximal hemideferentectomy is compared to the classical vasectomy in rat. The effects of these surgical models are evaluated on morphological and functional bases. The anatomo-pathological parameters considered (stenosis and leakage of the anastomosis of the epididymal tubule conseguent on local ischemia) have been correlated with functional parameters "in vitro" (spontaneous motility and field stimulation) in order to plan the best microsurgical procedure in the experimental tubulo-vasostomy.

[Localization of the accessory pathways using surface ECG in Wolff-Parkinson-White syndrome]. / Localizzazione della via accessoria mediante ECG di superficie nella sindrome di Wolff-Parkinson-White.

During recent years criteria for localization of bypass tracts in the Wolff-Parkinson-White syndrome from the conventional ECG have been acquired utilizing epicardial and endocardial mapping data. The polarity of delta wave and QRS in the frontal and horizontal plane and the morphology of retrograde P waves during orthodromic reciprocating tachycardia, are the most indicative elements. An accurate analysis of QRS complexes during atrial fibrillation confirms the site of pre-excitation and could suggest the presence of 2 or more accessory pathways with sufficient spatial separation. Some criteria for identifying multiple accessory pathways are discussed.