Simultaneous pulmonary vein cryoablation and cavotricuspid isthmus radiofrequency ablation in patients with combined atrial fibrillation and typical atrial flutter.

Pulmonary vein isolation (PVI) using cryoballoon (CB) technique and cavotricuspid isthmus (CTI) ablation using radiofrequency (RF) are established interventions for drug-resistant atrial fibrillation (AF) and typical atrial flutter (AFL). Twelve patients with a mean age of 62 ± 12 years underwent simultaneous delivery of RF energy at the CTI during CB applications at the PV ostia. Pulmonary vein isolation was achieved in all PVs and sustained bidirectional CTI conduction block obtained in all patients. The reported ablation protocol of combined paroxysmal AF and typical AFL did not result in prolongation of the procedure duration or in prolonged radiation exposure when compared to CB-PVI alone. No interferences between both ablation energy systems were observed. These preliminary results suggest that combined paroxysmal AF and typical AFL can be successfully and safely ablated using hybrid energy sources with simultaneous CTI ablation using RF during CB applications at the PV ostia.

Pulmonary vein isolation using a single size cryoballoon chosen according to transesophageal echocardiography information.

BACKGROUND: Pulmonary vein isolation (PVI) using cryoballoon (CB) catheter is a new technique for atrial fibrillation (AF) ablation. Previous studies used computer tomography (CT) or magnetic resonance imaging (MRI) scan to determine the pulmonary vein (PV) diameter and anatomy for choosing the CB size. We evaluated pre-ablation transoesophageal-echocardiography (TEE) as an alternative to CT/MRI scan in patients undergoing AF ablation for determining the appropriate size of the CB. METHODS: Fifty-five consecutive patients (men=43, women=12) with a mean age of 63 ± 12.5 years, and with drug-refractory paroxysmal AF (34 patients) or persistent AF (21 patients) were included in this prospective study. All patients underwent pre-ablation TEE. RESULTS: Hypertension was present in 19 patients (34%). Mean anterior-posterior left atrium diameter was 45.1 ± 8.9 mm. In total, 217 PV were targeted using a single 23-mm (n=14) or 28-mm (n=40) CB catheter chosen according to TEE-obtained measurements. PVI was achieved in 195 PV (90%). Mean number of CB applications per patient was 9.8 ± 2.1 (range 8-14). Mean procedure duration and fluoroscopy times were 131 ± 27 min (90-190 min) and 36 ± 12 min (22-66 min) respectively. Phrenic nerve palsy occurred in 3 patients (5.4%) and was transient (<1 month) in all of them. CONCLUSION: This study suggests that TEE is an easily available and effective tool to select the size of the CB for PVI according to evaluated PV diameters and anatomy.

Reduction of procedure duration and radiation exposure with a dedicated inner lumen mapping catheter during pulmonary vein cryoablation.

BACKGROUND: The Achieve catheter (AC; Medtronic-CryoCath, Pointe-Claire, Canada) is a circular mapping catheter introduced through the lumen of the cryoballoon (CB) catheter which is safe and effective to both navigate the CB to the pulmonary veins (PV) and allow PV potential recording during PV cryoablation. The aim of this study was to evaluate the impact of the use of the AC on procedural outcomes. METHODS: Sixteen consecutive patients (14 men) underwent AC-guided PV isolation (PVI) for drug-refractory paroxysmal atrial fibrillation (AF; AC group). Clinical and procedural data of these patients were compared to those obtained from 16 consecutive patients who had undergone PVI for paroxysmal AF with the regular "single transseptal" approach (control group). RESULTS: Clinical characteristics of patients enrolled in both groups did not differ significantly. In the AC group, 64 PVs were targeted using a single 28-mm (n = 13) or 23-mm (n = 3) CB catheter with PVI achieved in 62 PVs (97%). In the control group, 66 PVs were targeted using a single 28-mm (n = 12) or 23-mm (n = 4) CB catheter with PVI achieved in 62 PVs (94%), (P = non-significant for CB size and PVI rate). Procedure duration and fluoroscopy time were significantly reduced in AC group compared to control group (96.6 ± 26 minutes vs 125.9 ± 25 minutes, P = 0.003 and 24.4 ± 10 minutes vs 32.6 ± 11 minutes, P = 0.04, respectively). CONCLUSION: The use of the AC significantly reduced procedure duration and radiation exposure during PVI with the CB technique.

Slow pathway elimination for atrioventricular nodal reentrant tachycardia with the 8-mm tip cryoablation catheter: an 18-month follow-up study.

PURPOSE: The 9-French 8-mm tip cryoablation catheter confers a high rate of acute slow pathway (SP) elimination and an acceptable short-term outcome in patients with atrioventricular nodal reentrant tachycardia (AVNRT). The aim of this study was to investigate the long-term outcome of patients treated with this electrode in this indication. METHODS: Eighty-two patients (female = 52) with a mean age of 54.9 ± 17.7 years underwent SP elimination for typical AVNRT with the 8-mm tip cryocatheter in our institution between November 2009 to June 2012. Clinical and procedural characteristics were prospectively collected. RESULTS: Acute procedural success defined as AVNRT non-inducibility at the end of the procedure was obtained in 81/82 patients (98.7 %). Mean procedure duration and fluoroscopy time were 74.4 ± 28.7 min (range, 35-160 min) and 8.7 ± 5.3 min (range, 2-26 min), respectively. Mean number of energy applications was 4.0 ± 2.4 (range, 2-15). No permanent atrioventricular block was observed. Transient atrioventricular block occurred in 12 patients (14.6 %). Traumatic fast pathway conduction block occurred in one patient before cryoenergy delivery. Using an intention-to-treat analysis, 78 patients (95.1 %) remained free of AVNRT recurrence during a mean follow-up of 17.8 ± 9.3 months. CONCLUSIONS: This study confirmed that the 8-mm tip cryocatheter is both safe and highly effective for SP conduction elimination in patients with AVNRT and demonstrated a low recurrence rate during a long-term follow-up.

Characteristics of isolated atrial flutter versus atrial flutter combined with atrial fibrillation.

BACKGROUND: Atrial flutter (AFL) and atrial fibrillation (AF) are "fellow-travellers". AF may be a stable, "isolated" rhythm, a bridge between sinus rhythm and AF, or both arrhythmias can coexist. Whether the characteristics of isolated AFL are different from those of patients with AFL combined with AF is still unclear. AIM: To compare the clinical characteristics of patients with isolated AFL to those of patients with AFL combined with AF, in a series of patients referred for AFL ablation. METHODS: Seventy-six consecutive patients (mean age 66.9±12.2 years; 53 men) with a history of electrocardiogram-documented paroxysmal or persistent AFL, referred for catheter ablation, underwent clinical work-up including bidimensional echocardiogram. Patients were subdivided into group I (44 with isolated AFL) and group II (32 with AFL and a history of AF). RESULTS: Underlying heart disease was present in 62 patients (81.6%). Hypertension was the most common cardiac disorder (n=44, 57.9%) and was more prevalent in group II than in group I (75.0% vs 45.5%; P=0.01). Prevalence of prior cardiac surgery was higher in group I (22.7% vs 6.3%; P=0.04). AFL was persistent in 35 group I patients and 17 group II patients (79.5% vs 53.1%; P=0.01). Class I or III antiarrhythmic drug use was more frequent in group II (84.4% vs 45.5%; P=0.001). CONCLUSION: This study showed significant differences between patients with isolated AFL and those with AFL combined with AF, in the prevalence of underlying heart disease and the use of antiarrhythmic medication, which were higher when both atrial arrhythmias were combined. In turn, the history of cardiac surgery (including atriotomy), was more common in patients with isolated AFL than in those with AFL combined with AF.

ECG repolarization syndrome abnormalities (J wave syndromes) and idiopathic ventricular fibrillation: diagnostic and management.

Early repolarization (ER) pattern has been recognized for several decades and was interpreted as a variant of the normal electrocardiogram (ECG) as it was frequently observed in young healthy subjects or athletes. It is characterized by a J point elevation and ST-segment elevation inscribed as a QRS slurring or a notch of the S wave in the inferior leads or/and the lateral leads. The ER pattern has been the subject of increased interest since the report of its higher prevalence in subjects resuscitated from cardiac arrest related to idiopathic ventricular fibrillation (VF). Furthermore, population-based studies showed in healthy young adults that ER pattern was associated with an increased cardiovascular mortality and total mortality. A relationship between ER pattern and malignant arrhythmias is also supported by the experimental work of Antzelevitch et al. which provided the cellular and ionic basis for the J point elevation and its arrhythmogenic potential. The ER pattern may coexist with a number of cardiac or extracardiac conditions such as hypothermia. But this review will focus attention on the "isolated ER pattern" in healthy individuals. Antzelevitch and Yan proposed because of a number of similarities between the "ER syndrome" and the Brugada syndrome to group both syndromes under the heading of "J wave syndromes". The management of ER syndrome (associated with idiopathic VF) is clearly the insertion of an implantable cardioverter defibrillator (ICD). The ER pattern associated with symptoms such as syncope or a familial history of sudden cardiac death requires a complete work-up. Caution should be raised not to generate anxiety in the subject with asymptomatic "isolated ER pattern" as the odds of developing malignant ventricular arrhythmias or to suffer sudden death in this case are extremely low.

Long-term follow-up of patients with short QT syndrome.

OBJECTIVES: The aim of this study was to investigate the clinical characteristics and the long-term course of a large cohort of patients with short QT syndrome (SQTS). BACKGROUND: SQTS is a rare channelopathy characterized by an increased risk of sudden death. Data on the long-term outcome of SQTS patients are not available. METHODS: Fifty-three patients from the European Short QT Registry (75% males; median age: 26 years) were followed up for 64 ± 27 months. RESULTS: A familial or personal history of cardiac arrest was present in 89%. Sudden death was the clinical presentation in 32%. The average QTc was 314 ± 23 ms. A mutation in genes related to SQTS was found in 23% of the probands; most of them had a gain of function mutation in HERG (SQTS1). Twenty-four patients received an implantable cardioverter defibrillator, and 12 patients received long-term prophylaxis with hydroquinidine (HQ), which was effective in preventing the induction of ventricular arrhythmias. Patients with a HERG mutation had shorter QTc at baseline and a greater QTc prolongation after treatment with HQ. During follow-up, 2 already symptomatic patients received appropriate implantable cardioverter defibrillator shocks and 1 had syncope. Nonsustained polymorphic ventricular tachycardia was recorded in 3 patients. The event rate was 4.9% per year in the patients without antiarrhythmic therapy. No arrhythmic events occurred in patients receiving HQ. CONCLUSIONS: SQTS carries a high risk of sudden death in all age groups. Symptomatic patients have a high risk of recurrent arrhythmic events. HQ is effective in preventing ventricular tachyarrhythmia induction and arrhythmic events during long-term follow-up.

Usefulness of left atrial volume for the diagnosis of diastolic heart failure: an echocardiographic-catheterization study.

The present study attempted to determine the accuracy of left atrial volume (LAVi) by transthoracic echocardiography in the diagnosis of diastolic heart failure (DHF) in patients presenting with chronic, isolated dyspnea. We included 28 consecutive patients with a left ventricular ejection fraction >50% without prior history of heart failure. DHF was authenticated in 20 patients by invasive left ventricular end-diastolic pressure >16 mmHg. By logistic regression analysis, LAVi was predictive of DHF (p=0.015). LAVi>38 ml/m(2) was a useful predictor of DHF (area under the ROC curve of 0.84 [0.65-0.95], p<0.001, sensitivity 60%, specificity 100%). The standard cut-off value of 34 ml/m(2) was 70% sensitive and 88% specific.

Stenotrophomonas maltophilia prosthetic valve endocarditis: a case report.

INTRODUCTION: Stenotrophomonas maltophilia is an environmental bacterium increasingly involved in nosocomial infections and resistant to most antibiotics. It is important to recognize and efficiently treat infections with this bacterium as soon as possible. CASE PRESENTATION: We present a case of Stenotrophomonas maltophilia prosthetic valve endocarditis secondary to an indwelling catheter infection. The patient was cured without surgery. We review other cases of S. maltophilia endocarditis from the literature and describe the peculiarities of this case. CONCLUSION: S. maltophilia endocarditis is a rare disease that is often hospital-acquired and related to an indwelling catheter infection. The high lethality is likely related to the intrinsic resistance of nosocomial bloodstream infections to commonly prescribed antibiotics.

Increased expression of adenosine A2A receptors in patients with spontaneous and head-up-tilt-induced syncope.

BACKGROUND: Adenosine may play a role in the triggering of neurocardiogenic syncope, but no information on adenosine receptors is available at the present time. OBJECTIVE: The purpose of this study was to investigate whether adenosine A2A receptors expression is altered in patients with neurocardiogenic syncope. METHODS: Adenosine plasma levels (APLs), the expression of A2A receptors, were measured (mean +/- standard error of the mean) during tilt testing. Expression of receptors was assessed on mononuclear cells using a selective receptor ligand. RESULTS: At baseline, the APLs of 16 patients with a positive test were higher than those of 17 patients with a negative test and of those of a control group (2.10 +/- 0.30 vs. 0.40 +/- 0.05 and 0.41 +/- 0.06 muM, respectively; P <.0001). The number of receptors was higher in patients tested positive than in patients tested negative or in the control group (122 +/- 10 vs. 38 +/- 4 and 44 +/- 4 fmol/g of proteins, respectively; P <.0001). No difference was found in the affinity or synthesis among the three groups. CONCLUSION: This study showed an increased number and an up-regulation of adenosine A2A receptors in patients with spontaneous syncope and a positive head-up tilt, which in the context of high APLs may play a role in the recurrence of syncopal episodes.

Short QT syndrome: clinical findings and diagnostic-therapeutic implications.

AIMS: Clinical presentation, occurrence of sudden infant death, and results of the available therapies in the largest group of patients with short QT syndrome (SQTS), studied so far, are reported. METHODS AND RESULTS: Clinical history, physical examination, electrocardiogram (ECG), exercise stress testing, electrophysiological study, morphological evaluation, genetic analysis and therapy results in 29 patients with SQTS and personal and/or familial history of cardiac arrest are reported. The median age at diagnosis was 30 years (range 4-80). In all subjects, structural heart disease was excluded. Eighteen patients were symptomatic (62%): 10 had cardiac arrest (34%) and in 8 (28%) this was the first clinical presentation. Cardiac arrest had occurred in the first months of life in two patients. Seven patients had syncope (24%); 9 (31%) had palpitations with atrial fibrillation documented even in young subjects. At ECG, patients exhibited a QT interval < or = 320 ms and QTc < or = 340 ms. Fourteen patients received an implantable cardioverter-defibrillator (ICD) and 10 hydroquinidine prophylaxis. At a median follow-up of 23 months (range 9-49), one patient received an appropriate shock from the ICD; no patient on hydroquinidine had sudden death or syncope. CONCLUSION: SQTS carries a high risk of sudden death and may be a cause of death in early infancy. ICD is the first choice therapy; hydroquinidine may be proposed in children and in the patients who refuse the implant.