Rest perfusion abnormalities in hypertrophic cardiomyopathy: correlation with myocardial fibrosis and risk factors for sudden cardiac death.

AIM: To measure the prevalence of abnormal rest perfusion in a population of consecutive patients with known hypertrophic cardiomyopathy (HCM) referred for cardiovascular MRI (CMR), and to assess any associations between abnormal rest perfusion and the presence, pattern, and severity of myocardial scar and the presence of risk factors for sudden death. MATERIALS AND METHODS: Eighty consecutive patients with known HCM referred for CMR underwent functional imaging, rest first-pass perfusion, and late gadolinium enhancement (LGE). RESULTS: Thirty percent of the patients had abnormal rest perfusion, all of them corresponding to areas of mid-myocardial LGE and to a higher degree of segmental hypertrophy. Rest perfusion abnormalities correlated with more extensive and confluent LGE. The subgroup of patients with myocardial fibrosis and rest perfusion abnormalities (fibrosis+/perfusion+) had more than twice the incidence of episodes of non-sustained ventricular tachycardia on Holter monitoring in comparison to patients with myocardial fibrosis and normal rest perfusion (fibrosis+/perfusion-) and patients with no fibrosis and normal rest perfusion (fibrosis-/perfusion-). CONCLUSIONS: First-pass perfusion CMR identifies abnormal rest perfusion in a significant proportion of patients with HCM. These abnormalities are associated with the presence and distribution of myocardial scar and the degree of hypertrophy. Rest perfusion abnormalities identify patients with increased incidence of episodes of non-sustained ventricular tachycardia on Holter monitoring, independently from the presence of myocardial fibrosis.

Hypnotic communication for periprocedural analgesia during transcatheter ablation of atrial fibrillation.

INTRODUCTION: Hypnosis is a therapeutic strategy for pain control. We aimed at investigating the use of this technique in a large population undergoing atrial fibrillation (AF) ablation. METHODS: 70 consecutive AF patients referred for transcatheter ablation, underwent hypnotic communication for periprocedural analgesia (Group A), were compared with 70 patients undergoing conventional analgesia (Group B). Procedural data, anxiety, perceived pain, perceived procedural duration and the dosages of administered analgesic drugs were compared using validated score scales. RESULTS: Hypnotic communication (Group A) resulted in a significant procedural-related anxiety reduction (Pre procedural 4.7 ±â€¯2.9 Vs Intra Procedural 0.8 ±â€¯1.2, P < 0.001) and perceived procedural duration (Real length 108 ±â€¯33 min Vs Perceived Length 77 ±â€¯39 min, P < 0.001). Group A patients reported a painless procedure in 78% (Pain scale ≤2). Regarding analgesic drug, Group A used only Fentanyl and Paracetamol. The Fentanyl dosage was similar in Group A and B (mean 0.142 Vs 0.146 mg, P = 0.65) while higher Paracetamol dosage was reported in Group A (mean 853 Vs 337 mg, P < 0.001). Group B also used Midazolam (mean 1.8 mg), Propofol (mean 43.8 mg) and narcosis was required in 2 patients. Total radiofrequency (RF) delivered time did not differ between the two groups (mean 28.9 Vs 27.6 min, P = 0.623) as well as mean RF power (mean 35.3 Vs 35.5 W, P = 0.424). No complications occurred. CONCLUSION: Hypnotic communication during AF ablation was related to a significant reduction of intra-procedural anxiety, perceived pain, procedural analgesic drugs dosage and perceived procedural duration without affecting total RF delivered time and procedural safety.

Limited posterior left atrial cryoablation in patients with chronic atrial fibrillation undergoing valvular heart sugery.

OBJECTIVES: We sought to evaluate whether a limited surgical cryoablation of the posterior region of the left atrium was safe and effective in the cure of atrial fibrillation (AF) in patients with associated valvular heart disease. BACKGROUND: Extensive surgical ablation of AF is a complex and risky procedure. The posterior region of the left atrium seems to be important in the initiation and maintenance of AF. METHODS: In 32 patients with chronic AF who underwent heart valve surgery, linear cryolesions connecting the four pulmonary veins and the posterior mitral annulus were performed. Eighteen patients with AF who underwent valvular surgery but refused cryoablation were considered as the control group. RESULTS: Sinus rhythm (SR) was restored in 25 (78%) of 32 patients immediately after the operation. The cryoablation procedure required 20 +/- 4 min. There were no intraoperative and perioperative complications. During the hospital period, one patient died of septicemia. Thirty-one patients reached a minimum of nine months of follow-up. Two deaths occurred but were unrelated to the procedure. Twenty (69%) of 29 patients remained in SR with cryoablation alone, and 26 (90%) of 29 patients with cryoablation, drugs and radiofrequency ablation. Three (10%) of 29 patients remained in chronic AF. Right and left atrial contractility was evident in 24 (92%) of 26 patients in SR. In control group, two deaths occurred, and SR was present in only four (25%) of 16 patients. CONCLUSIONS: Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.

Long-term follow-up of right ventricular monomorphic extrasystoles.

OBJECTIVES: The purpose of this study was to verify in a long-term follow-up whether frequent monomorphic right ventricle extrasystoles may progress to arrhythmogenic right ventricular dysplasia (ARVD). BACKGROUND: Frequent monomorphic right ventricle extrasystoles are generally considered benign. However, in patients with this pattern, cardiac magnetic resonance (MR) has recently shown anatomical and functional abnormalities of the right ventricle. METHODS: Sixty-one patients who had been classified by noninvasive examinations as having frequent idiopathic right ventricle ectopy were contacted after 15 +/- 2 years (12 to 20) and submitted to clinical examination, electrocardiogram (ECG), Holter monitoring, stress test, signal averaged ECG, echocardiography and, in 11 patients, cardiac MR. The primary end point was to ascertain the presence of cases of sudden death or progression to ARVD. RESULTS: At the end of the follow-up, 55 patients were alive; six died, none of sudden death; eight stated to be well but refused further examinations. The 47 patients examined had normal ECG; in 24 patients (51%), extrasystoles were no longer present at Holter monitoring; late potentials were present in up to 15% of the patients; the right ventricle was normal at echocardiography. In 8 of 11 patients (73%), cardiac MR showed focal fatty replacement and other abnormalities of the right ventricle. CONCLUSIONS: In this long-term follow-up study, no patient died of sudden death nor developed ARVD; two-thirds of the patients were asymptomatic, and, in half of the patients, ectopy had disappeared. Focal fatty replacement in the right ventricle was present in most.

Different patterns of atrial activation in idiopathic atrial fibrillation: simultaneous multisite atrial mapping in patients with paroxysmal and chronic atrial fibrillation.

OBJECTIVES: We aimed to evaluate: 1) the behavior of electrical activity simultaneously in different atrial regions during atrial fibrillation (AF); 2) the difference of atrial activation between paroxysmal and chronic AF; 3) the atrial refractoriness dispersion; and 4) the correlation between the effective refractory periods (ERPs) and the FF intervals. BACKGROUND: Little data exist on the electrophysiologic characteristics of the different atrial regions in patients with AF. A more detailed knowledge of the electrical activity during AF may provide further insights to improve treatment of AF. METHODS: Right and left atria were extensively mapped in 30 patients with idiopathic AF (18 paroxysmal and 12 chronic). In different atrial locations, we analyzed 1) the FF interval duration; and 2) the grade of organization and, in case of organized electrical activity, the direction of atrial activation. Furthermore, in patients with paroxysmal AF, we determined the atrial ERP, evaluated the ERP dispersion and assessed the presence of a correlation between the ERPs and the FF intervals. RESULTS: In patients with chronic AF, we observed a shortening of the FF intervals and a greater prevalence of disorganized activity in all the atrial sites examined. In patients with paroxysmal AF, a significant dispersion of refractoriness was observed. The right lateral wall showed longer FF intervals and more organized atrial activity and, unexpectedly, the shortest mean ERPs. In contrast, the septal area showed shorter FF intervals, greater disorganization and the longest mean ERPs. CONCLUSIONS: Electrical activity during AF showed a significant spatial inhomogeneity, which was more evident in patients with paroxysmal AF. The mean FF intervals did not correlate with the mean ERPs.

Should stimulation therapy for congestive heart failure be combined with defibrillation backup?

Biventricular pacing has been proposed to resynchronize ventricular contraction in patients with congestive heart failure (CHF) and interventricular conduction delay. However, the sudden death rate is still high despite the improvement in cardiac performance. Devices combining biventricular pacing with implantable cardioverter defibrillator (ICD) backup are now under clinical investigation to demonstrate whether they can decrease sudden death. From the first implant of an ICD with biventricular transvenous pacing on August 1998 to April 2000, 96 patients underwent such implants: 67 (70%) received pacemakers alone and 29 (30%), who had class I ICD indications, received combined pacemaker/ICD systems. During a mean follow-up of 283 +/- 170 days, 13 (14%) patients died: 5 of 29 (17%) in the ICD group and 8 of 67 (12%) in the pacemaker group. A total of 15 patients (52%) had ICD shocks and 6 patients (21%) had 113 episodes of ventricular tachyarrhythmias, of which 96 (85%) were converted to sinus rhythm with antitachypacing. The echocardiograms showed a narrowing of the delay between the onset of right and left ventricular outflow from 40 +/- 37 msec to 17 +/- 16 msec (p = 0.03) and a reduction of the mitral regurgitation area from 7 +/- 3.8 cm2 to 5 +/- 4 cm2 (p = 0.04) at 3 months. Functional class improved from 2.8 +/- 0.7 to 1.6 +/- 0.5 (p <0.001) 3 months after implant. Thus, ischemic patients with reduced left ventricular ejection fraction and ventricular tachyarrhythmias seem good candidates for biventricular pacing with ICD backup. The sudden death risk for those with idiopathic dilated cardiomyopathy, however, is difficult to stratify, and the choice of ICD backup has to be considered on the basis of patient safety, as well as of costs.

Accessory pathway potential recording in a case of permanent junctional reciprocating tachycardia with decremental conduction localized on the atrial site.

Permanent junctional reciprocating tachycardia (PJRT) is an uncommon form of atrioventricular reentrant tachycardia due to the presence of an accessory pathway characterized by slow and decremental retrograde conduction. We report a case of PJRT where we demonstrated the possibility of recording a distinct accessory pathway potential. Decremental retrograde conduction was evident using ventricular extrastimuli and it was also adenosine-sensitive. Delivering ventricular extrastimuli a prolongation of the accessory pathway potential-atrium interval was seen demonstrating that decremental conduction was located at the atrial insertion of the pathway. The accessory pathway was successfully ablated using the potential as the target of radiofrequency delivery. These electrophysiological findings seem to support the hypothesis that a nodal-like structure may be responsible for this arrhythmia.

Atrial mapping by basket catheter in patients with atrial fibrillation submitted to linear ablation.

Recently non-pharmacological therapies for atrial fibrillation (AF) have been developed. The electrophysiological mechanisms of AF is thought to be the development of multiple reentrant wavelets circulating around anatomic barriers and variable regions of functional conduction block responsible of the perpetuation of the arrhythmia. Also the role of the triggering foci has been highlighted. To cure AF by means of non pharmacological therapy we may eliminate and/or modify the substrate. To better understand the mechanism underlying the AF and to choose the best ablation strategy is of fundamental importance to map the right and the left atrium during AF. Our experience shows that in chronic idiopathic AF disorganized atrial activity is observed at all atrial regions while in paroxysmal idiopathic AF the left septum and the right atrial posterior areas are highly disorganized while the lateral region shows more organized atrial electrical activity. Multipolar basket catheters are extremely useful in mapping right and left atrium in order to guide the best ablation strategy.

[Duration of QRS complexes in arrhythmogenic right ventricular dysplasia. A new non-invasive diagnostic marker]. / La durée des complexes QRS dans la dysplasie ventriculaire droite arythmogène. Un nouveau marqueur diagnostique non invasif.

Arrhythmogenic right ventricular dysplasia (ARVD) may result in sudden death of young and sometimes athletic individuals, while if properly treated it is associated with a good prognosis. It is probably more widespread than currently thought. Comparison of the electrocardiograms of 43 ARVD patients with those of 44 normal individuals provided a new criterion enabling identification of the disease. Measurement of a QRS interval longer than 110 ms in sinus rhythm in lead V1 in an individual with an apparently normal heart enabled identification of the disease with a sensitivity of 55 p. cent and specificity of 100 p. cent if used alone, and a sensitivity of 60 p. cent if used in combination with a prolongation of QRS in lead V3 to greater than 110 ms, but with a specificity of 82 p. cent. After elimination of appearances of right bundle branch block, sensitivity was 50 p. cent for V1. This parameter studied in a hospital population should be validated in minor forms before leading to compulsory ECGs for individuals in high-risk occupations (athletes, public vehicle drivers, etc.).

[Nodal reentry tachycardia: short- and long-term effectiveness and safety of a selective ablation technique of the slow pathway]. / Tachicardia da rientro nodale: efficacia e sicurezza a breve e lungo termine di una tecnica di ablazione selettiva della via lenta.

BACKGROUND: Various ablation methods have been proposed in the last few years in order to find a radical solution for atrioventricular nodal reentrant tachycardia. The first techniques were surgical, followed by modulation of the fast pathway, causing a prolongation of the P-R interval, the latter involving a 2 to 10% atrioventricular block risk. To reduce this risk, slow pathway ablation was then suggested, with the objective of abolishing atrioventricular reentry. The aim of our study was to evaluate how frequently the recording of peculiar slow potentials was possible in patients with atrioventricular nodal reentrant tachycardia, and to assess short-and long-term efficacy of an ablation technique involving the use of these potentials as electrophysiologic markers. METHODS: One hundred and eighty-eight patients with typical atrioventricular nodal reentrant tachycardia were studied (mean age 47 +/- 18 years). Radiofrequency ablation was guided by peculiar slow potential recordings; when this was not possible, fast pathway ablation, or slow pathway ablation guided only by anatomic markers, were performed. RESULTS: Potentials with peculiar electrophysiologic characteristics were found during sinus rhythm in the median posterior region of the septum, anteriorly to the coronary-sinus ostium, in 92% of patients. These characteristics included: low amplitude; the fact that they occupy the first part of the interval between the atrial and ventricular electrogram; their amplitude diminishes and disappears with increased frequency of atrial stimulation and/or with atrial extrastimulus. Typical atrioventricular nodal reentry tachycardia was no longer inducible in any patient at the end of the procedure with a median of 2 radiofrequencies application per patient. No II or III degree atrioventricular block was caused when ablation was guided by slow potential recordings. During an attempt at fast pathway ablation a complete atrioventricular block was caused in 1 patient. One hundred and eighty-four patients remained asymptomatic during a follow-up of 2 to 24 months; no one showed either a modification of atrioventricular conduction if compared to that found at hospital discharge or proarrhythmic effects. Four patients had one atrioventricular nodal reentrant tachycardia recurrence and a second successful ablation was performed in 2 of these 4 patients. CONCLUSIONS: Peculiar slow potentials, that can be used as electrophysiologic markers for slow pathway ablation, were recorded in the medio-posterior region of the septum in the majority of patients. The fact that this technique, using slow potential as an electrophysiologic marker, was successful in all patients, with very few recurrences and with no serious complications (no II or III degree atrioventricular block) makes it trustworthy and safe.

Typical atrial flutter ablation: conduction across the posterior region of the inferior vena cava orifice may mimic unidirectional isthmus block.

INTRODUCTION: The aim of this study was to map the low right atrium before and after radiofrequency ablation of the inferior vena cava-tricuspid annulus (IVC-TA) isthmus in patients with typical atrial flutter (AFI) to better understand the electrophysiologic meaning of incomplete or unidirectional block following the ablation procedure and its relationship with AFI recurrence. METHODS AND RESULTS: We performed atrial mapping in 12 patients using a "basket" catheter in the IVC orifice, Halo catheter in the right atrium, and multipolar catheters in the coronary sinus (CS) and His region. In patients in sinus rhythm, atrial activation was analyzed during pacing from the CS and low lateral right atrium (LLRA) before and after ablation. Atrial activation propagated across the isthmus and posterior region of the IVC orifice simultaneously before ablation. Mapping during AF1 in four patients showed that the crista terminalis was a site of functional block. After ablation, evaluation of Halo catheter recordings in three patients showed apparent unidirectional counterclockwise block, whereas analysis of basket catheter recordings demonstrated complete bidirectional block. The apparent conduction over the isthmus during pacing from proximal CS was due to conduction along the posterior part of the IVC orifice, which activated the LLRA despite complete isthmus block. CONCLUSION: Our results demonstrate that limited endocardial mapping may yield a pattern compatible with unidirectional block in the IVC-TA isthmus, although bidirectional block is present at this anatomic level.

Adipose replacement and wall motion abnormalities in right ventricle arrhythmias: evaluation by MR imaging. Retrospective evaluation on 124 patients.

We reevaluated the magnetic resonance (MR) examinations of 38 healthy volunteers (control group, CG) and of 124 patients with RV arrhythmia with left bundle branch block (LBBB) morphology: 45 with episodes of RV sustained tachycardia and of polymorphic RV premature beats (RVST-PPB group); 36 with only RV outflow tract sustained or not sustained tachycardia (RVOTT group); 43 with RV monomorphic premature beats (RVMPB group). All the examinations were reevaluated in a blinded fashion for detecting myocardial adipose replacement (AR) and wall bulges or aneurysms. In RVST-PPB patients, no AR was observed in 9%; 1 RV region involvement, 0%; 2 regions, 4%; > or = 3 regions, 87%; left ventricle (LV), 15%. RVOTT patients: 28%, 53%, 14%, 5%, and 0% [corrected], respectively. RVMPB patients: 33%, 46%, 19%, 2%, and 0% [corrected], respectively. In CG, AR was observed in 11% (in RV outflow tract), RV bulges were detected in 75% [corrected] of RVST-PPB, 39% of RVOTT, and 14% of RVMPB patients, none of the CG; RV aneurysms in 33% of RVST-PPB patients, none of RVOTT patients, RVMBP patients, and CG. A significant difference among groups for RV and LV AR as well as RV bulges and aneurysms was found (p < 0.0001). In the direct comparisons, significant differences were found for: disease duration (RVST-PPB vs. RVMPB, p = 0.0396); RV AR (all the patients groups vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0001); RV aneurysms (RVST-PPB vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0002); bulges (all comparisons, p < 0.0174). AR is confirmed as a structural substrate in RV arrhythmias. Number and extension of MR abnormalities are correlated to different degrees of RV arrhythmias.