Device interaction between cardiac contractility modulation (CCM) and subcutaneous defibrillator (S-ICD).

Combined implantation of cardiac contractility modulation (CCM) with subcutaneous implantable cardioverter-defibrillator (S-ICD) appears a suitable option to reduce the amount of intracardiac leads and complications for patients. Here we report on a patient with ischemic cardiomyopathy carrying an S-ICD in which a CCM device was implanted. During crosstalk testing post-CCM implantation, the S-ICD misannotated QRS complexes and T waves. The problem was solved through reprogramming the CCM, while preserving S-ICD functionality and improving heart failure symptoms. In conclusion, S-ICD combined with CCM seems to be a good and safe option for patients when device interference is being ruled out.

Determination of aortic stiffness using 4D flow cardiovascular magnetic resonance - a population-based study.

BACKGROUND: Increased aortic stiffness is an independent predictor of cardiovascular disease. Optimal measurement is highly beneficial for the detection of atherosclerosis and the management of patients at risk. Thus, it was our purpose to selectively measure aortic stiffness using a novel imaging method and to provide reference values from a population-based study. METHODS: One hundred twenty six inhabitants of Freiburg, Germany, between 20 and 80 years prospectively underwent 3 Tesla cardiovascular magnetic resonance (CMR) of the thoracic aorta. 4D flow CMR (spatial/temporal resolution 2mm3/20ms) was executed to calculate aortic pulse wave velocity (PWV) in m/s using dedicated software. In addition, we calculated distensibility coefficients (DC) using 2D CINE CMR imaging of the ascending (AAo) and descending aorta (DAo). Segmental aortic diameter and thickness of aortic plaques were determined by 3D T1 weighted CMR (spatial resolution 1mm3). RESULTS: PWV increased from 4.93 ± 0.54 m/s in 20-30 year-old to 8.06 ± 1.03 m/s in 70-80 year-old subjects. PWV was significantly lower in women compared to men (p < 0.0001). Increased blood pressure (systolic r = 0.36, p < 0.0001; diastolic r = 0.33, p = 0.0001; mean arterial pressure r = 0.37, p < 0.0001) correlated with PWV after adjustment for age and gender. Finally, PWV increased with increasing diameter of the aorta (ascending aorta r = 0.20, p = 0.026; aortic arch r = 0.24, p = 0.009; descending aorta r = 0.26, p = 0.004). Correlation of PWV and DC of the AAo and DAo or the mean of both was high (r = 0.69, r = 0.68, r = 0.73; p < 0.001). CONCLUSIONS: 4D flow CMR was successfully applied to calculate aortic PWV and thus aortic stiffness. Findings showed a high correlation with distensibility coefficients representing local compliance of the aorta. Our novel method and reference data for PWV may provide a reliable biomarker for the identification of patients with underlying cardiovascular disease and optimal guidance of future treatment in studies or clinical routine.

Age-related changes of right atrial morphology and inflow pattern assessed using 4D flow cardiovascular magnetic resonance: results of a population-based study.

BACKGROUND: To assess age-related changes of blood flow and geometry of the caval veins and right atrium (RA) using 4D flow cardiovascular magnetic resonance (CMR) data obtained in a population-based study. METHODS: An age-stratified sample (n = 126) of the population of the city of Freiburg, Germany, underwent transthoracic echocardiography and electrocardiogram-triggered and navigator-gated 4D flow CMR at 3 Tesla covering the caval veins and right heart. Study participants were divided into three age groups (1:20-39; 2:40-59; and 3:60-80 years of age). Analysis planes were placed in the superior and inferior caval vein. Subsequently, RA morphology and three-dimensional blood inflow pattern was assessed. RESULTS: Blood flow of the RA showed a clockwise rotating helix without signs of turbulence in younger subjects. By contrast, such rotation was absent in 12 subjects of group 3 and turbulences were significantly more frequent (p < 0.001). We observed an age-related shift of the caval vein axis. While the outlets of the superior and inferior caval veins were facing each other in group 1, lateralization occurred in older subjects (p < 0.001). A convergence of axes was observed from lateral view with facing axes in older subjects (p = 0.004). Finally, mean and peak systolic blood flow in the caval veins decreased with age (group 3 < 2 < 1). CONCLUSIONS: We have provided reference values of 4D CMR blood flow for different age groups and demonstrated the significant impact of age on hemodynamics of the RA inflow tract. This effect of aging should be taken into account when assessing pathologic conditions of the heart in the future.

Age dependence of pulmonary artery blood flow measured by 4D flow cardiovascular magnetic resonance: results of a population-based study.

BACKGROUND: It was our aim to systematically analyze pulmonary artery blood flow within different age-groups in the general population using 4D flow cardiovascular magnetic resonance (CMR) in order to provide a context for interpreting results of future studies (e.g., in pulmonary hypertension) using this technique. METHODS: An age-stratified sample (n = 126) of the population of the city of Freiburg, Germany, underwent ECG-triggered and navigator-gated 4D flow CMR at 3 T of the pulmonary arteries and the thoracic aorta. Analysis planes were placed in the main, left, and right pulmonary artery using dedicated software. Study participants were divided into three groups (1:20-39; 2:40-59; and 3:60-80 years of age). Subsequently, pulmonary blood flow was visualized, quantified and compared between groups. RESULTS: Time-to-peak of systolic antegrade flow was shorter, peak and average velocities and flow volumes were lower in older subjects. At the end of systole, retrograde flow in the main pulmonary artery was observed in all but one subject. Subsequently, a second antegrade flow peak occurred in diastole which was lower in older subjects. Age was an independent predictor of hemodynamic change after adjustment for cardiovascular risk factors and body-mass-index. During systole, abnormal vortices occurred in the main pulmonary artery in four male subjects. CONCLUSIONS: Comprehensive analysis of pulmonary blood flow was feasible in all subjects. We were able to detect an independent effect of ageing on pulmonary hemodynamics reflecting increased vessel stiffness and reduced pulmonary circulation. Findings of this study may be helpful for discriminating physiological from pathological flow in patients with pulmonary diseases in the future.

Impact of high-resolution 3D-mapping with micro-electrodes on catheter ablation of Wolff-Parkinson-White syndrome.

Background: It is currently unknown whether high-resolution 3D-mapping and micro-electrodes add meaningful benefits in catheter ablation of Wolff-Parkinson-White (WPW) syndrome and challenging, e.g. para-Hisian accessory pathways (APs). Objectives: To compare the mapping resolution, acute success and complication rates in patients with WPW syndrome undergoing a first-time catheter ablation using only a contact force-sensing ablation catheter for mapping or a multi-electrode high-resolution mapping catheter. Methods: Fifty consecutive 3D-mapping procedures for WPW syndrome using a 3.5-mm ablation catheter (n = 27) or a multi-electrode high-resolution catheter (n = 23) were retrospectively analyzed regarding mapping resolution defined as first 5/10 msec isochronal activation area, number of RF applications to achieve AP block, occurence of AP automaticity during RF delivery, and acute success and complication rates. Results: Catheter ablation was successful in 48/50 patients with a median of 1 (IQR 1-2) RF applications. Compared to ablation catheter mapping, high-resolution mapping showed a significantly smaller isochronal activation area in the first 5/10 msec (1.25 ± 0.29 vs 0.15 ± 0.03 cm2; P < 0.001 and 3.41 ± 0.58 vs 0.55 ± 0.12 cm2; P < 0.0001) and significantly higher incidence of AP automaticity during RF delivery (0 vs 22 %; P < 0.05). In para-Hisian APs, micro-electrodes recorded distinct His electrograms and AP potentials without fusion and without AP bumping permitting safe and effective para-Hisian AP ablation. Conclusions: High-resolution mapping increases the mapping accuracy of the AP and its insertion site leading to a significantly higher incidence of AP automaticity during RF delivery. Micro-electrodes provide clinically relevant advantages in para-hisian AP mapping improving efficacy and safety of para-Hisian AP ablation.

Genotype-Specific ECG-Based Risk Stratification Approaches in Patients With Long-QT Syndrome.

Background: Congenital long-QT syndrome (LQTS) is a major cause of sudden cardiac death (SCD) in young individuals, calling for sophisticated risk assessment. Risk stratification, however, is challenging as the individual arrhythmic risk varies pronouncedly, even in individuals carrying the same variant. Materials and Methods: In this study, we aimed to assess the association of different electrical parameters with the genotype and the symptoms in patients with LQTS. In addition to the heart-rate corrected QT interval (QTc), markers for regional electrical heterogeneity, such as QT dispersion (QTmax-QTmin in all ECG leads) and delta Tpeak/end (Tpeak/end V5 - Tpeak/end V2), were assessed in the 12-lead ECG at rest and during exercise testing. Results: QTc at rest was significantly longer in symptomatic than asymptomatic patients with LQT2 (493.4 ms ± 46.5 ms vs. 419.5 ms ± 28.6 ms, p = 0.004), but surprisingly not associated with symptoms in LQT1. In contrast, post-exercise QTc (minute 4 of recovery) was significantly longer in symptomatic than asymptomatic patients with LQT1 (486.5 ms ± 7.0 ms vs. 463.3 ms ± 16.3 ms, p = 0.04), while no such difference was observed in patients with LQT2. Enhanced delta Tpeak/end and QT dispersion were only associated with symptoms in LQT1 (delta Tpeak/end 19.0 ms ± 18.1 ms vs. -4.0 ms ± 4.4 ms, p = 0.02; QT-dispersion: 54.3 ms ± 10.2 ms vs. 31.4 ms ± 10.4 ms, p = 0.01), but not in LQT2. Delta Tpeak/end was particularly discriminative after exercise, where all symptomatic patients with LQT1 had positive and all asymptomatic LQT1 patients had negative values (11.8 ± 7.9 ms vs. -7.5 ± 1.7 ms, p = 0.003). Conclusion: Different electrical parameters can distinguish between symptomatic and asymptomatic patients in different genetic forms of LQTS. While the classical "QTc at rest" was only associated with symptoms in LQT2, post-exercise QTc helped distinguish between symptomatic and asymptomatic patients with LQT1. Enhanced regional electrical heterogeneity was only associated with symptoms in LQT1, but not in LQT2. Our findings indicate that genotype-specific risk stratification approaches based on electrical parameters could help to optimize risk assessment in LQTS.

Initial Clinical Experience With a Novel 8-Spline High-Resolution Mapping Catheter.

BACKGROUND: The Octaray (Biosense Webster) is a novel, multispline mapping catheter with 48 closely spaced microelectrodes enabling high-resolution electroanatomical mapping. OBJECTIVES: This study sought to report the initial clinical mapping experience with this novel catheter in a variety of cardiac arrhythmias and to compare the mapping performance with the 5-spline Pentaray. METHODS: Fifty consecutive procedures among 46 patients were retrospectively analyzed regarding safety, efficacy, and acute procedural success defined as termination or noninducibility of clinical tachycardia, conduction block across an ablation line, or pulmonary vein isolation. In addition, another 10 patients with sustained atrial tachycardia mapped with the 5-spline catheter (2-5-2 spacing) or the novel 8-spline catheter (2-2-2-2-2 spacing) were analyzed. RESULTS: Left atrial and ventricular mapping by either transseptal (n = 41) or retroaortic (n = 2) access was feasible without any complications related to the multispline design of the novel catheter. The acute procedural success rate was 94%. In sustained atrial tachycardia compared with the 5-spline catheter, the novel 8-spline catheter recorded more electrograms per map (3,628 ± 714 vs 11,350 ± 1,203; P < 0.001) in a shorter mapping time (13 ± 2 vs 9 ± 1 minutes; P = 0.08) resulting in a higher point density (18 ± 4 vs 59 ± 10 electrograms/cm2; P < 0.01) and point acquisition rate (308 ± 69 vs 1,332 ± 208 electrograms/min.; P < 0.01). CONCLUSIONS: In this initial experience, mapping with the novel catheter was safe and efficient with a high electroanatomical resolution. In sustained atrial tachycardia the novel 8-spline catheter demonstrated a marked increase in point density and mapping speed compared with those of the 5-spline catheter. These initial results should be validated in a larger multicenter cohort with longer follow-up.

Prosthetic valve endocarditis due to Actinomyces neuii successfully treated with antibiotic therapy.

Endocarditis due to Actinomyces neuii is a rare disease, with only 14 reported cases. Recently, A. neuii was added to the list of species implicated in endocarditis of native valves. We now report the first case of prosthetic valve endocarditis and the first successful control of endocarditis caused by this organism without surgical intervention.

Gender-related effects of prenatal administration of estrogen and progesterone receptor antagonists on VEGF and surfactant-proteins and on alveolarisation in the developing piglet lung.

BACKGROUND: Vascular endothelial growth factor (VEGF) is essential for embryonic lung development and has been shown to be regulated by estradiol (E2) and progesterone (P). AIM: To investigate the effects of prenatal E2 and P withdrawal by specific receptor antagonists on the mRNA expression of VEGF, surfactant proteins (SP-B and SP-C) and on alveolarisation in lung tissue of male and female pig fetuses. METHODS: Fetuses from 10 sows were randomized to receive either both an intramuscular injection of the E2 receptor blocker ICI 182.780 and the P receptor blocker RTI 3021-022 (ICI+RTI, n=5) or a placebo injection (n=5) at 90 days of gestation (DOG, 115=term). After delivery by cesarean section on 114 DOG, tissue of the left lingula of the piglet's lung (28 placebo, 26 ICI+RTI) was obtained to determine the mRNA expression of VEGF, SP-B and SP-C. Lungs from 15 placebo and 14 ICI+RTI group piglets were removed and alveolar counts performed. RESULTS: The ICI+RTI group showed significantly lower SP-C mRNA expression and alveolar counts compared to the placebo group (p=0.04 and 0.03, respectively). Diminished alveolarisation in the ICI+RTI group was mainly due to the reduction of alveolar counts in male piglets (p=0.02). Within the placebo group VEGF and SP-B mRNA expression in male piglets were significantly lower compared to female piglets (p=0.01 and 0.004, respectively). ICI+RTI treatment abolished this gender-related difference. CONCLUSION: Estradiol and P antagonism affected gender-related differences of key proteins for pulmonary function and development and especially in males was associated with diminished alveolarisation.