Multicentre experience with the second-generation subcutaneous implantable cardioverter defibrillator and the intermuscular two-incision implantation technique.

INTRODUCTION: The recently developed second-generation subcutaneous implantable cardioverter defibrillator (S-ICD) and the intermuscular two-incision implantation technique demonstrate potential favorable features that reduce inappropriate shocks and complications. However, data concerning large patient populations are lacking. The aim of this multicentre prospective study was to evaluate the safety and outcome of second-generation S-ICD using the intermuscular two-incision technique in a large population study. METHODS AND RESULTS: The study population included 101 consecutive patients (75% male; mean age, 45 ± 13 years) who received second-generation S-ICD (EMBLEM; Boston Scientific, Marlborough, MA) implantation using the intermuscular two-incision technique as an alternative to the standard implantation technique. Twenty nine (29%) patients were implanted for secondary prevention. Twenty four (24%) patients had a previously implanted transvenous ICD. All patients were implanted without any procedure-related complications. Defibrillation testing was performed in 80 (79%) patients, and ventricular tachycardia was successfully converted at less than or equal to 65 J in 98.75% (79/80) of patients without pulse generator adjustments. During a median follow-up of 21 ± 10 months, no complications requiring surgical revision or local or systemic device-related infections were observed. Ten patients (9.9%) received appropriate and successful shocks for ventricular arrhythmias. Three (2.9%) patients experienced inappropriate shocks due to oversensing the cardiac signal (n = 1), noncardiac signal (n = 1), and a combination of both cardiac and noncardiac signals (n = 1), with one patient requiring device explantation. No patients required device explantation due to antitachycardia pacing indications. CONCLUSIONS: According to our multicentre study, second-generation S-ICD implanted with the intermuscular two-incision technique is an available safe combination and appears to be associated with a low risk of complications, such as inappropriate shocks.

Cardiac resynchronization therapy by multipoint pacing improves response of left ventricular mechanics and fluid dynamics: a three-dimensional and particle image velocimetry echo study.

AIMS: To characterize the effect of multipoint pacing (MPP) compared to biventricular pacing (BiV) on left ventricle (LV) mechanics and intraventricular fluid dynamics by three-dimensional echocardiography (3DE) and echocardiographic particle imaging velocimetry (Echo-PIV). METHODS AND RESULTS: In 11 consecutive patients [8 men; median age 65 years (57-75)] receiving cardiac resynchronization therapy (CRT) with a quadripolar LV lead (Quartet,St.Jude Medical,Inc.), 3DE and Echo-PIV data were collected for each pacing configuration (CRT-OFF, BiV, and MPP) at follow-up after 6 months. 3DE data included LV volumes, LV ejection fraction (LVEF), strain, and systolic dyssynchrony index (SDI). Echo-PIV was used to evaluate the directional distribution of global blood flow momentum, ranging from zero, when flow force is predominantly along the base-apex direction, up to 90° when it becomes transversal. MPP resulted in significant reduction in end-diastolic and end-systolic volumes compared with both CRT-OFF (P = 0.02; P = 0.008, respectively) and BiV (P = 0.04; P = 0.03, respectively). LVEF and cardiac output were significant superior in MPP compared with CRT-OFF, but similar between MPP and BiV. Statistical significant differences when comparing global longitudinal and circumferential strain and SDI with MPP vs. CRT-OFF were observed (P = 0.008; P = 0.008; P = 0.01, respectively). There was also a trend towards improvement in strain between BiV and MPP that did not reach statistical significance. MPP reflected into a significant reduction of the deviation of global blood flow momentum compared with both CRT-OFF and BiV (P = 0.002) indicating a systematic increase of longitudinal alignment from the base-apex orientation of the haemodynamic forces. CONCLUSION: These preliminary results suggest that MPP resulted in significant improvement of LV mechanics and fluid dynamics compared with BiV. However, larger studies are needed to confirm this hypothesis.

Relationship between T-wave inversion and transmural myocardial edema as evidenced by cardiac magnetic resonance in patients with clinically suspected acute myocarditis: clinical and prognostic implications.

BACKGROUND: The pathophysiologic mechanisms and the prognostic meaning of electrocardiographic (ECG) T-wave inversion (TWI) occurring in a subgroup of patients with clinically suspected acute myocarditis remain to be elucidated. Contrast-enhanced cardiac magnetic resonance (CMR) offers the potential to identify myocardial tissue changes such as edema and/or fibrosis which may underlie TWI. METHODS AND RESULTS: We studied 76 consecutive patients (median age 34years) with clinically suspected acute myocarditis, using a comprehensive CMR protocol which included T2 weighted sequences for myocardial edema. At the time of CMR, TWI was observed in 21 (27%) patients. There was a statistically significant association of TWI with the median number of left ventricular (LV) segments showing both any pattern of myocardial edema (transmural and non-transmural) [5 (3-7) vs. 3 (2-4); p=0.015] and myocardial late-gadolinium-enhancement [4 (3-7) vs. 3 (2-4); p=0.002]. Transmural myocardial edema involving ≥2 LV segments was found in 17/21 (81%) patients with TWI versus 13/55 (24%) patients without TWI (p<0.001) and remained the only independent predictor of TWI at multivariable analysis (OR=9.96; 95%CI=2.71-36.6; p=0.001). Overall, topographic concordance between the location of TWI across the ECG leads and the regional distribution of transmural myocardial edema was 88%. There was no association between acute TWI and reduced LV ejection fraction (<55%) at 6-months of follow-up. CONCLUSIONS: This is the first study to demonstrate an association between LV transmural myocardial edema as evidenced by CMR sequences and TWI in clinically suspected acute myocarditis. As an expression of reversible myocardial edema, development of TWI during the acute disease phase was not a predictor of LV systolic dysfunction at follow-up.

Implantable cardioverter defibrillator therapy in young patients with cardiomyopathies and channelopathies: a single Italian centre experience.

AIMS: This study was designed to prospectively evaluate the risk-benefit ratio of implantable cardioverter defibrillator (ICD) therapy in young patients with cardiomyopathies and channelopathies. METHODS AND RESULTS: The study population included 96 consecutive patients [68 men, median age 27 (22-32) years] with cardiomyopathies, such as arrhythmogenic right ventricular cardiomyopathy (n = 35), dilated cardiomyopathy (n = 17), hypertrophic cardiomyopathy (n = 15), Brugada syndrome (n = 14), idiopathic ventricular fibrillation (n = 5), left ventricular noncompaction (n = 4), long-QT syndrome (n = 4) and short-QT syndrome (n = 2), who were 18-35 years old at the time of ICD implantation. During a mean follow-up of 72.6 ±â€Š53.3 months, one patient with end-stage hypertrophic cardiomyopathy died because of acute heart failure, and 11 patients underwent orthotopic heart transplantation. Twenty patients (20.8%) had a total of 38 appropriate ICD interventions (4%/year), and 26 patients (27.1%) experienced a total of 49 adverse ICD-related events (5.4%/year), including 23 inappropriate ICD interventions occurring in nine patients (9.4%) and 26 device-related complications requiring surgical revision occurring in 20 patients (20.8%). Lead failure/fracture requiring lead extraction was the most common complication (n = 9). A threshold for ICD therapy less than 300 ms was associated with a borderline significant lower probability of inappropriate ICD interventions (hazard ratio = 0.2; 95% confidence interval 0.02-1.2; P = 0.07), whereas underweight status was an independent predictor of device-related complications (hazard ratio = 5.4; 95% confidence interval 1.5-19.4; P = 0.01). CONCLUSION: In young patients with cardiomyopathies and channelopathies, ICD therapy provided life-saving protection by effectively terminating life-threatening ventricular arrhythmias. However, because ICD-related adverse events are common, the risk/benefit ratio should be carefully assessed when considering ICD implantation in young people.

Stress echocardiography pattern: a promising noninvasive test for detection of myocardial bridging with haemodynamic relevance.

: We reported a case of a young athlete with an underlying myocardial bridging in the left anterior descending coronary artery (LAD) causing myocardial ischemia suspected by contrast exercise stress echocardiography and confirmed by computed tomography coronary angiography. Our report demonstrated that a specific stress echocardiography pattern consisting of reversible focal buckling in the end-systolic to early-diastolic motion of the septum may suggest the presence of an underlying myocardial bridging in the LAD.

Differential diagnosis at admission between Takotsubo cardiomyopathy and acute apical-anterior myocardial infarction in postmenopausal women.

BACKGROUND: Takotsubo cardiomyopathy (TTC) typically affects postmenopausal women and clinically presents with chest pain, ST-segment elevation, elevated cardiac enzymes and apical left ventricular (LV) wall motion abnormalities that mimic 'apical-anterior' acute myocardial infarction (AMI). This study assessed whether at-admission clinical evaluation helps in differential diagnosis between the two conditions. METHODS: The study compared at-admission clinical, electrocardiographic (ECG) and echocardiographic findings of 31 women (median age 67 years, interquartile range (IQR) 62-76) with typical TTC and 30 women (median age 73 years, IQR 61-81) with apical-anterior AMI due to acute occlusion of the mid/distal left anterior descending coronary artery. RESULTS: Women with TTC significantly more often showed PR-segment depression (62% versus 3%, p<0.001), J-waves (26% versus 3%, p=0.03), maximum ST-segment elevation ⩽2 mm (84% versus 37%, p<0.001) and ST-segment elevation in lead II (42% versus 10%, p=0.01) than those with AMI. At multivariate analysis, PR-segment depression (odds ratio (OR)=37.2, 95% confidence interval (CI)=3.4-424, p=0.002) and maximum ST-segment elevation ⩽2 mm (OR=11.1, 95% CI=1.7-99.4, p=0.01) remained the only independent predictors of TTC and the co-existence of both parameters excluded AMI with a 100% specificity. The two groups did not differ with regard to age, first troponin-I value, echocardiographic LV ejection fraction and distribution of hypo/akinetic LV segments. CONCLUSIONS: At-admission electrocardiogram (but no clinical, laboratory and echocardiographic features) allows differential diagnosis between TTC and apical-anterior AMI in postmenopausal women. The combination of PR-segment depression and mild (⩽2 mm) ST-segment elevation predicted TTC with greater accuracy than traditional parameters such as localisation of ST-segment elevation and reciprocal ST-segment depression.

Axillary vein puncture using fluoroscopic landmarks: a safe and effective approach for implantable cardioverter defibrillator leads.

PURPOSE: Axillary vein puncture is an effective method for pacemaker lead insertion with less complications compared with subclavian vein puncture; however, there are limited data on implantable cardioverter defibrillator (ICD) implantation with this technique. We reported our experience with a blind axillary vein puncture using fluoroscopic landmarks consisting of the outer edge of the first rib and the body surface of the second rib for ICD lead implantation. METHODS: The study population included 103 consecutive patients (mean age 59 ± 9 years) referred for ICD implantation using axillary vein puncture without contrast venography. An 18-gauge needle was advanced toward the outer edge of the fist rib below the clavicle or the body surface of the second rib. If the vein was not entered, the needle was withdrawn and the puncture was repeated with slight variations of needle direction for a maximum of four times, then contrast-guided vein puncture was performed. RESULTS: The total implanted leads were 152 including 103 right ventricular leads, 35 right atrial leads, and 14 left ventricular epicardial leads. Blind axillary vein puncture was successful obtained in 96 (93.2 %) patients. The rate of success was higher using the body surface of the second rib compared with the outer edge of the first rib (88.7 vs. 100 %; p = 0.04).Contrast venography was required in seven (6.8 %) patients because of vein course abnormality (n = 5) or vasospasm (n = 2). No acute complications or device-related complications were recorded during a mean follow-up of 12 ± 5 months. CONCLUSIONS: Axillary vein access using fluoroscopic landmarks, especially the body surface of the second rib, is an effective approach for ICD implantation and offers the potential to avoid complications usually observed with traditional subclavian vein approach.

Incidence, management, and prevention of right ventricular perforation by pacemaker and implantable cardioverter defibrillator leads.

BACKGROUND: Cardiac perforation of the right ventricle (RV) is a rare but potentially life-threatening complication of both pacemaker (PM) and implantable cardioverter defibrillator (ICD) implant. Appropriate management is still uncertain. We assessed the incidence of subacute (24 hours-1 month) or delayed (>1 month) cardiac perforation by RV lead and the results of percutaneous lead extraction. METHOD: The study population included all patients diagnosed with subacute or delayed RV-lead perforation during the period 2007-2013. The incidence of perforation according to device type and fixation mechanism was calculated. The outcome of the percutaneous approach, consisting of lead extraction by simple traction, was assessed. RESULTS: Cardiac perforation was diagnosed in 14 (eight females, mean age 71 [range 47-83] years) patients out of 3,815 who received an RV-lead implant (0.4%). The overall incidence of RV-lead perforation was similar between ICD (0.3%) and PM (0.4%) implants (P = 1.0) and between active (0.5%) and passive (0.3%) fixation leads (P = 0.3). All perforating leads were originally placed at the RV apex. Five patients were asymptomatic, but all presented altered lead electrical parameters. Surgical removal of the lead was performed in one patient while in the remaining the leads were successfully extracted by direct manual traction in the absence of any complications. In all patients, new active fixation leads were positioned in the RV septum and the follow-up (42 ± 27 months) was uneventful. CONCLUSIONS: RV perforation is a rare complication of both PM and ICD implants, regardless of the lead fixation mechanism. In most patients, percutaneous lead extraction is a safe and effective management approach.

Prevalence of cardiomyopathy in Italian asymptomatic children with electrocardiographic T-wave inversion at preparticipation screening.

BACKGROUND: T-wave inversion on a 12-lead ECG is usually dismissed in young people as normal persistence of the juvenile pattern of repolarization. However, T-wave inversion is a common ECG abnormality of cardiomyopathies such as hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy, which are leading causes of sudden cardiac death in athletes. We prospectively assessed the prevalence, age relation, and underlying cardiomyopathy of T-wave inversion in children undergoing preparticipation screening. METHODS AND RESULTS: The study population included 2765 consecutive Italian children (1914 male participants; mean age, 13.9±2.2 years; range 8-18 years) undergoing preparticipation screening including an ECG. Of 229 children (8%) who underwent further evaluation because of positive findings at initial preparticipation screening, 33 (1.2%) were diagnosed with cardiovascular disease. T-wave inversion was recorded in 158 children (5.7%) and was localized in the right precordial leads in 131 (4.7%). The prevalence of right precordial T-wave inversion decreased significantly with increasing age (8.4% in children <14 years of age versus 1.7% in those ≥14 years; P<0.001), pubertal development (9.5% of children with incomplete versus 1.6% with complete development; P<0.001), and body mass index below the 10th percentile (P<0.001). Incomplete pubertal development was the only independent predictor for right precordial T-wave inversion (odds ratio, 3.6; 95% confidence interval, 1.9-6.8; P<0.001). Of 158 children with T-wave inversion, 4 (2.5%) had a diagnosis of cardiomyopathy, including arrhythmogenic right ventricular cardiomyopathy (n=3) and hypertrophic cardiomyopathy (n=1). CONCLUSIONS: The prevalence of T-wave inversion decreases significantly after puberty. Echocardiographic investigation of children with postpubertal persistence of T-wave inversion at preparticipation screening is warranted because it may lead to presymptomatic diagnosis of a cardiomyopathy that could lead to sudden cardiac death during sports.

[Preparticipation electrocardiographic screening for the prevention of sudden death in sports medicine]. / L'importanza dell'elettrocardiogramma nella visita medico-sportiva per ridurre il rischio di morte improvvisa.

Both the American Heart Association and the European Society of Cardiology consensus panel recommendations agree that cardiovascular screening for young competitive athletes is justifiable and compelling on ethical, legal, and medical grounds. However, there is a considerable discordance in the consensus guidelines on the pre-participation screening protocols used among European and US cardiologists/sports medicine physicians, with and without 12-lead electrocardiogram (ECG). In 1982 a nationwide program of pre-participation screening including ECG was launched in Italy. The aim of this article is to examine whether this long-running screening program should be considered a valid and advisable public health strategy. The analysis of data coming from the Italian experience indicates that ECG screening has provided adequate sensitivity and specificity for detection of potentially lethal cardiomyopathy or arrhythmias and has led to substantial reduction of mortality of young competitive athletes by approximately 90%. Screening has been feasible thanks to the Italian Health System, which is developed in terms of healthcare and prevention services, and because of the limited costs of cardiovascular evaluation in the setting of a mass program. The available scientific evidence suggests to adopt a screening protocol including ECG, which is the only screening tool proved to be effective. This article will also address the available data and criticisms concerning the screening program to prevent sudden cardiac death of middle-aged/senior athletes engaged in leisure-time sports activity.